small high speed dc motor

[gbritnell]

I am planning on building an auxiliary high rpm spindle for my milling machine. This will have a DC motor mounted on a bracket driving a spindle inside of one of my R8 toolholders. My question is: does anyone know of a suitable motor for this purpose? It would have to be continuous duty, fairly small and have an rpm range of 3-5,000 rpm. I guess it could be AC as long as the rpm could be controllable.
gbritnell

 

[mklotz]

How about a small router or laminate trimmer with a router speed control?

 

[Kermit]

Dremel?

Cheaper still: Dremel clone made in China? 19.99 with around 100 different bits as a kit. Don't remember which store, but pretty sure it was Horrible Fright.

 

[stevehuckss396]

does anyone know of a suitable motor for this purpose? It would have to be continuous duty, fairly small and have an rpm range of 3-5,000 rpm. I guess it could be AC as long as the rpm could be controllable.

Hi G!
I Ebayed 4 small 27V dc motors rated 15,000 RPM. They are military spec rated continuous duty. They are about the size of an RC car motor. Should run about 13,000 on 24 volt.

I have seen 24V motor controllers for $25 on fleabay also.

If you cant score a motor, let me know and i'll send over some photos of the nameplate and see if they fits your need. If so, i'll send one over too you.

 

[SBWHART]

Hi George

Marv's suggestion of a router motor is a good one I used a motor off a scrap router for my home made tool post grinder. I've just used it to grind the pistons for my three cylinder radial worked great.

You can find the build log her http://www.homemodelenginemachinist.com/index.php?topic=6437.0

Hope this helps

Stew

 

[gbritnell]

Thanks everyone for the information. I will give Ebay a look and if not I will look into a router motor. I have an older Dremel (variable speed) but I don't think it would have the torque to run a 3/16 end mill.
George

 

[cobra428]

Hi George,
How about a Roto-Zip (Dremel on steroids I think she turns upwards of 10k) it's like Marv's suggestion. Available at Home Depot....$$$ ??? 79?? Speed controller from HF $19 on sale.

Tony

 

[stevehuckss396]

The problem with the dremel and clones is, they dont take well to a side load. It would be fine for drilling and engraving but wont hold up to the milling.

I am in the same boat you are george except my spindle will go onto a home made CNC. I am experamenting with a cheap er11 collet holder.

http://cgi.ebay.com/ER11-C8-100L-Co...QQptZBI_Tool_Work_Holding?hash=item27ae49bd99

I have 2 angular contact bearings and am on the hunt for a piece of stock to make the body from. I plan to slave 2 of these motors together and run a 2:1 for 26,000 rpm. It is going to be used specificly for endmills smaller than 1/16 and engraving bits.

 

[mu38&Bg#]

Steve, I have intention to do the same this winter, but using an ER16 collet chuck.

 

[Blogwitch]

George,

If you want hi rpm and good controllability, if you have an air supply in your shop, you can have both in abundance.

At this very time, I am just building a very high speed sensitive drilling machine, and I am spoilt for choice as to my power source. I have a 1/8" spindle air die grinder that has a top speed of over 50K rpm, or a 1/4" collet one that goes considerably faster.

I am using a bearing spindle between it and the final chuck, but both grinders are designed to take side loads due to their design of use.

If you go part way down this post it shows what sort of size it is. BTW, I have decided I won't be using the spindle mounted chuck as shown.
This grinder has the speed control built into the knurled collar, turn it for higher or lower speeds. The larger one will require a cheap air control valve, or a small collar machining up with a screw in it, to adjust on the units' own hand control valve.

http://madmodder.net/index.php?topic=721.0

Just thought I would show you another cheapish option.


Blogs.

 

[Deanofid]

George, what are the approximate outside dimensions you are looking for in this motor? Length and diameter?

Dean

 

[gbritnell]

Hi Dean, I'm guessing somewhere around 2-1/2-3 inches in diameter and maybe 4-6 inches long. Here's the link to what I'm building. I wanted to locate a motor before I order the drawings.
George
http://www.jerry-howell.com/HS-Spindle.html

 

[kuhncw]

Hello George,

Have you considered the Sherline 90V DC motor and control? The motor tops out at 6100 rpm and seems well made. http://www.sherline.com/dimen.htm The motor specs are near the bottom of this link.

Regards,

Chuck Kuhn

 

[Deanofid]

George, the motor I use for my Taig lathe is 3" dia x 4" length. It's a 1/4 hp DC motor and will run up to 6000 rpm. Very good, stout motor. A guy on ebay is selling some right now;

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260297197099&ssPageName=STRK:MEWAX:IT

The flange on the front of that motor comes off, so you would have a nice round body to mount as you like.
You would need a DC controller, like an MC-60, to run it. That's what I use to run mine, and it provides a full speed range from about 60-6000 rpm on that motor.

Dean

 

[gbritnell]

What is an MC-60 controller?
George

 

[Kermit]

MC 60


It's a treadmill motor control board. ;D

 

[kuhncw]

John Bently posted a nice bit of information on the GS Electric motor as he modified it for use on his Taig Lathe.

http://lathes.jrbentley.com/motor.html

John's site is worth a look as he does very nice work of many different types.

Regards,

Chuck Kuhn

 

[Deanofid]

What is an MC-60 controller?
George

Hi George;
It's a motor power supply and variable speed unit for medium sized DC motors.
If you want variable speed, you need something like a controller. I don't suppose it has to be as complicated as an MC-60. That is just the type I know will work with the motor in the link from my previous post.

Darren on MadModder forum has a nice article on how to make a power supply. It looks simple enough that even I could build it, which is saying something. Have a look here;
http://madmodder.net/index.php?topic=1143.0

You might want to write him with specific questions about it, and what kind of motor it would run.

Using a DC motor and some kind of power supply is one way to get what you want. They seem to make quite a bit of power and torque relative to their size. Small AC motors, like those in the Dremel may work too, but from my experience using one, they are quite low in the torque department. Many of them have the advantage of being able to run from one of those small router variable speed units, though.

The motor in the link you have for your project looks like what I see on ebay quite often. It's hard to tell it's size, but I'll bet it is fairly small. Maybe 1 3/4" dia by 4" length, or in that range. Unless the O-ring shown in the picture is a great big thing, that motor wouldn't seem to be very large. BTW, the one shown on the JEH site is a DC motor.

Dean

 

[duckman]

If your driving a spindle with the motor and your not dead set on DC steal the motor out of a vacuum cleaner power head they are AC with a ton of torque then a simple rheostat to vary your speed and they run about 6,000 to 10,000 RPM.