Alternative Spindles

[Bob La Londe]

I've been using a Bosch Colt as a spindle on my Taig (and my MaxNC) in order to get better production for making molds with small cutters in aluminum. The higher spindle feed does seem to make a difference and allow me to remove material at a much faster rate than with the stock Taig spindle.

However the Bosch Colts seem to have gone down hill in the last year with progressively less life in the bearings and often failing catastrophically (overheating and melting out the nylon nose bushing). We are talking much less with each router. I am sure I am pushing them harder than when I first started using them, but still.

I am looking for an alternative that can take hard continuos duty, and is still relatively light weight compared to the stock spindle and motor on the Taig. I just finished the mount for a PC 690LR on the Taig, and I'll be setting it up for a couple 8 hour cuts in aluminum shortly, but if it doesn't work any better I would be curious what solutions you guys have come up with?

I know. I know. Quit trying to get production level work out of a Taig, and buy a Haas LOL. Sorry can't afford it.

I considered one of the 1.5KW VFD drive imports, but I haven't found and answers regading continuous duty bearing life, spindle weight, availability of parts, etc.

[cameraguy]

I have one size down of the same thing - a .8kw water cooled VFD spindle (ER11-I only use 1/8 shank tools), and I like it greatly. The bearings may not be up to the standards of the $5000 NSK spindle it is a copy of, but it does its job and is certainly better than the Bosch. Also even if they do become problematic, the bearings are easily replaceable and set into metal seats!
You could even buy a good set of Japanese bearings and put them in beforehand if you really felt the need.

If you are doing production work, the small cost of the VFD spindle is no more than the cost of two or three Colts.

I bought a Hitachi VFD. I heard awful things about the Chinese VFD's, but great things about the spindles. So far, my spindle rocks.

[awetmore]

I have one size down of the same thing - a .8kw water cooled VFD spindle (ER11-I only use 1/8 shank tools), and I like it greatly.

Can these be used at lower speeds as well, or they only really work at high RPMs? I mostly use 3/16" bits at 4000-6000 rpm and sometimes use 1/4" bits.

They are attractive to me for integrating the spindle and motor together (instead of having the motor offcenter like on the Taig) and for being 3 phase motors that work well with a VFD so that I can control the speed through G-Code.

[Bob La Londe]

From what I have been reading these pretty much bottom out around 8000 RPM.

[awerby]

I put a Perske 3-phase spindle on a Taig, mounted it to the dovetail, and ran it using a VFD. It's good for dealing with materials that appreciate more speed, like wood, and also for running really small cutters that need more RPMs to sustain a decent feedrate. But like Bob says, they're no good at running slow - better go back to the standard spindle for jobs (like cutting steel with a medium-sized cutter) that require low RPMs and a fair amount of torque.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[cameraguy]

and also for running really small cutters that need more RPMs to sustain a decent feedrate.

Exactly what I use it for.

By the very nature of a VFD, you should get full torque at all speeds, but since I don't use it for any speeds under about 10k myself I don't know how well it works running it slowly.

[Bob La Londe]

Several of those I see listed say 8000-24000. I think a motor optimized to run at high speeds just isn't goign to run that well at slower speeds.

Its just like regular 60hz motors run at different speeds depending on how they were designed.

[lsces]

Another alternative ...
Kress High Speed Spindles - Model Engineers Digital Workshop
They are available in 110V as well ...