Author Topic: Edgwick Lathe  (Read 2509 times)

Offline AdeV

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Re: Edgwick Lathe
« Reply #25 on: March 01, 2017, 07:40:04 PM »
Turns out it's a pretty simple mechanism actually... there's a base plate (the "shoe"), and a clamping "thing". The bar that goes up from the "shoe" to the lever is threaded, as you turn the lever it tightens, raising the base plate which squishes the clamping "thing" against the underside of the ways.

See photos (click to embiggen as usual):



Lever in unlocked position:


Lever in locked position (note: more thread sticking out of the top):



Looking at your photo Matt, I think all you need to do is to tighten that threaded bar up so it's just touching the bottom of the shoe when the lever is at the back of the tailstock. I'm going to take a wild guess that it'll be quite stiff, I'm assuming the lump on the bottom is designed to bind slightly in the "shoe" so the lever tends to tighten on the thread, rather than just rotating the whole piece. If not, then I'd tighten it anyway, then wedge a shim in there so that it binds up.
Cheers!
Ade.
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Offline mattinker

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Re: Edgwick Lathe
« Reply #26 on: March 02, 2017, 08:12:37 AM »
To adjust the tail-stock lever, remove tail-stock, rotate the  clamping bolt to screw into the handle. it is probable that the clamping mechanism has turned a full turn when it was removed at some stage. I would start by removing the tail-stock and turning the whole locking shoe a full turn so that the that the acme screw screws into the handle, thus shortening it. I don't understand why the image won't open on it's own, it's a .pdf!

Offline mat9900

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Re: Edgwick Lathe
« Reply #27 on: March 02, 2017, 09:10:39 AM »
Thanks very much guys- I was missing the fact that the handle is threaded onto the vertical bolt- I thought perhaps there was something missing off the bottom that raised the shoe.  The round piece turns inside the show so will need shimming out somehow as Ade suggested- anyway now i know what the issue is I will see what I can sort.  Thanks again, Matt

Offline mattinker

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Re: Edgwick Lathe
« Reply #28 on: March 02, 2017, 10:32:42 AM »
You  shouldn't need shims, take of the head stock, rotate the locking shoe so that the locking bolt screws into the handle a turn and try it again. As I said before, it is probable tha the locking mechanism was turned a full turn when somebody removed it. It won't have worn enough to no longer lock in it's life time!

Regards, Matthew

Offline seadog

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Re: Edgwick Lathe
« Reply #29 on: March 02, 2017, 10:43:32 AM »
If the bolt rotates, then there is a problem with the shoe. The slot should be straight cut and a close fit to the head. The design is not unlike the Boxford, and I dare say, a lot of other lathes, in that you can adjust the length of the screw by 1/6th of a turn by pushing the shoe up so that the head of the bolt disengages with the slot, then rotating it.

Offline awemawson

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Re: Edgwick Lathe
« Reply #30 on: March 02, 2017, 10:51:39 AM »
From the picture in post #20 it does rather look as though someone in the past has replaced the hex headed bolt with one that had a larger head that has been turned down to fit the slot, but doesn't grip - unless as I said in an earlier reply the circular head is actually eccentric and locks against the shoe.  :scratch:
Andrew Mawson
East Sussex

Offline philf

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Re: Edgwick Lathe
« Reply #31 on: March 02, 2017, 11:02:40 AM »
Has the previous owner turned the hex (or square) head off the bolt?
Phil Fern
Location: Marple, Cheshire

Offline awemawson

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Re: Edgwick Lathe
« Reply #32 on: March 02, 2017, 11:22:01 AM »
Could easily be cured by drilling the bolt head radially and pressing a roll pin in
Andrew Mawson
East Sussex

Offline mattinker

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Re: Edgwick Lathe
« Reply #33 on: March 02, 2017, 12:37:00 PM »
I just went back to the original pick, I had missed that it had been turned round. Andrew's solution is probably the easiest if you haven't got a welder to put a ridge on the head of the bolt. Normally the hex head is held in place in the groove.
Although Andrew's solution is viable, it will leave slack in the movement. Four welds to transform the head into a squar would eliminat play!

Regards, Matthew

Offline philf

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Re: Edgwick Lathe
« Reply #34 on: March 02, 2017, 03:08:49 PM »
How about making a simple clamp to stop the head turning:



A grub screw (or 2) from the side could lock the round head. The width of the block could be a snug fit in the slot in the shoe.

Phil.
« Last Edit: July 13, 2017, 12:56:05 PM by philf »
Phil Fern
Location: Marple, Cheshire

Offline AdeV

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Re: Edgwick Lathe
« Reply #35 on: March 03, 2017, 09:36:05 AM »
I realised I hadn't looked under the shoe to see what was there... and sure enough, it's a ruddy great bolt head:



So I'd be tempted to go with Matt's solution: Adjust so it works, then weld to the bolt head so it jams in the shoe.
Cheers!
Ade.
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Or: Zhengzhou, China. An even longer way from anywhere...
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Offline mat9900

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Re: Edgwick Lathe
« Reply #36 on: March 03, 2017, 11:56:16 AM »
I have found a nut the correct size- so I am going to turn the "lump" on the end of the bolt down to the size of the hole in the nut, then weld it on. Then it will be as it was originally. I will post some pics when i've done it, but thanks for all the info guys.

Offline mat9900

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Re: Edgwick Lathe
« Reply #37 on: March 07, 2017, 09:22:51 AM »
Hi again, I have fixed the clamp by turning the old bolt head down and welding a nut on the end as I had planned. Have attached a pic, not the smartest job I'v ever done but it seems to do the job! Thanks again for all the info.

Offline mattinker

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Re: Edgwick Lathe
« Reply #38 on: March 07, 2017, 12:09:39 PM »
 :thumbup:

Regards, Matthew