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Moose

Smiths Enfield Mantel Clock escapement problem

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Hello all.

My first clock to have a go at. I spent a day at the BHI on their introduction to clocks course, which was a great introduction. I have done work with mechanical watches, but this is my first clock.

It was bought cheaply off eBay as a learning project and is reasonably good nick apart from being listed as a "runs but stops". Once obtained, it was apparent that it likely had not been serviced since new, as the original "S" shaped wire retainers were still in place, having not been replaced.

NOW - I have uploaded a small video, which I hope will replace the 1000 words I would have had to use to describe the issue, had I not done so. This is after disassembly, cleaning and reassembly. The clock runs for for a few minutes of so (varies) and seems to partially stall a few times, before eventually stalling altogether. It was fully wound prior to testing. There is another issue with one of the bearings, which may be robbing power from the going work, but I would appreciate any views you have as to whether the pallets are adjusted correctly or not. I have tried adjusting then, but cannot get it to run for more than a few minutes before the movement stalls.

Key times 12 seconds = nearly stalls. 35 seconds stall.

 

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This is certainly a problem. Its on the big wheel between the barrels, is it the Time Intermediate Wheel?

Anyway, the back-plate bearing hole is completely shot, and may well be cause of this clock's woes. I think this really needs to be fixed, but as a beginner, I simply do not have the tools (not the confidence) to attempt a re-bushing without risking bu**ering the whole back plate.

Once again - all suggestions welcome. It may well be that. unless this issue is fixed first, it will never run reliably anyway. Again - comments appreciated.

IMG_2316.jpeg

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Hi  The bearing is definitley worn and will need a re bush as the   mesh of the adjacent gear  is wrong , and from the video clip the escapement looks a bit off on the beat, thats what is most  likley stopping the clock.  It should be  Tick....Tock yours looks a bit like   tick...tock as if the depth on one side is shallow.    I use a tick amplifier to enhance the tick tock sound for setting the beat makes the job easier. 

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Yeah, I know about the bearing needing a fix, but that’s the main issue for me. Being a hobbyist, I don’t have the tools necessary to do a good job. I know how it’s done with the correct bushing tools, but I have only seen a first hand demo, not actually done one. Even if I was to fork out mega bucks to get the right gear, I still would not have actually done one before.

Right now, I would pay to have someone re-bush it and return it, and then I could continue with setting it up. It’s either that, or I treat the whole mechanism as a training piece, and buy the minimum recommended hand-tools to do it by hand, and try to have a go and learn whilst doing it. Then if I make a complete cods of it all, at least I have a bucket of spare Enfield parts for whenever the next one might turn up. :-(

Hey ho...

 

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Hi  If you have a pillar drill and a set of hand cutting broaches and take care It is possible, That's all I use and have no trouble The bergeon and KLM bushing tools are expensive If you only do a few, They are commercial pieces. And like you a hobby repairer for many years. I personly would use it as a training exercise and have a go that's how I started faced with a duff bearing and no alternative but to learn the hard way. Remember if you do decid e to do it when broaching the hole  open up the side opposite the worn side the same as the worn bit then the broach cuts the center and not one sided, I cut from both sides untill the bush just stands in the  inside of the hole then use the drill with a punch in it to press the bush home from the inside untill flush with the plate. Then broach the bush untill the pivot sits in the hole with about 4 to 5 Deg lean to the side. Assemble the plates with the repaired bush and wheel and its adjacent wheel to check that its running even and not bottoming if all ok  reassemble the clock and away we go.    Easier said than done but just don't rush it Patience at all times.

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Thanks for the comments. Don’t have a pillar drill so will need to think this through a while to decide what to do next. I don’t think I will have too much of a problem with doing th cutting and fitting a new bushing. But it the ensuring that the cut for the new bush ends up in the correct place and is perpendicular and not cut at an angle that worries me more. I need to figure a way to support the plate securely (relatively easy) and making a good straight cut, whilst maintaining the correct centre (not so much...).

Still - we have at least two weeks of lockdown left...

Anyone know of a good tutorial of re-bushing by hand?

:huh:

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51 minutes ago, Moose said:

Anyone know of a good tutorial of re-bushing by hand?

We could probably describe the process here. Here's a very crude description which should be enough info to get a cheap clock re-bushed. It is absolutely not what I would do on a valuable clock and only serves to describe roughly how it can be done:

Firstly, that's a very worn hole. On a cheap clock like this, I might have suggested punching down to spread the material where it's worn, but I think you would be best to try and re-bush. It's not hard, and there are different methods which people employ.

Since you presumably don't own a lathe, I would suggest pressing in a pre-made bush. I may have one in my spares that I could send you if you are UK-based.

Now, your goal is to reduce that awful side-shake, but also to set the correct depthing. By that, I mean the depth that the teeth mesh between this wheel and the adjacent ones.

To get the depthing right, you need yo get the new hole (in the bush) centred where the original hole was. What you current have is oval shaped due to side-thrust. The easiest way to get the new bush centred is to open up the worn hole even further by wearing the hole in the opposite direction to make an even bigger oval, but an oval whos centre is where the original hole was. So use a rat tail needle file to cut an equal amount of wear in the opposite direction to the existing wear.

Now turn that oval into a round hole that we can fit a bush into.The bush will be very slightly tapered to make an easy friction fit, and we want to fit it from the inside of the plate so that it has no chance of falling out. So, get a broach and cut that hole from the inside of the plate. Try and keep it perpendicular to the plate. Keep trying the bush to see if it will enter through the depth of the plate. Once it reaches through the other side as a press fit, hammer it lightly into place. You'll need to use your judgement for that, but it needs to be tight. Don't worry if you deform the hole in the centre slightly as we'll be cutting that later. A wooden block with a hole cut on it would be suitable for supporting the plate while hammering.

The bush is now tight in position. Now carefully file down the excess of the bush on the inside of the plate until there is barely any protruding. There are tools to do a neat job of this, but you presumably wont have access to them.

Use a broach to open up the hole in the bush until your wheel's pivot fits freely. It's best to do this from both sides of the hole to aim to get a parallel-sided rather than tapered hole. Don't go too far.....

You can fit the wheel again between the two plates to check there is not too little end-shake (if the protruding remnants of bush stick out too far then it will jam against the shoulder of the wheel's pivot). If it binds then remove more material by filing. Make sure the face of the bush is smoothly finished as the pivot may ride up against this and you want to avoid friction.

You may or may not choose to file down the remainder of the bush on the outside of the plate. You absolutely would on a fine clock. And you would also add an oil sink where applicable. But this is not a fine clock!

Reassemble. Job done. Hopefully!

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8 hours ago, rodabod said:

We could probably describe the process here. Here's a very crude description which should be enough info to get a cheap clock re-bushed. It is absolutely not what I would do on a valuable clock and only serves to describe roughly how it can be done: ...

...

Reassemble. Job done. Hopefully!

Thanks rodabod.

Thats about where I was at after looking online and on YouTube to get ideas as to how to do it. I have some of the more usual watch and clock repair tools, but nothing for rebushing specifically. 

I’ll need to get a replacement bush and then a suitable size broach to cut the plate for it. I’ll have a look to measure the back plate and pivot size and see what size I may need. If you have a suitable bush, that would be much appreciated and I will make sure you are not out of pocket. (I’m in Norfolk.)

I’ll also need (may need) some smaller cutting broaches and a smoothing broach for the pivot hole, if I need to open it out a bit.

i do have a small engineers surface plate and a watchmakers staking tool set (vintage from eBay), which may have some useful tools in to assist, but may be too small for this job.

QUESTION

Do I first cut a new hole and then get a bush to fit, or do I get a bush first, then the correct size broach for the job? My tendency would be the latter... assuming I can estimate the size of bush required once the new hole is cut.

 

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The plate is 1.5 mm thick and the pivot measures 2.0mm.

I have ordered the basics (reamer, cutting and smoothing branches) as well as a pack of bushes. (If I am going to learn a bit and practice, I may as well invest in a few of the basics...)

Here is the "before" damaged hole.

Will be a couple of days before the "bits" arrive, so will try to update on progress once I begin work on this.

:unsure:

IMG_2318.jpeg

Edited by Moose
more detail

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Hi   Have a google  at  "clock bushing using a preacher".    The preacher is a little gadget with three sharp pointed legs you can make and use to position the bush using the triangulation of the legs . I made one and its useful for indexing the hole and checking the bush once fitted"

DSCF3347.JPG

DSCF3346.JPG

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38 minutes ago, watchweasol said:

Hi   Have a google  at  "clock bushing using a preacher".    The preacher is a little gadget with three sharp pointed legs you can make and use to position the bush using the triangulation of the legs . I made one and its useful for indexing the hole and checking the bush once fitted"

DSCF3347.JPG

DSCF3346.JPG

I’ll have a look, thanks.

 

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There's a lot of good info in this thread, just to chime in and stress that the hole really needs to be re-centered before proceeding. Often the wear is within the oil sink, and that is normally well centered, and you can use that as a visual guide. In your case the wear has gone outside the oil sink; ideally here I use a compass with a wide point and scriber tip and make a now concentric circle around the hole, then file up to that with a round file. Then ream to size for a bushing.

 

 

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First things first. That hole for the large wheel needs to be re-bushed. You also need to make sure the pivot is burnished, so any marks on the pivot will need to be removed. You do not need one of those horrid bushing tools, they are a waste of money, do the re-bushing by hand. The reamer if used correctly will self center to the hole.   The power is shutting off because of the angle of the wheel, it can not mesh correctly with the other teeth/ wheels. this will cause the beat of the clock to become shallow and stop the clock. I'm sure once this has be repaired the movement will have a better action from the escape wheel to the pallets, at the moment I can tell the power is shutting off causing the escape wheel teeth to become shallow to the pallets and it stops. The best clock oil to use is  Windles. 

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42 minutes ago, oldhippy said:

First things first. That hole for the large wheel needs to be re-bushed. You also need to make sure the pivot is burnished, so any marks on the pivot will need to be removed. You do not need one of those horrid bushing tools, they are a waste of money, do the re-bushing by hand. The reamer if used correctly will self center to the hole.   The power is shutting off because of the angle of the wheel, it can not mesh correctly with the other teeth/ wheels. this will cause the beat of the clock to become shallow and stop the clock. I'm sure once this has be repaired the movement will have a better action from the escape wheel to the pallets, at the moment I can tell the power is shutting off causing the escape wheel teeth to become shallow to the pallets and it stops. The best clock oil to use is  Windles. 

Thanks oldhippy. Great advice as always.

I must admit, I did think that due to the amount of wear on that hole, it would be causing an awful lot of drag and did not want commit to do anything with the escapement until i had done something about it. I think it is the Time Intermediate Wheel? Anyway, it’s the first, and really large wheel driven directly by the main barrel on the going side. Examined under full wind, you can see the wheel and axle are over at a completely unreasonable angle. What on earth made me think it would run at all Is beyond me. The confidence of inexperience, perhaps? :-)

My first thought (as a clock newbie) was to find someone who could just re-bush the hole for me. But then began to think that this was a total cop-out. This was in effect, bought as a “learning piece”, its not for refurb and selling, but for practicing clock repair techniques.

SO - as we are all still locked down it was all down to getting the correct (minimum necessary) tools, to do a good job. Having done a walk-through at the BHI with the instructor, I have the basic principles in my head, and also have De Carles book, which also explains the process. But as always, the best advice can always be found on the forum, from people who do it regularly.

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Thanks again. Not so sure about burnishing pivots. Again. I almost certainly won’t have the correct tools, but with guidance, could likely obtain what is required to do a decent job. 

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11 hours ago, Moose said:

QUESTION

Do I first cut a new hole and then get a bush to fit, or do I get a bush first, then the correct size broach for the job? My tendency would be the latter... assuming I can estimate the size of bush required once the new hole is cut.

 

Your bush outer diameter will need to be larger than whatever hole you wind up broaching in the plate - bear in mind that you are going to drift the hole into an even large oval than it is already which will increase its diameter. 
 

There are different ways to measure how much you need to elongate the hole to re-centre. One thing you can do to give you a rough idea is to poke some vernier calipers into the hole; compare the narrowest diameter to the widest. The difference gives you can idea of how far it may have already worn. You want to elongate that hole by the same amount in the opposite direction. 
 

If you can’t find a bush of the correct diameter then I’ll turn you one and put it in the post. 

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I have a set of cutting broaches, a set of smoothing broaches, both sets go up to 2.0 mm. A 100 mm long, round needle file. Max 2.1 mm dia. (No 2 cut)

MKS Staking set, tool with all stakes (similar to the K&D set I think) plus the usual assortment of hand tools (pliers, drivers, hammers etc. Small bench vice.

Also ordered some bushes ( 2mm pivot hole, 1.5mm thick, 4.5mm OD. Plus reamer and handle. Reamer is 3.97mm

Don’t think I have anything that might be useful for burnishing, but ask and I’ll see what I have or can get.

Edited by Moose

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You can make a burnisher out of a hardened piece of steel by “making” it, which is to abrade one surface. Itv just needs to be harder than the pivot itself. If it was me then I personally wouldn’t bother on a clock like this unless the pivot surface looked rough. 
 

You’ve got the tools needed to do the job satisfactorily for a clock of this caliber in my opinion. 

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Those ready made bushes are all right for this type of clock. Its the sort of movement to practice on. If you can burnish the pivot, do so it will give you good practices besides the steel is not hard and the so called brass is quite soft.  Reamer from the inside to the outside, do not reamer both ways, the out side of the bush is slightly tapered, with the new bush it needs to be in about a quarter way in, you should then tap it in with a punch that covers just over the size of the bush so it is level to the plate. If you intend to go into repairing clocks you are going to find re- bushing is all most part of clock repairing and a lathe will be a good investment, not only can it be used for pivot work but also for making your own clock bushes. I have a unimat 3 with loads of accessories, this lathe can take Longcase barrels and longcase center  wheels. 

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