Recent Posts

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1
Other escapements / Re: Retrograde motion
« Last post by KarlaB on May 12, 2017, 02:57:13 AM »
If you have thrown such photos, please send and me in a private message
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Wheels and pinions / Re: Wheel/Gear confusion
« Last post by KarlaB on May 12, 2017, 02:55:24 AM »
Tinker,
Here's an exerpt from the "Designing Cycloidal Gears" page located here:
http://www.csparks.com/watchmaking/CycloidalGears/index.jhtml

If you scroll down the page to the first illustration, the dotted circle about mid-tooth is the Pitch Circle.

"Imagine two disks of different diameters rotating against each other without slipping. The outer edge of each disk defines the pitch circle for that disk.

When we put teeth on these disks, the part of the tooth that rises above the pitch circle is called the addendum. In the case of cycloidal gears, the addendum is a curve is an epicycloid . The addendum curve is usually the same on both sides of the gear tooth tip in mirror-image. This is not strictly necessary when a gear train is driven in only one direction. Occasionally the winding wheels of watches are made with wolf teeth. These have an epicycloidal addendum on one side of each tooth tip and a straight or even slightly concave curve on the unused side of the tooth tip. This makes the teeth look like... Teeth! "

Basically, its the point on both gear and pinion where the teeth engage.

Marty

Thanks for this link, i was looking for it!
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Wheels and pinions / Re: Lantern pinion interference question
« Last post by KarlaB on May 12, 2017, 02:53:16 AM »
It is necessary to check the centering of the axes.
4
Bearings / Re: Bearings for a wooden clock?
« Last post by Neex on May 09, 2017, 04:33:21 AM »
Loved this post Rabbit, thanks for sharing.

I had a similar experience with ball bearings - not great. Mind you I was making from scrap components, so I was using sealed 608's (skateboard bearings) which were available but massively oversized - in the end I was pretty convinced that it was the viscosity of the grease that made it suffer the most. In retrospect I should have blasted the grease out and seen how they faired... might have been ok since the application is relatively minimal duty with light wooden gears.

Now I'm using PTFE tube inserts in the wooden gears, on stainless steel axles - the coefficient is fantastic. But thanks for your warning on creep in the high load areas. For those areas I am about to attempt acrylic bushes since I can laser cut them quickly and the acrylic surface is incredibly hard.... I haven't seen much work in this area so I'll let you know how I get on.

And completely agree on the logic of using different bearings for different areas. Ultimately each pivot handles a different range of forces... so ideally the bearing should match the pivot, a universal bearing will only ever attract inefficiencies.
5
General Discussion / Re: My first clock will not work
« Last post by jss on April 22, 2017, 09:34:09 AM »

This may give some suggestions

This comes from Clayton Boyer Woodworking Designs

http://www.lisaboyer.com/Claytonsite/frequentquestions.htm

Why doesn’t my clock run?


When I put a clock into beat and it has a good, even balanced 'tick, tock', and yet only runs for a few minutes, the first thing I do is start marking teeth and pinions.  I go through the train marking each set of gears where they have stopped together.  Then I start up the clock again and when it stops, see if any of the pairs match again.  I have lots of pencil marks on my clock wheels.

Eccentric wheels are another very common cause stopping new clocks.  Rather than using the original drawings in the plan, people use Xerox copies of clock plans, and the copy machines don't always copy true, leaving them with egg-shaped wheels. I never use copies.

When looking for what's stopping a clock, I ALWAYS start at the escape end of the train and work down.  Very little stops the weight end, but it takes very little to stop the escape end.  So, those are the three things I would check first, proper tooth mesh, out of round wheels, and internal friction.  There are, of course, a few thousand other possibilities, but those three are the most common reasons for a clock that wants to stop.


Just thought of another...Are you applying any finish between the teeth?  If you are, I have a suggestion - don't.  The application of any finish between the teeth increases internal friction of the clockworks dramatically.  Finish not only makes teeth gummy, it also takes up critical space between the teeth.  A clock that works great dry, will, many times, stop dead when finish is applied.  It's happened way too many times, and now when I finish a clock I spray it - and try to keep the spray out of the teeth and just on the faces.

Also, poly finishes never really dry.  In the fluctuating humidity here in Hawaii I found that during very humid times the clocks sprayed with polyurethane get just gummy enough to stop the train.  I've contacted the people at MinWax about this, and having never made a wooden clockworks, they didn't have a solution.  They recommended I use their Helmsman Poly since it was designed for boats.  It gums too.  Just not as bad.  So now I avoid anything hitting between the teeth.
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General Discussion / My first clock will not work
« Last post by Al Nelson on April 14, 2017, 10:59:51 AM »
This is my first clock (Mark Tovar 30 hr gear clock) and I can't make the clock keep working.  Very frustrating. I would appreciate any advice.
1. When I disengage the pallet and start a gear going all of the gears keep turning with a 3 lb weight until I stop the weight. 2. When I reengage the pallet and put up to 4lb 4oz of weight on it and swing the pendulum it works until the pendulum gradually stops swinging. It seems like it may not be enough weight but if I increase the weight by pushing down on the weight the same thing happens.  I really enjoyed making the clock and I want to start on the next one.  I'm stuck and would appreciate your help.
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General Discussion / Re: Clayton boyers simplicity
« Last post by steve323 on April 08, 2017, 01:57:22 PM »
Welcome to the forum Bobman.  It is not very active, but there are a few occasional gems.

The simplicity design appears to have a 1 meter pendulum.  Actually, 0.9939 meters should produce a 1 second beat.  Lowering the bob by 1.38mm should slow the clock by 1 minute every 24 hours.  13.8mm should slow it down by 10 minutes.

Steve
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General Discussion / Re: Clayton boyers simplicity
« Last post by Preechai on April 03, 2017, 03:36:10 AM »
I think there should be a better way.
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Gallery / Re: New clock
« Last post by gift01 on March 09, 2017, 01:36:52 AM »
so beautiful watch.
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tools / Re: Radial Vector Tool...
« Last post by jltrent on February 24, 2017, 05:35:33 AM »
Haven't been on the forum in a l..o..n..g time, but per previous post, have uploaded the latest version of the Radial Vector Generator to the original post in this thread...  Enjoy!  R, Jon
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