RBK upgrade for non ShopBot tool...

[steve_g]

My church has a CNC router that they use to help in making props when needed by one of the various ministries… That was the plan anyway. The MACH3 control system was less than friendly to occasional users and I had no interest in learning it. To make a long story short, I converted it to a ShopBot RBK controller.

The conversion was very simple and straight forward…I was even able to reuse the existing steppers. The ShopBot red haired stepchild now even has features it didn’t have before, a Z-zero plate and X-Y proximity sensors.

Many thanks to ShopBot’s Ryan Patterson who analyzed the original project for feasibility and got me over a wiring issue.

Any MACH3 users out there that need some parts?
I have a control box that includes:
4- gecko G203v drivers
1- PMDX 134 mother board
1- PMDX 126 Multi-Mode Breakout Board
1- Warp 9 SmoothStepper (USB)
1 power supply that includes an Antek AN-10440 toroidal transformer 1000VA 40 Volt

Buy it all and I’ll include the case and some mystery PCB’s!
$500.00 + shipping
I’ll consider parting it out if there is no interest in the whole package.
Reasonable offers considered!
The attached photo is a typical scenery… About 25 sheets of foam were cut on my ShopBot for this one.

SG

[James M]

Steve,

Nice job on the scenery background. What type of foam did you cut it out of?

James

[steve_g]

James…
Thanks for the compliment! It’s just 1” pink Home Depot extruded Styrofoam. I have a hard and fast rule about cutting foam… I don’t paint it! I feel like my part was very small compared to those who finish it!
SG

[WMNH]

Nice Steve, I'll bet Jon is super happy now! I really like that machine, I'm glad you have them back up and running right!

Geoff

[steve_g]

Hello Geoff! Thanks for chiming in! Jon is excited for sure! I agree about the machine… extremely well built for a no name, apparently home brew unit.
SG

[Bill I]

Is the control box still available?

E Mail me at Wiliamim@verizon.net
Thanks Bill

[steve_g]

FYI
The old MACH3 control box is sold…
SG

[steve_g]

This post is pleading for help from those who know stepper motors…

I Replaced the MACH 3 controller on my churches CNC router with a ShopBot RBK controller, a relatively straight forward conversion! Not satisfied with the Z axis, I swapped out the original with one from Velox.
http://www.veloxcncrouters.com/xz-za-series
The original setup had 3” of Z axis, by the time you subtracted the router bit length, you could find yourself without enough room to cut a 1” piece of foam, forget using any jigs! The Velox Z-axis is 8”. I can move the entire router and bit higher than the gantry and now have the entire 3” of clearance below the gantry to use as work space…

My problem is that the Z-axis requires 10 revolutions per inch of travel… At the standard RBK setting of 10 micro-steps per step, each motor revolution requires 2000 pulses. Times that by 10 to travel 1 inch. The control computer is a DELL it can’t handle unit values of more than about 5000, I installed a PCIe USB3 port that steps back to 2.0 with the SB. It can reliably handle UVs of about 10K. Still only about half of what’s needed. If I change the micro-steps to less than 10, I apparently get out of the stepper-motors torque sweet spot and it stalls.

I’ve attached what info I can find about my stepper motor. It’s 8 wires are hooked up in a 4 lead series configuration. Would a parallel hookup improve torque? Any other ideas?
Thanks!
SG

[srwtlc]

What about swapping out the ball screw for a different pitch?

[Gary Campbell]

Steve...
I agree with Scott that your best solution may be to replace the ballscrew with one that has a lesser pitch. A parallel setup may improve torque, and is my preferred, but not at the rpm required.

I may have a couple other ideas for you, email in signature