A newcomer writes

I began clock making in my late 80's and am truly hooked. Having gained my rudimentary engineering experience with steam, (Minnie traction engine etc), I embarked on John Wilding's Ornate Skeleton Clock, which is now happily ticking away and keeping reasonable time, though I can't get it to run seven days, six at the most.

I then tackled JW's Congreve Clock but am struggling to get a balance between sufficient torque to turn the crank and sufficient tilt to run the ball. The one compromises the other. I’ve fitted the strongest spring I could find and sometimes it runs for several minutes, but not reliably.

My current project is Peter Heimann’s Regulator Clock, and have finished all the machining. I’ve yet to try out the dead beat escapement. We shall see!

Any helpful suggestions would be welcome

Edited By Greville Ferry on 08/03/2014 16:21:09

I'm also a 'clock mant'ler' and member of Epping Forest Horology Club. An aquaintance at the club recently completed the JW 'Large wheel skeleton clock' which suggests that the pendulum be suspended on silk thread. My friend originally used fine man-made embroidary thread but was slightly disappointed when the clock only ran for about 5 days before stopping. Later he disassembled the clock for final finishing and upon re-assembly used fine Chinese silk threads (4) as specified.......We were very surprised when the clock ran for 12 days per winding and have come to see that the silk is less prone to friction than otehr materials and thus allows the clock greater endurance.

Congratulations on your nice skeleton clock which particularly interested me as I am currently designing my own clock based on this design.........

Edited By Bob Stevenson on 08/03/2014 16:52:42

Hello Greville,

Welcome to the forum. I can't help with your query as I have no experience of clockmaking. Hopefully someone who can help will be along soon?

Neil

Greville,

I think it's probably fair to say that the Congreve Clock is best seen a a decorative item.

Lovely idea, but horologically hopeless.

You might find something of interest here

MichaelG.

Running time is dependend on spring length, there is a optimum spring length given a barrel diameter. Either longer or shorter will give a shorter running time.

This is a calculater for spring length http://www.m-p.co.uk/formulae/sprlen.htm but for me it is only a indication since it is not very accurate. No doubt someone will have a more accurate formula but I have not found it yet and are left with experience and trail and error. Niko.

Its interesting to read that Silk strands are used as a suspension strands on the clock, a few days ago i watched a video showing the relative strength/toughness of silk compared to steel. A thin sheet of steel plate had a bullet fired at it and of course the bullet went through the plate. A wad of silk was then made up equating to the same weight as the steel plate, this came out to about 25mm thick. A bullet was then fired at it and it bounced off the wad of silk ! That shows how tough the silk is, mind you walking about in a silk bullet proof suit would make you look like Michelin man. It also shows the strength of silk strands.

Clive

Balancing the torque with tilt is one problem with the Congreve among a litany of others. In my experience, the situation can be improved by changing the ball size. Wilding calls for a 7/16 in. diameter but I found that I couldn't get the clock to perform until I used a smaller ball (13/32). Any ball bearing supplier can provide individual balls in any size as these are manufactured to great precision. The unfortunate thing is that they are not usually available singly but packages of 10 or twenty are reasonably priced. The choice is between having a ball that is too heavy to lift and too light to release the detent. Good luck.

Bob

Hello Grevelle. I too made the JW Concreve clock many years ago and although I can't recall just how much trouble I had in getting it going. It ran quite well and kept good enough time for it's type. This was stored for some years and when it came to light again I just couldn't get it going again.

I really don't think you have a spring problem. Surely It' just all revolves around the crank and associated parts. And I find the book a bit wanting in this respect. We should operate with the connecting rod vertically but this douse not allow the table to tilt enough in one direction so the adjusting piece must come into play and then this puts the rod off vertical. But the more angle that the adjusting piece is put at. the less likely is the table to turn over nicely. I find that a shorter con rod gives a nice positive action but not enough slope to get the ball rolling.

If anyone out there can help this old boy with measurements of crank radius, con rod length between holes and angle that you have the adjusting piece it would be much appreciated. I just wish that I kept the original rod before I started fiddling with it again I might have been off to a good start.

Although I say it myself the clock is very nice to look at and is on a Teak plinth and wrought iron scrolled stand. I aught to take a pic sometime.

Come on the Stephen, pics wanted!

neil

Neil. I'm sure the pics would not be such a problem as getting this clock going.

Thanks for looking. I'll get the camera out shortly. Stephen.

Well Stephen

You certainly have my admiration for making one. I find it has a certain hypnotic quality and I'm pretty sure that OWNING one would drive me nuts!
I would still like to see a photo though ( but preferably not a video)

Norman

Neil / NJH. I seemed to have talked myself into providing photo's. I can load pics into my lap top but can you tell me just how I can actually physically then transfer pics from this new fangled gadget so that you can see them. I don't see any lead for doing this. Thanks Stephen.

Welcome Stephen.

To add photos to a post you first need to make your Album to contain said photos and then as many folders as you wish.

Go to the top horizontal green bar and you will see a button labelled 'Album', click on it and just follow instructions.

To add photos to a post, click the camera icon along the top of the text window and it goes automatically to your Album, choose the folder that contains the photo and a list appears, no details of said photo are shown, so you need to select each in turn so it's shown in the rh panel, then click the 'OK' button once the one you want appears and the photo miraculously appears where you placed the curser in the text entry window.

Geoff - Hope that doesn't make confusing sense

Thanks for that Geoff. Of course I had a Grand child looking over my shoulder so that I didn't make a complete mess of it. They say we are never too old to learn. But I sometimes wonder.

Regards Stephen.

With regard to the Congreve problems. I have experimented further with the table turnover and have done away with the lower pivot at the moment. Replaced the pillar to take the 10 BA screw at the conn rod small end and assuming that we get a better turnover with a vertical conn rod I have made this 7 3/16 hole to hole with the crank at 9 /32. This gives an even turnover with the distance between the top edge of the tilted table to the base plate 13/16.

I still have a problem with torque. And perhaps Greville can advise me about getting a stronger spring. If I apply just a little finger pressure on the great wheel it helps the turnover in the one direction that's a problem. I've put more clicks on the barrel than JW suggests to no avail only to find that the spring gives a shudder within the barrel as it re adjusts so I'm wondering if I'm getting an even power from the springs entire length.

I find that I need a weight on the left end of the table to compensate for the conn rod etc. Without a ball on the table and releasing the detent the table will turn perfectly. And with the ball on. it turns over on the right hand release but I find with the added weight of the ball plus the weight it just refuses to turn at the left hand end. I will certainly try a smaller ball and thank Robert for suggesting that.

With the table slope at the 13 /16 measurement and keeping things running with that finger pressure. Using a stop watch I've got the rate spot on. I'm just wondering if the smaller ball size will alter that. Not ready to give up yet.

Edited By Stephen Spice on 21/12/2014 18:19:24

I have built three of these fascinating machines, the first I did as a test piece for my CNC setup, I subsequently built another two for friends, although I did deviate from the original plans on all three, I actually made the main table from solid, and machined the back out to remove weight from one of the tables as an experiment, this made no noticeable difference, I also experimented with differing sizes of ball, I eventually settled on 12mm dia, one other thing I did alter was lowering the tip on the inside edge at the turn, if you look careful the ball lifts on each turn very slightly, at one time I had all three running in sink for over an hour, but only once, its was mesmerising watching them and listening to the ball clicks in exact time, the longest one has ran continuously is 4 days, with a clean table and ball they will keep time to about two minuets per day, but are better described as novelty clocks rather than time pieces, they do look good.
Never had problems with power, and did you clean and oil the spring??


Shaun

Ill put some pics im an album later if I get time!!

Pics added.

Edited By Involute Curve on 21/12/2014 19:53:35

Well Shaun. Three Congreve type clocks. Did you receive some sort of bravery medal for that ?

Yes I did clean and then lubricate my spring. But you got me thinking and as my clock was built some thirty years ago I thought I'd get it out again and have a look at it. I couldn't actually detect any oil still on the spring its self but there was oil still in the barrel. These springs seem to be made so well and have so close a fit on the coils that it looked to be quite dry.

Can't remember how I did the job all those years ago without a winder but this time with a full face shield and leather gloves I wound it on the lathe in slow back gear. That was the easy bit but getting it back in the barrel was a bit more tricky. Apart from oiling the whole length it's got some more oil by capillary action so now I'm looking forward to trying it all again.

When first run. My clock ran well until the fuse was clear of line. Thanks. Stephen.

SHE'S UP AND RUNNING.

I did actually have a torque problem but not in the way that I thought. And am rather ashamed to say that I didn't fully understand John Wilding's instructions regarding setting up the spring. My previous experience only with weight driven clocks. I've gone over the book time and time again and still think it could be a bit better for the beginner in clock making.

I've obviously done just what John has said. But if it helps any one else with the torque and turnover problem leaving out the over wind stop which in my case was ok. With everything in place I filled the fusee with the line and then slipped the free end into the barrel slot and winding a few clicks on the barrel to hold the line in place and with the detent off the train starts to work. I then put on about 12 clicks to really get things going and not letting the movement race away too fast the line is now transferring from fusee to barrel. As things start to slow down and certainly before the line goes slack I put on another 12 clicks. This is repeated until nearly all the line is on the barrel with only half a turn still on the fusee. I then wound the clock down to the stop.

I now have a good turnover. Good release. And that lovely 7/16 ball doesn't hesitate. Many thanks to all who took an interest in my problem. Stephen.