Here we go again . . . MK4

**mekanik** · 16-03-2018

Does the grubscrew for your pulley locate on the actual ballscrew ?
Looked like it might be fixing into your extension.
Regards
Mike.
Thanks for the update

**routercnc** · 16-03-2018

Originally Posted by mekanik

Does the grubscrew for your pulley locate on the actual ballscrew ?
Looked like it might be fixing into your extension.
Regards
Mike.
Thanks for the update

Hi Mike
The grub screws in the hub go direct to the ball screw shaft. The green loctite holding the extension is good stuff but I wouldn't want to rely on it to transmit the drive.

Note to others - if you want to use pulleys ask for longer sections!

**routercnc** · 07-04-2018

OK, episode 14 is now ready. This time we finished off the Z axis ball screws and wire up the new steppers.

**Davek0974** · 07-04-2018

Amazing build, has to be the heaviest Z axis I've seen yet.

**routercnc** · 07-04-2018

Thanks Dave. Yes, glad I managed to squeeze two steppers on the Z axis. It is too heavy for my scales so I need to find a way to weight it. Certainly picking it up is a challenge (and there is no spindle yet).

The whole machine will run initially off 3 Nm steppers at about 70V, through some fairly old analogue drivers (DQ860MA) and a DB25 breakout board through the parallel port. Not massively high spec so it will be interesting to see how it copes with the weight of everything . . .

By the way, thank you for the grub screw insert idea. You might have seen your name mentioned in the video (faintly on the 'Grub Screw Insert' title page) ! I tried to get much larger inserts in there but there was no space on the upper part to go much bigger. I would have needed to counter sink them into the lower part (manually, no CNC!) but even there the space between other fixing holes was tight. The surface area of the 8 mm discs is much bigger than the 'ring' contact area on the base of the hollow cone on the end of the grub screw so will be better. I could always make new plates with steel pad inserts if the head keeps moving out of alignment.

**routercnc** · 03-05-2018

Episode 15 is now ready for viewing: Setting out the epoxy leveling for the X rails. This was my first time using epoxy like this and I certainly learnt some things along the way - especially those bubbles !