DIY Spindle

[TheBulk]

Please forgive me if there is a writeup on this somewhere but I haven't been able to find one.

I am in the precarious situation where I don't have a garage (carport), no basement, close neighbours, a wife who won't let me have the machine in the house at all and a budget which can't afford a spindle.

My "workshop" is a 10ft x 10ft shed in the backyard.

Obviously a router is going to be too loud in this situation but I'm pretty technically minded and think that I can make my own spindle by parting out a trim router and gearing it (with a belt) to an A/C motor.

Has anyone got any experience with this or can give me any tips or information.

I only need it to cut through max 3/4" mdf using a 1/8" bit and am happy to make numerous passes.

Thanks
Andrew

[wireb]

What sort of time frame / budget are you looking at?
Also do you happen to have access to a metal lathe?

Currently working on a design for a ER20 high speed spindle. Belt driven so you should be able to uses just about any motor to drive it. (I am going down the brush less RC plane motor route right now)

Will not see my ER20 chuck for a few weeks so will be a bit before I get the design fully done.

As for cost I am looking at $150 to $200 for everything minus the motor and controller. That includes a full set of collets (1/32" to 1/2") so if you just want to run 1/8" bits you can save quite a bit there.

My main use will be PCB routing so designing for high speed (~20k) and low run out.

[holyjewsus]

I'm messing around with rc brushless motors too, I've got a Turnigy 50-55 600kv with a er11 collet chuck mounted as the shaft directly in the motor, but I'm getting terribly loud noise and reving even at mid speed.

Do you have any advice for a more quiet motor, silence is really my hope...

[TheBulk]

My budget is very tight but my timeframe is a little less restrictive.

I was actually thinking about opening up my trim router and bastardising it by removing the motor from the shaft and running a belt gearing system between them so as to make the motor do a lot less revs yet keeping the bit at the same rpm and using primarily the same equipment. Yes it'll reduce the torque a lot but as long as the passes aren't deep I can't see the need to keep the torque high.......

Thoughts?

[wireb]

have not picked up a set of motor / ESC yet still working on the spindle. Decide to go with a separate spindle assembly (20mm ER20 chuck + 3 6004-2RS (I think) bearings) from the motor. My plan is to link the two via cog belt that way I can change the gearing as needed. This also lets me get started using my dremel/roto zip/palm router (which ever fits better) until I get my motor and ESC in.

What kind of noise are you getting? I high pitch wine (10 to 20khz) may be the switching frequency of your esc. Grinding noises are just bad all around and would suspect a bearing is failing / mechanical damage / grit in the magnets (its amazing how much a small steel chip stuck to a magnet can screw up one of these motors.)

Has the motor done this from day 1 or did this develop over time.

Also any way you can make a quick video with sound of the motor at various speeds? Not sure I will be able to exactly identify it but may be able to give you a better guess.

[wireb]

Originally Posted by TheBulk My budget is very tight but my timeframe is a little less restrictive. I was actually thinking about opening up my trim router and bastardising it by removing the motor from the shaft and running a belt gearing system between them so as to make the motor do a lot less revs yet keeping the bit at the same rpm and using primarily the same equipment. Yes it'll reduce the torque a lot but as long as the passes aren't deep I can't see the need to keep the torque high....... Thoughts?

I would have to say it depends on the quality of the router you start with. Just spent the weekend disassembling HF routers (cheap import units) Did not expect much to start with. What I found was the upper bearing was held in a plastic carrier. If you replace the motor with some sort of pulley system your going to have a large radial load the upper bearing would not have seen before (motor windings more or less balance out for radial loads).

Assuming you find a decent router to cannibalize (metal bearing holders on either end and a metal body preferably) I think it would be doable. The hard parts in construction would be pushing the shaft out of the old motor, cutting a hole in the body for the belt to pass through, and mounting the new motor to the old one to keep the belt aligned.

If you built the mount and have a dremal tool around the last two are not a big deal. pushing the shaft out of the armature can be a PITA if you don't own a press. But again since your cannibalizing and your careful you can cut the laminate off the shaft with a dremal / hacksaw (take your time and try not to knick the shaft. Next up is timing belts and pulleys. Currently been looking at stock drive products https://sdp-si.com/eStore/ at their .200" pitch by .375 belts for mine. No idea yet if they will hold up or not. Good news is they have a large selection of sizes and prices seems decent for single pieces.

One bad thing about running universal motors (most routers) at lower speeds is the torque drops off relay fast. If you get fancy (super-pid) and convert to a closed loop system you can recover most of that torque but for open loop soon as you load the tool at partial speeds you will see the spindle speed drop. Now you can compensate by setting your "idle" speed high so when its cutting it drops to the range you want. But since your gearing things up that would run the bearings fast than original and may cause them to wear and cease at a faster rate.

Another option would be to find a induction motor of the proper speed. Down side is variable speed is not really a option unless you go 3 phase via a inverter. But if you can live with just one speed (or set up a step pulley system to select your speed) they are usually quite quiet compared to a universal. (don't need as much air to cool the motor since the armature is passive)

DC treadmill motors may also work but making the belt adapters would require a lathe. The good is you can usually get one for free if you watch craigs list. The bad is they are big, heavy, and suffer the same speed shifts at mid to low speeds when loaded.

RC motors are also a option for you. Basically the same idea I am working on but use the existing spindle/collet/body of your router.

Wish I could give you a better answer but have not cut enough MDF to give you a good answer on what it would take. What you have going for you is your bit is relatively small (1/8") and your willing to take light slow passes. One test you can do for your self is to grab your "motor" router and a speed control for it. Set it to the fastest setting you can tolerate (max noise) and try routing some sample stock. That should give you a feel for how fast / deep you can go before the motor baugs down. The cuts will be nasty / some scorching due to the slow speed but you can at least get a feel if I push it this fast and deep I get this kind of slowdown on the motor. The gearing will help the cuts but will only reduce the total power out of the motor so you will not be able to cut or feed any faster than the test.

[TheBulk]

No I haven't even bought the router yet . I just know how loud they are even out of the box.

I wonder whether Gearing might be a better idea (like in a power drill) so there is no lateral load on the shaft.

I have a cheapo drill press which has a gear belt system which I'm thinking I might part out as it gets up to a pretty high RPM....

[davidmb]

Hi, Im currently in the process of converting my trim router to drive a home made spindle that I am making with it's own taper tooling, I have cracked the issue of setting a manual lathe easily to machine matching tapers to within 1 minute of arc, the noise from any sort of router is going to be quite high, I have been toying with the idea of using a single phase induction motor as spindle drive, but would have to forgo any sort of speed control, 3 phase would be doable with a phase inverter for speed control but the price starts to climb quite quickly.

[wireb]

Originally Posted by TheBulk No I haven't even bought the router yet . I just know how loud they are even out of the box. I wonder whether Gearing might be a better idea (like in a power drill) so there is no lateral load on the shaft. I have a cheapo drill press which has a gear belt system which I'm thinking I might part out as it gets up to a pretty high RPM....

gears are much more touchy about alignment than belts. Yep the belt arrangement on a drill press is what I was thinking for a induction motor set up. You get a few fixed speeds out of that. You can buy the stepped pulleys at most decent hardware stores (at least around here you can) else I bet stock drive has them as well. You may need to add one more stage of belts and pulleys to get the final ratio up to where the original router ran (most drill presses don't run that fast) but that can be a fixed belt and pulleys. Then you can adjust the speed of your mill how ever many steps the drill press / step pulleys you have.

[RomanLini]

Gears are also going to make a lot of noise! My metal mill has a gear driven spindle and even encased in a cast iron gearhousing it makes so much noise I'm, *forced* to wear earmuffs whether I want to or not it is that irritating!

Most of the modern routers of decent quality are reasonably quiet if you run them at low speeds (routers like the Hitachi M12VC which works well at 12000 RPM). Or you can add a router speed controller to use even lower speeds and run even quieter.

I'm not sure about runnign a router at a very low speed then trying to gear up the RPM though to make the spindle run fast, they have very little torque at low RPMs it's just not a good setup. You are better off with a quiet AC motor designed for low-RPM use, many people use sewing machine motors and then gear up for RPM.

[TheBulk]

Originally Posted by RomanLini many people use sewing machine motors and then gear up for RPM.

BRILLIANT!!!!!!!!!!!!

Variable speed motor and I'm sure there is a busted one on ebay somewhere for $1.

[kmacht]

If noise is the only issue then why not build a box around your machine and add some soundproofing to it? That would seem simpler than designing a new spindle.

Keith