Member postings for Dick H

Have a look at Solvay´s site for Ketaspire

**LINK** and download the processing and design guide. Look out for KT880-SL30 or FW30. The mechanicals don´t match exactly.

Or look at Victrex´s website **LINK** and look at PEEK FC30.

Both have some simple temperature data (tensiles etc.).

From the density and mechanicals you are probably looking at a higher melt viscosity PEEK grade with about 30% carbon fibre, some graphite and PTFE in it (+ some other non-reinforcing filler eg. mica to lower the mechanicals a bit more).

The crucial temperature is the glass transition temperature of PEEK at 143°C.

Did you see these threads on the NAWCC? Some nice pictures.

**LINK**

**LINK**

You don´t seem to be the only one having fun with this escapement.

Dick.

Reducto ad absurdum. If the spring is too stiff the resonant frequency depends on the spring not the length of the pendulum. The suspension spring should just store enough energy to keep it going, if too stiff it will kill the oscillation, the movement of the escape wheel will be countered by the stiffness of the spring it will not disengage. Too stiff and you can fiddle with the length of the pendulum as much as you like, you can never adjust it to keep time, the spring dominates gravity as a restoring force. Both books say 0.006" for the thickness, as far as I can tell mine is running with a 0.004" (0.1mm) spring, I tried 0.006" but had problems (perhaps for other reasons). In any case depending on the heat treatment of a steel the modulus should vary anyway. Regards, Dick.

Hi Jim, I don´t know how you have the movement mounted but you need to check that is in beat. You need a scale behind the pendulum rod, low down, so you can judge whether the tick and the tock are symmetrical about the neutral (i.e. vertical position). The movable collet that fastens the crutch to the arbour with the anchor / pallets on it. If the collet is not too tight you can hold the anchor with two fingers and move the crutch relative to the entrance and exit pallets. The adjustment is tiny. Listen to the tick whilst moving the pendulum slowly by hand. The kick from the escape wheel keeps the pendulum going. If you have a light clock oil, put a smidgen on the pallets. the clock has a eccentric on the pallet arbour to change the amount that the pallets engage the escape wheel. Turn it a fraction clockwise and it engages a bit more and you get a bit more kick, too much and it stops. What are you using for a suspension spring (thickness) etc.? Try a little bit more weight, once it starts to go it´s a bit like running a car in (nobody does it anymore) you are probably going to take it apart again anyway to clean it once you get it going. Regards, Dick.

PS. Based on my cousin´s experiences with her grandfather clock, cat hair is lethal to the smooth running of a clock

Jim C:- Before you start cutting metal, try the weight you have´, without the pulley and add some weight e.g. with a bottle of water/sand (a bit of thick wire should do to suspend it, make sure it doesn't turn and interfere with the pendulum) tagged on below your weight. By my calculations your weight is pretty much 2Kg. A drop of oil, even on the pallets? You can vary the depthing of the escapement with the eccentric at the front, start with it in the neutral position and turn slightly clockwise to make the pallets engage more. Move the pendulum by hand and listen for the tick and tock, they should be symmetric about the vertical neutral position. The clock has an adjustable crutch, i.e. you don´t have to bend the crutch to get it into beat. You can alter the position of the crutch relative to the escape wheel arbour. Conversely make sure that the tightening screw that holds the crutch in place is tight (given the moment on it, if it is slightly loose it can lead to strange effects, been there, done that)!

Once it starts to run, leave it alone for a while, go have a beer or whatever. Try and see how long it goes for.

Alan:- Sorry to hear of your frustration. Having taken the blasted thing apart many times to look for faults and one time even managing to put the anchor in the wrong way round I know how it can be. I messed about filing down the anchor pallets until there was nothing left and then made a second.

I´ve got lots of other peoples clocks going over the years but when it came to my own....

Hi,

Depending how you read the books the answer is different.

Without the weight pulley the answer is about 2.2 Kg, if you have the pulley in and hence half the drop and energy the answer can be more than double this. The second book (at least) has a second roller to try and counteract the effect that the cord wrapped round the barrel wanders back and forth, this roller seems also to add a bit of resistance/friction. The ideas that the clock should rattle and a bit of oil should be present are also good. If this doesn´t work go looking for rough teeth on wheels and pinions. At the beginning it even made a difference whether I hung the other end of the cord to the left of the pulley or to the right. Left, ( viewed from the front) worked best. At one stage I found I had put the thing together so tightly that with the screws on the pillars tightened, I could stop the thing by gently squeezing the plates together with my fingers. It should rattle! If in doubt test each arbour individually. I don´t think my clock is a particularly good example but it runs. Now how about a case for it? Hope this is helpful.

Many thanks for the replies, I was looking for a project for the winter. A Congreve clock now appears a bit ambitious. Any suggestions in the direction clocks or things that do absolutely nothing?

I was thinking in this direction **LINK** and thinking of a Jaeger LeCoutre Atmos clock.

I know, I think I was in Richmond in the early seventies.

I was born in the NE and went to school in the NW. We were up there either to see the aunts & uncles or to take my gran back to the NW. In any case I have a memory of a Congreve clock in a (corner) jeweller´s window on the edge of the market place. This was the first time I saw one of these clocks and long before I developed an interest in clocks.

Some time ago I obtained John Wilding's book on building a Congreve rolling ball clock. I know they are lousy timekeepers but ..

Jusr reading the book I'm struck by the size of the thing. Has anybody come across plans for a smaller version? Has anybody got experience of building one?

They seem to pop up in The Model Engineer in the past (1947!) but I haven't found any plans.

Any comments appreciated.

Many thanks for the link to "Der Letze seines Standes".

I know that BBC iPlayer is difficult to get work outside the UK but does this link work outside Germany?

**LINK**

It´s about a guy repairing tower/church clocks based in Rothenburg ob der Tauber.

Wiki has a list of some of the series (in German). some are available on YouTube and some direct from www.br.de (but as I said I´m not sure if you can get the latter outside DE). The locations range from Berlin to northern Italy and Vienna..

The series came from Bayern Alpha, now ARD-Alpha a documentary channel set up by Bavarian TV

´Hi Jim,

Your drawing would appear to fit my understanding based on the second book, the collar/collet being glued to the arbour and transmitting power to the motion work via the friction spring. However in the first book it looks as if the arrangement is different. If you look at Steve Bensons photo earlier in this thread you can see a shadow of the friction spring the other way round!?.

I must say I´m a bit confused, I know how my clock works.

Having a think.

Dick H.

Hi Jim,

The layout of the clock in the second book is different from that in the first. In the second version the collet is steel and also takes the centre wheel, the layouts are very different.

I think in the first book the spring is just a push fit in the protruding bit of the collet. In the second version there is a square filed on the collet end and a corresponding hole in the spring.

The wings/arms of the spring act on the back side of the minute wheel as a friction drive for the motion work.

The collet is just glued / "loctited" in place.

Hope this makes things clearer.

Dick.

I don´t know whether this helps but this is a side on view of the motion work on the clock as built according to the second book i.e. pinions instead of lantern pinions etc. The whole stack friction spring, minute wheel and pipe, hour bridge, and hour wheel floats on the centre arbour and is driven by the friction clutch that sits on a square that is filed in the steel collet that protrudes through the front plate. Attaching the hour bridge tensions the minute wheel against the friction spring. The minutes hand is held in place by a washer and a pin through the arbour at the end. A reverse wheel with a pinion translates and reduces the movement of the minute wheel to drive the hour wheel. In this version if you look at the clock from the front the reverse wheel stub sits at somewhere between 10 and 11 o´clock. The brass friction / bow spring is a critical bit, it is made springy by hammering and you have to adjust the tension, too slack and the hands aren´t driven and fall to the 6 o´clock position, too tight,nothing goes. The alignment of the wheels might involve the addition of a washer just to get the alignment right. The older version uses a small bridge to hold the arbour for the reverse wheel. The hour bridge´s position can be moved (big holes small screws) to centre the hour pipe.

My clock is a bit rough and some bits are going to be remade but it´s running.

Anybody know how to make a chapter ring which doesn´t involve too much sawing? My lathe won´t take anything bigger than 16-17 cim dia.

Hope this helps,

Dick H.

Thanks to everyone for the suggestions and comments.

I think the problem is with my bit tight depthing of the hour/reverse hour wheel in the motion work. Anyway it runs, sort of now, on the smaller weight without the pulley. I took everything apart, polished it and put back together.

Thanks for the input.

Dick.

Hi all,

I am finally trying to get my version of this clock going. I followed the later (updated) book which puts the barrel off-centre and uses a guide roller to help the weight cord across the barrel. If I use a straight drop with the weight, it runs with a 5.lb weight, if I use the guide roller I need a bigger weight, if I put the weight pulley in nothing goes. Either I´ve no idea how to string this thing up or I´ve got some massive losses somewhere. How far do the pallets enter the escape wheel, is the geometry of the anchor wrong or have I friction losses?

It runs but should have more ummph.

Any suggestions,

Any help appreciated,

Dick H.

PS: The "cure mechanism of an anaerobic adhesive (or anaerobic sealant as they are often referred to) is triggered when it comes into contact with a metallic surface. This will cause the anaerobic adhesive to gel and cure. To facilitate full cure, the anaerobic adhesive needs to have exclusion of oxygen in combination with contact with a metal. With both these boxes ticked, the reactive molecules inside the liquid adhesive become activated which triggers the curing mechanism, causing the monomers to polymerise and create a solid". (From Permabond´s website).

As to the lower limit on storage, it could have any number of reasons. Moisture sensitivity, bits of the mix might crystallise out. etc.etc...

These adhesives are a mix of lower and higher molecular weight components which polymerise to make a crosslinked solid.

The material is described as a urethane methacrylate. This is probably also moisture sensitive (depends on how/if the molecule is "capped". In any case it described as "anaerobic", so putting it a bag in a fridge might restrict the amount of air it comes into contact with, i.e. it will start to cure. On the other hand it might attract moisture, also not good. As to the difference between 5 and 8°C, go out on a cold morning and see when you can see your breath condense in the air when you exhale. All of these data sheets from manufactures tend to the cautious.

What you say about "chemical reaction rate doubles for every 10 °C rise in temperature" (Arrenhius) is a rule of thumb, it depends on the activation energy of the reaction and whether it is endothermic or exothermic.

This stuff comes in a bottle designed to allow air in to stop it curing prematurely but perhaps keep moisture out. I´m not sure whether throwing the bottle in the drawer is better than sticking it in the fridge.

The viscosity in use shouldn´t be a problem, its just the shelf life and storage.

In any case most methacrylates depolymerise if heated to ~150°C, so the polymethacrylate bit can be softened and will decompose with gentle heating (work in an open, well ventilated area ).

A couple of points:-

Loctite 638 is an anaerobic adhesive, i.e. it cures when you exclude air (oxygen).

According to the data sheet (**LINK**) the best temperature to store this stuff is 8-21°C.

i.e in a bag in a fridge might not be best.

Sorry I´m a chemist.

Dick.

Hi I´ve been subscribing to Model Engineers´ Workshop for a year or so now. I browse the forums for tips from time to time. I´m finally,after 8 years, ( I found the bill for the brass), trying to finish an Eight Day Wall Clock from a book by John Wilding. Up to now I´ve just lurked on the forums.

Hi Alan,

I assume you are working from the older book for building the clock. I started with this and then switched to the newer version.

Just looking at the old (red dust-cover) book the information you seek is scattered all over the place.

1) the arbor which supports the pallets and crutch is 3/32" (~2.4 mm), this matches the hole drilled when making the pallets (p.37, left hand column line 13).The escape and pallet pivots are 0.050" in dia. (p.29, Fig 42. bottom right). The newer book uses 1/16" pivots.

2) The back cock. The older book uses a back cock made of bits of brass silver soldered together, in the newer, a brass plate is supported by two pillars. I would take the drawing a p.42 Fig 68 as being a scale diagram (approx 75%). The holes back plate are drilled and tapped to suit the position of the back cock sitting on the pivot protruding through an arbor sized hole in the back-plate, even then there will be a little bit of potential movement, so it is suggested to add locating pins as well. This is before cutting out the upside down keyhole shaped hole in the backplate to accommodate the adjustable collet.

3) The crutch can be made out of one piece of brass and bent (the newer book uses 1/16" mild steel strip) or made from two pieces and soldered together (p.44). the top of the crutch has a central hole to sit on the arbor and is then held by two small screws ( approx. M 1.6-1.8 metric) to the adjustable collet. The two 10 BA holes in the foot of the crutch are to hold small plate to narrow and adjust clearance between the crutch and the lower brass block on the suspension spring, this is difficult to see in Fig 79 on p.45, and it is also visible in Fig 2 on p.5, once you have an idea what to look for. The crutch I made is simple steel with a slot. Hope this helps.

Living abroad my clock is a wild mixture of imperial and metric. The older book uses lantern pinions, the newer steel pinions. Having sat down to cross read the two, I see there are lots of differences.

Hope this helps.