12v motor to raise and lower sawhead

[jrokusek]

I've been reading the thread entitled "Power feed plans" and it got me thinking that using a 12v motor to raise and lower the sawhead of my homebrew mill may be a good idea.  I built the mill plenty tall and have it mounted about 6" off the ground.  I stand at 6'1" and have to stretch on my tiptoes to turn the handle to move the head.  It's a shelby-style winch so I have to turn the crank about 20 times to move the head one inch. 






Someone please enlighten me as to what I need for a 12v motor.  I was thinking of using a 12v winch with power in and out to raise and lower the head but I don't know if the winch will hold the sawhead in one spot or if it will creep under a load.  So my other idea was to use one of the motors below and connect it to my winch:

http://www.surpluscenter.com/item.asp?UID=2007121016203005&item=5-1566-R&catname=electric
http://www.surpluscenter.com/item.asp?UID=2007121016203005&item=5-1623&catname=electric

Am I on the right track? 

[submarinesailor]

Why don't you look at a 12VDC boat winch.  If the heads not too heavy, a boat winch should be able the handle it.

Bruce

[mike_van]

The first motor [link] won't work, power window motor just won't have enough snot.  The second one only has 30 inch pounds of torque, I think it's too small too, but to be sure, you'd have to put a torque wrench on the nut where your handle attaches, and see what it takes to move it.  I'm guessing you have 12V at the mill?  Any of the small ATV type winch's would work, I don't think they creep, the planetary drive in them tends to self brake them.

[pineywoods]

look for a wheel chair motor. They have a worm-drive gear box built in, won't creep down. Most are 24 volt, but they are beefy and should will work well on 12 volts. Ask around rehab centers and nursing homes.  Junked wheel chairs are pretty common.

[Tim L]

Turner uses a run of the mill atv winch

[jrokusek]

I checked out the Turner Hydraulic Mill and sure enough there's a 12v winch on top of the thing.  If you all think a 12v winch won't creep this may be the easiest thing to do.  I don't have 12v to the mill yet, however I have 2 deep cycle trolling batteries that aren't always used on the boat!  :D  I can't be in 2 places at once so I can steal one of the batteries from the boat and be in business.

[bedway]

I agree with what mike said. Find out what torque it takes to move your head up. I put a torque wrench on mine and it read 5 ftlbs to raise mine. I got a 12 volt gearmotor off ebay thats rated for 100 inlbs. Ive got a 16 tooth sprocket and a tarp switch in shipment. When i get things together ill post some results.,,,,,,,,bedway

[StorminN]

The electric wheelchair and scooter motors are very handy, and strong. Like pineywoods said, they are mostly worm gear and therefore won't creep. They are also mostly 24VDC... I've used them as 12V in a pinch and they seem to work just fine, but 1/2 the speed.

As far as strength, here's a pic of the Rascal Scooter motor I'm using as a lift motor on my Mobile Dimension mill... I'm not positive what my mill weighs, but between the VW motor, carriage, and truss, I figure this little electric motor is raising 1,000+ lbs. I got the broken scooter for free, so my total investment here was $4 for the correct chain sprocket from Surplus Center... I believe this one was a 3/4" shaft, to give you an idea of its size.



I've also got a couple of wheelchair motors that I'm using to move my sawdust conveyors. These are totally overkill, I could go with smaller motors... but again, these motors were free, so who am I to complain? I believe these were 5/8" output shaft.






-Norm.

[mike_van]

Just a thought I had on using the cable/winch setup - Check those cables often, especially the imports from you know where - The little 1/8 or 3/16 don't have many strands to begin with, and if it [the cable] fails, that heads coming down - As opposed to the Acme thread type, if the chain breaks, it just sits there.