New CNC Mill on the horizon

**fvfdrums** · 16-03-2015

Also.....

Planning on using grub screws on the steppers at 90 degrees to each other. What size would people use on an 8mm shaft and a 10mm shaft?

**njhussey** · 16-03-2015

Originally Posted by fvfdrums

Also.....

Planning on using grub screws on the steppers at 90 degrees to each other. What size would people use on an 8mm shaft and a 10mm shaft?

Depends on the size of the pulleys I guess, I've used M4's on the 20 tooth pulleys as well as the 40 tooth ones. My 40mm pulleys are a push fit on the ballscrews so I'm hoping that's enough. Could always put a bit of loctite on too...

**JAZZCNC** · 16-03-2015

Originally Posted by njhussey

Depends on the size of the pulleys I guess, I've used M4's on the 20 tooth pulleys as well as the 40 tooth ones. My 40mm pulleys are a push fit on the ballscrews so I'm hoping that's enough. Could always put a bit of loctite on too...

Larger grub screws the better so can get good purchase on them, fiddley Grub screws are a pain and definately loctite the pulleys on. You'll never really want them off again other than to replace and certainly don't want them spinning on the shaft. Also mark them so for easy visual reference so can check they are not spinning.

**Boyan Silyavski** · 17-03-2015

I did like Dean says, larger grub screws. I also filed flat recess on shafts, where grub screws go. It was quite easy using small square file. It seemed to me it would help. Locktite also. In fact my major mistake on the first build was not using locktite on all screws. Result was from vibrations or whatever at least 2 screws difficult to access
loosened so i wasted some time tightening again all screws on my friends machine. On my current build i use Locktite on all screws and i hope all will be perfect long time after i am finished. Same goes for the supported rails. When all was mounted and square, i carefully poured locktite between screws and rails. later checked it, it worked. Then i fit the plastic caps.

**fvfdrums** · 16-03-2015

Well I'm on 30 tooth pulleys. So I'm guessing that would work as well. I have a similar fit with the pulleys so that should work. Cheers

**Clive S** · 16-03-2015

Originally Posted by fvfdrums

Well I'm on 30 tooth pulleys. So I'm guessing that would work as well. I have a similar fit with the pulleys so that should work. Cheers

Hammer a bit of 1.5mm copper wire flat and cut a small piece off to drop down the hole where the grub screw goes I find it make a big difference and does not mark the shaft. Clive

**fvfdrums** · 18-03-2015

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** · 18-03-2015

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** · 18-03-2015

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.