Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Jaydeetol on April 08, 2015, 12:47:40 AM
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Hello all,
I've seem to hit a bump in the road. I've been using mach 3 for quite some time now and am now starting to do threading I went through all the literature for mach3 turn for threading. to do 32 TPI. However: when I post the code there's a red line that my machine follows. I thought that red line was homing or start point, is this correct? I have posted a pic any help would be much appreciated.
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The Tool Change position in the wizard is machine coords so likely that is where your machine coords zero is. Personally I prefer to have it home to a wok coords position and thus I altered the wizard.
Hood
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Now when I set the spindle rpm for 300 it says over max feedrate even when setting at different speeds. It will post when I set it for 50 RPM, but my lathe wont go that low....?
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Most likely the error is referring to the Z Axis, if the combination of RPM and pitch means the axis would have to be moving faster than you have set in Motor Tuning then you will get the error message informing you.
Hood
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Is there any other literature you could link me to to figure this out. I guess I am not understanding it.
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It is simply saying that to cut the required pitch at the called for RPM the Z Axis would have to move faster than it can, so it is impossible.
Say, as per your screenshot above you called for a RPM of 400 and a pitch of 0.031(32 tpi) then the axis would have to move at 0.031 inches per revolution. That would be a feedrate of 400 x 0.083333 = 12.4 Inch per Minute.
If your max velocity for the Z in motor tuning was 10 IPM then it would be impossible for Mach to carry out the threading operation.
If that is not your problem then please attach your xml and I will take a look.
Hood
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It's not letting me attach the file. Tried to rename it ect.
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Try another name, possibly someone else has previously used the name you are trying.
Hood
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thanks
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That is a mill profile you have attached.
Hood
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Sorry. Here it is.
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Ok your Z Axis has a velocity of 6, that would mean with a thread pitch of 0.031 inch the max RPM you could command would be 192. If you commanded a greater RPM then the Z axis could not physically move fast enough and thus Mach will give you that error message.
Ideally you would not want to try at 192rpm as there is a chance the spindle may be rotating slightly faster so for a safe value you would have to use about 170 or so RPM.
The best thing would be if you could increase the Velocity of the Z axis in motor tuning, that would allow you to have a greater RPM. Whether that is possible however will depend on your stepper and whether it can be set to a greater velocity without stalling.
Hood
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For those following this thread......
That's why one should always click the button to calc the number of passes just to make sure that
your velocity is ok for the intended thread at some rpm.
RICH