Thanks for the reply Kelly. For this, I wasn’t boring deep, just pocketing slowly. The hole in the center was supposed to be the next layer down in the pocket, but chose to continue into my wasteboard.
I’ve been experiencing the same problem. Out of the blue, the machine will plunge down into the center of the workpiece, around 1/2”. It’s not program related because the program has worked as intended, in previous runs. I did notice some sawdust caked on the rails.
Usually such difficulties are caused by a disconnect in how the origin is set in the file and how you are setting it relative to the stock.
Please review: https://docs.carbide3d.com/tutorials/tutorial-homing/
and check the machine mechanically:
- Pulley set screws: http://docs.carbide3d.com/shapeoko-faq/shapeoko-3-how-to-check-the-pulley-set-screws/ — be sure to check all axes/pulleys including Z.
- V wheels / eccentric nuts: http://docs.carbide3d.com/support/tensioning-eccentrics
- Belt tension — the Z-axis should be guitar string tight (but careful not to bend the motor shaft): http://docs.carbide3d.com/assembly/shapeoko/xxl/step-5-belting/ on deep cuts it may help to remove one spring from the Z-axis temporarily, esp. if one hasn’t added a spoilboard on top of the wasteboard — it also helps to install the router as low as possible (installing the Makita adapter upside down will help). Some folks have found it helps to remove bolts which won’t stay tensioned (M4 Z-axis tension bolt, various V wheels with eccentric nuts), apply a thin bead of threadlock along the length of the threads, then reinstalling. See the video at: https://www.youtube.com/watch?v=_lIIb_PdziA Note that the X-axis motor is held in place on standoffs and if those bolts are loose this can cause belt tension issues.
It is also important to be sure that the collet is correctly tightened, the endmill fits correctly and doesn’t slip, and the router is mounted securely in the mount, and that the mount doesn’t shift. Note than endmill pullout can happen gradually, especially when profiling against tall walls.[4]
Also feeds and speeds may be a consideration: https://docs.carbide3d.com/support/#tooling-support and see https://www.youtube.com/watch?v=S9bceJxpqG0 for concepts on this and https://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm for a testing technique and see the series #MaterialMonday: #MaterialMonday on YouTube
Beyond that it’s usually a matter of Calibration and Squaring the Machine c.f., http://docs.carbide3d.com/shapeoko-faq/how-to-calibrate-the-machine-for-belt-stretch/
If you continue to have difficulties, please send in the .c2d source file, generated G-Code, and step-by-step notes on how you are securing your stock and setting zero relative to it and we’ll do our best to help puzzle things out.
Thanks so much for the feedback Will! Per your recommendation; I increased tension on the “Z” belt, checked the pulley set screws, adjusted the eccentric nuts, tightened the router mounting bracket, and removed one of the springs. I will test it out once I receive some fresh endmills.
Thanks,
~Al
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Is there enough bit exposed to cut to that depth without the chuck hitting the surface?
Also if you have a Suckit; make sure the power cord coming out of the router is not interfering with it during the plunge.
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Hello,
After some closer observation, I figured out the root cause of the machine plunging to a “Z” depth that wasn’t intended.
When cutting a deep pocket (1-1/2”), the chips were being evacuated straight up and into the “Z” rail mechanism. Chips accumulated on the track, to a point where the wheels got stuck and the motor could not overcome the interference. Then I’d here the motor make a clunking noise, just prior to plunging out of control. I stopped the machine prior to the erratic plunge and tried to move the slide mechanism by hand. I couldn’t do it until I cleared the track of sawdust debris.
I confirmed this to be the problem after running successful build and ensuring the mechanism stayed clean with compressed air.
I think a good future long term solution is a vacuum dust boot. I’ve got one on order and look forward to trying it out soon!
Thank you to everyone for your suggestions!
~Al
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