clarke cl500 improvements

In the lockdown I have implemented some of the mods collected over the years. I bought this lathe secondhand more than 25 years ago, and although it has a poor reputation, it has served me well as a bench top lathe. I can now afford something 'better', but it's capacity and familiarity have always won through. The controls lack a quality feel, but accuracy has been fine; yesterday I clocked run-out on the three jaw (using a ground bar) at 0.0003 tir, which is pretty good I think.

Some years ago I fitted a VFD, which solves the problem of a minimum speed which is too high, as well as giving a smoother, quieter drive.

First is an extended banjo to permit l.h. screw thread cutting. There is room for an extra gear to reverse rotation of the lead screw. I needed this to make a new screw for extending the travel of the tailstock barrel by 25mm. Next was a cycle computer to give me rpm. The display shows kph which, with a wheel circumference of 1667mm, is an analogue of rpm.

Last is a reversed tailstock. This is possible because the bed is flat and the barrel is on a through bore. It substantially improves reach over the saddle, but requires the barrel clamp to be moved to the other end, which requires a block to be bolted in place, and boring of a 25mm through hole.

I made one vast improvement with mine, some time ago - I ‘put it out to grass’ and replaced it with a Raglan Little John.🙂

The Raglan Little John is a superb lathe only parted with mine when I treated myself to a Myford 254 just before retirement

+1 for the Raglan - I've got 2 versions, a gear change set and a gearbox model, also a Loughborough (currently being rebuilt). The other lathe I have is a Emco Maximat Super 11, mainly because it came at the right price and because it is a metric lathe. Somehow the Raglan is the go to machine for me though.

Nice work John - shows what can be done. I too have a Far Eastern lathe, the screws don't have the silky smoothness of of a Raglan, but I can turn to a couple of tenths if I need to.

Three tenths with a three jaw is indeed pretty good!

Robin.

Three tenths with a three jaw is indeed pretty good!

Cutting concentrically with a 3-jaw is clearly no problem - as long as one does not remove and replace the work-piece.

Mine was likely more like 5 thous, but so much that I never actually measured it. Re-chucking a part was simply out of the question, unless dims were unimportant (most of my parts were of that type 🙂 ). I don’t think I ever needed to get near to three tenths on anything I made.

Back then, the 4 jaw did not get much use. These days I use a 4 jaw more often than a 3 jaw.

Robin, perhaps it was a bit naughty to post the three tenths figure, but it was a true single reading. Having re-chucked a few times, the repeatable figure is in the range 6-8 tenths of a thou. Some people have clearly had a bad experience with this lathe, and manufacturing quality may well be patchy so some caution is probably advisable. I think my lathe was made in Taiwan, a country quite capable of quality work, but I suspect standards slipped when production first moved to China, though it may be better now.

My reason for posting, and admitting my ownership of an unfashionable machine, is that it can, as you confirm, turn out good work and be adapted to do better. I have even used the mill, before getting my Naerok; it is not a Bridgeport for sure, but for a hobbyist with not much room it can, with care, be made to work. In any event, the cross slide is slotted X and Y, so a milling vice can be fitted. What a pity a little more care was not taken with the detail.

You have made several useful improvements to what is, as you say, an unfashionable machine.

However the comparisons that have been made must surely be meaningless - comparing your lathe, available new for £1200 (or £1400 with mill drill) with one that went out of production nearly 65 years ago to be replaced by a model its manufacturer felt was better means condition and wear and repairabilty must be more important. Also a 'Little John' at 50% more expensive than a Myford in 1966 would retail new today, if still in production, at something like 8-10 thousand pounds.

Edited By Nick Clarke 3 on 04/07/2020 11:54:48

Great stuff John.

It's a nice feeling when you modify a machine to make it work for you.

I have a Chester Mini Lathe which also get a kicking but you can't beat them for the money.

The mods I have done are to make it more like the machine I want not because there was anything wrong with it.

The Great Sage SOD was saying £20K for a model engineers lathe with all the bells and whistles but who would pay that much money out?

Cheers Michael.

Hi John can I ask what size and make is the quick change tool holder. thanks

Bri

Toolpost is a model 100, as sold by Arc, Warco and others. I recall it was a straight swop, but they can probably confirm. Bought on offer at the MES from one of the big traders, with 4 holders. Tool capacity is 14mm. Best thing is the ability to set tool hieght without shims.

I have one of these machines and love it. The mill head needed stabilising as it used to drift around it's pivot but fitting a locating plate and locking bar resolved that problem without compromising access. I've also made a revolving stop bar for easy repeatability on small batch work. This meant reversing the position of the feed lever which was easy to get used to.

Other mods include a reversing gear for left hand threads for repairing one of the four jaw chuck jaw screws after accidentally over tightening it. And re making some drive gears after my son managed to smash the toolpost into the chuck when pratting around with it when I was away on holiday. I've also made some larger drive gears for an extremely fine feed for a job I needed to do.

I use it mainly for hobby work now but also for repairs to equipment for the school I work in. Take care of it and it runs well with a more than reasonable accuracy and repeatability.

Great machine for limited space and comparatively low cost.

I to have a CL500M, I use it regularly and have bought a VFD to improve the machining speeds, its the first time I've read this thread and it annoys me that the first post after your lead wasnt well done nice work but somebody with the need to knock a perfectly good machine, I like your mods and have a few I've collected, one in particular was to replace all of the gib strip adjustment with longer grub screws so that I could fit lock nuts as I found that the gib strips would come loose, I have made a a drawbar so that I can use an MT3 ER32 chuck in the headstock.

Martin P

I to have a CL500M, I use it regularly and have bought a VFD to improve the machining speeds, its the first time I've read this thread and it annoys me that the first post after your lead wasnt well done nice work but somebody with the need to knock a perfectly good machine, I like your mods and have a few I've collected, one in particular was to replace all of the gib strip adjustment with longer grub screws so that I could fit lock nuts as I found that the gib strips would come loose, I have made a a drawbar so that I can use an MT3 ER32 chuck in the headstock.

Martin P

A friend has a CL500M which recently developed an oil leak. With spares apparently 6 months away, He decided to fit a standard, easily available 65 x 40 x 10 lipseal. The original arrangement looked pretty crude to me, anyway.

He provided some 4" dia Ali and I made up a housing for it (By now, the original Bakelite housing had cracked )..

Once lockdown eases, he will be able to collect and fit it., to be up and running again.

Howard

john halfpenny:

Congratulations on your improvements!

Reversed tailstock: would it have been possible instead to extend the nose in standard orientation? I'm not an owner and appreciate the question may be misguided but my curiosity was aroused.

I think you could ega, but the tailstock screw is M12 left hand, so you would probably need a left hand threaded barrel extension. I didn't give it much thought because I also wanted to optimise barrel travel, for which I used a slightly longer piece of LH M12 studding, commercially available at low cost. The method I used did not require any extension to the tailstock housing, and the existing barrel was unmodified, but I guess several approaches are possible. In my case the dro scale eats up a little of the gain. These lathes are really very capable, lacking only a half nut on the leadscrew - but the Warco version has that feature.

I have heard a lot of adverse reports about the Clarke CL 500 M.A friend of mine has had one for 30 years. Contrary to many naysayers, it is an absolutely cracking lathe. Very smooth in operation and very accurate too. My friend has made some of the upgrades mentioned above and made it even better.

I don't doubt that there are many CL 500 M clunkers around, but this particular one is brilliant. I suspect it was a Taiwanese version being at least 30 years old. It was bought second hand and when it was tried by my pal, he snapped the hand off the seller, because it was so good!

Just goes to show that lack of quality control can actually produce a good one every now and again.

Andrew.

Deleated.

Edited By Andrew Tinsley on 08/12/2020 13:29:53

A "most ingenious paradox!"