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Member postings for Chris TickTock

Here is a list of all the postings Chris TickTock has made in our forums. Click on a thread name to jump to the thread.

Thread: Suggestions for drilling a v shape
28/10/2020 12:41:18

Thanks Guys for all posts all noted and appreciated.

I am buying in a 90 degrees spot drill which should do the job. Still chewing over using brass bushes which would allow me to use centre drills with various DIA tapers and end holes, but then this would mean making additional parts and possibly introduce errors. I will see how the centre drill does.

If I only had 1 or 2 tapered holes then maybe making a D drill would be the answer. The issue with making a simple jig to hold anything from under 1mm to 5 or 6mm and over a limited depth of 4 mm is limiting on the tools available off the shelf. From my calculations I expect the 90 degree 6mm centre drill will be acceptable...I will see.

Chris

27/10/2020 20:27:11
Posted by Mick B1 on 27/10/2020 19:28:51:

If it's just a shallow countersink, the ideas above are fine, but looking at the pic (which isn't easy to make sense of) I'm wondering if you're looking to make a long, tapered hole several diameters deep?

If so, you might have few other options than to make a tapered reamer out of (eg.) silver steel. I'd find that pretty challenging, but clockmakers might not. Probably start the hole by drilling a series of steps with reducing diameters to carefully-controlled depths, then finish ream.

Trying to bore it would be a bit like microsurgery, but there are probably folk on here who could do it?

Edited By Mick B1 on 27/10/2020 19:30:29

Thanks Mick,

I am as yet unsure as to depth but I tend to think the longer the metter interms of stability and diameters covered. Maybe a 60 degree spot drill or graver but still thinking and asking.

Chris

27/10/2020 17:09:18

v drill.jpgHi Guys,

I need to drill a v shape into mild steel for a depthing tool i am making.

I would like the outer diameter to be approx 5mm tapering to a point so the v can hold a variety of arbor diameters when so adjusted.

Any ideas?

regards

Chris

Edited By Chris TickTock on 27/10/2020 17:14:43

Thread: Depthing Tool Ideas
26/10/2020 22:17:10

Thanks Guys

I will poke around for ideas and then make one

Chris

26/10/2020 20:50:05

Hi Guys,

There are various views on depthing tools. Some argue not needed others important. So I would initially like to see if there is a cheapish way forward iether making one or even buying one.

Any ideas?

Regards

Chris

Thread: Reducing diameter cylinder bobs
26/10/2020 20:06:30

wonderful and interesting posts gentlemen

Chris

26/10/2020 16:58:03
Posted by Michael Gilligan on 26/10/2020 16:46:11:
Posted by Chris TickTock on 26/10/2020 16:34:02:

Thank you Michael,

As you can see adding the site link did not help answering my question as to the cutting the bobs on a lathe, which is why i saw no point adding it. […]

.

But it did at least let me see that:

  1. He is discussing bent-strip pallets
  2. He only uses the bobs for the two final stages of polishing
  3. The lathe tool, although zero rake, is not round-nosed

Your not reading the same pages as me Michael, look at page 41 there is a picture with words below;

'Above picture shows the setup where I used the round nose cutting tool that I use for brass i.e. that cutting tool with no rake to machine the 1/4” diameter cylinder bob down to 1/8” diameter. This 1/8” cylinder bob will get inside the Exit Pallet Inside lock surface nicely.'

He is also clearly discussing a deadbeat of anchor design in relation to the cylinder boss.

Shall we just leave it as a don't know and say no more about it?

Chris

26/10/2020 16:35:11
Posted by Steviegtr on 26/10/2020 16:12:11:

Its a shame the dremel ones were not small enough.

Steve.

Edited By Steviegtr on 26/10/2020 16:17:23

Yes Steve, that's my next port of call sourcing the little chaps.

Chris

26/10/2020 16:34:02
Posted by Michael Gilligan on 26/10/2020 16:02:43:

From p42 :

Hard Felt Cylinder Bobs:

To polish, the hard felt cylinder bobs illustrated above are used for the two final polishing steps

(1 st brown tripoli and 2nd red rouge). They worked great. […]

....

The turning tool is illustrated on p41, and I admit that I am surprised.

Unfortunately, however, I can find no specification for his ‘hard felt’ so feel unable to comment any further.

MichaelG.

.

Ref: for the convenience of others

**LINK**

Edited By Michael Gilligan on 26/10/2020 16:07:04

Thank you Michael,

As you can see adding the site link did not help answering my question as to the cutting the bobs on a lathe, which is why i saw no point adding it. I am told by Jerry Kieffer that David was one of his students a few years ago and is very bright with good ideas, from what i see i agree.

Chris

26/10/2020 14:52:31
Posted by Michael Gilligan on 26/10/2020 13:59:12:
Posted by Chris TickTock on 26/10/2020 13:39:37:
Posted by Baz on 26/10/2020 12:48:32:

Chris, you say you have found online an article, can you please share the link with us.

If you type into google Levers David Morrow grinding oldtymesclockrepair

it should take you to a pdf link

Chris

.

Pity you couldn’t have mentioned that earlier

I will search for it when I have some spare time.

MichaelG.

Michael its very easy to be rude back but no.

Chris

26/10/2020 13:39:37
Posted by Baz on 26/10/2020 12:48:32:

Chris, you say you have found online an article, can you please share the link with us.

If you type into google Levers David Morrow grinding oldtymesclockrepair

it should take you to a pdf link

Chris

Edited By Chris TickTock on 26/10/2020 13:42:01

Edited By Chris TickTock on 26/10/2020 13:45:20

Edited By Chris TickTock on 26/10/2020 13:46:28

26/10/2020 13:34:16
Posted by Michael Gilligan on 26/10/2020 12:45:24:

So your sources are secret dont know

... I’ve suddenly lost interest

MichaelG.

No not secret at all the article I found online is in the public domain and I downloaded a file so it may take time finding it and that is something I am short of. I will try and find it later on (though why you cannot take some one's word on it is beyond me) again though as i say it does not say anything more in relation to him reducing the hard felt cylinder bobs than he used his round nose cutter with no top rake that he uses for brass. The reason for my post was i too like John wondered about the plausibility of cutting it on a lathe. I believe him just is a different material than I would think you usually cut on a lathe. I am also contacting him for further information. Nothing wrong with a new way of doing something..if it works.

Chris

26/10/2020 12:27:58
Posted by Michael Gilligan on 26/10/2020 12:23:38:
Posted by Chris TickTock on 26/10/2020 12:12:30:

The reason that I ask is that I found online an article a clockmaker who does it using the same zero top rake round nose cutter he uses for brass. […]

.

Perhaps you could share a link to that article, Chris

... Then we might be able to comment on his materials, tools, and technique.

MichaelG.

The only details given are as I have stated Michael. I suppose I will wait till I have some and if needed have a go, providing the bob stays true it will work.

Chris

26/10/2020 12:12:30
Posted by Michael Gilligan on 26/10/2020 10:55:07:
Posted by Chris TickTock on 26/10/2020 10:48:09:

Hi Guys,

One of the ways of finishing pallets on escapements suggested the use of hard felt cylinder bobs.

[…]

.

dont know

Seems very likely to round various edges, and generally ruin the geometry.

... There’s a difference between ‘shiny’ and ‘accurate’

MichaelG.

The reason that I ask is that I found online an article a clockmaker who does it using the same zero top rake round nose cutter he uses for brass. Felt being softer than metal the zero rake makes sense but as I have no hard felt cylinder bobs yet I have no idea. if it cuts evenly fine and of course the quality of the bob may prove to be all important.

Chris

26/10/2020 10:48:09

Hi Guys,

One of the ways of finishing pallets on escapements suggested the use of hard felt cylinder bobs.

Can these be reduced on the lathe to get a reduced felt diameter?

I would be aiming for 3/32 Dia. Even if i can get that diameter I would still be interested if using a lathe the diameter can be reduced.

Regards

Chris

Thread: Deadbeat tooth design on the escape wheel
24/10/2020 15:08:51
Posted by Bob Stevenson on 24/10/2020 11:34:27:

I use a fly cutter for making escape wheels and shape these along the curve of the wheel blank...has always worked well for me...remember to 'pin' the blank during cutting as the action of the fly cutter being assymetric can nudge the blank making a not very happy day!

Good point with the pins Bob...cheers.

Chris

24/10/2020 11:20:04
Posted by Bazyle on 24/10/2020 00:00:30:

All the formulae are given on the other page of the spreadsheet. It is just 'simple' geometry to give clearances. The teeth are triangular only because it is an easy shape to cut - they could be arcs matching the curve of the pallet movement - just no point in being that complicated.

The only places where any science or even much choice comes in to it is to decide on the angular movement of the pendulum which depends on how much circular error you want in relation to your other choices of temperature compensaton etc.

Thanks for this Bazyle, I missed the other pages at the bottom initially. Largely I agree with your take. all I would add is this;

On the standard deadbeat escape wheel providing you first understand how it works then you have a fair bit of leeway in the tooth design. Teeth slope forward (CW wheel) and a minimum of 6 degrees is recommended as Thornton's cutters. Equally to much forward slope can weaken the teeth so Wild recommends keeping this to under 10. Backslope on the teeth not critical again but too much may impair clearance during the run on lock, so ball park 18 to 21 degrees may be a good starting point. As usual Tooth witness (tip flat) should be there but small so I would go for 0.5 a degree.

Chris

23/10/2020 21:06:10
Posted by martin perman on 23/10/2020 18:51:03:

Having done a quick search on the internet and looked in the books I have I tend to agree with Chris's rule of thumb idea but I've found this http://www.davesclocks.net/uploads/5/8/9/1/5891949/dcr_deadbeat_calc.xls which may be of use to you.

Martin P

Thanks Martin, I have this spreadsheet it does not explain any formula though. Obviosly there must be a limit on forward tilt of teeth as well as back slope. Circa 20 degrees forward slope is about the mark. Still on the case.

Chris

23/10/2020 18:44:06
Posted by John Haine on 23/10/2020 18:29:53:

You think there is science behind them?

 

There is some but there is apparently a selection of shapes possible. Still need more detail to voice a more solid opinion. With triangular teeth certainly some science that could be used...that's as far as I have got. There appears to be a relationship between the number of teeth and the angles. I suspect many old clocks were made by rule of thumb. But even rule of thumb escapes me at present.

Chris

Edited By Chris TickTock on 23/10/2020 18:44:35

23/10/2020 17:47:43

Hi Guys,

Currently trying to understand the deadbeat escapement. All is fine apart from none of my books appear to state any design criteria for the selection of the angles of the back slope and undercut for the teeth. Yes they all state they point forwards for an escapement going clock wise but it would be nice to understand how such angles are derived.

Any pointers gratefully recieved

Regards

Chris

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