Messages

21

General Mach Discussion / Re: Problems threading on the lathe

« on: March 17, 2009, 10:30:01 AM »

Yep, Art, that summarises it for me. Also, I'd say about 10 to 20% speed dip triggers it on my machine.

If you want to suggest I test with an older / newer version of Mach, let me know.

Woody.

22

General Mach Discussion / Re: Problems threading on the lathe

« on: March 16, 2009, 06:29:23 PM »

Art, sorry to say all the work I do in the lathe is in Exact Stop mode and I have this problem of a wayward X axis during threading. I've just gone in the workshop and checked again and yep, exact stop.

Attached is my .xml file and one of my G-Code files that I had problems with. I've just run that again and whilst in the (air) cut, slowed the spindle down during the "cut" with the VFD and sped it up again on the way back. And yep, the next cut has X motion. I also noticed, if the spindle is still changing speed at the end of the Z coming back to the start point, the Z axis is then stuck (VERY slow moving) and I have to stop the code - I hadn't noticed that before, but this never happens in real operation.

Hope that helps and I'm very grateful you guys are looking into this.

Woody.

23

General Mach Discussion / Re: Problems threading on the lathe

« on: March 01, 2009, 06:29:36 AM »

Art, yep, same with me, version .020 and parallel port. No missed steps and no backlash. Single index and usually threading at 400rpm. Exactly the same issues as Trevor and others. Fine with light cuts, crazy X with cuts over about 0.05mm deep in steel when the spindle slows noticably.

Nice movie Trevor!

24

General Mach Discussion / Re: Problems threading on the lathe

« on: February 28, 2009, 01:40:40 PM »

Hi All, just wanted to add, this is exactly the same issue I have, as in previous post.

I know this is brash to say but I am fairly sure this is an interference issue or a G32 bug with the parallel port. Its not G76 as this topic seems to have shown and I don't think it can be.

So, a quick poll - does everyone who has this problem have a VFD? I wonder if this can create interference at low speed and high motor slip when the cut slows down.

Next, does everyone with this problem use the parallel port?

I do wonder if there is a very small, very good at hiding bug in G32. I know that is a rash and arrogant statement and I apologise for that, but I just can't see how so many can have the same exact problem?

I've now cut 11 threads perfectly, M16.3 x 0.97 pitch (don't ask!) and with very light cuts (0.03mm - thats light!) they were all absolutely perfect, so I know the lathe and Mach3 is working well. But as soon as I move to deeper cuts and coarse threads like M1.5 or M2 and the spindle slows then the X axis starts to move after about the 3rd or 4th cut, so I have to stop and start again - eventually I can complete the thread after about 6 re-starts.

No matter what the spindle or Z axis does, the X axis should not move during a thread with no taper and it should not suddenly start moving when in the previous initial cuts on the same thread it didn't!

I'm sure we will get to the bottom of it!

Woody.

25

General Mach Discussion / Re: thread problem

« on: February 27, 2009, 08:05:41 AM »

Hi TrevorH,

I still have the same problem, but like you no missed steps and no errors coming up anywhere in Mach3. But, when the spindle slows more than about 5%, the "X" axis is then messed up in the next cut. Z axis is fine for me. Its 100% repeatable which makes me think it is in the coding somewhere. The solution for me is lighter cuts, with which I can then make perfect threads, even with "normal" spindle speed change.

So, I believe there are now four people posting with a similar issue with this Mach3Turn version. I still have more experiments to do when I get time and I will post them back here.

Looking through the G76 macro, I can't see how that is a problem, all it does is repeatedly call G32 and work out the correct parameters for each call. It can't make any direct X axis movement requests. So, I think there is a problem with the G32 macro with some setups.

However, others do not see this problem, esp with smoothstepper. So it could be a combination of settings or setup which then allow this error to occur.

Hmmm... Any ideas out there? No matter what the setup, the X axis should not move with a non tapering thread!

Cheers,

Woody.

26

General Mach Discussion / Re: Xylotex and C11 Issue

« on: February 22, 2009, 02:57:14 PM »

Yep, that is strange. I did not see any behaviour like that JigSaw!

Good luck with it.

Woody.

27

General Mach Discussion / Swarf in Keyboard and Mouse!! Ahhhh!

« on: February 20, 2009, 12:52:12 PM »

Dear All, I'm getting really bothered by swarf in the keyboard and mouse with my CNC lathe setup (ORAC + MACH3).

Its shielded but the sharp, springy and keyboard-deadly stuff gets everywhere. I even had an unexpected event (i.e. crash ) when a bit of swarf lodged in the side of the jog key and held it down!!

I just wondered what the more established users do to solve this problem.

I'm thinking vertical keyboard with integrated roller ball - but I expect its uncomfortable to use?

Any pics, advice and suggested products greatly appreciated!

Thanks, Woody.

28

General Mach Discussion / Re: Xylotex and C11 Issue

« on: February 20, 2009, 12:33:04 PM »

I have a 4 axis Xylotex board and its great. I've had no noise issues with my own breakout board, Xylotex and parallel port.

(I don't think Xylotex ships to the UK.)

I wired all my X, Y and Z limit switches to the BOB, then inside the BOB it "OR"s them all giving one "limit" out the the PC. Same with homing.

I think single ended shielding of all signal and stepper cables is the key - at least, it worked for me.

Woody.

29

General Mach Discussion / Re: thread problem

« on: February 17, 2009, 06:06:22 AM »

Thanks Hood, they look rather nice! I can achieve that but with VERY gentle cuts - 0.03mm diametrical depth per cut at about 400rpm. What depth and speed did you use?

Do you think running SmoothStepper makes any difference to this potential issue?

Thanks Rich, I'm tending to agree at the moment!

Woody.

30

General Mach Discussion / Re: thread problem

« on: February 16, 2009, 04:46:00 AM »

Hi Rich, yeah, they look great - thanks for the info. I think your SmoothStepper is doing very nicely. What version of Mach3?

This is very cheeky of me but is there any chance you could try a metric 2mm pitch thread if you get a moment? Could it be a metric thing for me?

I've cut a few 1mm pitch threads, gently, with no issues over the weekend. It only seems to be with the deep, over 1mm pitch threads that problem shows up for me. When I get the time, I'll do more experimentation.

I'm stuck with my trusty parallel port...

I did look at the M76 macro code and that can't vary the X axis during a thread. It also outputs good G32 code when run in diagnostic mode, and the taper "bit" is set to zero. So, I'm still hunting for the reason!

Cheers,

Woody.