vacuum motor grinder

[big o]

What ? another vacuum motor driven grinder for a 6"Atlas lathe. This one uses the switch that came with the original cleaner, it runs on 120V.AC. Drive shaft runs in 2 ball bearings,grinding wheel screws on end of shaft. Knurled knob slides in a slot,a quarter turn locks in the rpm's.
Motor leads switched to run counter clockwise.

[rossbotics]

Kool idea

Doug

[SpenceChicago]

What ? another vacuum motor driven grinder for a 6"Atlas lathe. This one uses the switch that came with the original cleaner, it runs on 120V.AC. Drive shaft runs in 2 ball bearings,grinding wheel screws on end of shaft. Knurled knob slides in a slot,a quarter turn locks in the rpm's. ... Motor leads switched to run counter clockwise.

"Knurled knob slides in a slot, a quarter turn locks in the rpm's". I see a knurled knob on the right side, but I not only do not see a slot, but how does this knob influence the rpm's? And is this a DC motor where "Motor leads switched to run counter clockwise" makes sense?

I like the source of the motor, esp since I have a few household vacuums that I could canabalize for the motor. But besides the source for a motor, this project isn't making sense to me with just one picture and just a few sentences.

I obviously missed something important. Could you illustrate more and/or explain more?

[Al8236]

Glad I'm not the only one confused!

[DIYer]

Thanks big o! We've added your Grinder to our Grinding category,
as well as to your builder page: big o's Homemade Tools. Your receipt:

Grinder by big o

tags: grinder

[ncollar]

The only thing I can say is be very careful and get a guard on it. Those motors are designed for very high rpm and if your grinder wheel is not high enough you can blow it apart. That is something very dangerous because of the speed. I would not use a brushed motor from a vacuum.
Good luck
Nelson

[big o]

This small grinder is used to true the fingers of the chuck on my 6"Atlas lathe. The grinder is mounted on the cross-slide, a small grinding wheel is mounted on the
threaded end of the shaft. The motor rpm's is controlled thru a modified finger trigger switch off a 3/8"drill, that is reason for the slot. Knurled knob slides in the
slot and controls the position of the switch, which in turn controls the speed of the motor. The motor runs counter-clockwise /opposite the rotation of the lathe, used
for reducing diameters of shafts for other tools. The motor is a brush type ,it is converted to 120v. thru the circuit built in the drill switch.

[big o]

My lathe has a 1/2" thick plexi-glass shield that covers the working area of this grinding wheel. It cut's down the weight of the tool on the cross-slide, making a more compact tool. The slot was cut short to limit the full movement of the switch,top rpm's are not reached.

[big o]

Here is a better view of the slot for the switch control. Move selector knob to the right, motor is off, move the knob to the left you can select
the rpm's. Brush motors can be reversed simply by changing positive and negative leads. The vacuum cleaner motor is a brush motor that
runs on DC. voltage thru the drill switch which changes the AC. current to DC. Same as any pistol drill. The length of the slot limits the
movement of the slide switch,which in turn limits the speed of the motor.