[rojhan]

Ordered a 6040 4-axis CNC from eBay. It came with an 800W spindle, the "SX-CNC" controller with JP3163B controller board, "Nowforever" VFD (supposed to be 1.5kw), and 57HD5401-14S steppers by AnChuan Motors, and a clone/counterfeit UC100 USB adapter.

One the plus side, the electronics and wiring inside the control box look really clean. I still plan on replacing them and the USB adapter. I was mainly looking for a solid platform to start with.

The drag-chain bracket was bent on one end, one of the steppers is noticeably harder to turn than the other two (and the knob is cracked), and both the X&Y axis take effort to move and have obvious grinding noises.

I've sent e-mail to the seller to see what will be done to get this fixed, but what is "normal" on the X&Y axis. Should they be smooth and quiet, or is some noise and drag normal?

Thanks!

[Tomcat104]

They should be smooth. Quite is a had thing to say, the amount of noise I deem normal may be more than you can tolerate. All that said I do not consider mine at all bad.

You deserve and should expect smooth & no grinding. They should gladly replace them, but......well good luck with that.

[rojhan]

They should be smooth. Quite is a had thing to say, the amount of noise I deem normal may be more than you can tolerate. All that said I do not consider mine at all bad.

You deserve and should expect smooth & no grinding. They should gladly replace them, but......well good luck with that.

The seller is at least responding to messages, although he wants to see what caused the damage so far rather than "so, how are you going to fix this for me?". I haven't mounted the steppers, yet. I tried moving the Y-axis shaft by hand and can feel easy/harder/easy/harder movement. I also tried loosening screws on the gantry to see if it would fall into a neutral/better position, but no change. I need still need to check with my square to see how far off anything is.

[rojhan]

Basic functional testing is OK. There seems to be a very small amount of wobble on the Y (gantry) Axis and an occasional dropped step. Waiting for the seller to get back from holiday to nail it down.

I've been working on rebuilding the electronics. I've kept the controller box, switches, and VFD, but have replaced the electronics and most of the wiring. It's now a 36V/500W supply. The size is physically bigger than the original, so I had to re-arrange the internals; essentially swapping the location of the power supply and VFD.
Stepper wiring is 18 gauge. Control wiring is 22 gauge, shielded. I also added a 36V to 24V converter so I can keep the fan and the pump. I couldn't readily find 36V versions of either.

I replaced the clone USB controller with an official UC100 powered by USB (I want to keep the electrical isolation) and the TB6560 stepper drivers with individual DM556T. The DM452T was out of stock, and ~3A on a 5.6A driver makes it a bit more robust. As much as "everybody knows" how bad the TB6560 is and how great the Gecko is, I like individual replaceable components in case something fails. I may replace the existing steppers with 3.1NM/3.5A Nema-24 depending on how further testing goes.