Dark Lady Clock

[john carruthersParticipant @johncarruthers46255]

I set it all up at the right height then marked and drilled the plates. I haven't slotted the holes.
I set the pallet top face level with the top of the scape teeth.

[AjohnwParticipant @ajohnw51620]

Posted by Bazyle on 09/07/2016 17:54:11:

Overhaed gear? Just because motors became smaller and get one dedicated to each machine or operation doesn't mean the old ways are not worth considering.

When I rebushed the counter shaft on my lathe and replaced the shaft I extended it to allow the possibility of an overhead drive. One other option is what Schaublin did on the 70's. A double ended motor. The motor sits on a hefty cast iron base and carries an upright shaft for the drive, maybe 30mm dia. It wouldn't be difficult to make one up for suitable lathes. As double ended motors seem to rare just add a countershaft.

I find I have the Ace toolpost grinder though and that can be adapted. Also to make up a tool grinder of sorts. From Pultra info it looks like 1/5 hp out is needed for external grinding running in their case at something like 4,500 rpm. I'd guess that the motors they used were probably conservatively rated suggesting a 1/4 hp would be ideal. A 1/4hp is plenty for milling going on what can be done on a Peatol.

John

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Edited By Ajohnw on 13/07/2016 10:09:31

[john carruthersParticipant @johncarruthers46255]

A well spent morning assembling the motion and hands.

[AjohnwParticipant @ajohnw51620]

Looks good john.

John

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[Neil WyattModerator @neilwyatt]

Nice mediaeval look to it.

Neil

[john carruthersParticipant @johncarruthers46255]

That's the dial fitted. It still needs numerals and maybe silvered one day.
It is a timepiece.
Next the strike works.

[John silverParticipant @johnsilver78232]

You are motoring ahead John – I wish I had the time to keep up

Now I have a slightly off topic question (hopefully I can be forwarded to the solution).

When I've been turning, I am in perpetual fear of the work running up over the tool. I always set the tool height to the centre line (as best as I can tell) – it seems to be worse when trying to turn a shoulder and you get a bit of rubbing).

I suspect it's down to the lather? In my case it's a Warco Mini lathe (I don't recall having this problem with my Taig – maybe I should get my finger out and wire it up since fitting a sewing machine variable motor).

I think it might be due to flexi/play in the cross slide (I have tightened up all the jib screws) or maybe it's position during turning.

Anyway, any pointers would be most appreciated (especially to my nerves !!)

Cheers

John

[john carruthersParticipant @johncarruthers46255]

I have an sc3 and have had similar worries, Ican only offer the usual;
Keep the tool short, use a tailstock centre when you can, nip up the gibs, use a really sharp tool, etc.

I have an old bit of 12mm hex I've turned to a point at one end and centre drilled the other end to make male and female centres.

For parting I use a hss tool upside down and run the lathe backwards. I find it also gives a very good finish for normal turning too, ideal for the minute stud.

[Neil WyattModerator @neilwyatt]

If work runs up on to the tool , it is more likely it is too high. If too low you will just get a pip. Too high and you have to force the tool in and when it grabs it will dig in and possibly ride over the top.

Another cause can be that your cross-feed nut is loose, so the cross-slide will jump forwards if the tool starts to dig in, making things worse.

Other causes are blunt tools, lack of tailstock support for thin work and, yes, the gibs too loose (doesn't mean they have to be to tight).

Neil

[AjohnwParticipant @ajohnw51620]

It's probably best to check tool height with a facing cut and not to set high.

Brian John is now managing parting off on a baby lathe with this tool

**LINK**

Not suggesting buying one but note how the blade is ground. It will probably be best to put say 5 degrees or so on and try that first. The T shaped ones that are being introduced may not be any good as grinding the back rake on will probably weaken them too much. A taper ground blade should be ok. Parallel blades need relief grinding on. I can't help wondering why some sell those. They are asking for problems without any side relief.

I usually use a 1.5mm thick parting tool for squaring up shoulders as all tools I use have a small rad on the end. In the size i use these are getting rather hard to find. How useful this is depends on the length of the part that is going to be fitted to the shaft with the shoulder. A very narrow parting tool or something like one can also be ground onto a toolbit.

2 styles of HSS tool I use a lot are these – crap photo as the camera focused too far back

They may not look sharp but they are and polished but that is for use on aluminium.

The top one is a simple bar turning tool. Easy to grind all angles around 15 degrees but the rad on the tool has been stoned on and is SMALL. Not much back rake on the top. Just a couple of degrees. The end could be ground at an extreme angle and used to square up corners leaving a very narrow recess, it just needs to be the size of the rad. That style will need significant back rake as it's cutting into the work end on.

The lower tool can do that too and the angles can be the same. It can also bar turn and face but for facing a bigger rad is better. Facing from the centre out often gives a very high quality finish. It's best to grind the shape slowly so that the temper of the tool isn't wrecked. The tool works out well on a Boxford as it can be angled and the work can still be reached. Some mini lathes may need the compound slide moving.

It seems to be important that the grinding wheel runs true in order to leave sharp edges. It does for me anyway. Not sure why this is. I've long suspected that some grades of HSS result in sharper edges. Might turn out that cheap junky M2 is the best. I intend to buy a piece at some point and find out. It's just a suspicion that I have had about M42 for some time but it probably comes down to grades and types of grinding wheel as M42 milling cutters can be extremely sharp.

John

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Edited By Ajohnw on 15/07/2016 12:28:08

[john carruthersParticipant @johncarruthers46255]

You may be right John, I found some old Victorian carbon steel tools which can be sharpend to razor edges. I keep them for finishing cuts.

[john carruthersParticipant @johncarruthers46255]

The strike work arbour and some fittings, still needs the spring retainer and stop lever.

[John silverParticipant @johnsilver78232]

Many thanks chaps for the advice on how to stop the work jumping up over the tool – I guess rigidity is the key

A quick question on the Dark Lady clock…how are the pinions secured to the arbor or the second wheel??

BTW I'm miles behind John – rather depressing

[john carruthersParticipant @johncarruthers46255]

I Loctited it, could have soldered it, or a fine pin?
I'm waiting on the bell and some silvering powder, might get here today.
I found the 60mm cast bells on eBay to be aprox half the M&P price once they add VAT and P&P.
I'm also looking out for a suitable weight or weight shell. The dumbell weights work ok but look rough.

Not a race John, the important thing is to enjoy the project. I could be laid up tomorrow and not touch it for a month so I try to get on when I can.

[john carruthersParticipant @johncarruthers46255]

Pretty much finished, it still needs a decent weight and a back board to hang it on.

[John silverParticipant @johnsilver78232]

Very nice John I'm just making up some bushes for the depthing tool …

[john carruthersParticipant @johncarruthers46255]

I had some flex in my depthing tool which led to errors.
I got round it by making the clock bushes with an eccentric hole which allows slight adjustment.
("if you can't make it fit; make it adjustable" )

[John silverParticipant @johnsilver78232]

Well I think my Depthing tool is fairly rigid and straight and i made sure all the bushes/adaptors are a close fit to stop wheel wobble.

However, I don't think I drilled the pinion holes very straight . You can tell as the wheels jam fairly easily even when only making slight engagement with the gear. I used a milling machine with a pin vice but it looks like the drill bit splayed out slightly and so the pinion pins are not parallel and are therefore jamming. You can see a a neat set of 8 holes in a circle where the drill enters but where it re-enters the pinion, the holes are not in a circle

I think I'll have to machine the pinions again

[John silverParticipant @johnsilver78232]

BTW I don't know if it makes any difference but I used commercial MOD 1 involute gear cutters (I bought 2 to cover all the gear sizes) – I did make the tooth cutting tool – BUT I think at that point I was using the wrong harder brass (CZ108) and not the softer engraving brass (CZ120) – The joy of being a beginner

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John silver on 24/07/2016 19:04:29:

BTW I don't know if it makes any difference but I used commercial MOD 1 involute gear cutters (I bought 2 to cover all the gear sizes)

.

John,

I'm sorry to break this to you [and I really hope someone can provide 'the exception that proves the rule'] but; Lantern Pinions are normally used with Cycloidal Wheels … I think you may be struggling to get smooth running with Involute; however nicely you make the Lanterns.

Please, somebody, prove me wrong !!

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

PostScript to my previous ^^^

Strictly speaking [according to 'Gears for Small Mechanisms'] the correct wheel tooth form would be Epicycloidal, not Cycloidal … But in practice, the differences are small.

Here is some useful info. **LINK**

http://www.abbeyclock.com/gearing3.html

MichaelG.

[roy entwistleParticipant @royentwistle24699]

The main difference is that in a clock the wheels are driving the pinions  If the pinions were driving the wheels I don't think it would be as critical  Also in clock making it is usual just to use one cutter for all wheels

Roy

Edited By roy entwistle on 24/07/2016 20:54:59

Edited By roy entwistle on 24/07/2016 20:57:05

[John silverParticipant @johnsilver78232]

Bugger !! Looks like I have to make some new gears then using the cutter I never used

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John silver on 24/07/2016 22:16:27:

Bugger !! Looks like I have to make some new gears then using the cutter I never used

.

I'm really sorry, John … But I thought it best to mention it.

That said : I'm still not 100% sure that you wouldn't get away with it …

[Some early clocks ran acceptably with pretty crude wheel-work.]

MichaelG.

[AjohnwParticipant @ajohnw51620]

Is this crude wheel work Michael? The flanks are radial.

John

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