Just wanted to show off my spindle upgrade. I had bought a Bosch Colt palm router about the same time I bought my Taig from Nick Carter. I tried to make an erzatz mounting bracket for it, but didn't really like the results. I also didn't like being limited to 1/4 shank tooling. I shelved the project, and learned to cut with the conventional ER-16 spindle.

Still, I wanted something more in the performance department from my mill. So I looked around, saw that K2 sold a bracket for the Colt, and ordered it. Simultaneously, I found a source for precision collets and a closer nut from precisebits.com. I ordered the parts, fabbed up a mounting plate for the bracket, and here are the results. A Taig CNC mill with a 1 HP spindle, capable of up to 35K rpm. We'll see how the bearings hold up to extended duty, as my tool paths can take hours, if not days, though the Bosch is reputed to be quite solid.

And if I need to switch back, it's only a matter of 4 10-32 bolts.

Here's the pics...








Best,
John Bear Ross

Hi John,

I replied about this over on the CNC Zone but thought I add it here as well.

Interesting, as I considered doing this same exact thing at one point.

Unfortunately I saw the inconsistencies in the Bosch Colt laminate trimmers as I own one and the runout is just too great for the work I do.
http://www.precisebits.com/lab_repor...h_colt_TIR.htm

How much runout are you getting and, if you don't mind me asking, what kind of work to you do? What's the smallest cutter you use?

Thanks for sharing-
Dave
__________________

Dave,

I do mostly wax and delrin, maybe some epoxy. 5 thousandths runout is acceptable, since I'm just doing sculptures, models, and figurines for wargaming. If I need super-precise stuff, I'll probably put the conventional Taig head back on, and just slow my feeds way down.

Some of the stuff I do can be seen over at my site... http://www.johnbearross.com

Thanks for the response, though.

Best,
John Bear Ross

Ah, thank you for the response, John, I appreciate that.

Dave

Using the Colt on a Taig is an interesting idea John. Keep us informed of the progress.

Was there a weight savings?Less weight would have to help.Of course the extra rpms are nice to.

I'd say the weight savings were pretty substantial. The new spindle and bracket weighs about the same as the old head, without the motor attached.

Best,
JBR

Just as an update, first cuts were done in machine wax with a metal-cutting 4-flute bit at 22.5K rpm and 26.5K rpm, 15 ipm. The slower speed actually worked out nicer in surface finish. The spindle held up well, even if the test run was only 25 minutes. I'll start cutting delrin soon, and report back.

Best,
JBR

Delrin results are in!

I roughed with a .125 diameter 4-flute end mill at d/5 step/tool paths, 15 ipm, and results came out nice. I did the same with a .250 4-flute end mill, and it hogged out nicely as well, for roughing. Both were at speed setting 1, around 16K rpm.

I then did a finish pass with a .031 diameter ball mill, at speed setting 5 (around 26.5K rpm). Things were moving at 15 ipm. Step/tool paths were at d/9, or .003 inches. Finish and detail are beautiful. Length of cut is only .300 inches on the cutter, though, so I'm limited to that depth for now (per toolpath layer).

Overall, I'm very happy with the results of the spindle swap-out. I'm going to be switching back and forth for stock prep and such, but for fine detail, I like the Bosch.

Best,
JBR