The 24 I was referring to looks like a 24T which has had its teeth tuned off. I wouldn’t destroy an original gear but I’ll happily turn down my existing spacer.
Thank you by the way.
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Lead screw question.
- Thread starter Exuptoy
- Start date
Thank you by the way.
- Joined
- Aug 23, 2014
- Messages
- 222
There ya go, and looks like you've got an oddball quick change gearbox to boot(pic in post 38). Handy little jigger.
- Joined
- Dec 25, 2011
- Messages
- 10,552
We have I think instructions for building two QCGB"s for the 618, 101.07301 and 101.21400 in Downloads. It would probably be worthwhile to look at those, compare them to the partial one that you have, and see whether or not it matches one of them. Other pieces may turn up or someone may decide that they want to buy what you have and make the missing pieces.
Fitted my gearbox, then took an ally bar, turned it down as a press fit, took one of my spare 20T gears and knocked off the teeth to make a spare spacer then the existing 24 spacer I turned down to 27mm then parted it off to make a 5mm spacer as I wanted to align the transfer gears correctly, then when I went to fit the screw gear I found my stub shaft had been turned down to fit the homemade gearbox!! Not a problem, I managed to swap the stubs over but kept the unmarked bevel gear as it was just roll pinned.
Following repairing the gearbox I fitted the bull gear pin and detent / spring but first I managed to drop the spring inside down the back of the bull gear into the pulley, which caused me some consternation, so I made the decision to remove the head and retrieve the spring.
Whilst off I decided to use Mike Kurns’ original new old stock bull gear pin with detent feature as it was longer than my one which seems to have been made to fit. I’ve told Mike he can have the spare pin as it does work and when spares dry up he will at least have another spare for someone who is desperate.
Next up was the saddle, I removed the apron and immediately found the gear housing was snapped but still sat in the same position it should be due to its dowel pins. I replaced the gears and shaft as I had intended but also managed to stick the 2 parts together with my Tig . I say stick it together as it was clearly not welded! (I can tell you that it’s either cast or Zamak and it didn’t like being welded! It was fizzing and giving off a white residue on my torch). I have dropped Mike a line as he has a spare gear case for £32.
I will at least have piece of mind then that all is well inside.
Anyway, all in all I now have a lathe which is in rude health and does all it should with no backlash in the carriage and runs fairly quiet, but that’s not to say I won’t buy more parts to refine it even further and get rid of any evidence of it having seen much work in the past.
[media]
Following repairing the gearbox I fitted the bull gear pin and detent / spring but first I managed to drop the spring inside down the back of the bull gear into the pulley, which caused me some consternation, so I made the decision to remove the head and retrieve the spring.
Whilst off I decided to use Mike Kurns’ original new old stock bull gear pin with detent feature as it was longer than my one which seems to have been made to fit. I’ve told Mike he can have the spare pin as it does work and when spares dry up he will at least have another spare for someone who is desperate.
Next up was the saddle, I removed the apron and immediately found the gear housing was snapped but still sat in the same position it should be due to its dowel pins. I replaced the gears and shaft as I had intended but also managed to stick the 2 parts together with my Tig . I say stick it together as it was clearly not welded! (I can tell you that it’s either cast or Zamak and it didn’t like being welded! It was fizzing and giving off a white residue on my torch). I have dropped Mike a line as he has a spare gear case for £32.
I will at least have piece of mind then that all is well inside.
Anyway, all in all I now have a lathe which is in rude health and does all it should with no backlash in the carriage and runs fairly quiet, but that’s not to say I won’t buy more parts to refine it even further and get rid of any evidence of it having seen much work in the past.
[media]
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- Joined
- Dec 25, 2011
- Messages
- 10,552
Looks promising, anyway! Yes, the carriage traverse gear case is cast in Zamak. So is the lead screw right bearing and FWD-OFF-REV gear box casing, most of the gears and AFAIK, all of the cranks and hand wheels and the two tailstock ram locking cylinders.
Cheers @wa5cab
I have a spare lead screw and carrier bearing and plenty of gears. If I can find my low temperature alloy welding rods I might try to repair the reversing box. Tig is too much for Zamak, even with the amps right down it didn’t like it. For the thickness I should have been up around 60-80 amps but even at 30 amps it was turning to gloop! I had to turn off the up slope and try tacking then added a little filler once I stopped meting it!
I have a spare lead screw and carrier bearing and plenty of gears. If I can find my low temperature alloy welding rods I might try to repair the reversing box. Tig is too much for Zamak, even with the amps right down it didn’t like it. For the thickness I should have been up around 60-80 amps but even at 30 amps it was turning to gloop! I had to turn off the up slope and try tacking then added a little filler once I stopped meting it!
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