doc_here_ wrote:
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.
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 appropriate 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 bookmarked it and can't find it again, but the author had made some tests of various types of bearings and came to three key conclusions:
1) Don't use the sealed type ball bearings, the rubber shrouds rub on the races.
2) Soak the bearings in mineral turpentine to remove all the lubricant. Lubricant adds drag and is not required in such a low-speed application. 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 Australian 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/
Another source of bearings, especially if you are building to metric sizes, is your local hobby shop. Radio controlled cars seem to use a lot of them. And they are very small.
Yes, that's it. I've now bookmarked 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 remoteness of where I live.
I live in Exmouth on the North West Cape of Western Australia. Resident population 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 ;D
The availability 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 edited by kit on Tue Sep 26, 2017 1:13 pm, edited 1 time in total.
doc_here_ wrote:
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
The start of a new service, the Gerotic Delivery Net? I didn't think of it this time, but if they drag me off on another expedition. The youngest girl (the one I owe an international trip to) is starting to hint about South America.
I can't be the only one who's wife wants to turn into a global traveler; perhaps we need a pending international request and delivery list. Likely slower than Kickstarter but less likely to fail
I’ve just completed David Atkinson’s Sextus design and it is the first clock that I installed steel bearings. Although David has bearings in several locations I only installed them on the pendula. Since the escapement is a grasshopper type it is highly sensitive to the drive weight to regulate the time, I found that sufficient weight to maintain the running of the clock meant that the clock was being overdriven. By installing the bearings in the pendula I was able to use a much more acceptable drive weight, and thus more overall time accuracy.
Here is a picture of the finished clock.
6F57D4E9-DB1E-4D6F-BC4C-0233673F1B1D.jpeg
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Awesome work. I agree totally with you, a bearing can do wonders for almost any work, and I
really advise using them when one can. Merry XMas and thx for showing us your work.
That's a nice example of the Sextus. It's a very hypnotic design to watch!
I was surprised at how much difference there is between ball and plain bearings. Soaking them in solvent to remove any manufacturer-installed grease apparently helps as well. At the speeds we run these bearings, grease and oil simply add drag.
