Threading op (Lathe) - Stepper stuttering

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martyscncgarage
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Re: Threading op (Lathe) - Stepper stuttering

Post by martyscncgarage »

brassmanwithaplan wrote: Wed Jul 22, 2020 11:54 am
martyscncgarage wrote: Wed Jul 22, 2020 11:39 am
brassmanwithaplan wrote: Tue Jul 21, 2020 1:28 pm Not quite sure what you need for the intercon program? I'm assuming what I have attached for that one is not what you need?
You didn't post the intercon file generated when you used CNC12 to create a threading cycle.

Marty
The file "conversational thread test v1.cnc" is the one generated from using CNC12 CAM to create the threading cycle. If there's an additional file from this somewhere other than the .cnc , I'm not aware of how to find it.
Intercon creates an ICN file that should be located in the c:\icn_lath directory
You uploaded the created G code file when you POST from Intercon
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cnc_smith
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Re: Threading op (Lathe) - Stepper stuttering

Post by cnc_smith »

Dan (brassmanwithaplan),

Looking at the 3 g-code programs you sent and your max rate of 50 inch per minute (IPM) on your machine that is where some of the problem is.
For threading take the RPM times the pitch of the thread that will give you the inches per minute the cross slide will be moving. PRM x pitch of thread = IPM

1) "conversational thread test v1.cnc" program generated by Intercon the RPM is 500 with a thread pitch of .125 so the inches per minute is 500 x.125 = 62.5 IPM. This is faster than you machine can travel so that is why the thread looked worst than the other 2 programs.

2) "1.4-20 UNC test 1.nc". The RPM is 500 and the pitch is .049213 This is 24.6 IPM

3) "rpm test.nc". The RPM is 250 and the pitch is .049213. This is 12.3 IPM.

In the parameters in the CNC12 you need to change Parameter 240 to 0.050 and parameter 241 60.0000. From the main screen F1 (Setup), F3 (Config), the password is 137 if you have the Wizard set for password required, F3 (Parms). Use the F8 key to page down to get to parameters 240 and to 241. After interning the above values press F10 to save and the ESC to go back to the main screen. If this does not correct the threading problem then someone that is more familiar with the setting for the steppers can help.
Dana

When requesting support, please ALWAYS post a current report.
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Re: Threading op (Lathe) - Stepper stuttering

Post by cnckeith »

Threading is simple and impressive on how it works so well with Acorn, but you got to get the details right!


1.) correct encoder. https://centroidcncforum.com/viewtopic. ... der+basics

2.) 1:1 mount

3.) Z axis motor sized so it can actually move the Z axis fast enough to keep up with the threads. (remember the Z is electronically locked to the encoder while threading! you can test this as well before doing your first test thread)

4.) Use intercon until you get it working only then introduce yet another unknown.

Test with simple threads using Intercon at slow RPM speeds using brass or wax.

Watch out for unrealistic g code program speeds and feeds during testing.
Need support? READ THIS POST first. http://centroidcncforum.com/viewtopic.php?f=60&t=1043
All Acorn Documentation is located here: viewtopic.php?f=60&t=3397
Answers to common questions: viewforum.php?f=63
and here viewforum.php?f=61
Gear we use but don't sell. https://www.centroidcnc.com/centroid_di ... _gear.html


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