Bridgeport Manual to CNC conversion...

[Davek0974]

No the quill pinion is pretty firm. Yes the screw on the front is a popular method because its the only place you can get a direct connection to the quill, trouble is its an awkward connection and i'm not happy with it yet.

[Davek0974]

Finally scraped up the cash for proper thrust bearings on the X & Y axes. Got Nachi P4 matched pairs from BearingBoys Ltd


I fitted them in DB or back-to-back style, seemed the best option here - the preload is taken up by the screw nut rather than the bearing retainer.

What a difference, smooth as silk now and no shims needed :)

Will measure backlash again to see what change it has made.

[m_c]

Dave, have you get any pictures of the existing setup/quill?

[Davek0974]

A few pics here...




The weak spot is the joint between the coupler and the quill - there is a flat recess milled on the quill about 15mm dia and i picked up on that face, it really needs more contact above and below the bolt but then you lose more z axis travel and thats bad enough already.

Its the little round boss on the right of this part...

[m_c]

How much Z travel would you lose, if you bridged between the current single bolt mounting, and the end of the quill (where you currently clamp on the second spindle bracket)?
.
If you were to bridge between the two, then you should get a stable piece to then mount the ball nut to.

[Davek0974]

I can see where you are coming from here, nice idea and would certain strengthen it 100%.

But as always there is a negative - it would stop me being able to fit the aux spindle.

By having the support on the end of the quill when running as a normal bridgeport, I would maybe lose 12-15mm of travel - not too bad. But to allow me space to fit the aux spindle as well below it, the support would have to be that much further up the quill, probably losing 40mm + of travel permanently - this would cause big issues when doing normal work.

But it is a nice idea though.

[m_c]

Rework the Aux spindle mount, so it attaches to the new adapter?