forum.cncdrive.com

Over the past few years I've been chipping away at my home-built CNC router. I am far more confident in my mechanical abilities than my electrical and programming abilities. At this point it's 95% built, and I'm starting on wiring. I could use some help. I'll introduce my machine and bring you up to where I am at - then I'll start posting some of the questions I have. I will greatly appreciate any guidance and coaching you may have for me.
Thanks
rust_bucket

... and this kind of delay is why it's taken me 2 years to build this thing. I have a zillion other higher priorities in my life. This is a hobby that fills in the gaps when they arise. But I am committed to getting it done.

This is Pinky and the Brain. The controller is obviously "Brain" and everything else is "Pinky." (What can I say? I was an Animaniacs fan as a kid.)

Specs:
X: 1000mm
Y: 700mm
Z: 150mm
200x150mm extruded gantry
2x4" (1/8" wall) and 3x3" (1/4"wall) steel framework large enough to swallow my tool chest.
2.2kW water-cooled spindle (on a VFD... someday when I figure out the wiring.)
5mm lead 20mm ballscrews
20mm HIWIN (knock-off) rails
425 oz-in NEMA 23 steppers (X2 on the X-axis)
DM542T drivers
UCC-300ETH on a UB-1 BoB
36V and 24V power supplies
and a partridge in a pear tree

Here are a couple of shots of the gantry. The keen eye will notice the Z-axis rails and bearings aren't installed in this photo.
I cut the uprights by hand on my knee-mill. It was both fun and tedious (an odd combination actually...) I had collected parts for over a year and the Pandemic was the perfect opportunity to start building. These two uprights were my isolation symphony.

I salvaged this "High Voltage" power box from an odd-ball shop called Archie McPhee's in Seattle 20 years ago. It was just a couple bucks and I thought it would make a funky treasure box or shop decoration etc. It works perfectly for all the DC / signal wiring. I first planned 4 or 16 pin headers for all the wires, but soon realized I was only introducing opportunities for noise and poor connections, so I went with plastic glands and just ran the wires all the way to the components. I cut some vent holes at the top and added a 5V fan at the bottom to keep air moving.

The triangular panel for the AC / VFD stuff was just kicking around the shop. I'm a big fan of re-use, repurpose, so I put it to work. I may live to regret it when the dust starts flying and building an enclosure around the odd shape becomes a challenge.

Currently I have all 4 steppers running and can jog it around. I've crept up to 4000mm/min rapids without step losses. That's more than enough to scare me so I stopped there.

My limit switches are all connected and working as expected.

The spindle is not wired up at all. - A project for a little further down the road.

My first question for the collective hive mind is with regards to the "Enable" function on the steppers. I'm using the "50% power" switch, which understand cuts power to the motors by 50% after a few seconds of inactivity. Neither the motors nor the drives seem to be heating up much. Maybe a 10°F rise from ambient after an hour of idle or slow jogging... Seems fine to me. But am I doing long term damage? Should I add the enable circuit? None of my axes back-drive due to Uncle Gravity, so I'm not concerned about that. Thoughts?

rust_bucket wrote:My first question for the collective hive mind is with regards to the "Enable" function on the steppers. ... But am I doing long term damage? Should I add the enable circuit?

I have no answer about whether any damage is being done, except to say, "I hope not". I have the charge pump on my UC300ETH enabled whenever UCCNC is active, whether or not a program is running. So, I'm in the same boat as far as idle time and heat gain while sitting there doing nothing. It doesn't seem to bother anything, so far.

I did connect the disable pins on the Gecko 203V drives via the charge pump relay so that:

• The machine is quiet and safe whenever UCCNC is closed. When I was rebuilding the machine, I wanted the control box powered up so that I could test and position switches and sensors by moving the gantry around by hand. Without UCCNC, the charge pump isn't there, and that sends a disable to the drives, allowing the steppers to free wheel. I would then start UCCNC and move things around through the program to test that the sensors trigger when expected.
• When the eStop is triggered the disable cuts in and stops motion. The eStop on the UC300ETH will also turn off the spindle (if you have it wired that way).

So, there are some benefits by setting up the disable circuit (or Enable, in your case).