The Shop > Tools
Gingery Lathe Mods
vtsteam:
Tricky part is going to be boring the headstock to fit new bearings. There's a sequence you go through to bore it originally on a Gingery lathe, but it's not exactly reversible because you remove your reference boring jig when done.
The actual bore location is not critical to start with as long as the bore is parallel to the ways. But once the lathe is built, and the tailstock made, the bore location is determined -- at least in the vertical dimension. The tailstock can be set over horizontally, but the height is fixed.
Not impossible of course, but will take a little thought about procedure to maintain alignment.
vtsteam:
Sorry Kjelle no pics yet because nothing is being made so far, just thinkg things over, but pics will come, promise!
I found some really nice heavy duty oilite bushings 1" ID that I had left over from a job. These are the silver kind, not the sintered bronze. I pulled the caps off of the headstock and checked how they might fit.
Looks like the 1" bushings could just be made to fit if I bored the headstock. Unfotunately, any larger would hit the cap hold-down screws. I suppose these could be moved, but that would be a much bigger project.
So I'm dropping 1-1/4" nose side bushing idea. I think I'll go with the full 1" spindle for the time being.
I noticed that I had the cap screws somewhat offset compared to the spindle centerline. The spindle is about 1/8" closer to one set of screws. I'll need to adjust that by boring along the mid distance between them if I'm to fit the bushings between them. That will offset the spindle in relation to the tailstock, but the tailstock set-over can be adjusted to compensate in the horizontal plane.
To get something done today, I cut some 3/4" pipe for spindles and measured the diameters.They are about 50 thou too large for the bearings. Rather than thin the spindle walls too much, or ream the bearings too thin, I think what I will do is shoot for a spindle diameter of 1.032, and ream the bearings to that. That should take minimal material off of the spindle, and only a 64th off the wall thickness of the bearings.
I also took apart the tailstock, to check if it was suitable for holding a bar to bore the head with. That would solve the boring position problem. Looks do-able. I'd set the tailstock over before boring the head, to center the bore between the cap bolts, as mentioned already. The new position of the tailstock would be the new center.
So, I think it's settled then - 1.032" spindle and bushings, and bore the headstock from the tailstock after setting over about 1/8th. Use heavy duty bushings I have onhand..
vtsteam:
I've been waiting for the new belt to arrive before doing any work on the lathe. If I bore the headstock, I want to have everything ready to reinstall the new spindle(s) or I won't have a working lathe in the tiny shop.
So I've been working on the new cone pulleys. Here's a pattern and a baked sand core:
[ You are not allowed to view attachments ]
Will_D:
In the course of tidying up the shop for the new mini-mill I remembered/found my old Centec 2 horizontal mill.
Some time ago I did a basic refurb that involved replacing the CI Pulleys (A section V-belt) and the like ( 3 step) with a more useful 4 stage pulley and a 2 step on the motor. Rather than cast the pulleys I made them from MDF.
[The original 4 step geometric speed pulley design came from Tameside Tech College Toolroom teacher who lent me the patterns and then we cast a pair for my drilling machine] Those were the good old days when a Tech college had an "In House Foundry" plus more big machines to play on. (They also had a rolling road in the car/motor vehicles bit of the college but thats another story)
Anyways BOT:
These were tuned to size and profiled with a Z section HSS form tool and mounted on some metal bits with some long screws plus lots of PVA glue. [Vague I know but it was a long time ago]
The pulleys were then soaked in diluted Polyurethane varnish and after that had dried more neat PU. The slight roughness of the MDF and the PU gives agreat "Bite" on the belt.
Some photos:
I really think that for this level of belt drive why cast aluminium?
Will
vtsteam:
Hi Will your pulleys look great, and I'm sure they work as well! :bow:
Personally I greatly enjoy casting aluminum and truly dislike working with MDF, but that's just a prejudice on my part. I don't make patterns from MDF either. That doesn't mean I don't greatly admire your finished pulleys, I do! :clap:
A few more (admittedly arguable) reasons I'll be casting -- I only have to make one pattern for the two pulleys I need (and however more I want in the future), I don't have to add metal hubs as you did (and so make and connect two parts for each pulley) , and I'm making 6 groove poly-vee belt pulleys, not standard vee belt types, I think the fit will be better. And aluminum castings fit my lathe style. Plus I have an excuse for setting up a casting capability in the tiny shop!
I might make a Potts spindle at some point, and then I would probably make wooden pulleys for the traditional fun of it, though likely cherry or other hardwood -- as I have lots of that from my sawmill.
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