The Craftmans Shop > New from Old
Boxford back from the dead
PekkaNF:
--- Quote from: AdeV on June 04, 2019, 06:29:04 PM ---The next step was to test for twist. Now... I don't have a single proper level/flat surface in my garage, but I found a bit of concrete floor to sit the bed on which didn't obviously rock. Using the machinists level, we can clearly see that there's a twist right where the headstock sits. My guess is this happened when it was dropped; I'm now reasonably sure that it's fallen over backwards, landing on the pulley drive plate. More on that momentarily.
So... what to do about that? I'm open to ideas. I may try shimming the headstock when I refit it to try to level it with respect to the rest of the bed (which seems to run straight, as best as I can tell). Or maybe just mounting the headstock on it and clamping the bed down to to a good solid flat surface will allow it to straighten out? Any ideas gratefully received.
If I got the photos in the right order (they're out of sequence slightly), then the measurements are from the tailstock to the headstock in approximately 1/5th intervals. +/- half an imperial brick (3/5ths of a metric brick).
--- End quote ---
0,6 mm in standard units of twist over the entire length of the bed? That is not too bad. Those cast lathe beds are actually pretty slender and bendy. When mounted into solid sheet metal welded base or such care must be excercised not to introduce greater twist. I would not try to "straighten" it by bending it energetically, because a) it will not respond to it predictable way, b) it will nnot stay put, c) it will take any shape you will bolt it into.
I would leave it to be something noted and verified after mounting and test run.
Pekka
RussellT:
Your last picture shows the belt tensioning mechanism. As far as I know there was a lever on the front of the lathe foot which tensioned the belt to allow speed changes. The part at the left hand side of the picture looks like a slot to achieve that with a quarter turn of the shaft - so somewhere there should be a pin which engages in that slot which might be the cause of the problem.
Have you thought about replacing all that with a conventional countershaft assembly - Boxford did that before they went under drive.
Russell
seadog:
3656 is the model number. All of the 4 1/2" Southbend clones use that reference. The serial number is 1105 dating it to 1948, a Very early model - http://www.lathes.co.uk/boxford/page8.html
Now to read the rest of your posts...
My bed had over 1/8" twist. whilst it was stripped down the twist unwoud and the final twist was adjusted by shimming one of the feet as required.
Try contacting Mark Lord, he has a lot of spares and is reasonably priced, especially if you join the Facebook Boxford group - marklord44@Hotmail.co.uk
He may have a replacement foot.
AdeV:
Thanks guys, this is proving incredibly useful!
Pekka - OK, I'll leave the casting alone for now; hopefully, once I've sorted out the headstock foot, it'll be sufficiently flat to pull the casting back into shape. I'm not sure what the graduations mean on that spirit level, other than the usual "keep the bubble between the lines = flat". An imperial brick, BTW, is 2" x 4" x 8" approximately. Metric bricks are a bit smaller...
Russell - Aaah, that makes sense. I think the pin has vanished. There must still be a spring somewhere as there's quite a force pushing outwards. Maybe it's in that knurled collar.
Seadog - I'll get in touch with Mark, thanks. If 1105 really is the serial number, then I suspect the headstock is a replacement; as it's got the 4 V-pulleys, which started with serial# 1791 according to the lathes.co.uk site. I suppose it's possible the info plate was replaced at the same time. Do you happen to know if there's likely to be a serial number anywhere on the headstock casting?
I guess the proof of the pudding will be if it has a Whitworth or US thread form. If it's Whitworth, then it's almost certainly a replacement headstock; if US, then it's had the pulley upgrade.
Interesting times! Again, thanks all for the info so far.
AdeV:
A thought occurs to me (that's what the burning smell is :lol:)
From http://www.lathes.co.uk/boxford/index.html:
--- Quote ---In January 1950 the flat-belt drive was abandoned, with lathe No. 1791 to become the first fitted with 4-step V-belt drive
...
According to Work's literature seen by the writer, at the same time the tumble-reverse mechanism was altered: the inconvenient and slow-to-change bolted-up arrangement being replaced by a simple, quick-action, spring-loaded plunger design (though it's a fair bet that the change was not immediate and some lathes might have had the old parts fitted).
--- End quote ---
One oddity, mine has the "inconvenient and slow to change bolted up arrangement"... it would seem unlikely they still had any of those left by 1952/3; but as it now appears to be a 1948 model, that suddenly makes more sense - and points to maybe it having had the V-belt conversion after all...
So... should I try to restore it back to 1948 spec for historical curiosity? Or leave it as is? I think the Black & Gold paint scheme is out of the window though, I'll have to buy another wrecker that's not so old before I get to use non-factory colours. :coffee:
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