Have an extra lathe chuck now my wheels start turning.

admin

I purchased a bunch of lathe faceplates and two big chucks from a local surplus dealer. The one is a 13" 3-jaw and the other is a 14" 4-jaw. The pics are of the 4-jaw that after seeing it was repaired kind of has me questioning spinning it up on the lathe.I originally planned on using the 3 jaw to eventually make a rotary positioner or pipe beveling machine. What kind of shop built creations have you made. Pics please. Attached ImagesTOO MANY TOOLS & NO MORE SPACE
Reply:Here's a little positioner I put together from an extra lathe chuck.  Thermal Arc Fabricator 281Miller 350PMiller Syncrowave 200Lincoln ProCut-55Jackson NexGen
Reply:Originally Posted by jschulzeHere's a little positioner I put together from an extra lathe chuck.
Reply:Yeah, it's a variable dc drive.  I think it's a Bodine, but I can't remember exactly.  Motor/drive was a couple hundred bucks on eBay.  The only thing that is a problem is using it for AC tig,  it seems to screw with the drive and makes the speed go funny.  There might be an easy fix, but I don't do all that much round aluminum, so I just deal with it.Thermal Arc Fabricator 281Miller 350PMiller Syncrowave 200Lincoln ProCut-55Jackson NexGen
Reply:Standoff insulators. That's what I've got for mounting the dc motor on my positioner. I also want a 3 jaw 12" or larger chuck for my pre 1900 American lathe if you know of one. I'd show a picture of mine but now I'm ashamed. It's going to the scrap heap.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:Originally Posted by blawlessStandoff insulators. That's what I've got for mounting the dc motor on my positioner.
Reply:Originally Posted by blawlessStandoff insulators. That's what I've got for mounting the dc motor on my positioner. I also want a 3 jaw 12" or larger chuck for my pre 1900 American lathe if you know of one. I'd show a picture of mine but now I'm ashamed. It's going to the scrap heap.
Reply:That is really awesome! Great job..
Reply:Nice positioner, now you need a tailstock & gantry for a torch! The chucks OK for an old lathe, it may not be too accurate though.For isolation on the positioner, it's better done at the bearings and ground stud locations, then the only thing "hot" to the weld circuit is the spindle and chuck. Make pop case cardboard spacers for under the bearings, cardboard washers to place under all hardware washers, get or make plastic sleeves for the bolts/capscrews going through the frame. Do the same for your grounding setup where it attaches to the frame and your good to go.Even DC welding will arc through the bearing balls to get to the work over time and degrade them (electricity is funny that way).Good luckMatt
Reply:a quick and easy solution is a piece of welding cable, where you remove the isolation, and wrap that around the axle just behind the chuck. bolt both ends together and attach your ground clamp to that.a better solution is to take a piece of carbon (2x2x2 inches), mill the same radius as that axle, and place it in a holder so that is is spring-loaded against the axle. The exact same principle as in handheld machinery, but that with a contact surface big enough to transfer 200+ amps. solder a ground cable to that piece of carbon, and screw a dinse connector (or whatever your flavor is) to the other end, and you're set to go.
Reply:Thanks Steve ^^, no problems bud! Originally Posted by kingneroa quick and easy solution is a piece of welding cable, where you remove the isolation, and wrap that around the axle just behind the chuck. bolt both ends together and attach your ground clamp to that.a better solution is to take a piece of carbon (2x2x2 inches), mill the same radius as that axle, and place it in a holder so that is is spring-loaded against the axle. The exact same principle as in handheld machinery, but that with a contact surface big enough to transfer 200+ amps. solder a ground cable to that piece of carbon, and screw a dinse connector (or whatever your flavor is) to the other end, and you're set to go.
Reply:Originally Posted by Matt_MaguireThanks Steve ^^, no problems bud!He's already done that with a braided strap over the spindle tube (which will last a long time and are easy to get). That still doesn't get to the fact that current can still find its way into the frame through a bearing and back to the spindle the same way. It kinda works like water, as soon as you think you got it beat it finds another way of least resistance (were talking millisecond leaks but it happens).The last one of these I put together used (6) t-900 motor brushes before I got the ohms I wanted. The brush is 2"Wx3"Lx3/4"thick with (6) #12 leads (pigtails). Ran pretty cool to the touch till about 300amps, safe to 600amps. The braid or a brass brush gets you 0 ohms but will erode the spindle over time (a long time), and graphite (carbon) brushes will always have some resistance but they last longer and never eat into the smooth contact surface.Matt