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Author Topic: Bearings in clocks  (Read 306 times)
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David Morrow
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« on: September 11, 2017, 09:09:02 PM »

Since I requested this clock section, I'll kick things off with one of those hotly debated topics - should I use bearings ?

I won't debate whether or not to use bearings with this post. I have made wooden clocks with no bearings, with brass tubing for bushings, and real  bearings. But, when I do use bearings, I use router bearings that I buy from Lee Valley Tools here in Canada. Normally I use 1/4" OD x 1/8" ID bearings for most arbors. For the wind arbor, I use 1/2" OD x 1/4" ID router bearings.

Brian Law and Woodentim ers plans show the bearings as being mounted in the frames and the wheels / pinions being locked to the arbor with a set screw. The arbors then turn in the bearings. That OK when you can get them almost perfectly aligned and thereby avoiding any binding. It's also ok when you have zero frame sag, which also causes binding. What I do is press fit the bearings in the wheel / pinion assembly which I glue together, and and let them spin on the arbor rather than locking the gears to the arbor which turns on the bearings in the frame. I find that I have no alignment issues and, frame sag, if it occurs, becomes a non-issue.

The downside is that I have to make brass tubing spacers to keep the gears properly aligned.

I hope my descripti on makes sense.

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John T
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« Reply #1 on: September 12, 2017, 12:30:40 PM »

Hi,
I have made a total of 34 clocks and none of my clocks uses bearings although I have used brass bushings from time to time.  In actual fact I've found that the problems a alignment are not worth the effort of using bearings or bushings unless the wheel is turning on steel, that is not to say that if properly aligned bearing wouldn't be effective, I just find them not worth it. 

My longest running clock was put into beat in December 2005, and runs without problems other than keeping it wound.  This clock uses wooden plates, wooden gears and wooden (dowel) arbors.  It is a 30 hour movement running on 3 pounds.

John
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1% inspirati on 99% try, try again
ArtF
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« Reply #2 on: September 12, 2017, 08:45:16 PM »

John:

 Impressiv e. Thats a good run from pure wood IMO.

 I use bearings where I can, Im not opposed to them anyway. With acrylic I find
sinking a bearing in the acrylic gear helps center it. Lasers dont cut very straight
holes, but a 15mm hole that you press a flanged bearing into makes it run very true.

  Depends on the project and medium Id suppose..

Art
 
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doc_here_
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« Reply #3 on: September 22, 2017, 10:34:20 PM »

Hi folks, please understan d that I am in no way an expert but recently reading through some very obscure documents I discovere d that the discovery that turned clock making around way back when they were trying to make reliable and accurate ship board clocks to work out longitude was the use of Lingum vitae. This wood was able to self lubricate the bearings, is unaffecte d by water, salt or fresh, and its use marked a new era in clocks. I read that one of the clocks built back then has been refurbish ed and is still keeping good time 300 years later. I did a search and found that one of your power companies over there turned to Lingum vitae bearings a few years ago and it has been remarkabl e in removing all maintenan ce required and saved them thousands . Another search and a knife making supply company here in Aus. sent me a small block of Lingum vitae which I intend to use in small sections by inserting small blocks where my brass rods will go and hopefully will be able to get around using bearings that way. Unfortuna tely I then found with further searching that this wood is on the restricte d list and is very hard to buy so I seem lucky to have gotten the piece that I did. Hope that this small thought is of interest, thanks for your time, Phil
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David Morrow
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« Reply #4 on: September 22, 2017, 11:12:04 PM »

I don't think I have heard of anyone in recent years getting any lignum vitae so yes, you are very lucky. Best to use it very sparingly . It would be a nice tribute to your find to use it for clock bearings.

Another thought that comes to mind when you say it is self lubricati ng is to use graphite plugged bronze bushings.
http://www.nationalbronze.com/News/self-lubricating-graphite-plugged-bronze-sleeve-bushings-now-available-online/




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ArtF
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« Reply #5 on: September 23, 2017, 06:48:24 AM »

Funny, they sell Lignum Vitae , I have a chunk on my workbench . The Navy used
to use it for the drive shaft bearings up here. It really is well known as bearing
wood and lasts a long time.. strangely, Ive never used it, I tend to steel bearings. Smiley

Art
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Mooselake
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« Reply #6 on: September 23, 2017, 03:41:25 PM »

The local (that's 100 miles east of here) exotic hardwoods place had some the last time I was in there.  Bought a 1 inch square by 12 inch piece, $5 from their web site.  No real intended purpose, but thought it might be handy to try making some bushings out of it.

Wife picked out a 2" square by 36" chunk of purplehea rt.  She's not a woodworke r so it might be a clue stick...

Kirk
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ArtF
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« Reply #7 on: September 23, 2017, 04:01:37 PM »

Theres a few types of it I notice, the real good stuff is sold by the pound, not by board foot.

Art
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David Morrow
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« Reply #8 on: September 23, 2017, 06:10:46 PM »

Funny, they sell Lignum Vitae , I have a chunk on my workbench . The Navy used
to use it for the drive shaft bearings up here. It really is well known as bearing
wood and lasts a long time.. strangely, Ive never used it, I tend to steel bearings. Smiley

Art


The only time I ever heard of it being used for a bearing was John Harrison when he was in the race to build the clock trying to win the British Admiralty prize in order to more accuratel y calculate longitude . I suspect anyone using it today is making an effort for something as tradition al as possible. Here's an episode of PBS's Nova about Harrison and his clocks. Really interesti ng.

https://www.youtube.com/watch?v=NENPdT4LASw


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doc_here_
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« Reply #9 on: September 24, 2017, 12:19:26 AM »

Yes, that is who and what I was referring to. An amazing tale and a shame that he died before he could collect the prize money.
There is also a great article on their modern use as bearings to be found here : http://www.hydroworld.com/articles/hr/print/volume-32/issue-4/cover-story/bearings---seals--wood-makes-a-comeback-for-hydroelectric-turbin.html
Ps the piece that I got here down under was 1 " x 1 " x 6" and cost me $30 and $25 shipping, sucks being here sometimes lol
« Last Edit: September 24, 2017, 03:03:54 AM by doc_here_ » Logged
Mooselake
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« Reply #10 on: September 25, 2017, 03:02:44 PM »

Ps the piece that I got here down under was 1 " x 1 " x 6" and cost me $30 and $25 shipping, sucks being here sometimes lol
Just went through the Sydney airport twice, to/from NZ.  Would have brought you some (if you're close to there) if I'd known.  The sort-of local guys want $6 for the Argentine variety.

Kirk
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kit
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« Reply #11 on: September 25, 2017, 08:01:36 PM »

David,
I like the idea of fixing the bearings in the wheels rather than at the ends of the arbours. I have a small lathe here so making brass locking collars with the appropria te profile to hold the wheels in place without rubbing on the outer race of the bearings will be no problem. Avoiding binding has been an issue with both the Sextus clocks I have built, but the second one, which has ball bearings on every shaft, runs with less weight than the first.

A while back I stumbled upon an article online on the use of ball bearings in clocks. I don't apear to have bookmarke d it and can't find it again, but the author had made some tests of various types of bearings and came to three key conclusio ns:

1) Don't use the sealed type ball bearings, the rubber shrouds rub on the races.

2) Soak the bearings in mineral turpentin e to remove all the lubricant . Lubricant adds drag and is not required in such a low-speed applicati on. Corrosion is unlikely to be a problem indoors.

3) Once 1 and 2 are taken care of, ball bearings have by far the lowest friction of any of the common bearing types used in clocks.


For our Australia n readers: I've used Plaig Bearings a couple of times and been happy with the speed of delivery and the price/quality of the product. They have a wide range of the weeny bearings we might want for a clock.   http://plaig.com.au/shop/

Kit
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David Morrow
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« Reply #12 on: September 25, 2017, 08:12:11 PM »

Kit, this may be the bearing article you are thinking of :
https://www.bocabearings.com/general/ball-bearings-in-clocks

Another source of bearings, especiall y if you are building to metric sizes, is your local hobby shop. Radio controlle d cars seem to use a lot of them. And they are very small.





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kit
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« Reply #13 on: September 26, 2017, 04:56:04 AM »

David,

Yes, that's it. I've now bookmarke d it for future reference .

"...your local hobby shop..." Here are some notes I made for a Pommie (sorry, English) friend who didn't quite get the remotenes s of where I live.

I live in Exmouth on the North West Cape of Western Australia . Resident populatio n is about 2500. Once you leave Exmouth on the only road, your first fuel stop is 220km and the first town going South, Carnarvon, is another 150km after that. The nearest set of traffic lights are in the first town after Carnarvon, which is Geraldton, a total of 850km from here. The state capital, Perth is a total of 1300km which is the same distance as Land's End to John 'o' Groats (the two most distant places on the mainland of Great Britain), but with only the two sets of traffic lights to hold you up for the first 1250km. Perth is the only place you can fly to from here so that is the quickest place to get to and is where the nearest decent shops are to be found along with theatres, cinemas, car parking you have to pay for and all the other wonders of a modern city including hotels above 'motel' status.

On the other hand we have a fabulous climate, no traffic holdups getting to work (except the ocasional emu), no through traffic as we're on a long peninsula, wonderful beaches, many with very few people on them even in the tourist season and a fabulous fringing reef within swimming distance of the beach in places where you can snorkel out see coral, many type of fish, turtles, sharks (mostly harmless) and a variety of local and foreign maidens (mostly harmless).

I suspect there are some equaly remote places in Canada, but we don't get the snow over here  Grin

The availabil ity of internet shopping has been a boon in Exmouth, the small Post Office is always brimming over with boxes and parcels of every shape and size.

Kit
« Last Edit: September 26, 2017, 08:13:16 AM by kit » Logged
doc_here_
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« Reply #14 on: October 06, 2017, 06:59:32 PM »

Ps the piece that I got here down under was 1 " x 1 " x 6" and cost me $30 and $25 shipping, sucks being here sometimes lol
Just went through the Sydney airport twice, to/from NZ.  Would have brought you some (if you're close to there) if I'd known.  The sort-of local guys want $6 for the Argentine variety.

Kirk
Oh if only I had known Kirk, that would have been brilliant as I'm about half an hour from the airport in Oatley.
If you're ever coming back let me know and maybe we can sort something out for the next time. Thanks for the kind thought
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