Motor for Small Drilling - Milling Spindle

I am currently sketching ideas for a small drilling and milling spindle to use on my Flexispeed. I had planned to use a sewing machine motor, of which I have two, but am wondering about using a motor from an old twelve volt battery drill. I have a couple floating around.

Does anyone have any experience using these for this type of purpose and, if so, do they have the power to drive a small slot drill or end mill?

Regards,

James.

I have a couple of "failed" cordless drills which I regularly use in my workshop. As always its the batteries which lets them down. I removed the batteries and soldered a lead to where the batteries originally received the power and run them from what is home made battery charger with a smoothing capacitor across the charger terminals. My 12 volt drills actually run on 16 volts without any apparent problems. The down side is the chuck speed is quite low, even on the top speed. If you are handy on a bit of simple electronic construction I could send a circuit diagram via a PM.John

I have no experience of using a drill motor in the way you describe, but I would have thought that it wouldn't have sufficient speed for the type of application which you are envisaging. I built a couple of spindles using sewing machine motors. They are clamped in the toolpost and can be used at any angle to the lathe axis.:

These motors are only rated at about 90W - so they are never going to rip great chunks of metal off. They do however, rev to about 10,000 rpm (according to the blurb) so are suitable for small mills and even engraving. For scale, the collet is an ER25. By substituting the "spare" pulleys on the right of the picture, the speed can be increased even further, albeit with a loss of torque, of course. These sewing machine motors come with a three-step variable speed pedal arrangement, which makes for exciting hand/eye/foot coordination!

Hope this helps,

John

Edited By John Hinkley on 04/12/2016 09:59:57

If you want more power there is a selection of these about

**LINK**

I understand that the motors are pretty small and light. I've wondered about getting one for some time but they were more expensive than this last time I looked. They may be cheaper on the general web or amazon. On the other hand a universal motor of this rating would probably cost a lot more - pavalux etc. They don't state that this unit is brushless so best ask about that and size of the motor.

One thing to be aware of is that just like treadmill motors they rate them on input power. This seems to be the case on the majority of sewing machine motors. Should be safe to assume at least 1/2 that power gets out. There will be the usual HP reduction when the motor is slowed down via the drive unit. Some one is also selling a more powerful dc motor drive set up but it's more expensive. This probably wont be current limited as with just about all electronic drives for this type of motor.

John

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Edited By Ajohnw on 04/12/2016 11:39:37

James,

I sent you a private message...

John

I have been playing around with stuff from Minicraft with good success, I converted a Cowells Pillar drill originally for a Proxxon industrial die grinder but the Minicraft MB150 drill works much better for Clock work and should suit your application well with the variable power supply more pictures in the album, as with the Proxxon there is a 20mm dia ally collar to grip securely

I think this design of sensitive drill is the best I have encountered

Edited By Stephen Benson on 04/12/2016 12:43:00

The motors in cordless drills are usually geared down significantly, so if you want speed rather than torque, investigate the motor-gearbox arrangements and see what can be sorted for a direct drive.

Regards, Tim

Thank you for the feedback and suggestions. I shall look into the ideas given.

James.

Couple of spindles driven by RC motors in Joe's thread , should be about the right size on the small Flexspeed