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Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Sun Dec 03, 2017 3:33 pm
by 762x51
At the end of July I picked up a Techno-Isel CPM-3020 Router and initially thought I’d convert it to a MACH 3 or 4 based system using a GECKO G540 and then I heard about the Acorn. After a lot of reading and watching Marty’s videos, I decided that the Acorn would be a better way to go.
Here is a photo of the router when I went to pick it up at the school where I bought it.

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After I got it home I contacted the manufacturer and found that they wanted around $500 for the simple software program that was needed to use the existing controller shown here:

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After deciding to go with the Acorn, I removed the existing controller, bought an Acorn, and made a sub-panel from a piece of sheet aluminum to mount all of the devices. Here is a photo of getting started making the new sub-panel.

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Here is a photo of it taken last night once I had it up and running. As you can see there is a “rats nest” of wires that I need to clean up.

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I also need to change the wire color for the 5 VDC wiring to orange as yellow is the color that should be used for logic 24 VDC power. I haven’t mounted and wired the spindle motor control relay yet because I didn’t want to have any chance of the spindle starting while I was doing testing.
The next “chore” is to calibrate the XYZ axis and I hope to start that this evening.
Here is a photo of the work area and the white part on the spindle mount is a dust collector sweep mount that I made on a 3D printer. The horseshoe shaped piece will have the brush mounted and it’s held to the base plate by magnets.

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Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Mon Dec 04, 2017 9:21 pm
by MecTechMike
Nice job. Let us know once you get it going.

Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Tue Dec 05, 2017 8:44 am
by 762x51
Good Morning and thanks for your nice comment regarding the layout but I should have used DB9 breakouts instead of cutting off one end of the cables and wiring direct to the various terminals. That was a big mistake and it really added a lot of time to getting the panel wired. Live and learn....

I have it up and running except for the spindle and I have left it unconnected while I go through the calibration process. The router has 4mm pitch ball screws so I'm calibrating in metric units. The initial setup was 200 steps/rev (1.8 deg steppers) and 4 microsteps (800 steps/rev) which was what Isel suggested but I have found that with 16 microsteps (3200 steps/rev) the accuracy is improved and the steppers run much quieter and smoother.

Right now it looks like I'm going to have to tweak the axis ratio a little. I set the ratio at 4 but the XYZ axis appears to be off by approximately 0.04mm or 0.00157 inches. I want to try to get the XYZ axis as close to "perfect" as I can because the primary use will be to use the router as a cheap CMM machine to reverse engineer antique firearm parts.

Orin

Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Tue Dec 05, 2017 9:29 am
by DICKEYBIRD
762x51 wrote:
Tue Dec 05, 2017 8:44 am
The initial setup was 200 steps/rev (1.8 deg steppers) and 4 microsteps (800 steps/rev) which was what Isel suggested but I have found that with 16 microsteps (3200 steps/rev) the accuracy is improved and the steppers run much quieter and smoother.
Hiya Orin, nice machine you have there! Are those Leadshine drives or clones thereof you're using? I have the Longs Motor DM542 clones running 8 microsteps and they don't sound particulary smooth. Didn't try 16 microsteps yet but need to try it & see! Thanks for posting that. :)

Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Tue Dec 05, 2017 11:43 am
by 762x51
Hi Milton,

I'm using these stepper drivers https://www.amazon.com/gp/product/B00DF ... UTF8&psc=1 Low cost and they appear to be working just fine.

Like I said, there was some improvement in the accuracy by changing the steps/rev but the change in stepper sound and smoothness was really great. They were really noisy at 800 steps/rev and now they kinda sound like a buzz or buzzy hum. I'll be increasing the steps/rev to see if 3200 is the "sweet spot" or if some other setting would be better.

Orin

Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Wed Dec 06, 2017 12:07 pm
by martyscncgarage
Coming along nicely Orin. Nice work!
Hopefully you will be fully operational soon. Just going to use a relay to turn on/off the router?
Marty

Re: Techno-Isel CPM-3020 CNC Router Acorn Conversion

Posted: Wed Dec 06, 2017 1:08 pm
by 762x51
Hi Marty,

Thanks for the reply and yes, I plan on using RL1/RO1 to energize a isolation relay to control the spindle motor. I bought a couple of the SANWO 24 VDC relays that you mentioned in one of your videos and I'll use that to isolate the Acorn from 120 VAC.

Orin