Depth of cut consistently off

[dlcw]

Neville,

Yes, the Z V wheels are moving freely. The router moves very smoothly up and down without any binding spots or lurches from binding.

Don

[richards]

Don,

I've only seen the PRS Buddy at the Maker Faire in California. It is an impressive machine.

Let's go over some Unit Values. My understanding is that the standard model uses Gecko stepper drivers that require 2,000 steps per revolution.

A 20-tooth gear has a pitch diameter of 1-inch. It travels 1 X 3.14159 inches per revolution, or 636.620 steps per inch. With a 3.6:1 gearbox, it needs a unit value of 636.620 X 3.6 or 2291.83.

A 25-tood gear has a pitch diameter of 1.25-inches. It travels 1.25 X 3.14159 inches per revolution, or 509.296 steps per inch. With a 3.6:1 gearbox, it needs a unit value of 509.296 X 3.6 or 1,833.465.

Count the teeth on your Z-axis's spur gear. If might be 25-teeth.

At any rate, try changing the Unit Value for the Z-axis to 1833.4648 and see what happens. If you get correct distances, then that is the correct number for your machine.

[dlcw]

Mike,

You nailed it. It appears that the Z-axis gear is exactly the same as the X and Y gears at 25 teeth. I changed the Z unit value to 1833.465 and the cut depths are exactly on the money.

I guess I shouldn't have trusted that the Bot was ready to run from the factory as advertised. A little due diligence on my part was in order.

I guess that as a word of advice for new ShopBot buyers, check all the settings before going through the headaches I've had to endure. It will save you a lot of time, patience and MDF....

Thank you to all for the suggestions on getting this problem worked out.

[erik_f]

Its possible to load the wrong set of unit values. Or its possible they put the wrong pinion on your Z. Glad you got it worked out. Owning a CNC is like owning a classic car...it seems there are times when you really get to enjoy it...but there are also times when you get to learn the joy of trouble shooting.