Toolpath Jumps with DX32 programs

Hey Everyone, I've got a VMC760/22 older machine running a DX32 controller. I'm starting to see issues with programs where my toolpaths will jump randomly or make arcs improperly. I'm not sure where to begin breaking down the problem.

Here is one example. This is the toolpath generated in FeatureCAM (I have very similar issues with Fusion360)


And here is the resulting simulation:


I'm not sure where to begin debugging this. The file size is 175kb so it loads just fine. I'm using a USB Floppy emulator, but I'm not sure how to tell if the program is getting corrupted or something?

Any ideas?

What does the code look like where the toolpath jumps, can you tell if its always on an arc? I've had problems with arc motion causing jumps due to not enough numbers after decimal. Its trying to go point to point, then the arc throws it off. If you can output all point to point and it goes away, it might give you an idea of how to proceed.

Steve_Boi said:

What does the code look like where the toolpath jumps, can you tell if its always on an arc? I've had problems with arc motion causing jumps due to not enough numbers after decimal. Its trying to go point to point, then the arc throws it off. If you can output all point to point and it goes away, it might give you an idea of how to proceed.

Click to expand...

You may have hit the nail on the head. It is in fact always on arc, I saw this with both post processors. In that screenshot example, the program fails with "Y move too far minus" at line N5860, where there is one less decimal. I'm not sure what lines cause the other large jumps. I may make a quick excel sheet to output decimals per line and see if there's a correlation

N5845X-0.8957Y-1.3083I-0.6665J-1.2661
N5850X-0.8962Y-1.3052I-0.6649J-1.2658
N5855X-0.8967Y-1.3021I-0.6646J-1.2658
N5860X-0.8972Y-1.2989I-0.665J-1.2658
N5865X-0.8982Y-1.2913I-0.6651J-1.2658
N5870X-0.8989Y-1.2837I-0.665J-1.2658

You can also get the 'y move to far minus' depending on where you work shifts are set. As for the file being corrupted, you can look at the g code in fusion when you post process and compare it to what is being loaded into the machine once its on the machine. Using smoothing makes a big difference in fusion. I haven't used featurecam. Have you actual run this program that you have previewed? How does it perform?

I have a VMC1000/22, VMC760/22, and two torq cut 22s all with dx32. They are pretty capable as long as you know how to set up drip feeding and get the bugs worked out.

I have run the program and it does the same jumps as seen in the simulation.

I can't compare files for some reason. the file size is 177kb, so when I try to look at it in the edit window it will not load. I tried reverting back to the floppy and see the same issue....

This time i filmed the simulation so I could see the lines scrolling at the top. I noticed that there are a few jumps in the program. Each program jumps at different points. When I say Jump I mean I'm seeing scroll across the screen: N4565...N4570...N4700...N4705 etc. In some cases it jumps back a hundred lines or so, in some its jumping forward. At this point I'm pretty sure the issue is either:

1) The IDE/Floppy controller on the Motherboard has an issue
2) The ROM inside the CNC has an issue

I'm leaning towards issue (1) since I also tried to transfer the file from the floppy to C drive and get a "Bad Sector" error. This happens both with the USB adapter, and with the stock Floppy.

Can someone walk me through transferring data via the serial? I tried to do some basic transfer with a USB-Serial cable from my laptop but couldn't seem to get any data onto the machine.

Griffin said:

You can also get the 'y move to far minus' depending on where you work shifts are set. As for the file being corrupted, you can look at the g code in fusion when you post process and compare it to what is being loaded into the machine once its on the machine. Using smoothing makes a big difference in fusion. I haven't used featurecam. Have you actual run this program that you have previewed? How does it perform?

I have a VMC1000/22, VMC760/22, and two torq cut 22s all with dx32. They are pretty capable as long as you know how to set up drip feeding and get the bugs worked out.

Click to expand...

I'm sure its not my work-sets, I verified the location is within limits. I get that error only on occasion when the jump/arc created is too large

It may very well be a hard drive going bad. On my VMC1000 it would make bizarre moves and randomly decide to skip lines when the hard drive itself was going bad. I also got the bad sector error when trying to copy files to the c drive. I ended up just getting a preloaded DOM setup from EMI. I think it was around $300 already loaded with DX32 software. It fixed several other weird issues I was having with the control. Make sure you back up the parameters if you haven't already. EMI will send a list of 'default' parameters. What it won't have is backlash comp values, etc. Post up if you need help figuring this out. Mine was being problematic for a few days then just died completely one day.

If you want to send me the part file, I'll quickly do a program for you and send it back so you can see if it's something wrong with the post processor. It wouldn't be something to run, just to see if it shows correctly in your mill.

I have the same machine as you do. VMC 760/22 with DX-32 and I use Fusion360 to program it. I've never run into this issue and I've programmed many parts similar to yours.

My machine is setup differently, the original hard drive was replaced with a larger/faster one and I have a second hard drive that boots into windows. So I do not drip feed or use floppys. I simply restart the PC, boot into windows, copy my files over and then restart into the DX32 control.

If you send me your full code and a basic setup guide, I'm willing to run it on my machine. This will rule out any of the code corruption concerns.

That being said I've never had my machine spit out any errors like you mentioned or "jump" on arcs and I've milled many gears just like yours.

p.s. I hope that's a low speed gear or a sprocket. 3 axis mill's aren't ideal for machining the involute profile of high rpm gears.

ondori said:

I have the same machine as you do. VMC 760/22 with DX-32 and I use Fusion360 to program it. I've never run into this issue and I've programmed many parts similar to yours.

My machine is setup differently, the original hard drive was replaced with a larger/faster one and I have a second hard drive that boots into windows. So I do not drip feed or use floppys. I simply restart the PC, boot into windows, copy my files over and then restart into the DX32 control.

If you send me your full code and a basic setup guide, I'm willing to run it on my machine. This will rule out any of the code corruption concerns.

That being said I've never had my machine spit out any errors like you mentioned or "jump" on arcs and I've milled many gears just like yours.

p.s. I hope that's a low speed gear or a sprocket. 3 axis mill's aren't ideal for machining the involute profile of high rpm gears.

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Hey, this is the CAM file here: https://drive.google.com/open?id=1nR1v9Jp1wgiJHfheiLScj2dHR3AY54IJ It uses G56, with the center as the center of the sprocket and bottom face. It would be awesome to validate the program, thanks!

I'm really interested in your setup, do you have any documentation on how you did it? I'd even just like to replace the HD with a newer once since someone also suggested that could be the issue. I've got two disks labeled "Make Disk" and "Full Installation" #V4.79.22/6.89.57 that I'm pretty sure are the installation disks for the HD. So to replace would I just backup my parameters file onto another disk, put in a clean HDD, boot to floppy and install like any other PC system?

And yes its a #25 Sprocket. I run a High School Robotics team and in the past I've machined sprockets for different systems so we can put in custom bores, lightening patterns etc. I actually just tried this as a test on our machine (It was donated a few months ago), but started into this rabbit hole of issues