Member postings for Cedric Norman

Howard.

Michael's comments are correct. It will be helpful to know that the mod you both are talking about have already been outlined in the Model Engineering Workshop. The slow speed adaptation is in Issue 118 and in Issue 119 there is a reverse threading gear. A tumbler gear with a lever would be easier to use than a fixed gear and there are ample examples on the internet to use as a base. The issue with the screw-cutting on this lathe is that the leadscrew engages on a hex bolt head, so if you disengage the leadscrew there is no easy way to ensure you pick-up the correct point. This would negate the use of the tumbler when screw cutting as you can not ensure the gears re-mesh in the exact same place. The solution I developed uses a single dog clutch and constantly meshed gears so that the drive can be interupted and re-engaged without concern. Presumably, if you do not interupt the gear train (ie. use a tumbler), you could set the chuck in a given orentation, with the saddle in a specified position and the clutch should re-engage in the correct place. This concept might be OK if you are turning the chuck by hand to cut the thread.

Cedric

I agree with Carl. I enjoy making things, be it a model steam locomotive or mods to my lathe. There has to be a balance so that I can focus on what is important. Likewise, I have been priveledge as a machinist to have used machines across the spectrum, having trained at the locomotive works, but also worked at Rolls-Royce aero plant, so I accept that to get the best result, the best machine is required.

The point I am bringing across, is that I could afford a Clarke lathe and have found it great for my model making. I do not want to put down people who can afford better equipment (I would love to drive a Rolls), but I want to encourage others like me who can not afford expensive equipment. Theses lathes can do a really good job and enhancing them can be a way of getting better.

Carl, I look at the more expensive lathes at exhibitions with yearning, but I am pleased with what I have. When I look back and think of what I could not afford to buy 40 years ago; I am pleased to have my lathe.

One thing we should agree on is that the lathe is a tool to achieve a goal.

A final comment was that my dad always told me when buying tools to buy the best you can afford! I still use tools that I have inherited from him.

This lathe provided at competitive option to the Myfords and more expensive industrial lathes when they first came on the market. Most of the adaptations are done by owners to improve their lathe and apply equally to more expensive lathes.

The fist addition was a digital scale on the tail-stock, cost around £5 to £10. You can use an old 150mm digital calliper. It makes it easy to drill to depth as you can zero the scale when you start the hole.

The addition of a similar, but longer scale on the length of the bed cost around £60 and makes turning to depth a lot easier and accurate. I still set the dial on the hand-wheel to zero at depth, as this is easier to wind to on repetitive cuts.

The collars to reduce backlash are just more accurately turned pieces of steel bar to replace the existing. You will always have some backlash and this can be overcome by winding back 1/2 a turn and feeding in. Cost pence.

The reversing gearbox for the lead screw was based upon the article in Model Engineer Website
**LINK**
The cost was negligible using bits of steel plate and bar I had in stock. I made the gears using a home-made fly-cutter.

The motor unit was around £400 at the time. It gives infinitely variable speeds and saves belt changing. Having said that, there is nothing wrong with the original system which is just as good as any others out there that uses belts and gears to select a pre-determined speed. In industry there is always a need to save time, but the home model maker should not be bound by saving seconds in the same way.

This mod led to me buying a Digital Speed Display off ebay. Cost around £7. Again useful with a variable speed motor, but not essential. 4-Digital-Red-LED-Tachometer-RPM-Speed-Meter-with-Hall-Sensor

These enhancements in no way compare with the cost of an more industrial lathe which in the main have 3-phase motors, which can be adapted to work with domestic supplies, but at an extra cost. Yes they offer screw-cutting gearboxes, but in the main taps and dies are used, and you can achieve good screw-cutting results on the Clarke lathe using the change wheels.

Personally, my lathe which in total has cost me less than £1000 including the enhancements does a great job and fits in a hobby workshop. The motor is a nice to have, but not a game changer. If I had unlimited room in the workshop and my bank balance I would no doubt buy a nice expensive lathe, but the parts made on it would be no better and still depend on my skill in the use of the tools at my hands.

It is good to have different views on lathe solutions, but be it a Mini or a Rolls-Royce, it does the same job.

Cheers Cedric

Edited By Cedric Norman on 03/10/2016 08:24:03

Edited By Cedric Norman on 03/10/2016 08:27:30

I bought my CL500M off ebay about 20 years ago. Initially I used the milling head, but have invested in a small vertical mill, so removed this and put a cover plate on the headstock.

I fitted a motor an control unit, pre-wired CL750 by Newton-Tesla in December 2012 to my Clark CL500M. It is much quieter than the original motor and I am delighted by the flexible speed range. The motor pulley fitted straight onto the shaft so all I had to make was a new motor mounting plate. Change belt ranges gives quite a choice of speeds. I generally run on the small motor pulley to the large spindle pulley which gives me 75 to 1000 rpm.

It was an expensive Christmas present to myself, but I have no regrets and it would be high on my list of things to do on a new lathe. I chose the Newton-Tesla because all the wiring work is done for you.

The improvements I made:

1. Lapped in cross-slide as the machine was 2nd hand
2. fitted DR scales to the lead-screw and tailstock.
3. made a QC toolpost which is a boon.
4. made a new collar for the cross-slide to reduce backlash and a new collar with needle thrust bearings for the leadscrew.
5. built a reversing gearbox for the lead screw so that I can power feed in and out of bores and cut LH threads if need be. It also engages at the same point every time for screw-cutting. This was based upon a design off the internet.
6. fittted a digital speed display, bought off ebay complete with magnetic sensor. It is 12v and easy to fit.

It has been a great little lathe and is very capable of accurate work.

Cedric.

I bought my CL500M off ebay some 15 to 20 years ago and it came with only one belt. I remedied this by buying a 10 x 914 for the motor to the spindle and two belts, 10 x 584 belt from the motor to the idler / 10 x 560 belt from the idler to the spindle.

The pulleys look correct on your machine. There should be a small pulley on the back of the motor set, which is connected to the large rear idler pulley when in use. This allows you to get 3 x low speeds by moving the idler to top belt on the front three grooves. The high speeds are gained by taking the drive directly from the motor pulley to the spindle pulley, and once again this gives you 3 speeds using the same 3 grooves.

This is illustrated on page 17 of the manual, which can be downloaded from https://www.clarkeservice.co.uk/manuals2/cl430M.pdf

I bought my belts off ebay as they were cheaper, but did get a couple of replacement gears from Clarkes, who gave a good service.

I made a couple of C-washer/spacers to fit onto the belt tension bolt at the back of the lathe; this made changing belts a lot easier. It saves screwing the nut up and down the thread.

Fitting a 1HP variable speed motor has enhanced the flexibility of the lathe and means I seldom have to do belt changes any more.

Daryl

I have a 10 x 560 belt from the idler to the spindle. A 10 x 584 belt from the motor to the idler and a 10 x 914 from the motor to the spindle. These may not be the original sizes as I bought it 2nd hand and sourced my own belts, but they work.

You may like to see the modifications I have made to my Clarke CL500M over the years. It certainly makes it a more versatile lathe and I have no complaints.

http://www.bsa-c15.org.uk/engineering/clarke_cl500m_modifications.htm

Cheers Cedric

I fitted a motor an control unit, pre-wired CL750 by Newton-Tesla in December 2012 to my Clark CL500M. It is much quieter than the original motor and I am delighted by the flexible speed range. The motor pulley fitted straight onto the shaft so all I had to make was a new motor mounting plate. Change belt ranges gives quite a choice of speeds. I generally run on the small motor pulley to the large spindle pulley which gives me 75 to 1000 rpm. I made some interchangeable speed dials that fit over the potentiometer shaft and are held in place by some small magnets so that I can change these if I change pulley ratios. It was an expensive Christmas present to myself, but I have no regrets and it would be high on my list of things to do on a new lathe. I chose the Newton-Tesla because all the wiring work is done for you. Working with Inverters, etc. was not an option that I wanted to mess around with. There is nothing wrong with the lathe and as improvements I fitted DR scales to the lead-screw and tailstock. Next I made a QC toolpost which is a boon. Then I made a new collar for the cross-slide to reduce backlash and a new collar with needle thrust bearings for the leadscrew. Finally I designed and built a reversing gearbox for the leadscrew so that I can power feed in and out of bores and cut LH threads if need be.

Edited By Cedric Norman on 27/04/2014 15:51:32

Are the Ayesha II articles available throught the Digital Archive Subscription?

I intend building this model and would dearly like to read up on this before setting out on this project.

Thank you in advance
Cedric