Hand turning a clock fusee

[David CarneParticipant @davidcarne27247]

I am trying to hand turn a clock fusee for an English dial clock I am making. I have turned it cone shaped and now want to shape it. I have the original I am copying so I know the shape required.l want to know what shape of graver I need to make and at what height and angle to cut. I have experimented and find I keep getting "dig ins". Any advice would be appreciated. Regards David.

[David CarneParticipant @davidcarne27247]

[Bob StevensonParticipant @bobstevenson13909]

This job is NOT easily accomplished using a "graver" without considerable experience as a graver is really unsuitable unless fairly special equipement is used…..

Turning fusees is relatively striaghtforward using a fixed lathe tool. To turn the basic concave profile use a 'round nosed tool' well secured in a tool post which is allowed to pivot freely…ie, the tool is screwed down tightly but the main tool post bolt/nut is left only finger tight……This pivot is placed at the radius of the curve to be turned and then simply turn the tool by hand against the workpiece thus cutting along the required curve. This is well documented online and can be read about in the description given in John Wildings book; 'Eight Day Skeleton Clock' as well as in other titles.

To cut the continuous groove on the fusee the lathe is set up for thread cutting by arranging the required wheel (cog) train for the number of grooves, or pitch, per inch…then remove the cross slide thread so that the cutting tool may be slid against the curve of the piece by hand to cut the groove along the concave surface. This process is also well documented and described by JW.

If you really MUST use a loose engraver then grind a round nose and concentrate on applying the cutting edge to the brass exactly at 90 degrees to the surface….there should be no top rake to the tool when cuttign brass (unlike steel) Round nosed tools give a better finish when cutting brass especially the curved surface of a fusee.

[David CarneParticipant @davidcarne27247]

Thanks. I am going to try the JW method and have tried the round nose tool method without too much success. I have seen an old ME article on using a hollow round cutter either ground with an external angular edge or an internal angular edge? What speed is recommended ?

[Martin KyteParticipant @martinkyte99762]

This is not a difficult thing to do. Once you have your basic cone (frustrum) You need a flat scraper with a large radius end. Arrange a hand rest for the scarper and off you go a' la woodturning style and hollow out the middle. Cardboard template for testing the curve and there you are. For grooving use round nose tool in the toolpost to produce a curved bottom screwcut. Remove the leadscrew on the cross-slide. Set the lathe up for screw cutting and apply the cutting pressure by hand working from the large end of the fusee to the small. Ensure you have the right 'hand' on the thread direction.

regards Martin

[Bob StevensonParticipant @bobstevenson13909]

David,……without any wish to be rude or unkind, if you are not able to turn ordinary brass satisfactorily with a sharp correctly ground round nosed tool then I have to assume that there is something fundamentally wrong with your set-up…… The round nose gives almost seductive pleasure when turning brass such that it's, for me at least, just about the simplest turning task! The brass needs very little finishing to a fine quality and is very quick and easy to turn.

If you are not able to do this easily then you really need to go back to basics and look at your set-up for plain errors such as blunt, or incorrectly ground tool,……incorrect tool height…..loose tool post components……long 'hang out' of tool from tool post…….excessively wrong speed or too deep a cut etc, etc.

Sorry to rattle your perch but there is something wrong about your posts that makes me wonder how we can help you!

[AjohnwParticipant @ajohnw51620]

This page on a thread on making a particular clock might help

**LINK**

I'd guess in days of old they would have used a hand chaser set up. This isn't difficult to do on a plain or tapered diameter with a multipoint chaser as they tend to self correct. A fusee isn't a plain diameter though.

John

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[MWParticipant @mw27036]

I'm surprised nobody has mentioned using an appropriate rest when using hand turning tools, the tool will skip and jump if you don't have a rest of some description to take the natural deflection.

Michael W

Edited By Michael Walters on 20/04/2016 11:28:16

[David CarneParticipant @davidcarne27247]

I am using a hand rest, and experimenting with different tool shapes/angles etc.

i haven't tried the scraper yet but so far the tool which cuts best is the hollow pipe with 30 degree outside angle. I used 5/16" dia silver steel 3/16" hole.

Hardened and tempered and sharpened on my tool grinder. I am OK turning brass normally with the lathe slides but not so experienced with hand turning.

[David CarneParticipant @davidcarne27247]

I have successfully hand turned the fusee profile now. The best cutters I have found to be the hollow pipe and a graver made from 1/4" HSS ground and honed at 45 degrees. I haven,t yet tried the scraper or J Wildins method but I have 2 more to make so will also give those a go. It was a fairly slow job so maybe I was being a bit too impatient. Thanks to all the advice.

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