Brocot open escapement alignment issues

[Chris]

I'm working on an open escapement movement that has been rebushed in its life. It seems ok and the ruby pallets appear to be original, but the edges of the pallets seem to catch on the tips of the teeth, depending on how I adjust the eccentric bushing. I've tried increasing the space between the two pallet arms as well, with minimal success. It ran all last night, but today I stopped it and restarted it to see if it would be ok and it started hanging up again. Does this sound like a power issue or a pallet issue? How would you proceed? Thanks, Chris

[Joseph Bautsch]

I presume that you have done the requisite cleaning of pivots, bushings, springs, etc.? From what you describe if it's just one pallet hanging up on a tooth I would suspect a mainspring power problem. If both pallets are hanging up at the same time on a tooth then you have an escapement problem.

[Scottie-TX]

I think you could determine whether it's a power problem by observing it closely both during operation and at stoppage. Watch the escape wheel. Does it appear to move BRISKLY from lock to lock or is it kinda lazy and lethargic? If it appears lazy - it is probably a power problem. If there is no or little power to the EW at cessation - power problem.

[jz]

I assume you aligned the jewels the right way. It is critical.

Jerry

[shutterbug]

I'm with Jerry. Check to be sure the curved portion of the jewels are facing the EW teeth and that the flat edge is not hanging up. You may have to heat the shellac and turn the jewel a bit. You can use a soldering iron - be sure the jewel stays straight :)

[glwryw2]

I assume you have checked for any bent teeth on the escape wheel - if not, next time the clock stops check the condition of the escapement wheel teeth immediately in contact with the jeweled pallets when the clock stopped. If there is a bent tooth, it can be straightened but be carefult not to break off the tooth.

[Chris]

I did the complete cleaning, including pivot polishing and pegging the pivots. Someone else rebushed it before me, so I ASSUME it was working after they did that.

It seems like it's a power issue first off; it will tick a couple times and then immediately stops. I will also check tension on the back at the crutch leader as I tweaked it a bit the other day to remove some slop at it was ticking. It may have too much friction there. I think I'll then pull the verge and see if it spins.

The pallets look to be correctly aligned and untouched. Wish me luck!

[awolff]

I have experienced similar symptoms with my Gilbert open escapement crystal regulator. (This is the 3 plate movement often voted 'least favorite movement to work on.') One thing I have found on open escapement movements is that it is very easy to bend or misalign the front escapement mount, resulting in the escape arbor having insufficient end shake. Grasp the escape wheel with a tweezer and test the end shake of the escape arbor. You do not need much, but if there is not any, the movement will exhibit symptoms similar to a lack of power like you are describing.
Good luck, Allan

[Gordon Andersen]

I had been having a similar problem with a French open escapement movement. It acted as though there was a loss of power. After checking everything out, and finding anything wrong I was ready to give up. I finally noticed that when I would put in the key to see that it was fully wound, it would start running without my doing nothing more than just inserting the key. Upon very close examination, I discovered that the center part of the dial wasn't anchored in place and that the edge of the hole through which the scape arbor goes would move close enough to the arbor to make it stop. I ended up having to broach open the hole just a tad to give the scape arbor more space.

[Chris]

OK, here's all the things I found to be wrong. First, it seems the brass for the front and back pivots for the verge fit too tight. There was no end shake on the verge. So, I took some spring metal and placed it under the front arm. This gave it end shake.

It was still very fickle, sometimes running and sometimes not. As it turns out, there was still some issue with the pivot spacing, for when I gently squeezed them, it would go dead. I tightened them up and gently pried (I hate prying on anything) on the front one until it freed up. It now has a strong tick and good entry/exit.

Also, I noticed the brass collar surrounding the escape wheel looked close to the shaft, so I moved it up to clear.

It was by far the worst French clock I've ever worked on. Usually, they're a breeze, showing little wear. Someone had rebushed this one, so I knew something would go wrong.

Keep your fingers crossed that it stays going for the month of April!