The Eddgwick arrived!

[Pete.]

You CAN do it, but since you have to reverse the lathe either way you might as well wind it back with the half-nuts closed.

[awemawson]

But Ox's way means you don't have to stop the lathe quickly - so coming up to a shoulder is more 'relaxed' !

[RussellT]

Making a screw adapter to take the backplate shouldn't be too taxing

I wondered whether the two extra holes in the back plate were there for bolting it straight to the spindle?

Russell

[Pete.]

But Ox's way means you don't have to stop the lathe quickly - so coming up to a shoulder is more 'relaxed' !

Yeah it does have the advantage when threading to a shoulder.

[mattinker]

Thank you all, I'm putting my bad memory down to heavy metals, I had actually seen the Ox tools video, completely forgot it, maybe, now that I have a lathe with a thread indicator I might just remember the technique! Definitely take the panic out of things!

Russel, the face plate wont bomt up, there is a boss on the back, modification is going to be in order.

Thanks AdeV, I haven't cleaned up my thread indicator plate much yet, I could probably do better! Steve's photo editing methods should improve things.

Building up the end of the shaft.


The shaft was broken between the hand wheel and the dial. Underneath the dial, was a buton to adjhust the friction on the dial. A screw in the shaft pushed against a taper, pushing out the friction piece. You can see where the shaft had been heated to remove or straighten it. The bearing part of the shaft is straight and untouched.



I was lucky, I got the wedge out easily!



I began by building up on the side opposite the bend.



more building up. I used some Castolin rods that I bought for welding railway track! They don't quench harden. I was able to keep the shaft both cool and soft.



Faced off and centre drilled.



Turning down the weld.



As the bearing part of the shaft was untouched it was relatively easy to cut the major diameter.



It's not very photogenic! This was after a little touch up with emery paper, it looks better "in the flesh"!



All the bits fit, it needs the key way and drilling and tapping for the friction adjuster!

Regards, Matthew

[awemawson]

Good work Matthew 

It must have had a wallop to bend that pear handle to that artistic shape - they are often just in on a taper so I'm surprised it didn't detach

[mattinker]

Andrew, It must as you say have been a "wallop"! The shaft was bent slightly over about an inch, the part with the handle was sheared off. The pear handle is threaded on!

Regards, Matthew

[vtsteam]

You're working fast Matt! Now a little heat in the right place and that walloped handle will bend back into shape with mere taps. 

Nice to see things put back in order. 

[mattinker]

You're working fast Matt! Now a little heat in the right place and that walloped handle will bend back into shape with mere taps. 

Steve,
I'm not sure about working fast, here's a not very good before after pic. I added about 1 5/16" or 35mm in length which didn't take me more than an hour or two's welding, I used 4mm diameter rods which means the metal goes down fast. I find building up something like this much quicker and easier than constructional welding. It is probably scary to launch in and build things up, but it can be really worthwhile and I'd encourage people to try! For the end of this lead-screw, there is no load on it at all. The untouched part is the bearing surface, the second third is where the dial rides and the new part is only to hold the handle!




Regards, Matthew

[vtsteam]

That seems fast to me!

I've been thinking about your bed wear question Matt, and your mentioning grinding. I'm guessing the wear is beyond what scraping would accomplish in any kind of reasonable amount of time, but I'm not a professional scraper, and don't know how fast those guys can get a long bed down. Maybe better tools than I had (carbide, etc) can move faster than I do.

But if wear is really serious, then I guesss grinding, and/or Turciting (which I have absolutely no knowledge of other than Fergus occasional mentions here) is the solution most often resorted to.

Any grinding with a portable/DIY jig will duplicate whatever accuracy the jig has, so that would be the focus in designing one. If followed by scraping, then the required tolerance would only need to be enough to get it to the level where scraping could then take over and finish off. Grinding and scraping the ways though will alter other relationships to the various sliding parts and headstock, and these too would probably need attention. It's likely a whole lathe set of corrections and adjustments would follow. Not beyond doing, but probably part of the whole job needed.

One other thing though, which I don't mean in any kind of defeatest way, is learning to work with an older lathe as a specialized machinist skill set to produce good work. So I mean it in a positive way. Here is a brief discussion of that -- which may prove helpful for many of us -- those who have older lathes and lack the immediate means to correct them. It did for me:

http://www.eztram.com/helpfulhints_results.asp?Hints_ID=13

ps. though very helpful it is a bit hard to read straight through without enough paragraphs! 

For something like that, I like to select copy and paste the text into a word processor and add paragraph spacing to make it easier to read. I usually then save a copy of useful tips like that, because I know I'll come back to them.

[awemawson]

Steve, if the bed is a double inverted V, often there are relatively unworn ways - usually a flat and a V - that the tailstock bears on - these can at a push be used to grind the worn ways.

If you look at the first picture Matthew posted in this thread, where some reamers are laying across the bed, you can see the two pairs of 'V and flat' - one for the carriage which will be the worn pair, and one for the tailstock that should barely be touched.

Turcite is mainly used to build up under the carriage and / or cross slide, to bring them back up to original height so that shafts and lead screws still keep their original relationships. Although some machines do have ways entirely made of Turcite it's not usual to do this as a repair.

[mattinker]

Steve,

Thank you for your thoughts and the http://www.eztram.com/helpfulhints_results.asp?Hints_ID=13 I don't think your being defeatist, I think it's important to know how to go about compensating.
 I haven't actually tried the lathe yet so I don't know what I'm up against. The wear is visible without even touching, which is why I'm a bit apprehensive! There are unworn machined surfaces along the sides and the top of the bed that would make good guide surfaces for a grinding carriage. The "moglice" option I think is out for me because of the length of the bed, I may be able to use it on the cross slide, but I'm not sure that I'll need to.

I'm in the thought phase, I suspect that it would be a huge scraping task, I have to admit, I like the idea of making a grinding carriage we'll see about the reality!

I see Andrew has answered while I was typing. The rear "V" way looks to be in much better shape than the front. There are also the sides and the two places on the top that look good like nicely machined faces. Once I've got the carriage back together I'll know more!

Regards, Matthew 

 

[vtsteam]

So for a DIY grinding jig you could maybe use the tailstock (if beefy enough) as a sort of mount for a grinder. The tailstock would have to be fastened down to allow sliding without vertical play (depends on the fixing method).

I don't know how the headstock is attached to the bed. On a smaller lathe like the ones I own the headstock rides on top of the ways, though bolted down. If removed (and removable) the ways could conceivably be ground throughout, and the headstock scraped to lower to equal the removed material of the ways, bringing it into proper height with the tailstock.

If not removable, I guess the Turcite would be needed on the tailstock. Or maybe if the tialstock has a removable shoe (as mine does on the Craftsman and new lathe)  a new shoe could be cast thicker to compensate. I do wonder about the carriage -- how important is it that it remain the same height if the ways are scraped? I do think the vees for the tialstock would need to clear in it, but that isn't bearing fit, just a clearance fit and so probably fairly easy to do.

[vtsteam]

Actually, re. above, if the headstock set on the ways and was removable, whether it needed to be scraped to equal the drop in the ways would depend on what it bears. The tailstock part of the ways would remain at original height. The carriage portion would be the lowered part.

Likewise the tailstock might not need Turciting/shoe thickening, and maybe the opposite - scraping. It all depends on whether the headstock center height moves down with the grinding process or remains where it is in relation to the tailstock (and how it moves after the operation). Complicated to describe in words, but probably quick to see on the actual lathe.

[hanermo]

I believe several peeople have successfully ground lathe beds with all sorts of cartridges and carriages, from a router motor onwards.
Several threads, even video on youtube.

The only question is what is your reference plane, and how do you effect movement.

I, myself, would use linear rails, and a temporary carriage mounted on them.
I import and sell linear rails, so I have them in stock - this does have an effect.

I originally made a temp carriage to grind the ways on my very large shop built cnc mill.
It ran on a large glass table, and the grinder was a std double end grinder from the home store.
Worked fine.

This time, I have just fit the linear rails to large tool steel flats directly as first step.
The flats are first smoothed with a large belt sander.

And no, it wont dig in, because the flats are very large in comparison to material removal rate of a sander.
Even using a top end industrial hand sander (Festo, 1400 W), 50 mm tool steel flats, 2.4 m long, 20 mm thick.
45 grit belts.
35 mm linear guides bolted onto the 50 mm wide flats. The edges got rounded a bit, by 1-2 mm. Doesnt matter at all, as the edges are not used.
The assy runs smoothly, and one end of back side has a bit of twist.
This is very clearly felt by moving the back carriage by hand as it gets stiff.
I will qualify the error a bit with a few DTIs, and then later smooth or shim the underlying part as needed.

Moral of story:
Its doable, and not all that hard.

[mattinker]

The Edgwick has a built in head stock, so no removing it! It also has a movable gap bed piece that would need to be ground too. The head-stock is more than solid enough, but would in my view be too cumbersome. The carriage that is evolving in my head would have four skateboard bearings arranged to sit on the "V".  The top of the carriage ways are unworn in the horizontal plane on which a Teflon pad could maintain the height. The whole thing could be held down using the tail-stock clamping way with bearings and springs to apply pressure to the grind stone. It seems to me to be better to use a spring than some kind of solid slide, as the wheel can then lift until it's sparked out. Grinding is not like milling. It would be nice to be able to use the cariage feed to move the grinding caridge!

Steve, Any grinding would be in preparation for a final scrape to get things back into line.

Thanks Hanermo, I think it would be quite a lot of work to mount linear rails, not worth the effort and I don't have them in stock! I like the moral of the story!

Regards, Matthew

[vtsteam]

Well that sounds like a plan for the ways grinding. 

And presumably the tailstock would remain at the same height it is now, since you wouldn't grind the part of the ways it rides on? And the headstock as well, so no need for Turcite, unless there has been wear.

The only tricky part if you don't have one (or access to one) is using a straightedge for the scraping part.

whatever grinding carriage you build can be driven by a nut slipped onto the leadscrew -- it doesn't even have to be a halfnut, if you can reverse the carriage back.

[mattinker]

Well that sounds like a plan for the ways grinding. 

And presumably the tailstock would remain at the same height it is now, since you wouldn't grind the part of the ways it rides on? And the headstock as well, so no need for Turcite, unless there has been wear.

The only tricky part if you don't have one (or access to one) is using a straightedge for the scraping part.

whatever grinding carriage you build can be driven by a nut slipped onto the leadscrew -- it doesn't even have to be a halfnut, if you can reverse the carriage back.

I think it would be easy to drive the carriage. The tail-stock way would remain as is. The straight edge is another problem for another day!

Regards, Matthew

[awemawson]

So Matthew, is the headstock and bed one casting? Quite unusual if it is, and it must have made planing and grinding the bed un-necessarily hard when the made them. Most head stock sit on the way, and many can be swivelled for alignment down the bed. Colchesters having a pivot peg at the rear and a pair of adjusters sitting between the shears to tweak it.

[mattinker]

So Matthew, is the headstock and bed one casting? Quite unusual if it is, and it must have made planing and grinding the bed un-necessarily hard when the made them. Most head stock sit on the way, and many can be swivelled for alignment down the bed. Colchesters having a pivot peg at the rear and a pair of adjusters sitting between the shears to tweak it.

Headstock and bed one casting! Removable gap.

Regards, Matthew

[mattinker]

Oops my bad, the headstock is separate, well diguised join!

Regards Matthew.

[awemawson]

I'm not overly surprised. It would be a nightmare to make as one piece.

[AdeV]

They're definitely separate - I have a spare headstock

[krv3000]

good work so far keep it up 

[mattinker]

They're definitely separate - I have a spare headstock

Ade, Wow, a spare head stock, has it got the intemediary gear you need? What happened to th rest of it?

Thanks KRV!

Regards, Matthew