Welding lathe and positioner

[Frank S]

I wasn't going to post this until I am finished with the build, but I have been using this thing for the past 6 months or longer as it is. There will probably always be some tweaks I will be doing to it. It just functions too well not to go ahead and share.

I started out a beam from a 1950's era globe 4 post lift as the frame.
I made the headstock from scratch I wanted the main shaft to protrude out the rear to have a place for my ground clamp this meant I had to make it a right-angle gear box for the gears I used a spider gear and axle drive gear from the differential out of a Kenworth The housing is a length of 6" pipe split and spread then a piece welded in to make it large enough to house the gear and the bearings both ends are threaded to 20 TPI internal threads for the end caps and the oil seals I pressed the splines into the shaft for the drive gear to turn. The chuck backing plate and shaft are threaded to 1 3/4-12 TPI and locked in place with a grub screw between the threads from the end. To be able to make the head stock rotate from the horizontal position to vertical and anywhere in between I made it trunnion mounted the input shaft drives the smaller spider gear and has 2 bearings and a seal. the input side of the trunnion has a 12 TPI external thread for the end cap the saddle mounting clamps can be loosened or tightened to position the headstock at any angle between horizontal and vertical and there are adjustable stops preset at those positions. The main drive motor is from a 1960s era 450-amp Miller welder not sure what the gear reduction in it is. Moving to the drive for the 3/4-10 lead screw I started with a gear reduction drive motor from a 1980s era Miller 300-amp machine then I married the gear heads of 2 Dewalt 4 1/2" angle grinders to give me some offset for my lead screw drive In retrospect I probably could have done without them as the total reduction of the 2 ,ade the lead screw too slow for some operations like making long straight welds when the work piece was not being rotated. but not bad for rotational welding Just something I might change later maybe go to a CVT gear change system to either speed up or slow down beyond what the speed controllers can compensate for. I made the half nut out of an acme coupling nut that fits the 3/4-10 Acme lead screw and an old barn hinge with a couple of springs to hold it open the half nut is closed via a cam and lever. the Tail stock was made from a scissors jack with cross drilled platres so if need be, I can locate the rollers in different positions for larger or smaller diameter work pieces.
It may take several posts to show the whole build process and some of the projects

[Frank S]

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[Frank S]

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[Frank S]

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[Frank S]

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It is worth noting that the carriage rolls and is kept square to the frame rail by bearing the vertical post to hold the mig gun is telescopic with 12 inches of vertical travel this is accomplished VIA a 12-volt linear actuator salvaged from a powered elevating recliner to allow the mig gun to be placed in almost any position I used the dovetailed slides and angle positioners from 2 Mathey pipe beveling machines

[Frank S]

Sixth post






Sometimes it takes a while to match rotational speed with directional speed


It can get a little hot if I am not careful


Repairing the broken main sprocket drive for my Kubota KH191

I have sleeves over the shaft to protect bearing surface and splines




A near perfect repair

[Frank S]

Seventh post







My current project in the welding lathe One spindle is too badly damaged t6o repair so I will cut it off and machine new one



These V pulleys are from old evaporative coolers they will eventually be changed out for a CVT of my own making because to change from horivontal currently I have to remove 1 of the pulleys from the lead screw which is not used when welding in any position other than horicontal


A view of the half nut

I have the spindle made just need to thread the end. 1 note, the factory axles have the spindles just friction welded when I replace them, I have a 7-inch stub that is pressed inside the axle tube. then weld them in place. This is not only a stronger method because I have seen spindles actually break off it is very rare that it ever happens but in my 60 years of being around this type of equipment I think I've seen it happen 5 times. There is almost no possible chance any of mine can ever break off

[DIYer]

Thanks Frank S! We've added your Welding Lathe and Positioner to our Welding category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Welding Lathe and Positioner by Frank S

tags: welding

[baja]

Great job, Frank, but how do you have time to actually do the build amidst all the picture taking?

[mr mikey]

Its always nice when you can repair something that most would scrap, plus your machine will come in handy for other projects. great job Frank.