I have a problem with my 'New To Me' CNT Motion router. It is 'getting lost' in X. I need some help it finding a CNC technician who can repair my machine. See attached PDF for a further explanation of the problem.

Thanks,
Joe T.

Click the link below to download the file included with this post.

CNT_Motion_Router_Problem_Explanation__7_25_2015.pdf

Wincnc is a Pretty easy controller have you called Wincnc , Kelly and those may charge you but they support their software.

Yet

I do not think this is wincnc, first I would flip the file to run mirrored and make sure the loss is in the same direction. then look at all connections, as it is equally incremented it may be software, have you run varitions of other files or just this one.

Remember you are there and We cannot see what you are doing or what is happening.

is the control computer online could a tech log in and check it ? Wincnc is a doaughterboard based card autonomus of the mother board this allows for onllne access while machine is running.

also check card in cpu to make sure it is seated correctly and not slightly loose, you may want to disconnect the board and insure pci card and daughterboard are well attached to each other, pull the 37 pin cables and look for dust and bent pins. do not blow air directly into female pin holes.

is the machine stepper or servos ?

Jim,

First, this is the weirdest forum I have ever used!!! Odd way to respond and I can not figure out how to see all responses at once!!

I have spoken to Kelly many times. He has remotely logged onto my machine and checked macros, etc. He does not believe it is a WinCNC problem. But, I just sent him the PDF I posted and asked if this could be a 'scaling' problem.

I located a Wichita, KS based CNC technician this morning and chatted with him for a few minutes before he had to leave for work. He has experience on CNT Motion machines and WinCNC. He said, with the limited information I could relay to him over the phone and not seeing the PDF yet, that it seemed to him that the problem was a scaling issue. I have no idea - - -

I would much prefer a trained CNC technician check connections, etc. I am uncomfortable doing that. As a note, when I first hooked up the machine to the electrical system, it would give me a 'Limit Z+' error. I could not find the problem. I hired another CNC Technician who came and worked with Kelly to find the problem. It was a loose ribbon cable connection inside of a connector box.

I will post the Teknic information (servo/stepper, series, etc.) after I return from my shop tomorrow morning.

Thanks again for your advice.

Regards,
Joe T.

All good,, Tell Kelly I said Hello, He and I have worked thru many Wincnc learnings together they are some ace guys.. I absolutely understand the need for the tech, Beauty is wincnc has thousands of users and is a very stable platform,, Z+ errors are 99% of the time a software parameter setting I saw a problem like yours a long time ago turned out to be a drive type on 9 machines once we found it all went well and all of those machines are in use today.

you have a really nice machine with that tall Z I can think of a few uses for it myself !! how are you producing the code (Cam)?

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CMI,

I would like to post your message and my reply on Woodweb.

You responded:

“Call Paul at CNT we have had a CNT CNC for 8 yrs only had couple issues and he fixed them in short order.
(412) 244-5770”

My reply:

Thank you. Paul Cullen at CNT Motion will not reply to my repeated emails requesting support nor will they respond to a trouble ticket I submitted. Paul was very helpful when I was considering the purchase of this machine. However, once I purchased it, he has become less helpful and has recently (March 2015) stopped all communication. I have tried to set up a support account for technical consultation via the trouble ticket I submitted several weeks ago. No reply.

Regards,
Joe T.

Chad,

I would like to post your response to my posting, and my reply seen below, on Woodweb. I know of at least one other person who is having problems similar to yours. He will benefit from your experiences.

That is SCARY!!!! Paul told me to have a separate 7’ ground for my machine. I did that (actually, my electrician did it). But, as you can see, I have a problem.

Thanks for the reply.

Regards,
Joe T.

Hi Joe,

We have a CNT 1000 also. It was purchased in 2007. We started having problems with the X axis about a year after the purchase. Just like you, it showed up at the tool change. Bent the tool rack, bent tool forks, even had to replace the cartridge in the spindle. Had guys from CNT in here a couple of times. Normally the problem was blamed on interference, so we drove an 8' grounding rod into the floor. Didn't seem to help. We then replaced the cables from the control to the machine. I thought this had solved the problem. We took the machine out of production due to a change in our manufacturing for about 2 years. Early this year, we resurrected it. Ran all new electric, and drove another grounding rod beside it. One of the first programs I ran, I noticed it was loosing the x axis again. I'm at a point that I don't know what to do. If you get anywhere with yours, I would appreciate any feedback.

Thanks

Chad

Guys,

The standard for grounding, from what I know, is to ground everything to the building common ground. Anything else can cause ground loops....there is some good information out there but I don't have the links at hand. Suffice to say I would not be driving spikes for individual machines at my shop.

The bigger problem that I see with the CNT is that they have not grounded the data signal cable shielding, properly or at all (properly being all the way back to the control not on the machine side at all)

The motor cable shields are likewise cut away and not connected, but I think if the data cables were done correctly that would not be of great importance.

Hence, my plan is to totally redo the data cabling with modular ethernet cables (shielded and most important wires with the twisted pair wire to ground as well) running on the other side of the machine, keeping wires as far apart in the gantry cabinet as possible.

The other possible good solution is to re-do the data cabinet and move the drives to that cabinet, thus having closed loop motion all the way from cabinet to motors and route wires in the cabinet to minimize interference. Would need a bigger cabinet than stock. This is how the chinese machines are built and I'm sure it helps.

Joe T
Did you ever solve your problem with X getting lost on your CNT router? I have a older Didital Tool Meta904,the same as that 20' long one that James Mcgrew has except mine only has 48x74" cut path. I recently mortised out a set of stair stringers. I could only cut 5 risers at a time then move material. I use Bob Cad and MOC 3 controller. I did not think that the tool path was the most effiient but ran it any way. long story short, a lot of lines of code and lot of zig zags, machine was .090 out in the X axes. Never noticed it before this but I guess the error is compounded on a long program. It would be a big help to me if you posted your findings. Thanks Bill

Bill you may need to do a resolution test and set, also look at the limits set in the INI file.

Thanks James I don't know exactly what you are talking about but my partner on machine should know. Old dogs and new tricks you know. he is pretty good with that stuff, if not he may want to talk to you his name is Erick. While I have your ear What feed and speed and cutter would you recommend for inlay work with HPL . on this machine ? Thanks for your response Bill

I had a digital , Does it have the Wincnc controller. runt a test, cut a 12" x 12" square .25 deep with a measured .25 bit. then measure the length and width both should be 12" if not then a resetting of resolution is needed.

I do the male inlay first by slightly gluing it to say some .75 melamine, (best to run a test with an older piece of plam before screwing up the Money piece) once I am ok with the male (I use a .125 endmill set just below the thickness) I then set the female piece (already on final surface or on melamine) and run it an .005 offset for fit. may have to do this again so never move the female till you have a good fit and are satisfied.

I use Aspires inlay tool path feature. run several practice test before trying a good piece

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View higher quality, full size image (1024 X 681)

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James the machine had win cnc when we bought but we installed MACH3 as wincnc was the basic license each and every feature you turn on is three to five hundred and five hundred to transfer. I think the machine ran smother in and out of turns with win post. yes we did the resolution test and set , I beleave every thing was fine then I will do the 12x12 cut test but I do not think it will show up just cutting a square.

All,

Once again, this is the most confusing forum I have EVER tried to use!

An update:

I have been trying to understand why my CNT Motion router 'gets lost in X' for a long time. I decided in early July to take a more structured approach to trying to understand this problem. I have performed a number of simple, parametric tests.

So far, this is what I have learned:

1.) The machine works very well. My problem is not a CNT Motion router issue, except that there is no programming info/training guide available. So, it has been a long learning curve. I don't consider the WinCNC reference manual a programming guide. It provides no syntax, etc., on how to properly use many of the G and M codes. Also, that manual does not have all of the M codes available on my machine. Many have been written by CNT and I can not get a listing or any other info about them. Purely trial and error. Not a good way to run a business - - -

2.) It is a software problem, not hardware. I have eliminated WinCNC and editNC (my G-Code editor) as the root cause of my issues. It is CATIA and how I, and others, have the basic CATIA options set up.

3.) If I run a simple G-code program I have written, including tool changes, work offsets ("HOME" as CNT calls them - how STUPID!), etc., the machine works flawlessly. These programs can be written in a basic text editor or editNC. Doesn't matter. When I try to run a more complex program from CATIA, I have problems.

3.) So, I am trying to identify the reasons the CATIA I use does not give me the tool path output needed to make a part. The WinCNC viewer shows the program tool paths are PERFECT, but the actual part is not correct - sometimes WAY OFF!

So, still working on the problem. I will update again when I have more data.

Regards,
Joe T.

Jim said:

" you have a really nice machine with that tall Z I can think of a few uses for it myself !! how are you producing the code (Cam)?"

Thanks. I seem to be getting close (at least closer!) to solving my problem.

How do I produce G-Code? GREAT QUESTION!

I am currently using CATIA that is owned by a friend who has a machine shop. I am trained in CATIA including the Prismatic and Advanced Surfaces Machining workbenches.

So, after hours, I use one of his seats to make part solid models/surfaces, etc. Then I program the model typically using the Advanced Surfaces Machining workbench in the "3-axis" mode.

I output an APT.CL file. This part of the process is most likely where I am still having problems. There are MANY options that have to be selected CORRECTLY to get an APT.CL file which will work with a given machine.

Now, here is the trick: The APT.CL file is not useable. It has to be 'transformed' into G-code. I searched for several months until I found a G-Code editor that would take an APT.CL file input and translate it to G-Code. I found one - editNC. It works GREAT!

From there, I have to modify the G-Code to work on my machine. I don't change the tool paths, just the tool changes and work offsets, G92 (as needed), etc.

Pretty simple, except I still don't get the CATIA output exactly correct. I will get there - - -

Regards,
Joe T.

All,

I have identified the source of the problem. But, that 'source' could have one of several root causes.

I have continued to run diagnostic tests.

If you remember, I originally thought that the source of the problem was something about the CATIA APT.Source converted to G-Code that caused the 'X-Drift.' Actually, it is an 'X-Shift.' This X-shift only occurred when I ran a CATIA generated tool path. When I ran one of the existing simple programs that were on the machine's computer, everything worked fine.

Well, I started performing parametric tests when I only changed one variable at a time. I would work the X axis. I could not cause an X-Shift using only X motion. Then I would work the X and Y axes. I could not cause an X-Shift using only X-Y motion. Then I would work only the X-Z axes. I could not cause an X-Shift using only X-Z motion. The simple programs I wrote to test the X/Y/Z axes were all written directly in G-code - no CATIA.

Each of these were 'saw teeth' The X/Y were in a horizontal plane and when I ran these programs I cut traces of the saw teeth in the MDF spoil-board. Each set of saw teeth had six 'teeth.' I would run them down the X axis and back to X=0.. I ran 20 saw teeth per test run. They were perfect.

I ran the X/Z saw teeth in the vertical plane. Again, six saw teeth along the X axis. This time, each vertex at the bottom of the saw teeth would touch the MDF and leave a mark (-0.1" cut 'spot'). Again, PERFECT! No X-Shift!!!

HUMMMM - - - -

A CNC tech I have used to try and diagnose the problem said he thought it was a matter of the acceleration rate (feed rate) used on the X-axis. OK, I'll test that - - - -

Well, I decided try running some slant lines (X0 Y0 to X35 Y35 back to X0 Y0, etc.) at increasing feed rates. For each increase in feed rate, I changed the starting and ending X position by 2 inches. So, each set of slant lines were parallel but offset by 2". I kept the Z axis off the table EXCEPT to mark X5 Y5 at the beginning of each set of 20 lines (feed rate) and at the end of each set of 20. Each run had 20 'slant lines' at different feed rates (accelerations). My program had one set of 20 slant lines run at a feed rate of500 in/min. The next set of 20 had a feed rate 600 in/min, etc., through 1,000 in/min. All of these were in one the same program - hand written G-code. Each set of 20 was offset in X by 2".

Well DANG!!!

The 'touch mark' at the beginning of the program and the first one after 500/in/min were in the same spot. But, each successive touch marks (after the 600, 700, 800, 900, sand 1,000 slant lines of 20 each) were offset (SHIFTED) by ~3/4" from X=5!!!!!!

So, CATIA is not the problem.

But what is?

By yesterday, Friday Nov. 6, 2015, I had convinced myself that it was either a problem with the x-axis servo motor's encoder or the X-axis servo drive. I went to the shop yesterday (Friday) to try and remove the X-axis servo motor and the servo drive. But, before I did that, I had to try some more 'tests.'

I tried running a set of 20 X only acceleration tests, These started at X0 and ended at X65 then returned to X0, etc. for a total 'back and forth movements' of 20 sets. I ran this at 400 in/min and 1,000 in/min. Again, 1,000 is the maximum my machine will run. Obviously, not an X-axis only acceleration problem.

HUMMM - - - - What's next??

I run an X-Y acceleration test. X from 0 to 65, Y from 0 to 2 (I didn't have much Y to work with since I was near the end (Y+) of my table for the work offset).

Again, sets of 20 with a touch mark at the beginning of each set of 20 and at the end of the run. Like before, i ran two runs - one at 400 in/min, the second at 1,000 in/min.

HUHHHH???? Every touch mark was PERFECT!!! NO X-SHIFT!!

OK, must be the combination of the X-Z axis.

So, I run another pair of test runs varying the X axis from 0 to 65 and the Z axis from 25 to 20. Again, each test run had 20 back and forth movements with a tough mark at the beginning and end.

You guessed it!!

P-E-R-F-E-C-T!!!!!! No X-Shift.

Out of desperation, I decided to make true '3D' moves - changing X, Y and Z simultaneously.

So, this set of runs started at X0, Y0, Z25 and went to X65, Y2, Z20 and then back to the start. Each feed rate had a set of 20 'back and forth' moves with a touch mark at the beginning and then again at the end.

Well, there is a GOD!!!!!

The touch marks are about 4" apart in X!!!! See attached photo (PDF).

So, this has been a LONG harangue. What did this tell me?

1.) It is not a CATIA problem
2.) It is not a servo motor / servo drive problem
3.) IT IS A WinCNC PROBLEM!!!!!

Let me clarify the above:

The 'X-Shift' occurs ONLY when there is a 3-D movement. What I mean by this is that the spindle is moved in the X/Y/Z axes simultaneously. If it is moved in only one axis or two axes at a time, there is NO X-SHIFT. The shift only occurs when there is a 3D move.

This has to be a control software problem. Either the WinCNC executable is corrupted, or the .ini file is corrupted, or the MACROS are corrupted, OR perhaps there is some damage to the two daughter boards - or a DIP switch is incorrect.

Remember, I am the forth owner of this machine. It does not have much use, but it has been moved 5 times!!! Anything could have happened.

AND

WinCNC does not protect its executable code, macros, or .ini files!!! ANYONE can change (corrupt) them.

One final comment:

When I was running these 'acceleration tests,' I stood near the work offsets 'X0' location. During the single and two axis moves, the spindle came back to the X0 location after every 'back and forth' move. But, when I ran the '3D' moves, regardless of the feed rate, then spindle never made it back to X0. Each time the spindle returned to 'X0', it was just a little further int he X+ direction. Each of those shifts in X was the same increment.

The approximately four inch offset shown int eh photo above was the difference between the start of the run and the ending (finishing) position. Each run was 20 'back and forths.' If I had run 100 'back and forths,' the X-shift would have been 4 x (100/20) = 20 inches!!!!!

I suspected this from the beginning of this ‘quest for truth.’ But, Kelly and Mark at WinCNC ASSURED me it was not a WinCNC problem.

I will be talking to them again Monday morning.

Thanks for being patient.

I am open to any and all comments. If you think I have not identified the problem source, please let me know.

Joe T.

Attached PDF: 'Acceleration tests' photo NOTE 'Touch Mark' points. ALL start at 'X=0' ONLY the X/Y/Z 3-D moves have different 'FINISHING' touch marks!!

Click the link below to download the file included with this post.

Acceleration_Tests_11_6_2015.pdf