Setting up new workshop for clocks. Need advice.

[bpriskParticipant @bprisk]

Greetings.

I’ve started repairing clocks – as a hobby only – and am very confused about the equipment or add-ons I need for my lathe to enable me to cut clock wheels. I have a Sherline 4000 lathe and an old clockmaker’s lathe, but I need some sort of attachment to be able to index and cut gears with one of them. I’ve searched all over the ‘net and can only find information on HOW to cut the gears, not what I need to be able to cut them. What extra equipment do I need to add on to do this?

Any advice or guidance?

Thanks!

Brad

[Mike CrossfieldParticipant @mikecrossfield92481]

Brad

There are so many variables involved in answering your question that it would be hard to cover all the possibilities in any detail in a short message.

When I started out in clockmaking I began with an inexpensive and readily available book entitled Clockmaking for Model Engineers by Colin Thorne. I can heartily recommend it, and I think you will find that it covers most of the basics.

Mike

 

[BazyleParticipant @bazyle]

You need a book on clockmaking. Laurie Penman, Collin Thorne, Donald de Carle are the first few I have picked off my shelf. And John Wilding did a book on clock repair, or most of his books on clockmaking show the tools.

A cutting frame  https://camdenmin.co.uk/products/flycutting-frame is the simplest route with the lathe spindle used to hold the wheel blank and index it. Lots of ways to do the indexing have been covered on this forum. Search terms like index and divide, division, gear etc.

Blow me a quick google brought up this thread from a year ago. https://www.model-engineer.co.uk/forums/topic/watchmaker-gear-cutting/

But you could also look at small milling spindles, (a bit larger than a Dremel), the famous Potts spindles, getting posh and Arrand spindle, various ones used by ornamental turners etc.

[John HaineParticipant @johnhaine32865]

https://www.brownsbfs.co.uk/Product/Thorne-Colin/Clockmaking-for-the-Model-Engineer/9780954713119

Either you use the lathe spindle to run a cutter or as a dividing head with a dividing disc of some sort on the “other end”.  The first way you need a dividing head of some sort, the second you need a spindle for the cutter.  Not sure what you mean by a “clockmaker’s lathe” – do you mean a watch lathe?  If the latter you might be able to use its headstock fitted to the Sherline cross slide in either role.

Another good guide is This one

There is/was a US author called Bill Smith who made some nice clocks largely on a Sherline – I think he has a book too, not sure if it’s available.

[bpriskParticipant @bprisk]

Thanks for info guys, and the quick replies!!

I have some books on clock REPAIR, but I see that you’re all right. I need to get some books on clock MAKING.

My immediate need is just to repair a single gear that I damaged recently. I’m having a hard time finding a way to cut the teeth after replacing the damaged section. Perhaps I can find a local clock guy who is willing to do one-off work.

(Yes, it’s a watch lathe. It’s an old Wolf John lathe that my dad had. He never used it very much.)

Brad

[bernard towersParticipant @bernardtowers37738]

Clockmaking and Model making, tools and techniques is the one from Mr. Smith but I fear it might be in short supply.  Tools for the clockmaker how to make and use, byjohn wilding, get from I T Cobb.

[bprisk]

On bprisk Said:

…
My immediate need is just to repair a single gear that I damaged recently. I’m having a hard time finding a way to cut the teeth after replacing the damaged section…

Brad

Worst possible problem almost – how to repair a single gear without having to spend money on equipment that might never be used again, and without having to explode one’s brain learning about cycloids!

The old boys did it by hand with a file and simple indexer.

The indexer is simply a device that holds the gear blank in a series of fixed positions, so the blank doesn’t move whilst the tooth is filed.  When a tooth is finished, the indexer is clicked one position so the next bit of the blank is moved accurately.   An old trick is to make an indexer by bending a section of old saw blade into a circle containing the required number of teeth.  It can be mounted on a lathe so the spindle can be notched around one tooth at a time, whilst the gear is held in a chuck for hand filing.

If you have a watch makers lathe, it may already have a built-in or accessory indexer: it’s a disc full of holes, in circles, that correspond to common tooth counts, with some way of clicking in around step by step.

For a repair, the tooth shape can be copied from the unbroken ones, or fitted experimentally against whatever the wheel drives.  A coarse file is remove most of the metal, then the notch is carefully finished with a fine file, and probably burnished.

Not conceptionally difficult, but it needs skill and patience.  The most likely mistake is removing too much metal.

Didn’t take long for clockmakers to get fed up with making gears by hand, but it sounds like you don’t need a fast complicated way of doing a one-off repair.   I notice many clock repairers on the web replace rather than repair broken wheels, either buying standard parts from a dealer, or by having a stock of old clocks to cannibalise.

Dave

 

 

[DC31kParticipant @dc31k]

The Smith book appears to be available direct from the author:

Clockmaking and Modelmaking

Not only can you use one of the undamaged teeth to make the correct shape cutter, you can use the undamaged portion of the gear to index itself (I think you would need minimum of two undamaged teeth on the gear). Make the inexing pin with some angular adjustment. Drop the cutter into an undamaged tooth and then adjust the indexing pin to drop into another tooth. Raise the cutter and index around until the uncut part is below the cutter.

With any indexing device, you have to time (align/synchronise) it with the thing you are cutting unless you are cutting every tooth anew.

[bpriskParticipant @bprisk]

I would love to just purchase a new gear to replace the damaged one. It has plenty of teeth left that are sound – 76-tooth gear with just 6 or 7 damaged ones.

I’ll likely play with this type of activity for quite a while so I don’t mind spending a “reasonable” amount of money on new tools. (“Reasonable” being completely subjective!!) I inherited the Sherline lathe, much to my surprise. It’s been in a box hidden in the shed for 14 years that I didn’t know about!

I’ll pick the book(s) you all recommended and proceed from there.

Thank you SO much for your advice!

 

[Peter Cook 6Participant @petercook6]

One place to start would be the US based NAWCC forums. Free to join and full of very helpful clock people.

If you search those forums for Wheel cutting, you will find lots of helpful suggestions and ideas. In particular lookout for posts by Jerry Kieffer. He is a genius micro machinist, and uses Sherline lathes and mills for much of his clock work.

[bernard towersParticipant @bernardtowers37738]

I dont think that buying from the author is an option as postage from Tennessee would probably need a defillibrator`!!

[HuubParticipant @huub]

This is how I make gears and gear cutters on the lathe and the milling machine. You always need to rotate a gear cutter at some speed and a way to position (rotate) the gear (blank).

https://www.youtube.com/watch?v=ImloYwHc-BY

Currently I am working on a procedure for the CNC router to make gear cutters. That will take a few months to finish.

 

[bernard towers]

On bernard towers Said:

I dont think that buying from the author is an option as postage from Tennessee would probably need a defillibrator`!!

I was pleasantly surprised by how reasonable the postage was when I sent a parcel from UK to US. The problem might come if there is import duty to pay. Not the amount of duty, the handling charge levied by the courier.

[bpriskParticipant @bprisk]

I’m in the US, and shipping is free!!! Yay!!!!

[Russell EberhardtParticipant @russelleberhardt48058]

As well as reading books it’s worth watching some of the excellent Clickspring videos.  You will find that wheel cutters are very expensive to buy particularly for one off jobs. This video demonstrates how to make and use cycloidal profile fly cutters instead:

https://www.youtube.com/watch?v=6M2yAUEmJbE

Russell

[BazyleParticipant @bazyle]

Buy a junk clock mechanism off ebay to practice on. Some have solid wheels that you can turn the teeth off and start from scratch, though the brass they use may be less than the ideal freecutting version you would use if buying specifically for the job.
In the course of time (pun intended) you will need to practice repivoting and all sorts of stuff on scrap parts.

[Alan Wood 4Participant @alanwood4]

William Smith books are available in the UK via Ian T Cobb.  He also sells the John Wilding range of books.  Both these authors are good sources of information on clock related designs and techniques.  Bill Smith also made a number of videos.

https://www.clockmaking-brass.co.uk/clock_construction_books.html

[Tim StevensParticipant @timstevens64731]

Don’t forget that if your worn or broken wheel is brass, it is easy to solder a new section in place, and then cut the teeth relying on the original bits to provide the indexing. But do remember to balance the finished work or it might stop the clock as soon as the heavy side has to go uphill.

And do practice on an old clock of no value first.

Cheers, Tim

[bpriskParticipant @bprisk]

Tim,

I was lying in bed last night thinking that I’d just do basically what you said. The gear is gear/wheel 2 of the chiming train, so not critical. At this point I’m just on a quest! The rest of the clock works fine.

Brad

[jaCK HobsonParticipant @jackhobson50760]

You could just file the teeth by hand if it is a section of a gear. Which gear it is will influence how accurate you have to be. If you are  now handy replacing sections, then why not try it? If it goes bad just put in another section and try again.

Gear cutters are expensive – like £70+ a pop and you probably need a few for a whole clock.

One of the classic books on the subject: https://www.amazon.co.uk/Wheel-Pinion-Cutting-Horology-Historical/dp/1861262450/ref=sr_1_1

Malcolm J Wild website suggests they still sell tools etc but you have to contact them direct to get prices and order. His spindle is good if you can find one second hand – then it goes on the vertical slide of your lathe and you get some indexing attachment for the lathe head.

If you going to do a lot of cutting, then a wheel cutting engine is probably best in long run.

 

[Peter Cook 6Participant @petercook6]

Have a browse at  Dave Morrow’s website 

There are some PDF’s covering the basics of what you want to do. Section 1 covers the basics of  making single point cutters for gear teeth, and the last PDF covers replacing wheel teeth.

[Alan Wood 4]

On Alan Wood 4 Said:

William Smith books are available in the UK via Ian T Cobb.

Did you actually look at that page to find out the price and availability of the book which we are discussing?

Maybe there has been a run on the bank so to speak since you posted, but when I look there, it is shown as out of stock, with no price listed.

[bpriskParticipant @bprisk]

Working on filing the teeth, but my “micro” files aren’t micro enough. I don’t see anyone around (i.e. Timesavers.com) who carry anything finer. Based on the plethora of YouTube vids I’ve watched over the months SOMETHING has to be out there! 🙂

Maybe I’ll just take some X-Acto blades to it and chisel away with those… LOTS of those! 😉

[Martin KyteParticipant @martinkyte99762]

Fly cutters for cutting clock wheels are simple and cheap to make and work very well. Essentially you turn the profile on the end of a piece of silver steel (drill rod) for those of the American persuasion. The profile is a parallel section and an end of specific radius. The embryo cutter is filed to a little over half diameter and hardened. Finally it’s taken to exactly half diameter by grinding and honing. The form tool to shape the radius can be made by drilling a hole in a piece of gauge plate and filing away the bits you don’t need and then hardening. If the tools are made with care and nicely polished you get a very good result. Fly cutters can be used to create pinions in steel but it’s more of a challenge so I would recommend commercial pinion cutters.

regards Martin

[Martin KyteParticipant @martinkyte99762]

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