Thread: First clock... A small one

Wow Russell overall very impressive and a rather quick build. Love the idea of the angle meter.

Dean.;

Hi Russell any chance of some video of trhe running clock?
Dean.

Dean
I have never got into the video side of things,,,looks like I am about to learn

Hi
Had to remounted the clock for the wall was that out of square that the clock keep stopping after 3-4 hours.
Used some plastic core board 16mm thick mounting this 1mm of the wall to try and remove the drum effect of the wall as the ticking could be hear from any where in the house and that's with the door closed.

What I want to do next is to go back thought the clock with the aim of reducing the friction and lowing the weight needed to run it. Have seen so good video on this and it got me interest in the fine tuning.
So any hints let me know.

Russell

Hi
Found one lot of friction in the escapement wheel bearing,This runs on the minute hand shaft and I had used a aluminum bush in the wheel I know not a good thing, so polished the inside of the bushing and shaft and add a the smallest drip of oil. This allowed the whole mechanism to rotate by just blowing on it.
How much do the little things matter, the minute hand is not counter weighted so from top of the clock the minute hand gains about 30 second in half an hour and loss it on the up hill side but it is keeping good time over all.
Need to make some new hands as these one are hard to see being the same color as the frame. I have some sheet brass laying around, no have to keep polish them.

Russell

I'm following this one closely, because I've just started the same build. Will have to get some photos up when I have more than the main frames cut out. Weird about the minute hand gaining and then losing. It's that sort of thing that I hadn't even considered as a potential problem.

With Dean's great result of dropping his weight from 10kg to 3.4kg well I better have a look at mine.. always said I was, so I did.
Now it is running with about 3kg (to be measured) and on one weight box hanging directly off the shaft. Boy is it the tick quieter.
The main problem was one ruff spot on one gear tooth. Found this by marking the all engaged gear teeth when it stopped and seeing if it keep stopping at one spot which it did. A 30 second sand and it has now run past this spot twice ok.

Well we shall see how it run tonight

Thank to Dean's fine work, it got me to look a bit harder and make a better clock
This is good news for the group clock that is being design at
https://www.woodworkforums.com/f168/n...n-part-154708/
as it using a similar construction method.

Russell

Well it would not keep going it run for a hour then stop.
The problem is friction in the drive train as the escapement wheel stop turning.
I will have to pull it apart and find the tight spots in it. So for the moment It back the way it was till I get the time, but it is running better for the exercise.

Painting the out side of the shed has become a priority I was told by SWMBO

Russell

I hear you!
Dean

Well it was just hanging there on the wall not doing much, I mean not running keeped on stopping and when it did run it was for only about 13 hours and the tick was very loud.

The first problem was there was to much friction and this came from having the pendulum attached to the rocker arm. The weight of the pendulum created friction on the ply and brass bearing.
So Ii put a two ball bearing in on the rocker shaft and gave it a test. Halfed the weight from 6kg to 3kg. It ran with no problems so halfed it again still ran ok, and again I have it still it ran ok. Catch up on the maths the bottom line it run on 720gr for a while took it back to 1kg and it ran for 10 hours ok. This extra weight was a bit of over kill but cheap insurance.
Next to extend the run time.
Made some brass pulleys for the top of the weight boxes with Teflon bushing and restrung the clock with twice the string it had. So theory is that it should run for close on 26 hours with this much string. Doubled the weight to 2kg and added bit for extra friction a total 2.4kg. Has now run all night and only stop when the pendulum hit the weights, Thought the clearance was close.
Move the fixed end of weight string which moved the weight forward a few mm to clear pendulum. Just did a measurement and I am getting 1 minute per 1mm of weight drop this equals a run time of 26 hours

Also the tick is much quieter with the lighter weight. This is the lead I removed.....
IMG_1655[1].jpg

Pulley on top of weight box
IMG_1653[1].jpg

Excellent news Russell! Bearings are the go with these wooden clocks if you ask me!. So you have a 2 compound set up right? You could try a 3 or 4!!
Dean.

Your right Dean it stopped again due to friction of gear train.
So next I will be to add ball bearings to all bear places. Trying to get some from china seeing speed and load are not big China cost is around 20-30 cent each + del, here $5 + me picking up. Hoping to get them before xmas.

Russell

Meant to say it did run for 22 hours before stopping.

Hi Russell Have you noticed how humidity affects the running of your clock?
Dean.