New Power Finger File.

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Active User
Aug 22, 2014

I wanted to use aluminum for this project, 10mm thick would have done the job but I had no idea where to souurce that size sheet from; however, I did have some sheets of 25 mm Delrin so I thought I'd have a bit of a play with that medium.

Delrin turns nicely giving a nice finish, but when grinding and filing the finish is quite rough. I expect some more work in this area to neaten the project up a little.

I cut a rough shape from a largish slab and set about shaping it with a finger file. The hole for the motor was turned on the lathe, this necessitated making the handle a little shorter than I'd like. As it turned out the handle fits the hand quite comfortably. I cut a slot just forward of the handle and tapped a hole from the top of the blank for clamping the motor in place. Next I mounted a small piece of Delrin in the four jaw and drilled a 10mm hole for the front wheel mount. After mounting the motor, I spun up a small piece of Delrin and sunk it into the drive drum and pushed the drum on the splined motor shaft. I was going to use some Delrin for the drum but thought it might melt so used a stell drum mounted on a Delrin Bush.

For the motor cover I turned a 12 mm thick piece of Delrin to fit over the motor and then turned down a piece of PVC to slide over that. The end is capped with another piece of Delrin I had lying about, yellow unfortunately. I mounted the swich in that.

The unit works nicely, but curiously the 18 volt motor I sourced from an old cordless impact driver smokes badly when run on 18 volts. On 12 volts it runs ok, if a little hot. P_20180422_170059[1].jpg



Aug 7, 2018

The machine tool that the motor came from has an electronic controller between the battery and motor, it might get 18 volts, but in short pulses. As you have found the motor is happier on 10 or 12 volts continuous DC.

Anyway it looks good and seems to work well. As it happens I'm in the middle of designing a power finger file, but intended for bench work using a 20 mm wide belt and a 550 watt induction motor. A bit over kill you might say, but the motor came for free.
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