Finally got some shop time today and installed the repaired BoB. Fired up the mill and it now works as it should. M3 and M4 work as expected. Here's a short video showing the spindle rotating CW then reversing. Looks like I need to look at reducing the lag between the spindle reversing and the Z retracting.
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Flood Coolant Set Up Questions
- Thread starter TomS
- Start date
How's the cycle coded? I'm just asking to see if the lag is in the code or in your VFD settings. I seem to remember you talking about a braking resistor - that should let you stop and reverse on a dime.
Good to hear you're up and running, by the way!
Good to hear you're up and running, by the way!
The gcode file is attached. I reduced the dwell from .5 second to .25. I can tighten up the accel and decel VFD settings and see how that works out. I haven't done any CNC power tapping so I'm being extra cautious. Don't want to break taps and ruin my only piece of material.
Edit: Yes, I have a braking resistor.
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- Feb 27, 2014
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I did not realize that it was possible to TAP using Mach3. The z-axis is tightly controlled but spindle speed, not so much. You don't have Acceleration control for instance on the Spindle speed. Looking forward to how this works out.
I guess I'm going to find out. The floating tap holder supposedly takes up the variances in spindle speed vs. feed rate. Tormach has a white paper that discusses a few tricks on using a floating tap holder (attached).
Reading through the list of parameter settings for my VFD (Hitachi WJ200) it appears that I do have control of spindle speed acceleration and deceleration. I'll play with these settings and see how it works out.
Tom,
I've attached my parameters for my WJ200-SF15. It's working rather well for me. Please keep in mind that I have a different motor (2HP Marathon vector duty with an encoder and a belt drive). The accel/decel work great - it's fairly aggressive but doesn't trip the breaker.
Don't copy everything, but these settings are working for a similar setup.
PS - I'm using UCCNC, so I can do rigid peck tapping using the motor encoder and a spindle index. Way, way nice. Not going back to Mach3.
-Spumco
Thanks for the info. I have to look but IIRC my accel and decel settings are 1.5 seconds. Our setups are similar. I also have a 2 HP Marathon Black Max vector duty motor and belt drive. No encoder though.
Finally had some time in the shop today. The lag at Z retract was due to the CCW Spindle Spin Up setting in Mach3. Changed it from 1 second to zero and no lag now. Here is a link to my media gallery showing the floating tap holder tapping six 1/4-20 holes in aluminum. http://www.hobby-machinist.com/gallery/albums/users/toms.24891/. I still need to fine tune the feedrate to reduce the amount of tension on the retract cycle but overall I'm pleased with the results.