[kvom]

I am purchasing a high speed spindle for engraving and using very small endmills, and need a way to attach it securely to the mill. The spindle itself is out as there is not a lock for it, plus the possible danger of the motor starting up. I've decided to use the ring at the bottom in some way. The spindle itself comes with a clamping mount that is 76mm, but the ring is 100mm. If I can machine the clamp to fit the 100mm diameter I'll do that. Otherwise I need to fabricate a mount.

I removed the ring, whose purpose is to seal the spindle cartridge keeping swarf out and oil in. It's attached with 6 screws. After measuring the hole separations, I derived the following . The outer three screws are M4-0.7x16 on a 90mm bolt circle, and the inner three are M5-0.8x16 on a 72mm bolt circle. One option will be to permanently attach a bracket to the ring using these screws. An advantage of this solution is that the distance from the mill spindle to the high speed spindle will be constant, so that after zeroing X and Y using the mill spindle, zeroing the high speed spindle is a matter of changing the DROs.

Should be an interesting project.

[kvom]

Here is my design in Solidworks. The bracket attaches over the spindle ring using the existing 6 screw holes and longer screws, using the ring as a horizontal reference. The nose of the secondary spindle is clamped using a 5/16 screw. The bracket is 1020 hot rolled steed 1/2" thick. The secondary spindle is offset 5" to the right of the Novakon spindle to give sufficient clearance from the mill's head.

[kvom]

Got to work on this over the past couple of days.

Stock is a piece of 6x12x1/2 CRS I had laying about. After machining the holes and pocket, the spindle ring was checked for a fit, along with the screw holes.



Finished bracket:



Test mount onto the mill:



With the Makra spindle mounted:



In principle, if I use the NM200 spindle to locate stock zero, then the Makra zero will be at X0 Y-5. I'll do some tests in the next couple of days to verify.

[yodaddy]

Nice looking bracket setup. How did it work out for you?

I've got an NM200 and plan on doing something similar. 6000rpm just isn't enough for small endmills.

[kvom]

I should have made the bracket so that the secondary spindle is to the side, but otherwise it works fine.

[yodaddy]

I was wondering if the second spindle got in the way of accessing your main spindle. If I add one it'll go to the right side.

Thanks.

[kvom]

It doesn't get in the way in terms of access, but I have bumped my head on the bracket when looking closely at an edge finder.

[yodaddy]

Does your mill have the Sangmutan 2200w / 3HP 6000 RPM spindle motor? The reason I ask is that the controller on mine has terminals for a spindle brake, tapping, fwd, reverse, as well as terminals for an encoder on the spindle motor. The company is out of business, and I can't find any information on how to setup rigid tapping (if that's what it is) with a BOB and LinuxCNC / PathPilot. If you have the same motor, have you ever looked into rigid tapping?

[kvom]

No, stock 2HP motor