New CNC Mill on the horizon

[fvfdrums]

Thanks for all that info guys very helpful. I can just about get away with2 m4 grub screws on these pulleys so that's the way I'll go.

Half finished up one side cover just waiting on some bits to arrive. I figured if I didn't do it now once the machine was running I would probably keep putting it off!

[njhussey]

I was looking at a way of protecting the ballscrew and was thinking of C section Ali but couldn't see how I was going to put the brush on the rail side to seal the gap. How are you doing it as I can't see a brush so I guess chips etc could still get in there?

[fvfdrums]

As I mentioned it's half finished. If you look there is a brush on the outside edge, I did try a 2" brush from one side but it was too much so opted for 2 1" brushes. The other just sits off from the bearing rails on the inside of the gantry so the two pretty much meet in the middle.

[njhussey]

So you did....I must have glossed over that bit! How are you fixing it by the rails? Looking forward to seeing it finished...

[fvfdrums]

The brush sections fit neatly under the bearings with enough clearance for some countersunk m5 screws to hold it down along the full run. Just haven't got round to that yet.

[fvfdrums]

Btw tool station are pretty good price wise on these brushes.

[njhussey]

Where did you get your brush strip from, how thick is it?

I wasn't quick enough!!!

[fvfdrums]

Right we are wiring up the psu. Transformer wired correctly giving 52 Vac. Connected to the Bridge rec at correct terminals. Output from the rectifier on the dc terminals is 45v ?? Shouldn't this be 70ish? Do we have a broken rectifier?

[Jonathan]

Have you put the capacitor(s) on the output of the rectifier? If not then that reading seems about right, as the meter is reading the rectified AC waveform, not a smooth DC output.

[fvfdrums]

Thanks Jonathan,

so we have now connected the caps up to the BR, on powering up to check what voltage we were getting instead of even getting there we got a huge amount of humming and some extreme heat through the negative cable coming from the BR so immediately turned it off.

any ideas what could be going on / we are doing wrong?

we have checked that it is definitely the +ve of the BR going to the +ve on the caps and the same for the -ve.

does there need to be a load on the PSU before we power it up?