CovMac Lathes

Right!! I am going to ask the question here and all the other sites I frequent, Is there anyone out there who owns, or knows of the existence of a Covmac 17" Lathe as illustrated here http://www.lathes.co.uk/covmac/page2.html

We don't want to buy it, but would love some photos and history if known..

Phil

If you decide to take the bed off the plinth, you might just about need 3/4" drive sockets, the bolts will be tight.

Ian S C

Ian,

Many thanks for that. I am checking out the status quo tonorrow. I do want to take it to pieces, as I have no experience moving a lathe this big, on its legs. I feel alot happier withthe bed on its own.

Phil says th eheadstock comes off easily. We are less sure about removing the carriage.

Chris.

CovMac Lathe Move - Day One.

As a non-engineer, one who has approached this subject as an historian, wanting to save a piece of our industrial heritage, I think it may be of interest to you accomplished engineers, to see how a complete novice took in his first day as an engineer.

What a day I have had! Firstly, I have not been so filthy dirty since being a child. Crawling around under that lathe in years of accumulated dust was an experience. I will try and post pics of this CovMac soonest. It is in a dusty old environment.

My CovMac lathe is the 13" geared head, as shown on lathes.co.uk but with a 54" bed, and a headstock plinth similar to the bigger 17" geared head model.

Progress:

1) Have removed all four big Whitworth bolts holding bed to legs and tray. Three were not much more than finger tight, one was loose.

2) Have removed back gear guard, tail-stock, gap-bed and wooden pole.

3) Have dropped the banjo, taken three gear wheels out, and loosened three out of four of the headstock bolts - the 4th has a bit of face damage, which I will have to dress with a file; I could not get a socket on it. I will have no problems getting the headstock off, I feel.

Lack of progress:

1) I Cannot yet see work out how to get the tool post off, or the slides.

2) I had not noticed, on my first visit, that this lathe is actually concreted into the floor, both ends, tail stock end more so than the headstock plinth. The bottom of the tailstock legs are encased in a fillet of concrete, about 1 1/2 inches deep. This is raised off the floor, by that I mean the legs are not sunk into the main floor. There is less on the headstock plinth end, more just a skim of screed along one end.

This presents me two problems:

1) Making sure I don’t break any cast iron, on de-concreting the plinth and legs.

2) My inclination is to lift the bed and remove the lathe before tackling the concrete, to leave that to last.

Thing is, the lathe is only one foot away from a wall, and I don’t see how I can get the base struts of an engine crane in far enough.

A bonus for a military historian, like myself, the CovMac was a War Department owned item, still with its War Office serial number.

Well, I am not ashamed of myself, on my first day as an engineer, although it was a bit daunting when I first began.

On the feed gearbox, I can move the gear lever, but the lever to the right of that seems seized solid. The spindle turns, and the lead screw does, too. The apron wheels nicely, and the slide work. There wis nil backlash in the side slide, but some in the compound slide.

Tailstock was a massive, heavy mother, and so is the back gear guard.

The motor is huge, and hangs off a cast iron plate your could tack a battleship to.

I shall enjoy a few beers tonight.

Many, many thanks for all your help, gentlemen. This would have been so much harder had I not spoken to you all in advance.

There will be two more days; firstly, when I remove the headstock, carriage, and take the bed off its legs, and shackle it down to a pallet. Secondly, we move the bed, and finally get the legs out of the concrete.

Any further help and advice will be very gratefully received, particularly on the nexus twixt cast iron and concrete..

Today, well, I did not break anything, and did not lose anything. Phew!!!

Chris

Hello Chris,

I have followed your progress with great interest. Last time I moved heavy things I used a stack of breeze blocks and hefty lumps of timber cut from a 9 inch deep joist.

You say the lathe is close to the wall. Build a stack of blocks, broad faces up, at both accessible ends, against the wall and on the lathe operators side of the lathe. You will then have 4 stacks all laid broadface up. It needs a lot of blocks for this stage.

With good section angle iron, 3 x 3 inch if possible, but not less than 2 x2 laid vees uppermost, use a hefty jack to lift the bed clear of the leg at one end and lower it onto the angle iron arranged as a bridge between a pair of towers.. Repeat at the other end of the bed.

It should now be possible to inch it out from the wall using suitable lengths of 4 x 2 timber for leverage, it will slide quite easily on the inverted vees. Take it out as far as you need to get the engine crane legs in position, with the hook suspended from the point closest to the hydraulic ram and best able to take the weight.

If you are clear of the grouted in legs and the crane is both stable and man enough for the job, pull out the angle irons and lower the bed down onto baulks of 4 x 2 on the floor.

Now it can't move or fall over. Remove all the debris of battle, blocks, angle iron etc to get a clear working area and space to move it across the floor to the loading point.

Stopping swing and pendulum action with ropes tying both ends of the bed back to the crane will help before finally lifting it high enough to get it onto the transport.

Best of luck

Brian.

Edited By Brian Wood on 17/09/2014 18:47:50

Edited By Brian Wood on 17/09/2014 18:49:16

Brian,

Many thanks for that; I will give this lifting and shifting method every consideration. Any thoughts on de-concreting the legs and plinth?

Chris.

Hello Chris,

Use a decent 1 inch wide, 8 inch long cold chisel and lump hammer to chip away the grout, starting about 1 -1.5 inches away from the leg. Don't tap at it, give it some wellie.

Chip towards the leg and step the cut back away from the leg if needed to deepen it. It should come away in satisfying chunks if you work all round the leg. You might also find the leg with the deepest grouting is bolted down to the floor. If you can't shift the bolt head with a well fitting ring spanner, belt the head end, using a brass drift to protect it from bruising and try again. The shock may well have 'sprung' the thread .

If the installation is old [WW 2] the bolt head may be leaded into the floor, it was the practice in those days.

If all else fails, hacksaw off the bolt head or split the nut depending on what you find

Regards

Brian.

Edited By Brian Wood on 17/09/2014 20:08:21

Hi Brian,

I am happier, by reading this advice. The lathe was put into position in the early 1990s, we believe. It looks very ad hoc, and I will be surprised to find it bolted down, too.

This was an old boy, and I don't think he considered the lathe might survive him, and be worked. It has, and it will.

Whacking the 'crete hard, rather than tapping, encourages me that I will not shatter cast iron.

It is good to talk to real engineers. I feel welcomed.

Best.

Chris.

Brian,

Just to clarify: We are agreeing that concrete does not have the tensile strength to break cast iron in which it sits in contact, when shattered by a cold chisel?

Best.

Chris.

Removing concrete - If you are at all worried about breaking the cast iron you could drill a few holes with a masonery drill in suitable places, often the concrete will just break up in lumps.

Hello Chris,

That was the reason I suggested starting the breaking up of the grouting spaced away from the legs; it gives the grout space to move without affecting the leg. I don't know if these legs are blunt sided as in a block, or radiused over. You say one is deeper into grout than the other, so start on the easy one you can see most of!

I think the fill is most likely to be cement rich rather than concrete, it puddles in easier and is weaker without the pebbles content, but of course that might not be the case here.

One thing I didn't make clear was to chop down on the grout, angled only slightly toward the leg so that the energy is directed into the material rather than sideways into the leg. If you get a good channel going you can vary the routine by chopping along it parallel to the leg. If chopping parallel to the leg doesn't start break up the fill at first, try varting the action with the chisel tip at right angles to the leg to promote cracking in the other direction. You might find the leg itself gets in the way of hammer action, try from a different spot in that case. If it is really hard work a series of drilled holes with a big hammer drill will give you a start, once you have a section chopped out you can exploit that and use the broken edges to continue.

Don't though let the chisel impact the cast iron, that way lies trouble. Put props in place to stop the legs falling over as the grout clears, certainly so if there is no bolting down.

Again, good luck

Brian

Brian and Gordon,

Many thanks. I am trying to upload some pictures of my CovMac, please bear with me, while I work out how to do it.

Chris.

Even cheap carbide tipped drill bits will munch through concrete nowadays

You might save a lot of sweating time by drilling instead of hammering

A decent drill will have a hammer action for stonework

Edited By Ady1 on 18/09/2014 09:54:32

There is a visual of my CovMac lathe, still concreted to the floor. Beneath the grime of years, I think it is in good shape. Needs cosmetic attention, and a thoroughly good clean.

Chris.

Hello Chris,

It suddenly occured to me today that when you have the lathe bed supported by the engine crane, you might find the bed is long enough to bridge the wheel forks, in which case I would be tempted to lower it onto those, retain some tension on the crane to ensure it remains upright and use ithe crane like a wide wheel base trolley.

It will save all the lashing etc I mentioned earlier. I am also inclined to recommend the hammer drill route to break up the concrete, in preference to my earlier suggestion.

Looking at your pictures, it IS a big beast isn't it, but I'm sure it will sparkle in a new home

Regards

Brian

Hi Brian,

Much appreciated. I think, actually, I have at least 18 inches from the centre of the lathe bed to the wall behind it. I reckon that is going to give me room to have the engine crane go in on its one ton setting.

With the back gear cover, headstock, carriage, tailstock and gap bed removed, I don't reckon that bed on being any more than 1/2 ton.

I am going to practice with the engine crane, firstly by removing the headstock.

Agreed on the drilling - I think it safer. I think the base of the legs has a sort of a curl on it, too. Better to go easy with a drill.

I am quite determined not to break anything in this move. I love this lathe.

Best.

Chris.

Is that piece of wood a roof support? I want to go there and tidy up! I looks like he has lots of interesting bits and bobs I could put to good use.

Phil

Phil,

The wood strut is indeed holding up the roof. It is to be replaced by a scaffold pole before the CovMac comes out.

There are a million useful looking bits and pieces.

It includes five chucks, but some are rusty. How rusty can a chuck get before it is past renovation?

The fixed steady, a wonderful piece of artwork, has one every rusted (solid) screw - how best to deal with that?

Chris.

.

Chris,

I have generally had success using Plus Gas

... Buy a 500ml tin, not the aerosol !!

The MSDS does not reveal the exact ingredients, but it seems to be broadly in the Kerosene family.

First; make sure that the thread "interface" is clean [i.e. not blocked by paint/dirt/grease] ... Pick out the debris with something like a scriber point ... then apply a small quantity of fluid as a neat fillet, with the bolt vertical.

Then let it stand ... With luck, the fluid will get into the assembly by capilliary action and that fillet will disappear.

[whereas, if you just soak the whole thing in fluid, you will have no way of knowing]

If it doesn't seem to be getting in, try applying heat with a gas torch, then [having killed the flame] apply more fluid whilst the screw is stll hot.

If that fails; you will probably need to drill it out

MichaelG. ... [following your exploits with interest]

Edited By Michael Gilligan on 19/09/2014 08:33:43

Edited By Michael Gilligan on 19/09/2014 08:35:52