Hello People,
I am in the process of designing an ISO20 spindle for a small CNC mill I'm planning on building. The idea behind the mill is to use it as a production mill for aluminium parts. I would fill up the machine clamps with stock and have the machine work independently for several hours, freeing me up to work on other stuff.
So i was looking at different threads here and on other cnc websites and decided that the ISO30 spindle is way too large for my need. My CNC mill will have a machining area of 330mm(13.1 inches) on x axis, about 300mm (12 inches) on y axis and about 125mm on the Z-axis (5 inches) - fairly small mill then. Having a spindle, whos cartridge is 130mm in diameter and weighs a ton is too much.
So I decided to design a new and smaller spindle for my mill. Currently the design weighs in about 5.5 kilograms (with toolholder(ER16), without motor) and is 160mm high, 80mm in diameter(theoretically I can go one size smaller with the spindle housing, at 70mm, but that leaves only 4mm on the side of the bearing wall). The pullstud is also custom made.
The spindle housing and spindle itself is going to be made from 1045 steel (including toolholders). The bearings are going to be NSK tapered roller bearings, 2x 30206. Upper bearing so far is still open, probably a simple deep groove.
I am planning on using 30206's since I already have them from a previous project (unused) and the 7606 angular contact bearings are too expensive for my blood (almost 100 eur where I live, per pair).
The motor right now is planned to be 3KW BLDC motor, at 48volts. Can go up to 6000RPM. Pullstud is going to be operated by a ball bearing puller. Spring is planned to be either 1500N or 2000N strength (die spring, no bellville washers). The pneumatic piston has a travel of 6mm, diameter of 70mm (piston dia 60mm, 2200N @ 8 bar of pressure).
So far thats it, If i get the spindle built before the year is out, I will be very happy . I will try to make regular updates on the design and build itself.
Thanks!