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Vintage Australian lathe issues/repairs/overhaul

pman92

Plastic
Joined
Aug 1, 2021
Hey guys,
This is a follow up to a vintage Australian lathe I was recently given (https://www.practicalmachinist.com/...vintage-benchtop-lathe-identification-393201/).
This is the first lathe I've owned but I have used lathes quite a bit before (but I'm no expert). Before I start using this thing I want to go over it and get it right instead of running it into the ground and turning it into scrap metal. When I received it it was very dirty. There's numerous components that have been broken and repaired before.

1. The T slots on the cross slide are broken. There's bronze brazing/solder where its previously been repaired but has since failed again. Until now its had a bit of mild steel plate bolted onto the cross slide in each corner that the top/compound slide was bolted to. It looks like a reasonably simple part (a dovetail on one side, T slots on the other, and a few threaded holes). I was thinking have someone make me a new one of these, or improve on the bent up steel plate bolted to the top. The dovetail has a quib (is that what its called?) to adjust it. What should I do?
20210804_173830.jpg20210804_173847.jpg

2. One of the mounts at the top (what do you call this part?) has broken and been rewelded/brazed on. Its not pretty but has worked fine for the past 10 years dads had it. I'll probably just leave this as is. Recommendations?
20210804_173919.jpg

3. The spindle had a lot of end float. There a nut with a slot in it on the rear, with 2 holes that look like it should be clamped onto the thread? however the bolt there is missing and I assume its came undone somewhat. There's a countersunk screw on the front side of it (not in photo) which I'm guessing someone has added as a solution to the missing clamping bolt. The casting on the rear bearing clamp is also broken (it only had the one bolt at the front holding it down).
I haven't pulled the spindle apart, just lifted it out, as I'm not sure of the correct way to go about it and don't want to damage anything.
The spindle and this broken casting are my biggest concerns, does anyone have any ideas?
20210804_174127.jpg20210804_174152.jpg

4. The top slide mounting has also been broken and repaired, the top slide nut has a lot of backlash, and there's a bit of slop sideways in the dovetail (but it appears to be adjustable). I'm guessing this isn't the end of the world because I can replace the topside with a solid block until its fixed or or even replace it completely?

5. The lead screw half nuts have a bit of wear. This probably isn't critical yet. I'm hoping they are the same as something else and I can find replacements eventually.

Honestly it seems like its in pretty rough condition, but considering its approaching 100 years old, and it didn't cost me anything, I would love to get it going again (at least going as best as possible).
On the plus side I've noticed the bed seems to be ok (at least to my untrained eye). The carriage didn't feel any different at the tailstock end to the end where its always used. The cross slide has no real backlash in the nut and the dovetail seems fine (shame about the T slots). The tailstock seems fine.
Its only had occasional use by dad in the last 10 years, and I would guess it probably hasn't done that much work for its age. But it seems its been driven to hard or crashed and abused at some point to cause all the things to simply snap off.
I would love any expert advice or ideas from those more experienced than me.
Thanks in advance, Daniel
 
With the cross-slide, I'd attempt to repair before replacing it, but Instead of covering the damage with another plate, a common repair that I would do is to mill the broken lips out and graft in smaller steel plates with countersunk screws. The finished assembly would have the same dimensions as the original unbroken piece.

That damage is typical of a lathe that didn't have the tool post set correctly for an operation and/or the operator was asking for too heavy of a cut. The above repair would restore the same function and durability that the lathe previously had, provided it is set-up and used correctly in the future.

T slot repair.jpg
th.jpg

The bearing clamp on the spindle bearing is a tough one. I think brazing or skilled welding would be my first stop, but you'll need to ensure that it is put back on exactly straight and square. I'd probably make a sacrificial plug to go in place of the spindle that you could clamp in place using the original adjusting screw and some other clamp to hold the middle/back portion in place. Make sure it cools very slowly after pre-heating and welding so that it doesn't crack or warp. The other option would be to make a repair bracket that would bolt the piece in place, but I doubt it would be strong or accurate enough to function correctly. Also be sure to totally dismantle and clean all of the paint and oil off the casting before starting.

The broken piece that was already welded, I'd start by cleaning and grinding the raised part of the weld down a little and see if there are any cracks or gaps around it. If the weld wasn't clean or the heat wasn't controlled, It might not have bonded well with the surrounding metal, but if it did the then I would leave it alone and if the sloppiness of the weld bothers you you could fill in the voids with some auto-body filler like Bondo. I wouldn't try to smooth it out too much trying to make it look like it never happened though. If it was done properly then the break would have been ground back a little so that the weld could get down under the surface, but there is probably still a section in the middle that isn't welded, which isn't always avoidable so you would compensate by having the weld piled a little proud of the surface. Doing so doesn't matter though if the pile of weld isn't bonded to the parent metal though, so grinding some of what's in that picture off won't hurt it.
 
poor little bugger has had a hard life but it can be brought back to its former glory its just a labor of love thing and if you have the time its a worthy project as it will give you hours of satisfaction and it beats the hell out of setting in front of the telly
 
I like the idea for fixing the T slots on the cross slide.

I think I will do something similar to what was done here if possible: Cracked lathe bearing
I don't like the idea of trying to heat or weld it and end up having it distorted. The break still looks reasonably clean and undamaged so I think it will join back together well. I might add a strap to hold it down as well.
 
...

I think I will do something similar to what was done here if possible: Cracked lathe bearing
...
The South Bend 9" has a thicker casting than your lathe. In order for that to have any chance to work, you need to shape a triangular piece bolted down to the strap holding the back gears and with pins/screws going to the broken bearing at a downward angle (10°-15°).

In general, before putting much effort into this lathe, I think you have to answer yourself a few questions.
1) Does it have sentimental value and you want to save this lathe because of it?
2) Are you more interested in the project of restoring it, rather than having a functional lathe to make parts with it?
3) Do you have access to a well equipped workshop or are you willing to tool up in order to do the repairs?
4) How difficult/expensive is to find machinery in your area?

Paolo
 








 
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