I'd like a fourth axis. :) [Archive]

Greolt

15th February 2008, 10:33 AM

Steve that looks good.

Can't make out your gearing method though. Or are you going direct?

Any thoughts of a tail stock?

Yeah software is another issue. You can do cylindrical work by tricking Vcarve. Swapping axis names.

Greg

simso

15th February 2008, 11:08 AM

Yes mate, its a direct drive, the picture doesnt show the main shaft that connects the chuck to the motor. I couldnt see any reason for reduction gearing, I havent made up a tail support yet, becuase my first goal was to design and draw some chess pieces like the rook and carve it out first as a trial, after perfecting this I was going to make a tail support and do pool cues, for the father in law and numerous friends requests,

I will take some better photos this weekened

I just worked out what yopu meant regarding tricking the g code program. your talking about programming your y axis to turn your A, never thought of doing that, but that would work a treat for engraving

Steve

Cruzi

15th February 2008, 03:01 PM

Thought from thread title you wanted the 4th dimension.

That being time so you can go back and fix your mistakes, be handy I reckon :-)

Greolt

10th March 2008, 04:42 PM

I have been hoping to find a second hand Jet Mini lathe (or equivalent in another brand). Preferably without a motor to use as the basis for a rotary axis. Had no luck so far.

A forum member, Mugwoody, contacted me to say he had some small right angle reduction gearboxes that were surplus and may fit the bill.

He also said, "don't pay me yet, see if it will suit your purpose first" ...... you can't get fairer than that. :2tsup:

I was a bit sceptical that they would have too much backlash in them but thought I would give it a go and see what happens.

So today I turned up a spindle shaft for it. Went with 1" - 10 tpi which is the same as my wood lathe so that I can use existing chucks etc.

Next step will be make up some mounts to take a Nema 23 stepper motor and give it a try.

Greg

.

WillyInBris

10th March 2008, 05:21 PM

Looking forward to see how it progresses.

bpj1968

13th March 2008, 09:55 AM

the 2nd video had a 5th axis. where the router rotated on the mount to cut a pineapple. You could even make a 6th and have the router rotate east-west and north-south.

WillyInBris

14th March 2008, 05:11 PM

How are things progressing Greg ? :D

Greolt

15th March 2008, 09:21 AM

G'day Willie

I'm a bit snowed under at the moment with family stuff and work.:C

Progress might be a bit slow right now. Need to order a stepper for it while I'm held up.

Greg

Greolt

21st March 2008, 07:30 PM

Not a lot of progress right now. Work has got in the way. Don't you hate that. :no:

This little 260oz stepper drives it OK but I think I'll go with a bigger one with a little more torque at faster speeds.

Obviously I need to make a motor mount next.

Then I should be able to do some testing to see if it is going to be a good jigger and proceeded with. I'm optimistic. :U

Greg

twistedfuse

25th March 2008, 07:50 AM

Gee Greg,

Wont be long and we'll be seeing videos like the one above posted by you. Looks great. Im in the process of starting to build my own. Going to direct drive it for now until i can figure out how harmonic drives work and where to get one cheaply etc and ill then upgrade to that.

Daniel

Greolt

29th March 2008, 07:33 PM

I finally got some shed time today so I knocked up a motor mount for the little stepper I pinched of another machine.

Keen to give it a go I clamped it very dodgy like to the table and "What do you know....It goes!!!!!"

Had to dial in 0.225 degree back lash compensation in Mach3. That amounts to about 0.1mm or 0.004" backlash at 50mm diameter.

Too much backlash to live with but the compensation seems to work OK so far.

I've never done rotary axis stuff before so for a test I used a great little program that bloke called Andrew wrote.

See this link, http://vectric.com/forum/viewtopic.php?t=2920

It takes a gcode file that you have created in 2D and converts it to a rotary axis. Works great.

Anyway as you can see in the pics it all sort of worked as expected. Not bad for a first try. :;

Greg

rodm

30th March 2008, 10:43 AM

Hi Greg,
Quote
Sort of works.

I would be really pleased if my first lash up worked as well as that. Now I am going off to waste another hour reading about converting 2D to 3D.

Keep the posts coming. :2tsup:

crocky

30th March 2008, 11:01 AM

Wow!!!

That is so cool, I don't know about the not bad part of that :)

Congrats Greg!

Greolt

30th March 2008, 12:57 PM

Hi Greg,

Now I am going off to waste another hour reading about converting 2D to 3D.

What I have learnt so far is that Andrew's conversion program has one distinct advantage over just cheating and calling the rotary axis Y or X.

It maintains the use of degrees as units on the rotary axis. This is good because it maintains Mach's backlash compensation settings regardless of diameter of the job.

Greg

rodm

30th March 2008, 01:07 PM

Hi Greg,
So far a couple of cups of coffee and torturing the brain with converting linear to rotary and I have finally got a handle on it. Yes once in degrees the backlash compensation is true for any radius.

Andrew's conversion is very clever but I did nut out the manual conversion just to test myself.

All this and I haven't got a rotary table. :-

Do you have a encoder on the stepper motor or it that just a wheel to turn it?

WillyInBris

30th March 2008, 02:19 PM

Looking the goods Greg :2tsup: Cant wait to see a video of it in action.

Greolt

30th March 2008, 05:38 PM

Do you have a encoder on the stepper motor or it that just a wheel to turn it?

That's just a Jaycar knob.

Too lazy to turn up nice knurled knobs like yours. :)

Greg

Greolt

2nd April 2008, 09:03 AM

Just for fun I made a little video. :U

YouTube - Rotary 4th axis

rodm

2nd April 2008, 10:18 AM

Very impressive. :2tsup:

crocky

2nd April 2008, 04:29 PM

Hi Greg,

For a bloke who is wondering what to do next, I would say it is just the thing :)

Good one :)

Studley 2436

2nd April 2008, 04:39 PM

Very impressive stuff. Next you need some CAD/CAM software to really take yourself up a level.

Studley

twistedfuse

3rd April 2008, 05:07 PM

I agree with Bob,

I too am looking at what to do next while i wait for parts for a new CNC machine. I decided today that i would buy a 3" 3 jaw self centering chuck and start soon. So i too hope to make something at least half as good as the video. BTW, did you paint fill the grooves, looks extra black in there. Keep up he great work.

Daniel

WillyInBris

4th April 2008, 07:14 AM

Greg well done, something I would like to do as well but the question whats the best way to do this.

What can be brought off the shelf that would get me started? looks like more research thats for sure.

Sean

simso

4th April 2008, 10:33 AM

Hey sean, I dont want to steal gregs glory here, as he has done an excellent job. There are two options here, you can make your own, which I have and I have supplied a photo of another view of it. I have the plans that you hand of to a local laser cutting place and wolla you just assemble the pre cut bits.
Alternatively you can do what a work mate has done, he purchased a rotary indexing table for milling approx $350 which comes with a fitted chuck etc and then all you have to do is modify and fit your stepper to the fine adjustment fitting and wolla your done

Studley 2436

4th April 2008, 04:22 PM

Might be better to get a Dividing head to fit up with a stepper. I suppose the only hassle would be with backlash through the drivetrain. The good thing about Dividing heads is that they can be set at angles as much as 180º which might be useful for what you guys are trying to do.

Studley

Greolt

6th April 2008, 06:21 PM

Very impressive stuff. Next you need some CAD/CAM software to really take yourself up a level.

Yeah CAM software for a rotary axis is another matter. For now I will content myself with using the Wrapper program.

BTW, did you paint fill the grooves, looks extra black in there. Keep up he great work.

I put a bit of stain in it to make it stand out for the video. Job was a bit rough though. Next one will be better.

Greg

Studley 2436

6th April 2008, 11:43 PM

Actually one thing I do notice in the video is that the feed seems very slow. On Steel which is where my experience is you would want about 0,2mm per tooth with a carbide tool.

So once you have your speed multiply rpm x depth/tooth x the number of teeth you have.

You might be surprised. A sheet of copy paper is about 0.1 mm on something relatively soft like timber 0.2 will be pretty easy stuff. I think you could easily go to 0.5 mm per tooth.

Giving the machine really slow feed means you are rubbing the material off rather than cutting it. On steel you will see work hardening and the carbide suffering plastic deformation. On Timber when you get really slow you will see burning to the work.

Timber is a lot different to Steel or any metal. It can compress much more when the tool hits it. Look at the angles on a plane for instance which are standard at 45º "rake'. Do this on Steel and the tool will dig in severely causing a crash or breakage. On a jointer people don't like to set more than 0.5 mm depth but the feed they have would be pretty high compared to steel.

Carbide tooling definitely appreciates a some speed and feed to get it working properly. See how you go.

Studley

Khalid Khattak

20th October 2008, 01:37 AM

Hello boys:D
I am just here... you can see my 4th axis build and work in following thread...:2tsup:

"http://www.cnczone.com/forums/showthread.php?t=39588&page=27"
"http://www.cnczone.com/forums/showthread.php?t=39588&page=28"
"http://www.cnczone.com/forums/showthread.php?t=39588&page=29"

see it:no:

simso

22nd October 2008, 08:48 PM

Hey greg, heres revision two which I finished today, it runs super sweet and solid.

Revision one was okay but I found the lines were not perfect, I think not enough mass in the unit itself was causing the problem. Chatter

Greolt

23rd October 2008, 07:19 AM

That looks a nice bit of gear Steve.

Can you mount a chuck to it?

Some of those rotary tables have an adjustment method for the worm drive. For backlash that would be good.

Is this to be used on a mill or router? Do you have specific jobs in mind or just general? You need to make a tailstock for it now.

Perhaps if you start churning out jobs I will get motivated to pull mine out from under the pile of junk and do some more on it. :)

Greg

simso

23rd October 2008, 10:21 AM

Hey greg, I made this one up for my router, but Its portable so it can be used with a mill as well. I purchased a tail stock and chuck with it at the same time, just didnt get around yesterday to mounting the chuck yet

Yes it has an adjustment for removing backlash from the worm gear, it has a guick worm drive disconnect. and adjustment for backlash on the main gear as well.

I dont know if youve seen this photo, I sent it to rod a while back, the new cnc work centre at work, three coolant lines 8000rpm spindle super quiet, auto tool changer (20tools) etc etc

simso

7th November 2008, 08:06 PM

Hey greg, I downloaded that program that andrew wrote "wrapper" looks the part thats for sure, however it references the radius as a - figure, is this for when you use the bottom of your job as zero z ref,

Greolt

7th November 2008, 08:48 PM

G'day Steve

I have not used it for a while. As I remember zero is the centreline of the job.

Don't know why it wants a minus number for radius. But it does.

There is a reasonably good help file.

Should not expect too much. Andrew wrote this first try at programming as a learning exercise.

Greg

simso

7th November 2008, 10:35 PM

Thanks greg, just unusual using a - measurment, unless its designed around your zero offset being the bottom of the job and not the top during initial design

Thanks

Steve

Greolt

8th November 2008, 01:28 PM

Steve

Looking at it, looks like you must set zero to the bottom of material in Vcarve.

Not sure why it is like that but I guess there is some reason in the calculations that must be done.

To have it display on the toopath window, set it up in config.

Config menu, toolpath. Set the axis that the rotary lines up with and set "A-Rotations Enabled"

Also set "Use diameter for Feedrate". Then set the diameter on the settings page and it will interpret the feedrate correctly.

Greg

Greolt

20th February 2009, 11:18 AM

Finally dug the gearbox rotary out from under the pile and made up a tailstock and base for it.

Not going to qualify for the high precision machinery division but I reckon it will be fairly capable.

Made it so that it can be mounted on the X3 as well. If it is successful I will get a small three jaw chuck for it.

Now if only Vectric had a 4th axis module to go with Aspire. :roll:

Greg

.

rodm

20th February 2009, 11:30 AM

Nice bit of fabricating :2tsup:
Are you going to use a smaller chuck so that the spindle can get closer to the chuck end?

Greolt

20th February 2009, 12:04 PM

Yeah as I said if it proves useful and I want better holding precision than the wood lathe chuck will provide, then I will get a small 80 or 100mm three jaw chuck.

I already had the wood chuck from a wood lathe so that will do till I pine for better.

Past experience tells me that won't be long. :U

Also the reason I made it with the same spindle thread as my wood lathe is that I have a variety of work holding devices I have made for the wood lathe that will fit straight on.

Face plates, pin chuck, screw chuck, etc.

Another advantage that I can see is a job may be turned in the wood lathe then transferred, chuck and all, to the rotary axis. No re setup.

Time will tell. It may just be left on the floor again. :roll:

Suitable CAM software is my biggest problem.

Greg

Greolt

4th September 2009, 11:18 PM

I have been posting some 4th axis stuff on the Vectric forum to encourage users to consider the possibilities of adapting Aspire to a 4th axis.

http://www.vectric.com/forum/viewtopic.php?f=28&t=6449

Anyway I made this little youtube video. http://machsupport.com/forum/Smileys/default/grin.gif

Greg

http://www.youtube.com/watch?v=yWFSdogFx_g (http://www.youtube.com/v/yWFSdogFx_g&hl=en&fs=1&)

rodm

5th September 2009, 12:01 AM

Nice work Greg.
I was sitting there wondering if the pattern was going to meet up and it sure did so well done.Next gears?

ivan_351

19th September 2009, 10:26 AM

Hi , Greg has a eye for detail, nice work Greg

cheers

seafurymike

21st September 2009, 01:11 PM

Why does Greg leave all the really nice 4th axis pictures on the Vectric forum.

PS: Just starting our 4th axis. We have decided on using some planetary gears that Nigel has floating around. The backlash has been eliminated by pre-loading the gears.
Just have to decide on stepper motors for the unit that will work on the X4 and GRF.

Greolt

21st September 2009, 01:57 PM

G'day Mike

I wrote some tutorial, sort of, posts on the Vectric forum, using Vcarve Pro / Aspire toolpaths and Wrapping them onto a 4th axis.

Unfortunately Vectric were not so keen. They thought that it might lead readers to believe Vectric products had 4th axis capability. Fair enough, it is their forum.

The Wrapper program is going to have a version 2 released soon. I have seen it and it is really good.

When that happens, I will redo the tutorials to a more generic CAM focus and put them up.

Greg

John H

21st September 2009, 02:21 PM

I found this interesting thread over on CNCzone the other day on a backlash free rotary table

http://www.cnczone.com/forums/showthread.php?t=72261&highlight=backlash

seafurymike

21st September 2009, 03:23 PM

So what enhancements will be available with the new wrapper version? You have wet my appetite!!

I was only kidding about the pictures:U. I love the work that you churn out. It keeps us mere mortals in line with aspiration to someday knock out some of your tutorials.

John, there is some nice work being done on that thread but I don't want the hassle of making my unit from scratch. Plus we are making 6 units in total with bugger all revenue from them (jobs for friends). The units are already available in our hands and we have 6 in total already. 10:1 reduction should work fine. Plus i noticed on the X4 drivers you can set stepping quite high, so i will also look at trying some of the higher values and see how it goes.

Greolt

8th October 2009, 05:02 PM

The CNCWrapper is released in Version 2.

CNCWrapper - Home Page (http://www.cncwrapper.com/)

Only $20. Well worth it for anyone who has a 4th axis.

I will post some examples of what can be done with it soon.

Greg

rodm

9th October 2009, 12:09 PM

Greolt

9th October 2009, 01:02 PM

By the way I have a 5 and maybe 6 axis machine on the drawing board so this will be a good intro to that level.

Wow that will be something to see. :)

Greg

rodm

9th October 2009, 07:39 PM

Inspired by this site a couple of weeks ago and been doing a lot of reading since.
here (http://www.doughtydrive.com/)

John H

9th October 2009, 07:58 PM

ohhhh Nice

YouTube - 5 axis tab box

Generating the G Code must be scary as hell.

rodm

9th October 2009, 08:18 PM

Doesn't look that bad but it might be one of those things that looks easy but,,,,,,,,,,,,,
Free from Here (http://www.cnc-toolkit.com/)

seafurymike

12th October 2009, 10:58 AM

Thanks Greg,
I am building a 4th axis along with other projects so your post is timely.
I had a look at his earlier version and it was simple enough to use and it is cheap enough.
By the way I have a 5 and maybe 6 axis machine on the drawing board so this will be a good intro to that level.

I struggle with 3 axis, let alone 4, 5 or 6. Great to see the boundaries getting pushed by some.

PS: The 6 units were building are coming along. All the components have been acquired. Just made up some couplers so we can connect the stepper to the existing screw drive.
The machine plates are coming along. Hoping to have unit #1 online by this week, then the rest after that.

triden

28th December 2009, 09:42 PM

After seeing a 4th Axis in action i am going to have a go at one. I have looked at Wrapper and got it working in Mach3 following gregs tips in the various forums he posts in. Not having any metal work facility's i'm thinking of using a head stock from a old GMC lathe with a 60 tooth pulley on the shaft and a 10 tooth pulley on the stepper. This should give me 6 to 1. Would this be satisfactory? I will be using a 387 ozin stepper, g540, 48vdc power supply.
This will just be a learning thing untill i can find a gearbox. The reason i am using these pulleys is that i can get them reasonably cheap.

denis

simso

28th December 2009, 09:54 PM

Ive had my fourth axis running now for over a year and love it.

Be interesting to see what the new wrapper program is like, I had the first one and then gave it away becuase I found to many times the program would crash or not do what I was after.

Now adays I hand write any g code for the a axis and have no problems but you are limited to basic code not some of the fancy stuff like vcarve can do

Greolt

28th December 2009, 10:08 PM

I used the free version 1 Wrapper for quite a while and never had a crash that I can remember. It could take a very long time to convert a large file.

However the new CNCWrapper is a big improvement. Very fast. And some nice interface enhancements and utilities.

The latest upgrades of Aspire and Vcarve Pro have a wrapping post processor built in.

Greg

simso

28th December 2009, 10:17 PM

rodm

12th February 2010, 12:14 AM

Finally I got a 4th axis. I got it on ebay and it has a 50:1 harmonic gear drive so it is zero backlash. The motor is unipolar 6 wire so I will probably replace that with a stronger bipolar parallel in the fullness of time.
Tailstock is one I had for a rotary indexer on the mill and is only 1mm below centre of the chuck so I will make a bed and allow for the variation in the mounts.
As you can see from the spoilboard in the photo Morphy is getting plenty of use.

simso

12th February 2010, 01:00 AM

Very nice rod, you wont regret it, have done pool cues and all sorts of weird stuff now on mine

rodm

12th February 2010, 01:11 AM

Hi Steve,
How do you calculate steps per unit for a rotary. Been looking over the Mach3 site but can't jag the right words on a search to turn anything up.
Also what units are we calculating -one degree or one roatation?

Greolt

12th February 2010, 06:54 AM

Wow that is some rotary axis. :)

Looks expensive... but very nice. Wonder if it would be even better with a servo on it?

Units for a rotary axis are degrees. So presuming 2000 steps per motor rev.

2000 x 50 / 360 = 277.77777

Greg

rodm

12th February 2010, 10:01 AM

Hi Greg,
Thanks for the calculation.
That gives it quite a good resloution.
It was an impulse buy and I paid more than I would have preferred to pay but it is top quality. I have bits for a rotary axis including a 5 inch three jaw but not the time to put it together so this gets me going.
As you say a servo would work better than a stepper for higher rotational speed.

simso

12th February 2010, 10:49 AM

Well done greg, sorry rod I had gone to bed.

Wrapper is still probably one of the better programs out there still for us hobbyists

Im about to pull my machine apart rod, I need to completley redesign my workshop, running out of room very fast

Newest toy arriving soon and no where to put it,

rodm

12th February 2010, 11:29 AM

Hi Steve,
Nice tool and cutter grinder.
I can make room in my shed if it is too hard for you. :)

seafurymike

12th February 2010, 06:19 PM

Has anyone looked at just outputting the file instead of wrapping it via a program?

I mean there is no reason the 4th axis knows that it is rotary. As long as the steps are calculated for the diameter of the work piece, then a flat 2.5D gcode output would work, or am i off the mark here?

Nigel and I should have our 6 units finished soon, they kind of look like Rod new units, but his is very nice and shiny and ours are bland green -: (

Q. Does the wrapper program compensate for tapering round and does it also compensate for the depth of tool cut in this taper (if it does it)

/M

Greolt

12th February 2010, 06:53 PM

CNCWrapper does only two things.

It scales the positions of the axis that is wrapped according to the diameter/radius/circumference that was entered.

Also it changes the axis designation as required. For example from X to A in my case.

There are lots of ways to wrap an X/Y plane toolpath.

Having tried lots of them, I find CNCWrapper and the Aspire wrap PP to be the easiest and most intuitive.

Greg

seafurymike

5th March 2010, 02:00 PM

Well, i have to say it took us ages but we finally put the finishing touches last night to the 4th axis units that we were building over the last 5 months.

Steppers come from Chris, the chucks were sourced from Asset Plant and the reduction (10:1) were surplus from Nigel stores (Thanks Nigel)

Most of the unit was re-machined to some degree to produce a unit that had as little slop as possible.

Next is to make something on it. A job for the long weekend :U

/M

rodm

5th March 2010, 08:26 PM

Hi Mike,
Nice work. Looks like you are going to have some fun on the weekend.

seafurymike

10th March 2010, 01:25 PM

Legacy CNC Woodworking - Home (http://www.legacycncwoodworking.com/)

I liked some of the products produced with the rotary axis and especially the idea of embedding the rotary axis within the machine. My unit will allow for this and I think i'm going to look at the feasibility of doing it.

/M

spidey4fun

10th December 2010, 12:11 AM

This was a good read... handy info for those starting a 4th axis. :2tsup:

Brad.

spidey4fun

11th December 2010, 04:35 PM

Has anyone here enquired about the cost of the doughty Drive?

DoughtyDrive (http://www.doughtydrive.com/)

Or know anything about this software?

The CNC Toolkit - Creative Toolpath Control (http://www.cnc-toolkit.com/)

Brad.

WillyInBris

11th December 2010, 06:15 PM

HI brad I got a quote some time ago couple of years maybe when he first started out I think it was around the 1k mark he priced it in US$ and I think our currency was quite low at the time but it was some time ago so get a quote off him and see what price he is putting on them now maybe they are more reasonable due to the AU$.

I actully dont like that he doesn't put a price up on his site, but I guess that way he can price it as he likes depending how busy he is.