Motive power for a toolpost spindle

Halfway through my latest tooling project, my thoughts are naturally turning to the next one. I fancy making a self-powered toolpost spindle setup to replace the one I currently use. I have in mind using a model aircraft brushless motor as a power source together with some form of speed control. The spindle itself is no problem - I will probably utilise my existing one attached to a mounting plate. As I know the square root of diddly squat about these motors, my questions are these:

1) can I run one from a 12V car battery, for example? (I happen to have one lying around.)

2) how would I control the speed?

Alternatively, can anyone suggest a compact mains powered motor?

John

It seems to be a popular solution for cnc machines. See for example **LINK** It does however depend on what you want to use it for. They are great for high speed but I guess low speed torque would be a bit limited.

Russell

I've used motor and switch/ speed controller from a redundant battery drill, runs fine off car battery. O ring drive to spindle removes a lot of vibration. All my battery drills are now on car battery I've just realised, price of new ions I guess.

Here's an idea for a basic toolpost drill/'light milling' spindle.

The two-stage planetary gearbox from a battery drill installed inside the steel housing, new smaller chuck and a curry powder pot for a motor housing...

Care was needed to fit the drill bearing into the housing without end play. Extended fixing bar reduces overhang. Bar is below the C/L of the housing so that the drill axis is on the lathe C/L.

Neil

A usefull thread here: **LINK** I had thought of making one as an accessory to my little cnc mill but haven't got a round touit.

Russell

Thanks for all the ideas/links. Some food for thought there. Currently in the UK, but back home on Monday, so I'll carry on my research then.

Regards,,

John

My version using the same idea as Neil.

Les

I have used a conventional portable electric drill with a toolpost mounted flexible drive. More details here:

http://mikesworkshop.weebly.com/toolpost-drill.html

Mike

Mine tasted better than Les's

Neil

Is that because you used "SPICE" to design the electronics?

Mike

These spindles are very similar to the one that already use - see my album - I just want to mount a motor on it, or alongside, to reduce flexing to a minimum, the mount the whole lot in place of the topslide. I have a number of mains motors of the pillar drill powering sort and one that was supposed to replace a knackered one in our central heating boiler. The latter is two speed, or at least I can wire it to run at two speeds, but physically, it's still a mite on the large side. I thought that a compact 12V motor might just fit the bill at minimal expense.

John

This is my current set up using a 120W sewing machine motor from here. No load speed of the motor is 20,000rpm, no load speed of the Arrand spindle is 4000. It will happily mill or drill up to 1/4" diameter in steel, when the speed drops to about 2500rpm, although this can be lessened using the foot control - which I didn't think I needed but turns out to be quite useful as a hands free on/off switch.

HTH

Rod

Edited By Roderick Jenkins on 06/06/2014 20:20:34

A sewing machine! Brilliant! And just the job. I'll see if I can find one when I get back - there's no time to get one posted to a UK address before we go home.

John

John,

Just watch out for the power rating - standard motors are only 90W.

Cheers,

Rod

Hi Rod,

Apologies for resurecting a thread that's over a year old, but I curious as to the final warning about standard motors only being 90w. Will the 90w motor not be sufficient for a milling spindle?

My local supplier here in New Zealand only imports that model so will need to look for alternatives if that isn't going to be powerful enough.

James

As the original poster, I can report that the 90W motor that I used is perfectly adequate for the intended purpose. OK, it's never going to let you rip great chucks of stainless steel off in one pass, but for the sort of work for which I use it, it's just the job! In fact, I was so pleased with it that I bought another one and made a mark two version, just for the hell of it! (Pictures in an album, if you're interested.)

The first one turned out to be a little on the bulky side so I'm considering simplifying it and slimming it down to use just two interchangeable pulleys and fixed length belt to give two speeds. That'll have to wait until I've finished fitting the DRO scales to the mill.

John

If you want a lot more power, perhaps use a wood router. It has a chuck and speed controller. That well known supplier of tools and stock SCREW..X had them on promo last year for about £16, and it was cheaper to buy a router from them than buy a simple padsaw from a high street DIY shop.
BobH

James, I've used a 90W sewing machine motor to drive a Boley watchmaker's lathe for some years now and it's still going strong, mine is rigged up to a lighting dimmer switch for speed control rather than the foot pedal.

John.

Thanks guys, I think I will try the 90w motor. It's really only going to get pretty light work anyway so I doubt it will ever be pushed beyond it's limits.

James

There is a UK seller on ebay that offers 120w sewing machine motors. Could be in other countries people who sell sewing machine replacement parts offer them as well.

I'm basing mine on a motor out of a sheep shearer. 90w out which is close to 1/8hp. I'm happy with that as I understand Pultra made some small cylindrical grinders that used a 1/10 hp motor and want to try it for a number of things. It has a little electronic box with it to regulate speed so ok for grinding. In sewing machine terms though this is near 170w motor, permanent magnet type so probably more efficient. I'm fond of 500rpm so will be looking a speed something like 500,1000 and 4,000 rpm via a simple belt set up, circa 500 and 4000 for certain. Not sure about the other yet.

John

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