Fusee Turning and Groove Cutting on my MYFORD

Having never turned a Fusee for a clock previously, I wanted to look into it before I made any attempts.

I noted the two methods used by John wilding, and did not like them as I wanted to use a chain for drive not a twine etc. Therefore I needed a precise method of cutting the groove for the chain, maintaining constant depth.

I decided to adapt my taper turning attachment, replacing the sliding guide block with a fixed but adjustable radius cutting guide.

I was very happy with the result, here are some photos to show what I did.

1 Showing popular clock designed by John wilding

2 The dimensions of the fusee from the book by John wilding.

3 Cutting the dovetail to mount the block onto the taper turning attachment.

4 Cutting the radius for the roller guide.

5 Setting the attachment with the dial indicator.

6 Showing the first few cuts of the fusee

7 A overhead look of the cutting process.

I have not cut the thread as yet because I have a fusee chain of 54” long, but I do not think it is long enough, I still have to find out the actual length, so if you have made one I would like to know please.

Noel,

That's very neat. I shall file that use of the taper attachment away for future use.

Thanks for sharing.

Rod

Photo from above, now right side up....

Overhead view of turning process

How are you going to cut the groove?

That's very neat and ingenious.

Neil

Neat implementation of what is essentially a simplified mechanical version of the hydraulic copy units found on industrial lathes.

Of course what one really needs is a Myford Mini-Kop, anyone ever seen one?

I would imagine that the groove would be cut by normal screwcutting methods, but with the cross slide following the template. That's how I plan to make the BSP tapered threads on the blow down plugs for my traction engine boilers.

Andrew

How about using a milling spindle mounted horizontally on centre height, and a ball end mill. That way, you should be able to use your taper cutting method and template and achieve constant depth while 'screwcutting' using a spindle-mounted handle to turn the spindle and gearing slowly enough to suit the end mill.

Marcus

Hi Noel,

Although I’ve only built one clock, there are clever people who contribute here that will offer you a great deal of help.

However, I can’t resist mentioning that the 2” radius nominated for the fusee  does not compensate for the variation in spring output (Mr Wilding’s shows 2.2” radius). If you are looking for good timekeeping, you may have to carry out some torsion test beforehand.

You can see from my crude graph(s) at the bottom of this page the sort of variability which resulted.

**LINK**

By the way, I used a similar cam approach on my ML7, by way of parts from the taper turning attachment.

On the same page of photographs, you can see that I first used fishing line (yellow). It broke after three years, so I replaced it with twisted steel.

A chain would look even better.

If you are a contributor to Model Engineer, I wrote a seven-part article about building John Stevens’ skeleton clock.

It commenced with #4526 dated 22^nd Jan 2016.

Good luck,

Sam

Edited By Sam Stones on 11/06/2018 01:28:05

Hi Sam,

I just had a look at your Clock, very nice.

Thank you for the posting, I thing it will be my next clock.

I will check to see if the book is still available.

Thank you

Noel

Hi Noel,

Those were quick replies.

I'm only too pleased to help where I can. Especially having so much help from others on this site.

John Stevens' skeleton clock article commenced in Model Engineer in Jan '72 and ran for five editions. I started cutting brass for it in about '73.

However, I haven't seen his article in book form.

Regards,

Sam

Any curve can be cut with this method.

With a fusee this is my first try, and I know the radius is only an average of the correct curve.

With this method, the true curve of the fusee (Or any other curve) can be calculated.

The pattern can then can be reproduced with the aid of a CNC machine, put on to a lathe (Myford)

and cut exactly the way the calculations show.

Cheers

Noel

Nice job Noel. I wonder if the pattern can be 3D printed? Much easier and probably quicker than CNC. Even PLA would probably be hard enough and stiff enough for a limited number of runs especially if glued to a metal backplate. Nylon would likely be better but slightly more difficult to print.

John