My new 6040 improvement plan.

[Neale]

Like Doddy, I use XLR connectors for my steppers. Ideally these should be hard-wired but I found that I was taking the control box in and out of the router frame quite a bit while building and testing and the XLRs work fine in practice. I also use those "aviation" connectors for signal wires (limit switches, VFD control connections, etc) and they are fine for that. I bought a bag of 5 or 10 from eBay or Aliexpress or somewhere like that fairly cheaply. I think they were described as "GX16", and come with various numbers of pins. Watch for the ones with a lot of pins - they aren't the easiest thing in the world to solder if you aren't a dab hand with a soldering iron!

[PaisleyPCdoctor]

There are most definitely better connectors out there, but they are fine for the steppers. I still have one, actually 2 (male and female) at the VFD end of my spindle cable. Why 2?

The supplied VFD output connector was male. HUGELY DANGEROUS to have live connectors exposed like that! Live side of connectors must be female.
As I couldn't find a female panel mount socket, I opted to bring out the cable on a short lead with a female inline connector which mates with the male connector coming from spindle cable. I didn't want to wire it in directly cos I want to disconnect occasionally.

Anyway, after about an hour of constant (light) milling, the connector (inside) was no more than room temperature. I'm not worried.

[PaisleyPCdoctor]

I think for now, I've went as far as I want to improve the wiring- mainly shielding, replacing cables and repositioning components.

My next area that I'm going to look at is the flexing of the unsupported x-axis 20mm linear bearing shafts. They can be flexed, tilting the spindle back and forth on the y axis direction. With decent pressure on top and bottom of spindle, I can deflect it by as much as 1.5mm (estimate) either way.

I knew about this design weakness BEFORE I purchased the mill, knowing that I may need to address it. No big deal- I'm having fun!

I have some ideas to mitigate the effect and later to help cure it.

[PaisleyPCdoctor]

The first and easiest (and free) change is to the Z-axis assembly.
On this model, a 35mm spacer block has been added on top of the top bearing, increasing the Z axis length/travel by 35mm.

The way it's been built, I can very easily remove it and instead, mount it under the bottom bearing. The entire Z axis will be moved 35mm closer to the bed, but I can recover exactly that much by raising my spindle in the mount. I couldn't do that before as my tools wouldn't reach.

This will shorten the length of the "see-saw" motion, so in effect, the spindle tool will not move as far.

I'll measure deflection properly both before and after the modification.
Here a picture of the spindle and the 35mm spacer block.

[Doddy]

My next area that I'm going to look at is the flexing of the unsupported x-axis 20mm linear bearing shafts.

Give us a pic.

[Kev2960]

Hi, you seem to be fixing problems you may not have

[PaisleyPCdoctor]

Prevention is better than cure.

[Kev2960]

Yep I’ll go with that. Is this your first adventure into home cnc ?

[PaisleyPCdoctor]

Yes. Never had a cnc before.
I work with electronics. Computers, circuit boards and garage equipment (brake testers etc). I'm forever having to knock together an enclosure, adapter, circuit board or prototypes for my own test jigs etc. The CNC is gonna make my life better!

Just today I was going to order some m16 washers with earth lugs. £36 for 50. I only need four. I'm gonna cut them myself from some 0.5mm copper sheet. That kinda thing.

I'm totally looking forward to using it for fun though- 3d reliefs, engravings etc.

[Kev2960]

Morning, you sound like you have an interesting job. I also have a 6040 and had to iron out quite a few problems along the way. I've started a new blog to help newbies to home CNC to share the problems and solutions.
The CNC Blog