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Here’s a photo of the original parts.? Thrust bearing at the bevel gear end set the end play.? The shaft sat in the cast iron and there was dramatic end play but then it was designed to be turned slowly by hand.

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At the gear end the thrust bearings pressed against the gear and the cast iron.? I replaced the cast iron side with an bearing instead of a bushing.

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At the crank end I replaced the bushing with bearings and spacers and took out the end play to the bevel gear.? Now I can spin this to get 150 IPM on the knee which is scary fast.

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First trial was with a 650 oz-in stepper motor with 4:1 reduction.? If I was lucky I got 10 IPM before the motor locked up.? Stepper motors cannot turn fast.? Changing to a 1200 oz-in motor gave me 25 IPM and that worked until the GECKO controller developed corrosion on the terminal connector and failed.

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From there I changed out the motor to a 750W AC Servo good to 3000 RPM and now have 150 IPM.

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Eventually I’ll drive the vertical screw directly to reduce backlash but for now it’s been pretty good.

John

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Hit send too fast . The knee is the one that I will probably convert first . I had my chest cracked 7 years back & thinks like raising/lowering the knee reminds me that that work\was done to me . I have one of those electric seat motors , but i don't think it has enough power for this . I think my next plan is to remove the table & go down to the knee mechanism & clean, lube & adjust my way back up to the table .? I would be interested to see how ya / yer bud did the Stepper? & DC motor install .

thanks

animal

??? Sorry Forgot to mention , ye it's a knee mill I was told it was purchased new in the 80's . It Came from KBC tool's . I got it from the original owner whose work was 95 % plastic , no steel & some aluminum . He made some kind of optics stuff .

thanks

?animal

On 11/2/24 10:48 PM, John Dammeyer wrote:

Does your mill have a knee or does the head assembly move?? That's easier than moving the quill and leaves the quill as a manual option.

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There are all sorts of ways of doing this.? For the longest time I had a stepper motor on the knee shaft that I ran from one of my ELS units.? I could set zero where I was milling and then if I wanted to do a 0.010" cut just move the knee by that distance.

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A friend of mine with the same type of mill just added a DC motor with a variable power supply and a couple of toothed belts and uses it to avoid major tedious cranking operations.

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Or, start thinking about CNC now and start the conversion.? Just do the Z axis to start.? Whatever controller you use add a pendant with an MPG and now you are on the way with adequate control.

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-----Original Message-----

From: [email protected] [mailto:[email protected]] On

Behalf Of mike allen

Sent: November 2, 2024 10:27 PM

To: [email protected]

Subject: [digitalhobbyist] Diy Powerfeed for mill

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 ? Finally got my mill in my machine room & under power . Wondering if

anyone here has come up with a DIY powerfeed that could be used on a mill .

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thanks

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animal

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