Bushing Question

[lofty]

I have an Ogee movement which needs new bushes in the escape wheel. Now as this is an outside escapement, I am wondering what is the correct method to employ here. I am thinking that in order for the bush for the escape wheel bridge to be properly fitted from the inside, it would be necessary for the bridge to be removed, rebushed and fitted again with new rivets. Is this the way it is normally done ? Thanks

Lofty

 

[lofty]

I have an Ogee movement which needs new bushes in the escape wheel. Now as this is an outside escapement, I am wondering what is the correct method to employ here. I am thinking that in order for the bush for the escape wheel bridge to be properly fitted from the inside, it would be necessary for the bridge to be removed, rebushed and fitted again with new rivets. Is this the way it is normally done ? Thanks

Lofty

 

[bangster]

Don't you have to remove the bridge anyway, to get the escape wheel out?

bangster

 

[Larry]

Lofty,
Most suppliers sell a stepped staking block specifically designed for the american movement bridges (Merritts.com P-1320 $7.00). I use one when I need to and it beats the alternative.

Larry

 

[ChrisBeattie]

Hey lofty,

I do not remove the bridge to re-bush. I use a vice and place the front plate upside down and ream from the inside. After reaming I again use the vice for a flat surface and place the bushing on the reamed out hole and I use a tool similar to a punch to reach through the plate and get to the bushing/bridge, to hammer it in. You obviously have to use a flat surface so you do not damage the bushing.

I think you can do more than an adequate job without removing the bridge. All you have to remember is to make sure the bridge is supported fully when hammering in the bushing, not just the plate. I hope this helps.....

Chris Beattie

 

[Robert M.]

Like Larry I use the stepped staking support that I purchased from Merritts years ago,works great.Just slide it under your escape wheel bridge until it fits snug,align the hole in the stake with your pivot hole and ream your new hole.When that task is completed just slide your stke over to a a flat spot on the stake,insert your new bushing in the newly reamed hole and while using the stepped stake as an anvil just tap your new bushing in.All this can be done with the plate up.All in all the stepped stake is a great invesment.It really comes in handy.
Respectfully,Bob Fullerton

 

[John C. Losch]

Bangster wrote:
Posted August 11, 2006 03:15
Don't you have to remove the bridge anyway, to get the escape wheel out?

Good God! I hope that was a joke. --You mean I have been doing it wrong all these years? Jcl

 

[bangster]

Ulp. My newbie ignernce strikes again. If this here scapewheel has its outer pivot stuck in a hole in a bridge, what's its inner pivot stuck in? Apparently, something removable.

I guess I don't have a proper mental picture of the mechanism in question.

bangster

 

[Scottie-TX]

Usually BONG, one pivot resides in the back plate and the other pivot resides EITHER in the front plate or in a BRIDGE on the front plate. Some bridges are attached with a machine screw. This bridge is attached with rivets.
Do you also remove the pillars from the plate to take out the mainsprings? Thought so.

 

[harold bain]

Bang, just like an escape wheel between the plates, when you separate the plates, the wheel is removable. Back pivot in back plate, bridge is extension of front plate.
Harold

 

[John C. Losch]

8/11/06

To Bangster, and the list:

I am sorry if I embarrassed you with my comment. I really thought you were joking. I think there is confusion about clock movements. In addition, there is a confusion of terms if we are to be littoral. I think “Lofty” was referring to a Connecticut movement since he described the clock as an Ogee. Nearly all brass Connecticut movements have the escape wheel positioned forward of the front plate so that they can run with pallets attached outside the plates. The second confusing term is “bridge.” Those escape wheels are almost always held by what is properly called a “cock.” Modern euphemistic usage makes some people uncomfortable with that term.

Simply put, a bridge has two points of attachment while a cock, such as is used in Conn. Clocks has only one. Balance wheels in watches have a balance cock. Pallets in nearly all Grandfather clocks have a bridge holding the rear pivot. And so on.

The escape wheel cock in most Conn. Clocks is riveted to the front plate. The escape wheel is removed when the front and rear plates are separated. After the front plate has been lifted off, the wheel pivot can be withdrawn from its bearing, then the wheel will slide out from under the cock, and can be removed from the front plate by drawing the arbor and pinion forward of the plate.

There are clocks using bridges to hold the “scape wheel”. Visible escapement French clocks are the first to come to mind. The bridge is held by screws, not rivets, and has to be removed as a part of disassembly of the clock. Bridges holding wheels are used in numerous high-grade and precision clocks. In those clocks screws hold all bridges and cocks.

All the previously suggested methods for bushing a Connecticut ‘scape wheel cock are correct, and are little different from the method I use employing a bushing tool. The technique is too obvious to require repetition.

There is almost never a need to remove a riveted escape wheel cock. Jcl

 

[Scottie-TX]

"Embarass BONG"? Man! He NEEDS embarassed. Thanks.
Thanks also for the very interesting interpretation and description of the cock and bridge. I LOVE learning! Thanks. I liked that, JCL.

 

[lofty]

Hi, thanks to all for your advice. I did not know that a special tool existed for this type of bushing and I will enquire with my local parts supplier in Sydney abouts its availability here. It will certainly be easier than removing the bridge/cock. Regards

Lofty

 

[RJSoftware]

http://www.merritts.com/store3/main/product.asp?ProductID=81262&search=1320

I can vaugly understand this post. As I am not exactly sure what the problem is.

Is the problem reaming the hole out for the new bushing to set in, or is it peening in the new bushing in place?

Another thing I was under impression was that staking tools where old method of expanding surrounding brass material to pinch close material to be re-broached. My guess now is that you use staking tools to peen bushings in place as well. I do not own a staking tool set.

As per another thread, I was informed that reaming in wrong direction (from outside in) causes new bushings to eventually pop out as they have an overall taper on outside surface of reamer which creates bushing hole that favors pressure in one direction.

So pressure on the bushing from arbor/pivot causes bushing to tighten when pushed out, but would pop out if pushed in (opposite when reamed wrong direction).

Still, after examining the tool (stepped staking support) and envisioning as stated it does not seem to make more sense than just reaching in with staking tool with plate upside down and supported on flat metal surface to peen bushing into place.

Also don't see the reasons for holes in the steps. Is it to guide the reamer?

Me, I like to hand ream, and perhaps this is a lathe setup difference for reaming? Unless maybe the hand reamer can not reach into the bridge to ream the hole...?

Me, in this case I would simply ream from outside and peen the bushing in place. I have an awl that I customized for peening bushings in place. The tip of the awl is tiny and round like a bb.

After peening I have found that it provides a tight strong friction fit that does not pop out.

After peening the bushing in place then I broach with cutting broach. Then smoothing broach. I think the smoothing broach is important.

RJ

 

[Scottie-TX]

Lemme recap ARJAY like they do on the 6 : O Clock news: The question was, "Do I need to remove the EW cock to rebush?"
The unanimous answer is, "no".

 

[RJSoftware]

Well, no I was reffering to how to bush with that predicament.

 

[neighmond]

RJ,

The block is simply an aide for the bushing tool, or hand bushing, and holes are in the stepped block because the reamers pass through them as they ream the plate (cock) for its new bushing. The stepped block supports the cock so the bushing is upright, and the endplay is maintained.

From what I have seen of modern friction bushings, they aren't tapered, but are drum-shaped, and can be inserted from either side without injury.