I started work on my new electronics cabinet today. I got the 36v PSU and VFD mounted, along with some lever lock connectors for the 230V wiring. I had to change my layout to accommodate the VFD, but I’m happy with the results so far. I also decided to use direct mounting as the sheet steel is just thick enough to tap for M3 and M4 bolts.
Direct mounting onto the plate is a good practice, use steel spacers for the PCB mounts and drill a hole on the base plate for bolting the earthing strap.
I’ve got brass hex stand-offs that I’m going to use for the pcb’s - I think they should be adequate. The enclosure came with an earthing strap, and I’ll definitely follow your recommendation.
Brass or aluminium spacers is what I was meaning to say but they just slipped my mind and so instead of metal I wrote steel. I take it you will be solding all the motor and spindle connections using either GX12 or GX16 terminals for servos and GX20 for the spindle.. Also add provision for addition mains sockets and maybe relay switched outlets.
Yep, I’ve bought a stack of GX16’s in various pin counts, and I will be soldering all the the wires. For all of the internal terminals, I’ll be using crimped ferrules. I also have a nice tube of liquid tape to pot all of the JST connectors. Extra mains sockets isn’t something I’m going to bother with. I use power monitoring via my Hubitat home automation system and I use that to turn on/off dust collection and external mains powered accessories via Zigbee sockets.
I made some 3D printed drill guides today, but ran out of time to use them. Apparently building furniture for my daughter is higher priority. Edit: I somehow deleted my following post. So I’ve appended to this one for the sake of chronological order. I made some really good progress today. All the stand offs are installed, and I got a lot of wiring done. It still fits in the case too!
My electrical cabinet now has an eStop / power switch. I’m waiting for some wiring glands to arrive before I add the power cable. I was going to install a fused IEC switch / socket combo, but I’ve decided to use the eStop instead. I might look at installing a 240v breaker instead of a fuse. EDIT: I made a bit more progress tonight, I made a template in CAD to work out the GX16 and USB connector locations, and the result came out well I think.
My wiring glands, DC to DC step-down converter (to power the controller with 12v or 24v), and circuit breaker arrived today. I need to rearrange a few things tho to make better use of the space…. I’m using short piece of DIN rail for the breaker and lever lock terminals.
I see mostly all hobbist who have a VFD spindle, for obvious reasons the VFD controller ends up being fitted in the same enclosure where the psu, motor drivers, relays, cnc controllers etc also reside in close proximity. You know with some of us who have an electronics background, it might be worth putting some sort of wire gauze or wire mesh (Faraday cage) around the VFD controller grounded to earth, It will reduce any superfluous EMF affecting the signalling to the steppers. As we both have the same MKS controller, one issue I encountered with Stepperonline external drivers. I had to disconnect the ENA+ connection. In effect what this will do is the steppers are constantly powered ON and they make a white noise when they are in idle state. If I connect the ENA+ then I was getting inaccuracy of about -3.6mm. I connected with others who were using the same motor drivers as mine but with a more professional designed controller, they didn't have that issue. So the problem stems with something to do with the the MKS firmware handles the delay between the PUL signal, and the ENA signal needs to be disconnected after the PUL signal stops. I no longer have access to a signal analyser or an oscilloscope, so never manage to get to the bottom of it. I see you have different motor drives maybe you might not see the above issue.
My steppers are TMC 2160’s, so hopefully they won’t have the same issues. One nice feature is they can be set to 50% power when holding position. I’m also running grblHAL firmware on my DLC32 which provides a lot more control that the stock firmware.
I do enjoy visiting my garage after lunch when I'm working from home... I got most of the 240v wiring finished off.
I have been meaning to replace the stock firmware with grblHAL but haven't got round to doing it. I am planning to dismantle my cnc it and start again because the frame is too big and having space problems.
I’ve documented what worked for me, if it helps. One downside is, the LCD screen can’t be used anymore. However, if you run OB Control it’s pretty much irrelevant. GitHub - dJOS1475/grblHAL_Backup: My grblHAL Config Backup
Thanks for the link to your documented findings on grblHAL. For testing if I did replace the stock firmware, am i right to think it would still be possible to revert back to stock version?
I didn’t spend any time on the electronics today, because I finally found my cyclone dust separator. So I spend a few hours designing and printing some vacuum hose adaptors and adding the separator to a new lid. I also got a new black and decker shop vac, as my old Vax no longer has filters available for it. And tucked away in the corner out of my way. I got a bit carried away tonight, i removed the Makita, and installed the new spindle.
When I built my CNC I, like many, thought that the bigger the better and bought a 1.5KW spindle. I quickly found out that I had bought a way too big a spindle and that a 800W would have been plenty. Now looking at your video I even think that a 500W is way good enough. How do you like your Vac separator? I have one but I have to have a filter in the Vac since as much as the separator separates still a lot goes into the filter too and they are not cheap.
My 800 watt Makita was plenty powerful, just too freaking loud, so you are correct, a real 800 watt spindle would have been adequate. But I went for the 1.5 kW as the price difference was next to nothing. The dust separator works great, it's just this cheap one from AliExpress, but it's very effective when installed onto a hardware store bucket. https://www.aliexpress.com/item/100....order_list.order_list_main.17.1fb21802QPUaX9
I've finished my design for a new front panel plate - I think this should look quite nice made from 1mm thick 6061. I tried to upload the pics, but image uploads appear to have been broken since the new site theme was implemented.
Thanks Peter. The 3DP version came out great - but I will make an Aluminium version once I have my machine up and running. And tonight, I managed to cut a hole into the front case for the remote VFD panel too. I might 3D print a white bezel to hide my less than perfect cuts. Using a Dremel was taking too long, so I got out the angle grinder. Im pretty happy with the progress (although I need to change the 2nd X end-stop label to Z), and apparently my new "chain flex" style cabling should arrive today.
Hmm, the DIN rail PSU is a lot bigger than I was expecting, I might need to rethink my layout… again.
