Accurate Strong Gantry

[Ross77]

The general arrangement is really good. Back to back AC's and floating end bearing to allow for thermal growth. Are you making this or buying?

My only concern is that by driving it from the bottom you are increasing the distance from the cutter to the bearings and compromising the design. The belt tension will also pull the spindle off center. Can you drop the bearings down in side the pulley?

I'll try to find my old spindle designs and show you what I mean, I have gone over sized on the bearings so the taper of the collet is inside the bearing.

what size bearings are they? For 6000 rpm have you considered roller taper bearings?

This is of course me being super picky, your design will work but just offer suggestion to maybe improve :0)

[vargai]

The general arrangement is really good. Back to back AC's and floating end bearing to allow for thermal growth. Are you making this or buying?

My friend is renting a small shop and generally I got him to machine the part,and I will put them together.
There are a Bridgeport VMC, a Colchester CNC turn and a Hungarian CNC turn. I used to work here but recently after the daily office job I prefer to have a little brake. That is way I would like to have some machines at home where I can work any time that fits to me.
The bearing is 15 mm bore -for an entry level spindle is Ok but any design comes in handy, thanks.

PS: I have adjusted my setting so the vid is already visible at my previous post to you