Member postings for CHRISTOPHER MILLS 1

Thanks Phil.

Much appreciated.

Electrically, what might I have to do to my CovMac's motor?

Best.

Chris.

Phil,

Many thanks for this: I am so very sorry that you become dogsbody/gofer in this business so often, because you have one of these machines, and I make you run around, but your information is always absolutely worth its weight in gold.

Your combination of words and pictures is film industry standard!

You will get your rewards before you reach heaven!!

I cannot believe a camera can see right to the lower bolts, but there they are!

Interesting to see red oxide paint in the screw gearbox interior.

Good one Phil. Have a great weekend.

Best regards.

Chris.

Martin,

Tried you on your home phone, but got an unobtainable tone. WiIl try later on your mobile.

I will be in Totton on Tuesday, from about 9 am, and I would be greatly appreciative of any help on the day.

I want to try and remove the screw-cutting box, and take away, if I can, all but the headstock and main bed.

Many thanks. Speak later.

Chris.

Dear Martin,

I do not know how to access your message, as it does not yet appear in my box, in this site, or in my gmail account, but I do very, very much appreciate your offer of help in Southampton.

An engineer in attendance, next time I visit, would be like pennies from heaven.

My lathe is in Totton.

Best wishes, and many thanks for contacting me. I look forward to hearing from you further.

Chris.

Hi Martin,

Sorry, but I do not understand your post.

Thanks.

Chris.

Many thanks Phil - it is a very good, stable system. Certainly worked for me.

Partly due your cautions on carriage possibly impinging lead-screw, I am considering taking lead-screw, power bar and screw-cutting gearbox off before the main lift, in Southampton.

That way I can bring gearbox back to London for a winter project. (I will not be going to Yeovil much before the spring). This machine once suffered a major league crash which tore away 25% of an eight inch chuckface, and I fear there may be damage in the box - the seized A - B lever might not be unconnected. Although, I know the gearbox rotates okay, I have seen that moving.

We are reasonably sure lead-screw disconnects via a tapered pin on external attachment to the screw gearbox, and that the power bar is a grub screw or two onto a collar.

The tailstock end attachments are free, and with half nuts disengaged, and power bar in neutral there should be nothing in the apron holding them. I should then be able to with draw both out backwards off the tailstock end?

Only caveat I can see on removing the screw gearbox is that access to the two lower bolts (the ones you cannot see) is limited - I think I have to remove the bottom sump plate, and access those from beneath. My reach there is pretty limited. I only have a couple of inches beneath the box to play with spanners.

If you are anywhere near your own Covmac this weekend, I would very much appreciate any heads up on these aspects. If I do this, I am aiming to shoot for the coming Tuesday. Thanks.

Chris.

Phil,

I understand everything you say, and will act upon it on my next visit. I am unsure the carriage has come far enough left to have actually tipped - I do not think it has, but I will ensure that all of your concerns are addressed. I agree about protecting a lead-screw.

I will be making one visit prior to the day of the big move.

Chris.

The above shot of CovMac's drip tray shows extent of this lathe - the tray is about eight feet long, and made of mild sheet steel. You can see the remains of a pumped coolant system, a collecting tank at the far end, and rising pipe in the left foreground, but those are the only signs left of it. We will likely never know its nature.

Phil - Are there any signs of a pumped coolant system on yours? I know it has the tank.

Below is the lathe bed, minus headstock, awaiting collection. The steel rod, run through the bed's eyehole, was my salvation when lowering the bed, on the crane, when it had a really snakey wish to roll over forwards onto the screw-cutting gearbox. CovMac engineers of 1940 were very thoughtful, putting that handling eye in. I imagine, with lathe fully complete, that this is its perfect balance point, with carriage and apron rolled up to the tailstock end. At the moment the carriage is stuck headstock end, because I forgot I had removed the gap piece, and I accidentally rolled the carriage too far left, when giving it an initial clean-up, and disengaged rack from pinion - no amount of persuading would get it back on again. It is stuck there until dismantling time.

The twin green slings, 2 ton rated, are visible - the left hand one is one metre long, and I looped it basket fashion down through the head casting onto the steel bar through the eyehole; in this manner, basket handle fashion, the sling is rated to lift four tons. (This was a confidence builder).The other, two metres, went around one of the casting's bulkheads to right of centre. This inner method was much safer than looping on the outside, because I would have had to protect lead-screw and power feed bar.

The whole worked beautifully, apart from tailstock rising, and significant roll-over forward impetus on landing. Both were controllable.

We all survived CovMac, me, slings and crane. I have huge affection for this lathe, now. I am beginning to get to know it.

Chris.

Phil,

I am sorry - you are right, for key photos are still on my smart phone, and I have been too tight-fisted to download them, due to Vodaphone avarice. I shall conquer my miserliness, and post the proper photos very shortly.

You Yorkshiremen are very prescient, I know that much! Canny.

The only views I do not have are the main bed in the air, for I was too nervous to take them. Sorry.

I will post when the big lift occurs. We will organise some "right hairy" views, such as to impress even Geoffrey Boycott (Yorkshireman).

Chris.

Thanks Phil - Really, I would not be where I am today without your incredibly helpful input.

On the stuck carriage - the threading half - nuts are disengaged. But the half-nuts lever is stuck solid.

I just could not back-up the carriage enough to get it re-engaged on the rack.

You are right - the engine hoist is amazing.

The price of these rises on eBay, for they were well under-priced at £117,

Chris.

Many thanks, gentlemen.

Neil - It is very most certainly handier than the CovMac!

What is it? What can you make with it?

One pleasing aspect of the CovMac lift, to me, a beginner, was my engine crane.

Now, I am on a very small budget to rescue this lovely old machine, and I have had to do it all myself. (My wife will not help!!!).

The only method of lifting was by engine hoist, and I bought mine on eBay for £117.

Now, for something so cheap, I had doubts, naturally.

Yet, the build quality of it is just great - the main piston is an 8 ton rated hydraulic press, and I have every faith that this thing can lift its rated 2 tons.

It coped with my lathe bed, no problem - and I think the bed is likely 1300 llbs. I did the lift working quite alone, and at no point did I think this crane was other than my best friend.

It was both smooth and predictable, both on raising, and lowering. It really was silky smooth.

It was beautiful!!

Here it goes in on its prey, like a Tyrannosaurus Rex: Grrr -

COVMAC UPDATE

Finally, some real progress on moving my CovMac from Southampton - the job was badly delayed by tailstock legs being deeply concreted into the floor - shown above. Basically, the previous owner had compensated for a fall in levels in his shed by placing its tailstock legs into a broad, shuttered bath of raised concrete. And it was a very solid and heavy mix of concrete. 

I scratched my head, and pondered my own innermost futility, on two visits, messed about with hammers and chisels, and hardly dented the problem.

This was not successfully approached until I had full faith in my engine crane of 2 tons capacity.

Trying to free the legs, with weight of lathe bed still on them was just impossible. Access was very limited, and the drip tray was much in the way. It was not until I had removed the headstock, and came to shackle the crane up for a test lift of the main bed, and I had not to lift the bed by much, to have the sheer weight of  tailstock legs actually free themselves from the ground - (I think they weigh over 100 lbs - I could only just carry them to my car). I tumbled them out backwards. 

This was a great leap forward. I enclose shots of the culprit. Once out of the ground, the concrete was simply knocked off with a lump hammer. It was such a huge problem in situ. It was very easy once out of the ground.

The big move is due next week. I will post many more pictures, when I have them downloaded from my camera phone.

I now have five pieces - headstock, headstock plinth, main bed and drip tray to move.

Lifting the main bed off its legs and down to ground level was, as Phil Whitley predicted, a little bit "hairy" but I managed it okay. It was very headstock end heavy, for I had accidentally jammed carriage & apron near the headstock end, and the tailstock rose three feet in the air above it. 

The crane was magnificent, and the lift was very stable, aside of the bed, when being lowered, wanting to roll forward onto the apron and screw-cutting gearbox. I managed this using a bar through the eyehole under the headstock, and chocking with wood. 

I used twin slings, each of 2 tons rating, through a piece of straight bar in the jib of the crane.

It is a real relief, for a novice, to have it all at ground level. Suffice to say, I have never lifted something this heavy before. 

I have broken nothing on the lathe, and have not hurt myself, either.

Am presently finishing building the necessary pallets to get the big beast out to the road.

All in all, I think the weight estimated for this lathe, on Lathes.co.uk @ under a ton, is a significant under-estimate. 

Tailstock, headstock, tailstock legs, headstock plinth, motor plate and motor are all really massively heavy items.  I am beginning to understand Neil Wyatt's use for it of the word "behemoth".

I think, altogether, that this lathe actually weighs about 1.4 tons.

All input, help and encouragement from you engineers has been worth its weight in gold. I really have appreciated being welcomed into this forum. Many thanks.

Chris.

Edited By CHRISTOPHER MILLS 1 on 12/11/2014 10:39:36

Thanks, gentlemen - I have also heard that cider vinegar is effective, but it is expensive to buy.

I am making my own, from apples on my allotment, but it will not be ready for 6 months.

Chris.

CovMac Lathe resume - 17/10/2014

The big move of the CovMac might finally happen next week - headstock and bed in two parts. I decided to complete de-concreting tailstock legs after lifting the bed off. The fillet of concrete under the tailstock legs is so complicated, with legs two inches off the ground, and with a series of loose bricks, too, beneath, within a very hard, stony concrete mix, caution is the better part of valour here. Access is so limited, too, with lathe bed still in place. Were the legs steel, I would have done it, but with cast iron, I have been ultra-cautious.

In the meantime, I have begun renovating the first piece - one of the original CovMac chucks, circa 1940, (of which I got two with the lathe - plus two more modern Burnerds, smaller) a big, heavy four jaw.

Any advice as how to do this job best will be gratefully received. I attach two pictures showing interior and exterior. This chuck was quite diggered in rust, when I got it. So far, I have just liberally doused it in WD40 - three of the jaw screws now move a bit, fourth is still solid. Two backing plate screws are now loose, two solid.

I need engineering input as to application of heat on a chuck - I feel this might need a bit to free all threads. Might I spoil a chuck's temper by heating it, or over-heating it?

The chuck reverse, or interior, shows original CovMac paint colouring, a dark grey. I will restore the lathe to this colour. I think it might match Paragon enamel Colchester dark grey raven. I have some flecks of my original to send to Paragon, to get a good colour match.

I presume this is a non-scroll chuck, with independent chucks? What is the faceplate on the back going to reveal beneath it?

Apart from one chip which has come off part of the stepped jaws, bottom left in the picture, I can see no obvious damage - just a lot of rust and oily crud.

Many thanks.

Chris.

Edited By CHRISTOPHER MILLS 1 on 17/10/2014 08:51:35

Edited By CHRISTOPHER MILLS 1 on 17/10/2014 08:53:51

Second revisit to the CovMac:

4th Headstock bolt is now free, and the head is loose, ready for removal - I have secured it on two headstock bolts, because left loose it will topple off backwards, being very back heavy.

Plinth is de-concreted, but tailstock end is harder: Beneath a concrete fillet lies a series of loose bricks - the tailstock end is higher, and the lathe's feet are about 2 inches off the floor of the shed.

The lathe will have to be jacked at that end before completing it. I did not want it to drop two inches by overdoing it.

Motor and mounting is very inaccessible, still, because the lathe is so pushed up against the wall - that will be tackled when I have the headstock removed, hopefully some time next week.

I have removed all loose stuff, four spare chucks, and half a ton of cutting tools and assorted goodies, and a lapping plate. 

In the meantime here is a picture of the CovMac's clutch in more detail:

What is in the clutch mechanism? What can I expect to see?

Under the top cover there are five vee grooves on the pulley wheel. The clutch is really quite big. I have disconnected the two vee drive belts from the motor.

The lathe was reconditioned by the same firm which did Phil's; I.L. Berridge of Leicester. Mine was renovated by them in January 1955, using the same reference number as the War Ministry allocated the machine. There were comprehensive Machine Tool Orders in the Second World War, regulating use and ownership of machine tools. 

Chris.

Edited By CHRISTOPHER MILLS 1 on 06/10/2014 14:33:11

Edited By CHRISTOPHER MILLS 1 on 06/10/2014 14:34:14

Edited By CHRISTOPHER MILLS 1 on 06/10/2014 14:35:00

Neville,

Many thanks; the overall vote is for sling ties. Phil was demonstrating positioning with the rope. I can see how important it is to have the lathe held very tightly on the initial lift.

The more I looked at chains the more I found it hard to imagine protecting the lathe from them.

Chris.

Brian,

There are no bolts in the plinth end, as the holes are on the outside of the box, and empty. I shall be surprised to find floor bolts in the tailstock end, but on Thursday (my next trip to Totton, Southampton), I hope to prove it.

There is no power at the property, so I will be armed merely with hammer and cold chisel.

Chris.

Thanks gentleman, this sounds a very good, comprehensive and cunning plan.

From the general state of the lathe, I would be extremely surprised to find anything stuck up by paint.

I like the idea of not having to lift the lathe higher than it is, but just to lower it. The three point fixing looks sterling.

Where can I buy a rope like yours, Phil, strong enough to lift it?

Chains are horrendously expensive, and look like capable of easily damaging the lathe.

Brian - I believe spindle bearing on the head is 3 Mt - tailstock 2 MT - according to Tony of Lathes.

I would send my chauffeur up to pick you both up, but with the late recession I had to let him go!

Best.

Chris.

Many thanks Brian - I still have the option, though it will increase time pressure on the day, of de-concreting legs after the bed is lifted off.

Presently, nuts holding plinth and legs on are all off. I could replace them.

Almost certainly, the chip tray is presently a loose item sitting heavily sandwiched between bed and legs. There would not appear to be any other attachments aside of the four bolts, which I have removed.

I could de-concrete headstock plinth, but leave tailstock legs in their fillet of cement until the bed is moved?

That sounds a safe way of managing the tray?

I agree, the tailstock legs are a bit delicate looking, and Phil said his flexed alarmingly when he was moving his CovMac.

Chris.

Having thought this through a bit more, I am now sure you are both right, that the lifting chains need to be at the headstock eyehole, and at the end of the tailstock end of the bed. Then the weight will be better balanced and manageable.

Many thanks.

Chris.