New Aussie Build

[twistedfuse]

Hey all,

Well i finally got some time to sit down take a little break and start to get a fair idea of the collossus idea of the cnc machine i'm looking at building. This post is a way to finalise most of the design and much like rod and others mainly just to get me off my butt and do something other than research and price hunting.

Some background for the new build: I decided a little while back i wanted to do some things a little bigger than my current machine. Then ideas got bigger and bigger and ive realised that im better off going for it. So after getting the go ahead by 'she who controls the money' im really looking forward to it. I have a small deadline (not critical but it would be nice) of about 5-6 weeks max because there are a few offers on jobs i'd like to do and get into but i need the size first. Alot of the build will be funded by the good old tax man and the rest by the sale of the rails ive collected over time(will give everyone a heads up first) and maybe my old machine. I should go pretty close now i have a quote from rods supplier.

The design: As usual, i scouted the internet for many ideas, downloading many pictures of machines and designed many half complete ideas in solidworks(mainly cause im really bad at making up my mind), i settled on a simple setup design done by Greolt. It has a really nice solid design/balance for what i would like. I have drawn up a simple draft which is not yet 100% complete(attached). For the machine there were a few things i need it to do. These are basic profiling, 3d relief machining which i do a fair bit of, lithos, aluminum(not as often but i'd really like to have the option), foam(simple but it will be used to make some kite boards and surfboards as well as some prototype stuff for a local company) and fine engraving as this is also one of the jobs i am doing. The design will be using lsk25 rails for the main 2m axis, lsk20 rails for the 1.4m gantry axis, spring/gas strut engaged R&P on the axis too. Z Axis will be either an actuator or made using some rails sitting in the cupboard and finally the 4th axis which i will photograph when done which shouldn't be long now. All this means i will need 5 drivers(most likely keling 5056), some beefy motors and these will interface with a smoothstepper usb board.

Some questions: Firstly will this design do what i want. I had my doubt on the R&P until greg showed me how good it is at 3d and ensures me there is very little backlash if any. I have attached a picture of the stainless steel engraving of a chevy badge which i did and will need to continue to do. It is 70mm wide by 65mm high. This is my main concern as its extremely accurate and mainly because later these will be done by diamond drag spring tooling. Either way i guess if it doesn't work i can always change to dual lead/ballscrews.

Anyway, i think this is a bit of a read for you guys so i will have to stop boring you all to death and will start a new post as soon as i think of more questions or add more detail. Look forward to hearing peoples comments and ideas for improving the design etc.

Daniel

P.S Sorry for the second picture of the engraving. Camera didnt seem to work very well with the SS, also the engraving isn't the best because i broke the tip the AP Workshop 30 degree bit. Also some of the vectors have been changed since they had doubled up so it was machining 2 lines in 1 space.

[twistedfuse]

Just one last question...

What do people think about rail size. Going with rods suggestion i am going to use lsk20 on the gantry incase i upgrade to a proper spindle or if i decide to use a beefy 1500w router with 1/2' collet.

Anyway, what do people think about the main axis. Should i use lsk25 or lsk20. I just dont want to use the beefy rails if there is no real reason to. Either way im really looking forward to ordering the rails this week and starting the build. Hardest thing so far is trying to find a place to get the channel surfaced since people here charge sydney rates. Wish i had a mill like alot of you gusy out there. That would save so much time and money.

Daniel

[jb2060]

Just one last question...

...or if i decide to use a beefy 1500w router with 1/2' collet.

Daniel

Daniel,

Good luck with the build. Looks like a lot of fun. Just a comment about the size of router - one thing I came across in my build was that the weight of the Die Grinder and the Z assembly causes it to drop to the bed when the stepper motors are turned off. I always have to be careful with this especially if I have a very fine bit (0.4mm) attached. This would be quite a lot heavier with a bigger router - I am not sure how the others have got around this. Maybe my Z is too free and would benefit from a tightening up. Just a thought.

[rodm]

Hi Daniel,
Design looks good. Think about a gap between the table and sides so you can cross clamp your jobs. Another great idea from our resident chippie. The way I use my machine the T slots are of no bebefit as I always use a spoilboard under my jobs thus the T slots are covered. Same with a vacuum table if you want to go that way. Not saying the T slots are a waste of time though.

Having seen Greolt's machine operating there is no problem with R&P. The spring loading keep the gear mesh tight enough that there is no backlash.

Machining steel can produce some unexpected results. The machining process relieves the internal tension in the steel and you may find machining the top edge will bow the channel along it's length. Maching a 2m length requires a large machine so explore other options. I think a fellow on the Mechmate forum made a surfacing grinder from a disk grinder so you might want to hunt for that. Alternative might be to shim your rails along their length. Make up an MDF template and use feeler gauges to work out the high spot and then shim the rest of the rail to this height. Another option is to use exopy to create a new bed to lay the rails on. Just floating some ideas and if others know of a better way then chime in.

Hi Jason,
You might find with stonger steppers (internal magnets) that the Z axis will stay put. I have 269oz on mine and there is no problem. If I disconnect the motor it will unwind.

[twistedfuse]

Thanks for the replies so far. Jason, thanks for the heads up on the router. I agree with rod, mine is a 300oz/in motor and my z stays up but in the case of the heavier router i could always add an extra spring or gas strut to counterbalance the weight. I think at most this build will have a die grinder or proper spindle as i want to be able to machine as close to the edge of a full 1.2m.

Rod, thanks very much for the help. I guess i will have to explore my options for getting the rails flat. I know i have a whole heap of aluminum powder around so maybe it is worth while doing a metal epoxy, how well does this stick to the rails? In regards tot he sides having a gap it is a really good idea. Maybe ill make the sides removable to allow me to do this. The reason for the T-Slots is to make sure i can support small pieces still. I guess when i build a vacuum table it would get rid of that need. Either way the other option for later is to allow the full surface to be removed to reveal a water/coolant table for the use of a plasma cutter if i ever decide i need to do some small work for myself but i doubt i will need to do that but i also gives me the option to allow me to use coolant for metal cutting etc.

Another thing which cannot be seen in the picture (mainly because it has not been drawn yet, is that there will be a small section near the bottom end that will be about 2" wide along the front which will enable me to hold some wood vertical so i can machine the ends of stuff, or if i want to do dovetail joints or similar.

I will be looking at buying the channel and steel to make the bottom half of the gantry very soon, and as soon as i get my tax back the rails will be ordered. R&P Will be bought soon along with the timing belts and pulleys.

I guess the first job tonight is to get a photo of everything im selling and finish drawing up the design.

Daniel
P.S Btw, rehashing the Y axis. Which would be better. Using 4 blocks on some lsk15 or using 2 blocks on the lsk20. Sorta limited by the price atm, but either way im happy, i guess i could always order more bearings later if i needed it for the gantry.

[rodm]

Hi Daniel,
You do not want the rails stuck to the epoxy as all you are doing is creating a flat bed.

[Greolt]

Which would be better. Using 4 blocks on some lsk15 or using 2 blocks on the lsk20.
.

Are we talking THK type rails or round shafting? If THK type then 15mm will support a Mack truck. Plenty big enough for a gantry. Their strength comes from how well they are mounted and spread.

Use 4 blocks or possibly 3. You are going to the expense of using proper bearings, don't undo it by going 2. :)

If I remember correctly you have some large linear bearings left over from the previous build. Consider using one large rail and two blocks for the Z axis.

I know this seems to contradict my first sentence but in the case of the Z axis and the size of those rails (30mm as I remember them) it can work very well. I have seen this setup on a few machines.

Greg

[twistedfuse]

Rod,

Not sure what you mean by stuck to the rails. I was thinking along the lines of the madvac cnc machine where he leveled the tubes for his linear rails using al. powder and epoxy then filing it back to flat. Maybe i missed something or all the logic troubleshooting im doing at work has fried my brain. Either way i would prefer to do something less tedious and something i feel is more solid rather than a fear of it all cracking off with the vibrations.

Daniel

[twistedfuse]

Greg,

Im talking the THK style linear rails. My thinking was the fact that i thought the lsk15 with 4 bearings would be stronger than lsk20 with 2 bearings as it would reduce chatter/vibrations. Rod was right in saying that the lsk20 are better but now i will leave it as lsk15 profile rails. Im still contemplating using 20mm profile rails instead of the 25mm ones but i think for the main axis, the beefier the better i guess.

Your memory is pretty sharp too. I do have some 300mm long 35mm linear rails. I had looked at the 25mm ones i have at home for the z but hadn't thought about the others. I will probably just use an actuator to speed things up and then change it over after i build it.

Thanks for the suggestions.
Daniel

[Greolt]

Daniel

I used 20mm rails on top of the channel iron for X axis. I am convinced they are more than adequate.

Last year I attended the big engineering/automation show here in Melbourne. This year it was in Sydney.

Spent my time going around looking at all the big routers, plasma cutters, water jets and lasers. All but one of them had R&P drives and all but the very biggest had 25mm max sized rails with most having 20mm.

These rails are way over spec'd for how we use them. One rail on it's own with say a weight attached on a 300mm arm is working fairly hard but when you have two well
mounted rails spread say 900mm with a a rigid structure (gantry) coupled across them the bearings in that situation become enormously strong.

They must be seen in the light of the overall structure. All my opinion of course. :)

Greg

[twistedfuse]

Greg,

I was extremely fortunate this year as i actuall got to go to the Manufacturing expo in sydney. Sawmany amazing machines bu since i was there for work i wasn't able to take as much in. AT the time too i was concentraing on small routers so didnt take overly as much notes on the large. I am like you, im sure thy were 20mm rails or 25mm rails. Since they are completely supported. i would think that i should look at 20mm but since i would liek to do some aluminum stuff i was thinking 25 which is where my problem (indicisiveness). lol. Maybe ill save a few pennies and go for the 15 and 20mm set but still not sure. Its one of those things, you and rod both have great points. Just one of those things to think about.

Daniel
P.S I was just thinking about the rails. At the expo alot of the machines have rails mounted on vertical surfaces, hence why they would need beefier rails. Well thats my thoughts anyway.

[twistedfuse]

Greg,

I forgot to ask. Where did you get your timing belts and pulleys from, what about your R&P? I got a quote from a company in Perth but for the pulleys and belts, and got a quote from TEA for the R&P. Doing the rounds to see the price differences.

Daniel

[Greolt]

Got belts and pulleys from here,

http://www.piesau.com.au/

I used T5 but should have used AT5

R&P from TEA. Module1

Greg

[twistedfuse]

Thanks greg,

Will give them a shot. I'd have to say the price of the R&P from TEA isn't too bad. Will have to start ordering very soon. Steel should be organised very soon. I guess ill have to figure out the paint scheme sooon and get some metal primer and pint. lol.

Daniel
P.S Just curious too, the R&P did you get the stainless steel or just basic steel rack?

[twistedfuse]

This is just an update on the chevy logo. I did this on aluminum with the wood v bit from AP workshop. I think that changing the bit out for a proper d-shape engraving cutter or quarter round cutter will give alot better results.

I think i have a little rework to do, but its defintely gettingt here.

Daniel

[twistedfuse]

Hey All,

As much as it pains me to get rid of most of these, i must, as it was part of the deal with the better half in building the new machine. I am posting these here mainly because i felt that anyone on here can have first dibs before i put them on ebay. The main aim will be just to cover the costs of what i paid plus postage. Hopefully they will be right for someone else's build.

The first picture is of the smallest rails i have, these are of unknown brand but are 150mm long. The rails are wide rails at 18mm with a 30mm long bearing on each rail. These will be $60 for both.

Second picture is of some 240mm long IKO LWL12 rails with only 1 bearing on each rail. These will be $100 for both.

Third is a picture of some 350mm long IKO LWL12B rails with 2 bearings per rail. These will be $150 for both.

Forth is a picture of my better rails which i aquired. These are brand new NSK LY25AN rail and bearing combo. The rails are 400mm Long roughly and has 2 bearings on each rail. These will be going for $170 for both.

Fifth is pretty much the same as above, except these rails are 500+mm long with 2 bearings per rail. These ones are going for $200

Final picture is one of two linear actuators with 160mm motion, singular rail and leadscrew. They will be $200 each.

Now i hope doing this doesn't go against the forum rules. if it does i will remove this post. If anyone here has any questions, please don't hesitate to email me for extra dimensions etc. Deals can be struck for bulk buying. lol. These will be here for a few days before i post them to ebay. Payments be organised through paypal or money order etc.

Daniel
P.S Also if anyone is interested(i doubt it) i am also in the process of selling my kitesurfing package(Board, 12m kite lines, bar - everything minus harness). If interested just email me. Sorry i feel like a merchant dealer. Im more like a pack rat but if i want to build this machine i have to sell stuff im not using.

[twistedfuse]

Greg,

Just a quick question. Im about to order the R&P for the build as im getting the frame done and skimmed in the next day or two(photos will be posted along the way), but i was just curious if the R&P from TEA transmission was already drilled and tapped for mounting or did you have to do that yourself?

Daniel

[Greolt]

I did it myself.

[twistedfuse]

Thanks Greg.

[niall]

Why dont you have a brake on the z axis motor like the big guys use?

[twistedfuse]

niall,

What do you mean by brake? Looking to make this an ultimate machine so any suggestions welcome and ill look into it.

Disappointed atm, wanted to start work on the cnc today but didnt get the channel and such organised. Ah well. Tax will be ready so rails wont be too far off either. Did spend the day findig local supplies for things such as metal primer paint and heavy duty castor wheels cabling etc. Was good. Lots of design work done too. Man, just talking about it is making me gt all worked up, i need to do something to start it. lol.

Daniel

[twistedfuse]

Well,

Finally it begins, the channel has been bought and i've organised to get the channel skimmed to make them perfectly straight. I will need to organise the rest of the steel for the frame but at least its a start.

The second good news is that i have finally got my tax back, which means the rails will be ordered as soon as it clears. I will probably organise the rack and pinion this week too. That way i should have almost the entire main axis complete in a couple of weeks and then i can move onto the gantry.

Greg, witht he rack and pinion what was the mounting depth(or the depth of your tapped holes in the rack?).

Well im really looking forward to getting this machine built. Im sure it will suit my every need...until.....lol. Look forward to recieving alot of encouragment and ideas etc from you all during the build and hopefully i can help out someone else soon too .

Daniel

[Greolt]

Daniel

Don't remember. Just so they did not break through the face.

4mm thread. Counterbored from the top so the heads sit flush to top of channel.

Greg

[twistedfuse]

Thanks Greg,

From what i remember you used your mill to do most of the drilling and tapping. I was extremely pleased with the engineering mob locally. They have a huge cnc mill with a 2m long bed, so ill have to try and organise it with the local mob to get them to do it or im gunna be sick of drilling, counterboring and tapping holes. lol.

Daniel

[twistedfuse]

Just another quick question for Rod. I know you had a post on this forum somewhere with the details to a place to get the drivers, is it possible to post here again? Its just i cant seem to find it anywhere (probably looked over it 100 times) and when i get to that point it would be easier if it was altogether.

Thanks in advance,
Daniel

[rodm]

Here you go
http://www.ms-motor.com/HB1.htm
I think given the better performance of the Geckos I am going to get them next time.

[twistedfuse]

Thanks Rod,

Yeah i'd love to buy all geckos, but i will need 5 drivers as i also have a 4th axis and the price difference between keling and geckos alone is enough to put me off. All depends on the motor size i end up using i guess tho. If i dont need excessive amperage i might look at the new geckos that were on special. Only problem/question is that i rmember reading a while back that anything over 1/4 stepping causes loss of steps or jumping, and the G251 are set to 10 microsteps. Does gecko drivers have a better control and eliminate this?

Daniel

[rodm]

Hi Daniel,
I haven't got or used Geckos yet and I am going by the experiences Greolt and others are discovering.
There is a bit of mis-information out there and I have been running all my machines on 1/8 step for three years. I think the people that say don't use anything more than 1/4 step have actually got problems with their machines like binding. I tried 1/4 step once and the axis became very lumpy at lower speeds compared to what I was used to so I went back to 1/8 step.
Geckos seem to have it all worked out and have a very smooth pulse which combined with morphing (love that terminology :) ) the pulse to single step at the higher speeds.
If you interface thorugh a smoothstepper USB then you probably have the ultimate driver technology that is available now. As you rightly say the downside is the price difference.

[twistedfuse]

Rod,

Thanks for clearing that up. Either way i go, i will be buying the smooth stepper board and then after that i might use my old 4axis hobbycnc(forget about 4th axis for now) until i save enough money for geckos. I know for a start that keling would be another step furthur than hobbycnc boards but i do want this to be the best possible machine i can build. Again i will have to think about what size steppers i should use and go off that. Either way i think they will be pretty close to the last thing(other than a proper spindle) that i will buy for this machine. Time to sell more gear to pay for it all. lol.

Thanks again,
Daniel

[twistedfuse]

Greg,

Just a quick one, the width(face width) of the mod 1 rack from tea, is that 15mm? Also how far is the rack on yours from the edge of the channel. Im going to pay and get all the holes drilled and tapped with the cnc on the rails and the holes spotted for the rack. So just need some info to give me an idea how ill mount it. Also how many teeth were on your pinion?

Daniel

[twistedfuse]

Hey All,

Things have started strong with the frame being machined as i said, i decided to get the holes drilled and tapped by the cnc anyway, just a few last things to clear up before they do it. I have just ordered the R&P from TEA and will organise the timing belts and pulleys early next week. The rails are being ordered from the supplier rod mentioned. Its all guns blazing.

So ill order the frame steel next week and hopefully over the next 2 weeks ill have the entire main frame and X axis complete. Then it'll be onto the Y axis. If it all goes to plan...lol.

Daniel
P.S Will start posting photos as things start to arrive and milestones are achieved.

[Greolt]

Daniel

the width(face width) of the mod 1 rack from tea, is that 15mm?

15mm wide

Also how far is the rack on yours from the edge of the channel.

As close to the edge as practical and still sit on a flat surface. Want to keep the pinion drive shaft stout.

Also how many teeth were on your pinion?

24 teeth. With 4 to 1 belt reduction.

Greg

[twistedfuse]

Thanks Greg,

Your a champion. I scouted a few other posts of yours and found alot of the info. Ive ordered 2000mm or Rack and a 24tooth pinion for both sides. This should work a treat for the x axis.

Thanks again for everything so far, and thanks everyone else too.

Daniel

[twistedfuse]

Great news!!!

The rack and pinion arrived today. Very happy with the quality and the packaging from TEA components. They were sent strapped to a piece of pine. Ill be using the pine again as well as the R&P. lol.

Now the first of the parts have arrived, things will be well underway by this Friday. The channel was machined this afternoon (well it was supposed to anyway) so should be able to pick it up tomorrow. So Friday will be a case of painting the channel and probably starting on the framework. Im thinking about using some 50x50RHS for the main upright legs and not sure what ill use for the rest of the frame. Either way im looking to have 4 heavy duty castor wheels and 6 leveling legs which will adjust so the wheels do not touch the ground. I think it should work.

Any suggestions to the frame work? Im not 100% sure if i want to do cutouts and have the legs bolt to the back face of the channel or add a couple of tabs and bolt it to the bottom. Just not sure if cutting it out would cause the channel to bow by releasing some stress.

Daniel
P.S Will take some photos of the rack and pinion if i get a chance tomorrow.

[Aussie_Mick]

Dude

Weld the tabs on then bolt the legs to it. I personnal would use a mig welder rather than an arc welder as there would be less chance of structural change plus a cleaner weld.

Just my 2 cents.

Now get back to work.:2tsup:

[rodm]

Now get back to work.:2tsup:

You can stop for half an hour and show us some photos
Then get back to work :D

[twistedfuse]

Hey All,

Well downside is that i haven't heard much from the CNC machinist. Not overly happy with the servcie unless he's going to look after me well considering all i seem to be doing is being pushed till the end. Ah well it is something that needs to be done for the machine to be good quality.

I have attached a photo of the rack and pinions. It is module 1 rack from TEA transmissions and the pinions are 20 tooth. These didn't worry me too much since the pinions are the cheaper thing. If i do find backlash i have found a supplier of module 1 split pinion, which works similar to a split nut design with ballscrews, one pushes against one side and the other on the opposing side so there is no space to take up the slack.

The rails were expected to be here today, but alas i dont think it will. It will however be here first thing monday since according to TNT's tracking it has left customs in sydney and is close. Can't wait. Photos will definately be taken of the rails. The final sizes were 2200mm for main axis and 1400mm for my gantry. This should give me 2m x 1.2m , nearly the perfect size for a sheet of wood, the last 200mm of the sheet will be supoprted by rollers attached of the end, this will be encorporated to allow me to push the sheet along a little easier. For those out therethe supplier was abreeze to work with and very helpful.

Daniel
P.S Had today off so i dont think ill get a kick up the backside for posting photos(should have done it yesterday so sorry to make everyone wait) and not getting the drafting done at work. lol.

[twistedfuse]

Hey All,

Just a quick post with some photos of the rails. They arrived today and was lucky to get a small etended break in the afternoon to pick them up. When i got home it was like christmas, ripping the packaging open to see whats inside (or in this case the quality). Very happy with the supplier and definately recommend anyone interested should get in contact with him.

As you can see i have mocked up the basic size, im really excited. Also apparently my channels are ready and should be able to get them delivered very soon, hopefully with the long weekend i might be able to get the basic main frame complete depending on the money situation. lol.

Anyway, hope the photos come out ok. They are rails but hey, im excited to have almost everything i need.

Daniel
P.S I haven't had a chance to check their deflection software but im looking at getting 80/20 from a sydney supplier. Would the 160mm x 80mm extrusion have much deflection with the weight of a spindle router or really heavy 1/2" router hanging off the centre.

[rodm]

They are some seriously long rails. :)
I see you got a good luck braclet in the partcel as well.
On Greolt's advice I got 120 by 80 heavy and it is solid as a rock. I am spanning 12000mm and have no worries it will not deflect. It is expensive stuff.

[twistedfuse]

Rod,

Thanks very much for the reply. Yeah im hoping the good luck charm helps. Maybe it shold have been a prosperity braclet. lol. Just wondering if you could tell me roughly how much your length of extrusion cost for 1.2m. I'll be using something like 1.4 or 1.5m of extrusionand it will cost about $200 without postage. Maybe i wont need to use 160x80 and get away with 120x80. Either way im still contemplating using welded RHS so ill have to have a think about this one.

Thanks again.

Daniel

[rodm]

Hi Daniel,
It was $220 and the T nuts were $1.36 each so all up under $300. It is well worth getting the T nuts. You might get it cheaper as Perth is probably more than eastern states prices.
The 120/80 Heavy is the thicker walled version of the 120/80 and it is - well heavy. :)

[Greolt]

Daniel

Those rails look great. Those together with the channel as the backbone of your base have the potential to make a very decent machine.

The slotted aluminium is great to use but a piece of RHS could be OK too if cost is an issue.

It would need to have a wall thickness that tapped holes would be OK for securing rails. Min of 3mm I would think, probably 4 or 5 would be better.

That makes it fairly heavy but don't let that scare you. With R&P reduction drives you will still be able to get good acceleration.

One of the advantages of the al, is it has a series of holes in the cut ends that can be tapped for securing to gantry ends. The end cuts should be nice and square too.

RHS you will need to work out how to secure to gantry ends. If you went with RHS make sure not to weld any bits to it.

Also you won't get away with doing a skim cut for bearing mounts like you can with the channel. RHS is cold rolled and contains a lot of stresses.

Should not need to anyway. Pick a nice straight piece.

Greg

[WillyInBris]

What about Structural Aluminum channel http://www.smartaluminium.com.au/Web%20Page/page19.html.
I used a bit on my Y and it was strong and flat I looked at the bigger stuff as well but didn't get any prices may be worth a look as well.

[twistedfuse]

Well at last...i've finally heard back from the machinist after a month. Im really looking forward to seeing the channel tomorrow. The holes were all drilled and tapped for the rails and some intermediate holes drilled for the placement of the R&P.

First thing tomorrow, im going to get some paint and a box load of cap screws and lock-nuts. The lock nuts are overdoing it since there is enough thread on the top of the channel but i would think its better this way. Then ill have to get the rest of the metal for the legs and cross braces.

Its a bugger tho, this month i have to pay for the car, so i dont have alot to play with this month. Just means i have to do a little more travelling for work and sell off some stuff ive been holding onto that i dont need. lol.

Daniel
P.S Will post pictures of channel soon.
P.P.S What do people recommend for painting the channel?

[twistedfuse]

Good and Bad news.

Good news is that i finally got the channel today and it is everything i wanted. Surface is within 0.03mm and the holes were drilled and tapped. Great i thought, then came the bad news.

Bad news was that i got taken for a roll with this machinist(well i feel i have anyway). The final bill was alot more than he said it would be even tho it took alot longer than he said too. So all in all a great lesson to get everything in a quote and save alot more. This has put a strain on the budget this month and left me in a sour mood for the build so far. So the cnc will get painted and rails bolted on at best this month and the rest of the build will have to wait until i can get some more funds (***or a raise***). lol.

Anyway, hope everyone is having a better time with their build than me. Good thing tho, is i wont be done by my allotted time so i can cruise a bit more with the build and do some more design work.
Daniel
P.S Will post photos shortly.

[rodm]

Hi Daniel,
It is one of those things and in a couple of months you would have forgotten about it. It has happened to me a few times and will probably happen again - too trusting of people. Just balance it out with the times you have come out in front.

Yes we need some photos - been a lack of those lately and I have been tempted to post a boring progrss shot of my stand. :oo:
Help me out here and post some interesting photos. :2tsup:

[twistedfuse]

Thanks rod, its not a bad way of looking at things. Its just annoying when you budget for things and organise things around what you do and it just never works. I am a little too trusting sometimes too. As long as i can get somethings done, ill be happy. Hopefully with what i have i can get alot done. I have to bolt the rails on, get the rack and pinion drilled and tapped into place(once i figure out where the spring engaged pinion and timing gear will go) get the paint scheme going and oh of course the most important thing, think of a name to give this build. So i guess ive still got alot to do and wouldn't benefit from pushing too far ahead. (although, i wouldn't mind to put the main legs/spacers on to get it off the floor and make it look somewhat similar to a cnc. lol.)

As for the photos, i would like to see the stand and dont think it would be boring. Anyway, who said my photos were going to be any better. lol.

Daniel

[appiwood]

Sorry to hear about your financial upset, I think most of us here have the same " experience " one way or another, like you said get a quote, maybe ask another bloke for a quote to, after all when you get a builder in you get several quotes, don't you 8-)).

As a suggestion, have a look on the Mechmate site, they use a 3M double sided tape to tape the rack to the frame, big machines and appears not to be a problem, the tape isn't all that expensive either, I bought a roll ( 50m?? ) in sydeny last month and it was about $70.00ish ( age ) info on the 3M site indicates parts joined with the tape is stronger than welding - and easier to ( you won't need to have the holes drilled either ) This was lifted off the MM site, under " Driving Mechanisms: Rack/pinion, gears, screws, belts & chains " Specs:3M™ VHB™ Tape 4611, firm foam, general purpose acrylic adhesive, dark gray, thickness 0.045 in. (1.1 mm), red PE film liner. UL 746C

Hope this helps

Ed

[rodm]

Daniel,
That is going to be one big machine. :2tsup:

Ed,
I wish I had faith in adhesive but I have seen it fail where an mechanical fixing would not have. I am old school when it comes to these sorts of thing but I am sure adhesives have improved over the years. After all the Shuttle survives and the tiles are only held on with adhesive.

[Greolt]

On the Mechmate because of where the rack is positioned under the angle it would be impossible to bolt from the top. In this case it is not difficult.

If it is any consolation those rails look pretty smicko Daniel. :)

Greg

PS, the shuttle survives sometimes........

[twistedfuse]

Thanks all,

Its good to see some structure. The size has me in doubt sometimes, not knowing if ill use the size or wether i would have been better off with a smaller one which would have been cheaper and quicker but then i look at all the times i wish i had a bigger machine and i think that if i even use it once, it'll have paid for itself.

I agree with rod unfortunately, i just wouldn't belive that tape could replicate a solid mechanical mate, and even if it did i wouldn't bet my life on it and would prefere to be 100% sure. I may look at getting some to mock the rails in place with small bits and use that to drill the rack, then remove it once all the bolts are in place.

Daniel

[Ch4iS]

Just curious about your rack and pinion,

what lenth did you get and what did it set you back?

Ive been looking into the R&P and it just seems extremely expencive (only asked my local bearing shop who have to special order it in.)


BTW about sticking it down how about liquid steel? (Only just heard about this so not sure if its usable)

[Aussie_Mick]

well we all live and learn from our mistakes as well as others. At least you now have the rails and if anything can sitn back and look at the grand scale.

Sounds like you need to get on your knees and beg the other half (boss) for that pay rise.LOLRAOTF.:p

Keepus posted.

Mick

[Zoot]

Daniel,
I am at about the same stage as you, I think. I have my channels and got my legs back from a mate last night who welded some base plates on for me. I still have not got the bill from my machinist ... I hope that it hasn't taken this long for them to add up the cost!! Can you tell me what the machinist cost was ... either here or PM, so that I can compare when I get my bill?

I will probably be spending the next month trying to get the balls back into my ballnut that I stuffed!

Cheers,

Alan

[twistedfuse]

Hello All,

Blueray:
The rack and pinion was from TEA transmissions and it was basic spur gear and rack (module 1). It was just over $250 for 2 of 2000mm length, 2x pinions and postage to the doorstep by TNT couriers. I thought it was quite good. I was thinking about getting helical rack and pinion but it was dearer so i would check which type they are offering you.

Mick:
I may be desperate but im not that bad. lol. I think a few trips to newcastle will cover it. :-)

Zoot:
If your machininst was a manual machinist i doubt you'll get anywhere near what i was quoted, if he was a cnc machinist i doubt you'll get to the same price either. lol. As for your feet, did you bolt feet to the back face of the channel or are you bolting them to the bottom face of the channel. Im thinking of the second so i dont have to cut sections out. Also what size RHS did you use for the legs? Ill shoot you a PM.

Daniel

[twistedfuse]

Heres another good one,

Went to a local shop for some s/s socket head cap screws (M6 x 30mm long) got a quote of $90 for box of 100. Rang closest Blackwoods dealers and got quoted $25 pick up or $35 with courier. LOL. Just shows you should always double check your prices.

Now onto paint. I wentto the local paint peope to have a look at he paints available. There is quite a range of primers and paint. From wht i can see the best option would be to use some epoxy based paint. Im sure it would dry hard and handle the abuse. Now as ths is pretty much the most expensive, am i going overboard with the paint. What have others used, what do you all recommend? steps for prepping the steel etc?

Daniel

[Zoot]

Daniel,

My channels are 150 x 75 x 1800 long and my legs are 65 x 65 RHS. I have a 200 x 60 plate welded onto the top of the legs sticking up 100mm and I am going to bolt it to the back of the channel ... it reduces my effective width by 12mm overall, but I thought that the plate up the back would give better support for the channel. My cross members will also be bolted to the u/c of the channel and to the legs, so hopefully when it is all bolted down to the floor it should be nice and solid.

Cheers,

Alan

PS: thanks for the PM ... I will let you know when my machinist's bill comes in. He said about 2 hours machining. I am doing the holes myself ... Greg reckons it is good therapy!!

[Greolt]

Alan

In effect the legs become part of the structure and play a roll in truing everything up.

When the table support cross pieces are bolted under the channel and the legs are bolted to the channel as well, then the bracing between each leg comes into play.

What I did was get that much assembled and lay a good straight edge across the tops where the rails will sit. Then fit the lower cross brace to the legs.

The legs can be pushed apart or pulled together slightly till the straight edge reads perfect. Remembering the rail spacing needs to end up exact at the same time.

Does that all make sense? Probably not. :)

Greg

[Zoot]

Greg,
It all makes imminent sense. I was going to put the bottom spreaders in first, but will fit them as you suggest.

I hope to get at it soon ... BAS statements finished today ... bedroom painting finished and all my fixing turned up today from Coventry Fasteners. So there is not a lot holding me back! Oh! the aluminium!! Have to go to Sydney soon to meet up with Ned Kelly's friends at Capral.

I just bought a whole stack of Blackbutt to get me started on my signs when I finish 'Alpha Zoot' ... thinking of changing its name to 'Dooverlackey'. Blackbutt was 290 x 35 and 170 x 35 and whilst Blackbutt is not an overly brilliant timber, it is hard, will stand up to weather (I think) and is a light to medium colour which will allow me to paint the v-carved letters with dark coloured paint and get a goood contrast.

Thanks for your continuing suggestions, much appreciated.

Cheers,

Alan

[Greolt]

I remembered you are using round rails and not THK type. So what I was saying is not so critical in your case. So much for my waffle. :B

Blacckbutt sounds good.

I got my BAS done yesterday. That is good for me, it is usually a mad rush on the last day. :)

Greg

[twistedfuse]

Greg,

Thanks for the tips in trueing up the machine when it comes to assembly. It always makes sense and if it doesn't, i spend time trying to figure it out since it is normally very important.

Daniel

[appiwood]

Hello Alan

I was just talking to a mate with a CNC business business, we were talking about swarf and recycling it, he mentioned that the scap dealer he uses price for steel has gone from $440.00 per ton for bar, plate scrap to $70.00 per ton.

It would be interesting to know if Capral reduces the price of Aluminum, he was saying the global downturn affected metal as well.

One thing I have realised with Capral is it is better to order the size you want rather than go through their offcuts, the reason is they don't give a discount off the square meter price for off-cuts, so if you get a bigger piece than you need to allow for cutting you pay top dollar for the waste, whereas if you order the size you need, you don't, they only need 1-2 days to cut to size - in my experience.

If you PM me I'll give you a number that you can quote for their " trade cash " price, you still need to pay up front but it is the best price.

Ed

[rodm]

Hi Ed,
Yes the scrap prices have gone down as China is using their stockpiles so not buying new scrap. It is a bit early to see a drop in the price of new steel and ally although the stock market has adjusted to the downturn. Fingers crossed.
As you say if you can get off first tier pricing there are big savings to be made. The prices I got quoted for a half sheet of plate varied by 50% so it is worth having a contact in the game.
It's a mugs game when you price goods to what you think the market can stand rather than the cost of production plus a decent profit.

[Ch4iS]

Hello All,

Blueray:
The rack and pinion was from TEA transmissions and it was basic spur gear and rack (module 1). It was just over $250 for 2 of 2000mm length, 2x pinions and postage to the doorstep by TNT couriers. I thought it was quite good. I was thinking about getting helical rack and pinion but it was dearer so i would check which type they are offering you.

Daniel

dam a bargain in my books, maby my local was looking at the helical ones?

I needed some 2500mm Length so ill see if they can help :) thanks for that.

I was originally going to go timing belts but the length is just too long.

[twistedfuse]

Blueray,

Who knows. They might just be profiteering. I know the maximum length through TEA was 4m of continuous rack but it was secial order(I Think) as most are supplied in 2m lengths cut to be interlockable). Look forward to seeing that cnc going with a 2.5m long cutting space.

Daniel

[Ch4iS]

Blueray,

Who knows. They might just be profiteering. I know the maximum length through TEA was 4m of continuous rack but it was secial order(I Think) as most are supplied in 2m lengths cut to be interlockable). Look forward to seeing that cnc going with a 2.5m long cutting space.

Daniel

If its interlockable 2m would be fine, its just I want to be able to cut a full 2400,1200 piece of MDF.

Most likely will be months before its done the first one (thread: chris's first build) took me alot longer than I thought but its completed now and im looking to build a proper one now.

My original thought started with belts so it will need to be altered now with the good price of rack and pinions.


BTW still looking to see how yours goes together :)

[appiwood]

Hello Blueray

Don't give up on belts just yet, have a look at the Econobelt site in the US, FYI a T10 16mm wide 5360mm long belt is listed @ US$63.71.

I think Pies here will make one for you but it won't be AU$91.00ish.

Ed

[twistedfuse]

Great News,

Well didn't think i would get much done this month but this weekend i was able to progress a little. I was able to get my s/s cap screws and was able to get some rust prevention, primer and epoxy paint for the channels. Got "she who controls the money" to pick the paint scheme. We have our dog inside the garage after she was de-sexed, so i wasn't able to do any painting this weekend but next weekend i will get around to it before any rust gets going. Then I'll look at mounting the rails and working on drilling and tapping the rack as well. That way i should have the main channels completed before the end of this month awaiting the construction of the main frame next month. Before i go ahead and paint these channels, i am looking at notching the bottom face of the channel on both ends to have the legs at either end bolt directly to the back face of the channel to give the strength as mentioned above. I realised this shouldn't cause any bowing as the 'skin' holds most stresses and this was machined away. Also its only the last 65mm(depending on the leg size.) So next weekend will be interesting as i'll have to do this with a hand hacksaw(Hope this will work), then file it smooth before wire brushing and sanding the steel clean before painting. So all in all there is a bit to do before going on to the next steps. If all works out maybe i can get the framework steel organised before next month and get it welded so i can just paint it and assemble it. But thats all hopes and wishes, but who knows, ive been lucky so far.

Daniel

[Ch4iS]

Hello Blueray

Don't give up on belts just yet, have a look at the Econobelt site in the US, FYI a T10 16mm wide 5360mm long belt is listed @ US$63.71.

I think Pies here will make one for you but it won't be AU$91.00ish.

Ed


They dont stock the 2.5M lengths so I just asked them to order it in. ~ 2 weeks wait.

I wanted to give the racks a try as I have never used a machine with one yet.


BTW ed did you get module 1 or 1.5?

[appiwood]

Hello Blueray

Sorry I must have made myself less than plain, I was suggesting toothed belts not rack, I would like to try racks someday but am happy with belts.

Ed

[Ch4iS]

Hello Blueray

Sorry I must have made myself less than plain, I was suggesting toothed belts not rack, I would like to try racks someday but am happy with belts.

Ed


Probbaly just myself getting confused.

Nevermind thou, Module 1 and 1.5 are the sizes of the track.


I'll stop posting in your thread now. :D

[twistedfuse]

Blueray,

as soon as i get this machine together ill let you know how the rack works out.

In regards to the build. The dogs finally outside, so ill start hacksawing my way through the channel. Might have to look at a cheap jigsaw to save my wrists. lol. But hopefully some photos of the channels painted this week.

Daniel
P.S Greg, did you paint the top where your rails were mounted. How can i preserve the accuracy but still protect it from rusting?

[Ch4iS]

Blueray,

as soon as i get this machine together ill let you know how the rack works out.




Ahh I got my users confused.

I just wanted to know did you get module 1 or module 1.5? Its just I have the choice of either as they ordered both. and wanted to know if that is module 1 that you have in the pictures.

EDIT: I should read the thread, Module 1. As said I shouldnt be allowed to post questions :D

From the specs it looks bigger in the picture.

[rodm]

Hi Daniel,
Have you thought of using an angle grinder and cutting disk for the channel?

[twistedfuse]

Blueray, doesn't worry me, its good to help out. I'm the same sometimes.

Rod, I was thinking the jigsaw/hacksaw over the angle grinder to prevent heating the channel. Im sure it wouldn't make much of a diffeence would it? Sounds like a much better idea. Thanks rod.

Daniel

[Zoot]

Daniel, I started cutting mine with a metal cut off saw, but found it too slow. Then changed over to the angle grinder and it went through like butter ... not much heat build up at all.

Cheers,

Alan

[niall]

Try a brake on the z axis so it dosnt drop over night....

[twistedfuse]

Hey All,

Well went and spent some money today for an angle grinder and ended up spending a little more than i wanted to but i got something i can use on anything in the future. Its just a GMC but it was 2400w and had a 230mm cutting disk. So with that and some extra disks, i set to chopping some 70x70mm sections from each end of both channels on the bottom face. Well after getting used to the grinder on the first cut it made butter of the channel(thanks for the tip guys). I did try on the last one with the hacksaw and jigsaw just to prove to myself i had spent the money right, and did i ever. The hacksaw got nowhere fast and the jigsaw blades went blunt almost instantly. So tomorrow will be a quick wire brushing and sanding to smooth metal, then ill add the primer. Then on thursday ill spend the time to finish it with 2 coats of epoxy paint.

So steadily moving forward, getting some stuff done. Next week after the paint dries and i have some time, ill look at trying to drill and tap the rack. Then the two main channels will be complete until i can get around to getting the metal for the legs and cross bracing. Then i'll be in business.

Daniel

[twistedfuse]

Just some updates. Painting the channels came out great. I thought they were supposed to green (SWCTM paint scheme), but it was marine blue. Looks great tho. Very vibrant. Not sure if i should have a top coat but i would think the epoxy paint should be enough. Anyone knowing better, please let me know.

Anyway, im going to organise the steel and welding over the next week. Then the timing belts. So hopefully by the end of Novemeber, the table will be completed and all that will be left is the gantry and electronics. Getting closer now.

Daniel
P.S Sorry forgot to move the broom, but i guess it could be used as a comparison for the table size. lol.

[Ch4iS]

Looking good, nice to see some larger ones for reference when I build mine.

Still in the planning stages here.

Just wondering but wouldnt it have been best to weld everything then paint as the paint will need to be grinded away then repainted after the welding.

[twistedfuse]

Im trying not to weld everything together. There is a few reasons for it. One which i am not 100% sure about was speaking with a manufacturer and he said most of their parts are extruded or milled from billet since vibrations will crack the welds and he recommended i would be better off just having bolts from the frame to the channels. The main reason in my mind was the fact that i will need to transport this machine in the future as we are looking to buy/build a house. The easiest way i thought i would do this (as i wont be able to move it much/nor pay for a removealist) was to make it in sections. Each long side of the frame will be welded together, but each channel and cross strut will be bolted to flanges from these sections or the channel itself. This way it will dissassemble for easy transport, then in the future, i can weld up the frame. Also as it was sitting, it started to rust, and as much as it hadn't set in, i still wanted to prevent rust as much as possible(considering i paid so much for the machining...lol). I still need to drill holes tho, but ill just paint those spots when i get round to it. Good point tho, its mainly just my situation.

Daniel

[Ch4iS]

Im just for welding rather than bolting because I cant drill a 100% accurate hole :D

Understood about the rusting, ruins everything if it gets too bad.

Not sure about the welds cracking either, you wont get any serious vibrations from it to do any sort of damage I would gather.

[twistedfuse]

Blueray,

Yeah i agree, like i said its mainly because of my situation. As for the cracks in the welds, i wouldn't have thought so either since it is a heavy frame which should dampen the vibs anyway, but in saying that, ive seen cracked welds at my trusty metal fabricators from less vibs and the weld penetrated the metal well so it was almost unexplained, so im sure there is a reason that the guy said it, so it makes me a feel a little better nto welding it up just yet. lol.

Yeah rust is very annoying. Although, i bought a wire brush thing for the angle grinder(not brass but something else), and it made rust removal very easy. :-)

Daniel

[crocky]

looking good Daniel :2tsup:

[Zoot]

I am certianly a welding expert, have tried all types and am hopeless at it, but the machinist who ground my rails flat said to keep welding away from them as the heat will distort them.
I think other have found the same problem.
Just my 1 cents worth ...

Cheers,

Alan

[rodm]

Have to agree with the not welding. Apart from the risk of distorting metals we are trying to build a machine with very low tolerance and welding makes the parts stuck for good. Bolting the components together allows for shimming and other techniques so that we can get perfect alignment. In commercial machines the critical areas are machined flat and true and this is something we are not able to do. As a point of interest my milling machine has paper used as a shim, which has been fitted by the manufacturer, to allign the column vertical to the compound table.

Welding on some parts like the stand is better than bolting as the joint is stronger but if you do weld then my suggestion is to make things modular and split into the critcal components so that adjustments can be made.

The critical components are X axis rails parallel to cutting table and to each other - this is the foundation. Then Y axis rails to X rails (which means cutting table). Z axis rails to Y axis and vertical. It does not matter what is between those three components so long as this relationship exists and to achieve this the connections at these points needs to be adjustable.

[Greolt]

Have to agree with Rod. Weld the legs together as you wish but don't weld them or anything else to the channel.

Welding at each end (not the middle) will likely not distort in a manner that matters so much.

However the main thing is you want to be able to shim the joint to get everything spot on.

That is why I like the method of notching the bottom web and extending the leg up beside the vertical web.

Shim between leg and channel as needed. Soft drink cans are my usual shim material. :)

Greg

[twistedfuse]

Thanks all for the clarification on what to do with the legs. The steel will be bought today/early next week and ill have to get to and borrow a welder or get someone really cheap to knock it up for me. I have also put in a request for a quote for the pulleys and belts for the r&p drives. On this topic, Greg, how did your pinion pulley work in the housing. Did you use bearings and an idle shaft. Any photos to help me out. I know my cnetre distance will need to be 108mm so thinking i might do it with 100mm centres and have an idle roller which will push against the belt to take up the slack. Who knows with the time i have i might need someone here to machining the aluminum since im not getting much of a chance lately.

Daniel

[twistedfuse]

Greg,

What was the centre distance between your pulleys? Im not sure weather to use 100mm or go for something a little smaller say 85mm between centres. Also what were the teeth on the pulleys you used. Im thinking 12 and 48 teeth pulleys for the 4:1 ratio. I did try to find some 7.2degree gearboxes (like on shopbot) but can't find any suitable.

Daniel
P.S Does your machine home using independant switches for the x axis so it squares up the gantry?

[Greolt]

Daniel

From memory it was about 100mm

Use an idler for tension adjustment if you don't want to make slotted motor mount.

That would also have the advantage of engaging more teeth on the small pulley. Wrapped more.

I used "T5" belt but should have used "TD5"

See pics for ideas.


And an adaptation that was done to the Mechmate, They usually use a gearbox or drive pinion direct.

http://www.mechmate.com/forums/showthread.php?p=11184&postcount=299

Greg

.

[twistedfuse]

Thanks greg,

I was looking at the AT5 belts and pulleys from pies. Did your motor have tension adjustment/slotted holes?

Daniel

[Greolt]

Yeah your right. I meant AT5. I found Pies expensive but I don't know any better options.

I made slotted mounting holes for the motors. However if doing it again I might make an idler for adjustment and to wrap the belt further around the small pulley.

It is not a problem but I need the belt fairly tight which makes the bearings in the motor work hard.

Greg

[twistedfuse]

Thanks greg,

Yeah i think ill stick with an idle roller. Its extra work but i think it would be worth it and like you say it would be easy to engage the extra teeth. Im not sure which deisgn i like know, either way the main thing i want is to enclose the pinch points for safety.

Daniel
P.S Sent you a PM greg.

[niall]

Some of the machines i have seen use 20mm rails on the x axis these machines are able to route 20 mm alloy in a couple of pass's , so this should do most people. These machines are less than five years old are still going strong and are used in the kitchen,
caravan and plastics industries..

[Ch4iS]

Some of the machines i have seen use 20mm rails on the x axis these machines are able to route 20 mm alloy in a couple of pass's , so this should do most people. These machines are less than five years old are still going strong and are used in the kitchen,
caravan and plastics industries..


They would be using 6HP spindles thou right?

[niall]

You need a electric brake on the z ,so when you turn off the machine the brake comes on
so it does not end up on the bed by the morning...

[niall]

Well they were using 3.5kw up to 7kw spindels. so one bed fits all.

[twistedfuse]

Hey Guys,

Well been slow lately, but i am moving forward again. The steel i ordered arrived yesturday and it is sitting in front of the channels waiting to be turned from a pile of junk into a lovely frame. Its times like this that i wish i had a mig welder to do it all which would make it quicker. It is on the list(much like alot of other things) for the big red guy but alas with all the house talk i dont think ill be getting anything much.

But as soon as the frame is complete this machine will be well on its way. I just need to finalise some things for the spring engaged R&P and get it all mounted. Then its just the gantry to be done and then save save save for the never gecko drives (hoping to save enough to have it all controller by a GREX eventually).

Daniel

[Aussie_Mick]

daniel

If only you knew someone close by that had a mig welder, maybe you could ask aroud and see. Surely someone would be willing to let you borrow it.

Mick

[twistedfuse]

LOL. Well actually when i really think about i have two but ill have to borrow one soon probably from you. With all this rain around i want to get it up off the floor, oh and it gives me something to do on the weekend now. lol.

Daniel