Messages

171

General Mach Discussion / Re: Lathe spindle index quit working

« on: December 02, 2009, 01:23:25 PM »

I ended up going with the Cambell board. worked like a champ.

Derek

172

General Mach Discussion / Re: Servo Drive Review. First 4 drives Gecko, Viper, Rutex, Leadshine

« on: August 12, 2009, 11:59:39 AM »

First off thanks for taking the time and expense  for this test.

My experiences with Gecko 340 and Rutex drives is exactly the same. The 340's with 500 count encoders would fault unless I used the slowest of accelerations and even then It was just unworkable. I suffered with this for over a year and finally replaced them with 4 990 drives. It was a night and day difference. The machine just ran like a champ. I did find this link about tuning that helped me get my arms around it a bit better. http://www.eaglemotion.com/home/R9xHbdi/pg5.htm  Although I'm still not sure if it's as good as it can be. The new drives are great in that you can set the PID values with the software.

My only real complaint with Rutex is availability. Tom at Rutex US has great customer support and has helped me many times.


Derek

173

General Mach Discussion / Re: Is backlash causing these choppy cuts?

« on: July 14, 2009, 06:42:17 PM »

You guys may be on to something.
Here is a patch of code

N28 G01 X10.968 Y4.755
N29 G01 X11.061 Y4.777
N30 G01 X11.101 Y4.787
N31 G01 X11.234 Y4.822
N32 G01 X11.368 Y4.861
N33 G01 X11.474 Y4.895
N34 G01 X11.501 Y4.904
N35 G01 X11.608 Y4.942
N36 G01 X11.714 Y4.982
N37 G01 X11.768 Y5.003


And here is a screen capture of the code plotted against the tool path.


The larger segments are .140" long. Yikes that's a pretty long straight run.

Derek

174

General Mach Discussion / Is backlash causing these choppy cuts?

« on: July 14, 2009, 05:34:44 PM »

I've been dealing with this for a long time now. It's mostly a problem on larger pieces only because it's more noticeable. It happens on everything.

This was cut with a horizontal strategy with a .010" step over. The Intol and Outol are .001" and the piece is 15" in diam. The cut direction is mixed.

The piece has been primed and I sanded through to the base material so the ridges and valleys would show up.

Here is a wide shot. One think to look at is how symmetrical the chop is as it leads around the bell and the goes straight as the wall of the pattern goes straight. also notice how there is no chop where the axis is running nearly parallel.



Here's a closeup



I'm really getting tired of sanding this crap!!!

Derek

175

General Mach Discussion / Re: Choppy cuts in X-Y direction

« on: May 20, 2009, 08:16:08 AM »

Well I checked everything that was suggested and I'm leaning towards mechanics. I'll be making some changes today and I'll see if I can get a handle on this.

Thanks
Derek

176

General Mach Discussion / Choppy cuts in X-Y direction

« on: May 19, 2009, 10:08:38 AM »

I've been dealing with this problem for a while now. Like over a year! I do mostly 3D contour cutting and have been getting really weird choppy cuts. I messed with lookahead and CV settings but never had any success.

I finally attributed it to gantry shake and slowly but surely started making needed improvements. None of my changes made a bit of difference.  Including trying a more powerful computer.

I now have a more traditional piece I'm cutting.

I'm cutting a piece with 72 pockets laid out in a circle. The pockets that are at the 12:00, 3:00, 6:00 and 9:00 positions are smooth as silk. They gradually get choppier until they hit the 45 degree mark and then start improving. There is a noticeable amount of chop on the first pocket that requires X+Y combined movement.

I'm dying ova here!

Derek

177

General Mach Discussion / how can I disable the Home hotkey

« on: April 30, 2009, 07:07:44 AM »

Hi
I'd like to disable the "home" and the "shift 7"  hot keys for homing. Their proximity to the Z axis jog buttons makes them problematic for me. I really don't home so much that I need a hotkey for it!

Thanks
Derek

178

General Mach Discussion / Need help triggering NextEngine scanner.

« on: April 10, 2009, 10:06:32 AM »

Hi
I have a Nextengine 3D scanner that has a rotary table.  The table only holds 20 lbs. I have some heavy pieces I need to scan so I'm putting together a rotary table that I'll control with Mach.

The Nextengine software has an attachment feature that assembles all the scans. You manually align 2 scans and as long as you use the nextengine rotary table the rest of the scans will auto align. The work around for this is to leave the nextengine table plugged in but off to the side and then manually trigger the CNC table for every scan. I want to do this automatically.

I'm imagining something like a macro that says when I get a signal on pin #(?) run this code. The code would be the number of degrees I want the table to turn. This I really need help with.

Then I need to put a signal on the pin. One way would be to put a cam wheel and micro switch on the Nextengine table. The cam wheel would have the number of scans I wanted to do cut into it. When the table turns it triggers the switch.

I'm hoping for something better. The Nextengine table runs off of 1.5V dc. I'm thinking of triggering a 1.5V relay and that would trigger Mach. This should work but if I'm missing something I'd like to know.


Thanks
Derek

179

General Mach Discussion / Re: Z AXIS KNEE

« on: November 07, 2008, 08:46:24 PM »

Well just because you've never needed it doesn't mean it's a bad idea. At least that's the impression I got from the tone of your post.

I've been running mine for over a year and a half now almost daily. My rapid is 60ipm. I regularly run programs with over 100,000 lines of code.A lot of times it's a Z axis profile.
 I'm using a rutex drive and a surplus treadmill motor. I have gas assist on the knee but it's still heavy enough to reduce the backlash. So for me the knee conversion has been the best mod I've done to the mill.

Derek

180

General Mach Discussion / Re: No Hotkey for estop in Turn

« on: September 18, 2008, 08:07:45 AM »

ESC will do

Not on mine!

Derek