MadModder
Gallery, Projects and General => Project Logs => Topic started by: John Hill on January 07, 2012, 12:53:39 AM
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(http://farm8.staticflickr.com/7165/6650818123_7a0b5e8b81.jpg) (http://www.flickr.com/photos/25239206@N06/6650818123/)
power feed (http://www.flickr.com/photos/25239206@N06/6650818123/) by aardvark_akubra (http://www.flickr.com/people/25239206@N06/), on Flickr
This is the project so far, the motor is from an old computer mag tape drive, rated for 48V but able to (slowly) move the table at 8V, it is a very nice motor. I am sure it will be well up to the task with a PWM power supply.
The gearing is if anything just a little slow.
I still need to work out a better clutch than that screwed ring and the worm is quite rough which I expect will wear the teeth on the wheel quite quickly. I might need to make another, smoother, worm and recut the wheel.
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Looks like a pretty solid motor John, and a fairly compact installation. Nicely out of the way. Even got a color to match your mill.
Hope you will show us a video when you get it going. :thumbup:
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Off to a good start John :thumbup:
Will you be making the PWM power supply :zap: ?
Rob
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John
Looks good from here. :Doh: It will sure save a lot of cranking. :D :)
Cheers :beer:
Don
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Nice project, John. A power feed on the x-axis is really useful.
I put a power feed on my x-axis a number of years ago and just always left it engaged although at times I wish I had a clutch. I recently started designing a clutch or quick disengage mechanism for it when I realized all I had to do was loosen one, easily accessible set screw and disengage the gear. Now, I leave it disengaged most of the time and just engage it when I have long or repetitive cuts on the x-axis. Perhaps one day I'll finish the clutch mechanism...
Chuck
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Chuck, I intended to have the motor on a pivot so that I could easily disengage the drive but it proved too difficult to get the required rigidity. Now I am thinking of having the worm wheel loose on the shaft with a fixed wheel that I can drop a pin through.
Dean, I have three of these motors so naturally I choose to use the one that fitted in with the colour scheme!
Rob, I have not yet designed a control for it, so far I have just been using a variable voltage power supply. Maybe I will use a simple idea I have of being able to control it via a PC serial port, a very simple concept which gives 10 speed steps but I need to put a bit of thought into that one. If I do have PC control of the motor and I figure out how to read the DRO signals I could start on a CNC development programme. I have most of the bits for similar drives for Y and Z (knee lift).
Thanks for the comment Don.
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John, if you go the PWM route, I found a Velleman control board kit was cheap, easy to assemble and worked well. Have a look at the specs and PDF instructions to see if it would suit. Scroll down the menu on the left of this page:
http://www.esr.co.uk/velleman/products/index_kit.htm
until you get to controllers, and click on the first one - K8004.
Andy
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Thanks Andy, I have used Velleman kits for a few things in the past. In fact I think I have one of their usb to digital IO boards somewhere that could be useful testing and working out the desired voltages and PWM ratios etc.
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...it looks a bit rough but it does work!
Now I need to make a PWM controller for it and tidy things up a bit..
http://flic.kr/p/bb5py2 (http://flic.kr/p/bb5py2)
The motor is from a computer mag tape drive (about 35 years old), I made the worm and wheel and the rest is 9mm aluminium plate, also from the old tape drive. The motor is rated at 48v, it will drive the table down to 5v but is shown here at 13v smooth DC from an old bench power supply.
I feel the wheel will not last long and I am sure it would be OK being able to run a little faster so I will probably be making another, but smaller, work and wheel sometime.
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Neeter 'n skeeter, John. (Works well!)
I wonder if a spring loaded detent ball would work as a way to swing the motor in and out and still hold it firmly when the worm is engaged with the gear. Two shallow holes in the main mount, and the ball and spring mounted in a small housing
on the motor mount. Just a thought. Don't know if that will suit your setup, but might be convenient.
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Hi Dean, I am sure that would work but is seems quite secure held with a piece of spring steel. However I am working on a dog clutch which will allow me to keep the worm in mesh all the time.
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Hi Dean, I am sure that would work but is seems quite secure held with a piece of spring steel.
Oh, I didn't notice that spring, John. I thought it was just on some kind of swiveling stud.
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Work continues on the dog clutch for my power feed project....
http://flic.kr/p/bdDobi (http://flic.kr/p/bdDobi)
...Sally Shaper nibbles away at the internal spline for the sliding part of the clutch.
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Work continues on the dog clutch for my power feed project....
http://flic.kr/p/bdDobi (http://flic.kr/p/bdDobi)
...Sally Shaper nibbles away at the internal spline for the sliding part of the clutch.
John
Glad to see that you are keeping Miss Sally Shaper fed and in fine shape. I hope that Miss Liana Lathe is also receiving the same fine attention.
:D :D
Looks like your making good progresss on this. :)
Cheers :beer:
Don
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Oh yes Don, Sally Shaper will always have a place right up front for those little jobs and for the ones she can do better than any other such as this internal spline, I only cut one but it will be quite enough I think.
I got the dog clutch working well but I have used up my quota of video uploads for the month so you will just have to take my word for it! :coffee:
Now I need to make a little cover over the works before it winds my shirt tails in or somesuch. :palm: