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BrandanS
10-23-2015, 09:12 AM
Hey Sb'ers,

I have a special application for my PRS alpha dual spindle wherein we are doing thermal drilling (a cool process if you haven't heard of it). The application requires more force along the Z-axis while it is plunging than is conventional (or at least default). Is there a way that I can adjust or fiddle with the torque limit in the SB3 Control, to allow more torque before the drivers return a fault?

I should mention I have run about 10k parts in this process without issue. Suddenly this week, the control has been returning a driver fault will it is in the middle of the feed.

Brady Watson
10-23-2015, 11:01 AM
Torque is set at the driver itself, which should already be at "F".

I would inspect the Z linear bearings and races to make sure you aren't getting excessive friction. Going forward you may want to consider a higher torque motor, such as a 25:1.

-B

ted
10-23-2015, 11:47 AM
Per Brady, above: Make sure the current setting on the driver in the Control Box is at "F". It is the round, "Current" switch towards the top of the driver. With the alphaStep motors, you should be getting almost 200# of downward force at this setting.

Note that the fault is triggered by either being in alpha-mode for more than a few seconds, or by the motor shaft being more than a defined arc-distance out of location (I think this is about 6deg on the final output shaft of those motors). So to reduce the likelihood of fault: 1) limit the time of application of the force; 2) limit the over-travel of the force.

Ted Hall, ShopBot Tools

BrandanS
10-23-2015, 12:41 PM
Perfect Brady and ted! Thanks so much. I'll have a look,