Bent wheels

[Neverenoughwatches]

Morning watch peeps from the UK, i hope we are all well.  I'm just asking for a little technique advice/method with straightening the drive wheel of an indirect centre seconds. This is the extra 5 spoked wheel attached to the third wheel shaft on top on the train bridge. Its quite wobbly, looks like a previous repairer has removed it via its outside edges and bent one end up. A pair of homemade micro levers under the hub does the job without damage. The drive wheel is making an intermittent skip with the mesh of the center seconds pinion ( a noticeable wobble) . Ive confirmed that it is the wheel and not the shaft that is bent. I've tried to straighten on a staking block even by pushing the hub into a wide hole to over compensate for the bend returning to shape. Does anyone have a safe method before i resort to gripping with pliers and bending out. I've thought about mounting on a shaft to set into truing calipers.  Tia.

[nickelsilver]

I hold the wheel in a lever type jeweling tool, between a pusher and a stump on the wheel hub. You can turn it by finger and see where it's high/low, then adjust with stout brass or nickel tweezers gently bending until it turns flat. If it's flat in the tool, it should be flat in the watch, unless the hub has gotten tweeked in the wheel (rare), or if the extended pivot it fits to is bent (common).

[Neverenoughwatches]

53 minutes ago, nickelsilver said:

I hold the wheel in a lever type jeweling tool, between a pusher and a stump on the wheel hub. You can turn it by finger and see where it's high/low, then adjust with stout brass or nickel tweezers gently bending until it turns flat. If it's flat in the tool, it should be flat in the watch, unless the hub has gotten tweeked in the wheel (rare), or if the extended pivot it fits to is bent (common).

Brilliant thanks Nicklesilver, thats a great technique, i was trying to think of a flat platform to work off and still be able to use a bending tool. The wheel is visably bent out on it own but It has crossed my mind more than once that it is the pivot as well, i think  i need another closer inspection now that you've mentioned that as well. Thank you

[Nucejoe]

If its any consolation, I say, indirect center second mess is the culprit kind of pain..  watch detroyers create. 

Is this a pricy watch your working on? 

Rgds

 

[Neverenoughwatches]

3 hours ago, Nucejoe said:

If its any consolation, I say, indirect center second mess is the culprit kind of pain..  watch detroyers create. 

Is this a pricy watch your working on? 

Rgds

 

i know that feeling i broke the pivot on one 18 months ago, I'm pleased to say i learnt my lesson and this one is not my doing. No its not of any value really, something I've been back and forwards on harvesting parts for a few weeks in beween organising stock space in my watchroom. Its had a fair few issues this is just another to add to the list. Also looks like a bit of a design flaw, the pinion of the second hand sweep sits quite low in the bridge, should have had a bit more depth to it to engage better with the drive wheel. Just wondering if it has been pushed lower by a heavy handed second hand setter. 

[mikepilk]

9 hours ago, Neverenoughwatches said:

I've thought about mounting on a shaft to set into truing calipers.  Tia.

I've just assembled an ETA 2879 which had a wobbly sweep second wheel. As the pivots are small I managed to use my truing calipers. It's not easy to get the such a thin wheel perfectly flat - it runs close to other wheels/bridge in this movement. In the end I bought one from Cousins as they're only £7.

8 hours ago, nickelsilver said:

I hold the wheel in a lever type jeweling tool, between a pusher and a stump on the wheel hub. You can turn it by finger and see where it's high/low, then adjust with stout brass or nickel tweezers 

I hadn't thought of using the jewelling tool - great idea.

What about wheels with larger pivots - I guess you could hold them between two concave punches on a staking set?

[nickelsilver]

1 hour ago, mikepilk said:

I hadn't thought of using the jewelling tool - great idea.

What about wheels with larger pivots - I guess you could hold them between two concave punches on a staking set?

For something with big pivots, not holes like the sweep wheel, I have truing calipers that will take them (dozen or so different, some with replaceable nibs so they can be made as needed), but for instances where those are too small like center wheels on a pocket watch, I use a depthing tool, or put the wheel up between centers in a dead center lathe.

 

Depthing tools in watch sizes are plentiful and cheap, don't count on them for depthing, but for truing a wheel they're great! Clock size depthing tools on the other hand... expensive!

 

My 8th grade English teacher would literally kill me for the first  paragraph.

[VWatchie]

58 minutes ago, nickelsilver said:

My 8th grade English teacher would literally kill me for the first  paragraph.

[Neverenoughwatches]

3 hours ago, mikepilk said:

hadn't thought of using the jewelling tool - great idea

Well that was an interesting little game. I set the wheel up in a horia type jewelling tool using a stump that nicely fitted the hub of one side and a jewel pusher that fitted the rivet on the opposite side of the drive wheel. This gave a nice even free wheeling wheel as tight or as loose as i wanted . I needed an index to work to as the bend was actually only slight ( which now leads me back to a possible bent pivot as well ) i decided a physical sacrifice was called for, so a very small nick in the nail of my forefinger and pressed up against the stump served rather well. Held up at eye level with plenty of light and a x10 loupe, just pushing past horizonal to straighen. Did it work ? Bloody right it did, not perfect but much better than it was.Nicklesilver you're a diamond great tip. Now to check for a bent pivot.

2 hours ago, nickelsilver said:

but for instances where those are too small like center wheels on a pocket watch, I use a depthing tool. 

I see these all the time on ebay, now i have an excuse to buy one

2 hours ago, nickelsilver said:

My 8th grade English teacher would literally kill me for the first  paragraph.

And i thought i was the king of commas

[Jon]

13 hours ago, nickelsilver said:

I hold the wheel in a lever type jeweling tool, between a pusher and a stump on the wheel hub. You can turn it by finger and see where it's high/low, then adjust with stout brass or nickel tweezers gently bending until it turns flat. If it's flat in the tool, it should be flat in the watch, unless the hub has gotten tweaked in the wheel (rare), or if the extended pivot it fits to is bent (common).

Nice tip! I tend to put it on a staking block with the hub inside a hole and judge what is high and what is low then transfer the wheel onto a piece of soft wood or even thick leather with a small hole in to accommodate the hub and push down on the high spots whilst keeping the wheel flat, but I think I'll try your way next time.

[Neverenoughwatches]

5 minutes ago, Jon said:

I tend to put it on a staking block with the hub inside a hole and judge what is high and what is low

Thats exactly how I started my attempt but keeping track of the bend was difficult, putting in a horia worked really well. The depthing tool sounds better.

[Jon]

 

 

 

I posted some of these slides from a lesson I take on an indirectly driven sweep second movement. I hope it help anyone. I really should post the set of lessons on a sweep seconds movement sometime soon. The Bifora (Bidlingmaier) 934 has a great rocking bar winding system, which isn't usual to see, as seen in the last two slides

 

[Neverenoughwatches]

3 hours ago, Jon said:

 

 

 

I posted some of these slides from a lesson I take on an indirectijly driven sweep second movement. I hope it help anyone. I really should post the set of lessons on a sweep seconds movement sometime soon. The Bifora (Bidlingmaier) 934 has a great rocking bar winding system, which isn't usual to see, as seen in the last two slides

 

Very useful Jon thanks. i think you've posted the use of a mainspring to remove the  drive wheel before, handy tip. I had made some miniature levers for removing collets a while ago which made a good job of lifting it. The cs pinion sits really low on mine, i think its been previously forced down the arbor by someone installing the second  hand. The wobbly drive wheel was skipping it's mesh with the pinion because of. Your diagram illustrates perfectly how the positioning heights should be, mine is way off that.