CNC Gantry Router #A

[rodm]

I am posting this so I get off my backside and start a new build.
I have lost count of the builds so not wanting to tell any fibs this is machine number A - algebra
last machine build number + 1 = A
or if you want to be pedantic
next machine build number - 1 = A

It shall be named when something sounding silly enough to be a CNC machine name is thought of. Inspiration eludes me for the present so all suggestions gratefully received.

This machine was going to be a mid sized 500 by 700 by 125 envelope using some long actuators I got a while back but the planets have aligned and a new supplier in China has meant that I got long ballscrews and linear rails for good prices. I can give you links to this seller if you are interested and not just kicking tyres.

So an envelope of 1200 X 900 X 200 is now the target. Design will be my traditional steel base and aluminum gantry but the machine will be able to be used horizontal or vertical or any angle in between. This is an idea floating for a while to use gravity to collect the dust/swarf while it is cutting. Upside down would be really interesting but I won't be that ambitious this time.

First photo is the balscrews and two set of rails.
From left they are THK15 rails and four trucks, 1 metre 1605 machined ballscrew and both parts will be used on the Y axis.
Next are 2 by 1200mm 1605 machined ballscrews and then 2 by 1300mm 25mm linear rails and bearings. These are fully supported along their length and would have been good but I ordered some LM25 rails and trucks to replace. This will be a dual screw X axis.

Next photo shows the aluminum plate for the table. It is 1200 by 1400 by 8 and will be cut down a little when the final measurements are known.

Last photo shows the 5056 drivers, power supplies, Nema 497 oz motors, 1.5kw spindle, VFD and Z axis KR33 actuator.

I will be using 200 by 6 steel plate for the sides and hold it together with 50 by 6 steel angle.

Now I am committed keep give me a nudge if I slack off and we will see what this pile of parts can become.

[WillyInBris]

Well about Bloody time how long have you had the parts 5 days .

What are your thoughts on the Rails so far.


Sean

[rodm]

The quality of the rails is good and I will use them on another build. I have ordered the square rails and trucks to replace these as they are a stronger design. The advantage of the round rail is price as they are less than half the cost of the square rails. If you are going to get the round rails then get this type as they are supported along their length so you will get no flex in the rail.

I have had some of those parts for nearly twelve months but this has mainly been to spread the cost and pick things up as cheap as possible. I am probably over $3k in that stack but it is all new and good quality components. The aluminum plate was $434 but that was discounted from $550. One place I rang wanted nearly $700 and I suspect they were just on sellers and picking up their margin. Steel jumped 25% in July and to give you an idea the angle on the first photo was $130. Luckily I have a good stock of steel plate in the shed and I will source the rest of the aluminum I need from scrap yards.

The ballscrews and rails were a lot cheaper than expected so my local purchases have been offset by this. About all I need now is to get a couple of large pillow blocks so I can pivot the machine to do the vertical bit.

I will have to take a couple of motivation pills and get this started.

Thanks for the advice on the VFD wind up - it worked a treat.

[snowyskiesau]

Makes my planned efforts in MDF look very tame

The plus side is that MDF is much, much cheaper than that a big sheet of aluminium.
(how do you cut that by the way?).

So rodm, it's been 12 hours since your posting - how's the build progressing?

[rodm]

Hi Geoff,
The comparing of machines should be done by the work coming off the table. I have seen a machine made from water pipe, sockets and salvaged electronics and it worked. Built carefully your MDF machine will serve you well.

The ally plate will be cut very carefully on the sliding table saw but I have to say I am not looking forward to this.

I let Willy(who is no longer)InBris comment slip through to the keeper but now you guys are ganging up. The only way to answer this is to say watch this space.

[Greolt]

Rod

I cut aluminium on my table saw quite often.

Use a sharp blade, a sprits of WD40 or similar and some face protection.

The "sawdust" stings a little more than usual.

Never felt the need for any sort of special blade.

Greg

[snowyskiesau]

Greg,
Up to what thickness aluminium have you cut with the table saw?

[WillyInBris]

Well I have done up to 10mm But I prefer the Bandsaw.

[Greolt]

20mm Take it easy. No problems.

Greg

[rodm]

Thanks Greg,
I have cut my fair share of ally on the table saw as well but my confidence was shattered a few months ago by a kick back with aluminum. It took the side of my index finger off to the bone and then it went on and hit the back of the shed like a gunshot. Since then I have got a pair of Grippers which should stop it ever happening again but my toes curl under every time I use the saw now. It's just a confidence thing.

[twistedfuse]

Rod,

Would like to see the supplier link. I've decided that as i get some money im going to upgrade from my current machine to a 1.4m x 2m machine so i can do bigger work and instead of cutting up a sheet of material i'll be able to just load it up and cut what i need. So would love to see what the difference in price would be compared to what ive been quoted from NSK for ballscrews. I might look at selling the machine i have now to fund it but not sure yet. Eitehr way cant wait to see another great machine build log. I should do the same to get me off my rear too.

Daniel

[rodm]

Hi Daniel,
Sending you an email on the links.
To give you an idea I got 1605 - 12000mm long ballscrew and nut (with seals) machined both ends to my drawing and freight for under $200 Aus.
Linear rails are aslo good price.
A 2m ballscrew is probably stretching the limit of a screw - definately a 16mm diam ballscrew unless you go rotating nut. Have you looked at R&P?
Posting a build log does motivate me to keep going but I am doing renovations to my son's home so shed time is limited. See already an excuse.
You have gained a huge amount of knowledge from your first build so this one should be a lot easier for you.

[WillyInBris]

I so need to move to Perth and become another son

[twistedfuse]

Rod,

Thanks very much for the email. Just curious what accuracy the ballscrew is. I had a quote for a 20mm ballscrew but they are 0.210mm accuracy over 300mm. So that makes me think it would be similar to the R&P in accuracy and the R&P might be cheaper and better off. The price youve quoted sounds pretty good tho. I guess greg has some experience here, i like the design he has on his machine. I will be looking to do a fair bit of 3d and then some basic profiling. Maybe greg could post a photo of some 3d off the R&P system? Either way the x axis(1.4m) will be ballscrew most likely as i may have acquired a cheap ballscrew with C3 accuracy. But ill cross that as i go. I like the supported sides so i could look at doing some aluminum every now and then, where the others i would think chatter would be a problem.

Daniel.

[rodm]

WillyInBris,
You have to go easy on the red you're too old to be adopted

Twistedfuse,
Ballscrews are C7 accuracy so possibly similar specs.

You lost me on the supported sides. If you mean the round linear rails then he also has square rails and trucks - Like THK25HRS, etc. Don't be limited to what he has listed and just ask him on an email for specific parts or suggestions. He is very easy to talk to and no interpretation problems.

I admire you blokes that can draw your machine before you start. Mine evolve from a pile of parts and I never really know what it is until it is finished.
Actually thanks I now have a name for this beast - Morphy.