Thread: Quartus nears completion

Nice work!
How long did it take to build and how long does it last between winding?

Dean.

Hi Dean,

I built Quartus in my spare time over a fortnight. I'm not a particularly confident builder so I tend to make a kit first and if it works, then make others using my Zen CNC machine.

I have made several of David's clocks as I find them pleasing to the eye and quite unique. He is also always ready to offer advice as and when it's needed - which is essential for new clockmakers like myself. However, I do find his designs more challenging to get ticking than most for some reason.

I have put this down to the fact that most of his clocks only need winding every 2 1/2 days and so there might be less tolerance in the system for the friction I introduce during construction. This conclusion might be incorrect - but the fact remains that in my novice hands these clocks need more tinkering with than most. But don't let that put you off making one - the challenge should be enjoyed and the end result is certainly well worth the extra time.

I would be interested in your thoughts (and others) on the subject of winding frequency, friction and ease of construction.

Happy clock buillding.

A

Friction is very important in the clock build and will account for the issues in getting the clock going. The gears have to "bed" in for want of a better word and run for a couple of weeks to get use to each other. I have noticed this with my clock that has been running for the last week.
My almost finished construction will run for 16 hours between winding and this will mean 2 winds per day; say last thing at night and first thing in the morning. Like I said I haven't finished building and already sick of the winding. Every 2.5 days i could stand.
Having said that I built mine from plans (Brian Laws 7 Clock7) and like all handmade machines it will take some fiddling to get going; prephaps alot even if you have stuck to the plans. I did early on and then decided to re-design the whole gear train and cogs etc and it had taken a couple of years. What are you fiddling with to get your clock going?


Dean.

Dean,
Have you thought of adding a pulley to the weight, similar to what they do in "Vienna Regulator" clocks? Instead of attaching one end of the cord to the winding barrel and the other end to the top of the weight, you put a pulley on the top of the weight, pass the cord through the pulley and tie the end to the base of the clock mechanism. That effectively gives you twice the weight drop in the same vertical space, and should convert your 16 hour clock into a 32 hour clock. You might need to double the size of the weight though to compensate for the extra running time. (You can't easily change the energy consumption rate!)

Cheers
Walesey

I originally did but got confused about how that would work! How would that work? I would love to wind the clock less so I will look into it. It's a good thing that I havnt finalized the weights yet! Is their a website you know of to illustrate the concept?

Cheers
Dean
ps great looking clock!

Originally Posted by 1964deano

I originally did but got confused about how that would work! How would that work? I would love to wind the clock less so I will look into it. It's a good thing that I havnt finalized the weights yet! Is their a website you know of to illustrate the concept?

Cheers
Dean
ps great looking clock!

I'll see if I can post a diagram.

Clock.pdf

The idea is that the cord goes all the way down to the pulley and then up again to the clock, so by the time the weight has gone to the ground, it has spooled enough cord off the winding barrel to go from the winding barrel to the ground and back again. That is, you have spooled off twice as much cord per wind, so the clock runs for twice as long. It is the same as if you raised your clock 12 feet into the air instead of 6 feet. It would run for twice as long. This way, you just take that 12 feet of cord and run it 6 feet down to the ground and another 6 feet up again.

As I said, you would need twice the weight, because now the mass of the weight is shared between both sides of the cord, so the winding barrel only "feels" half the weight.

Does any of this make any sense at all?

Let me know if it does or it doesn't. There might be a different way to explain it.

Cheers
Walesey

Apologies for the delay in replying. As far as fiddling is concerned I don't think I do anything different from others. If and when the clock stops, I mark the contacting teeth with a pencil and restart. I repeat this until I get a pattern which identifies the offending gear which requies sanding. I then dismantle, polish the arbors, check alignment and position and adjust the offending gear. I reassemble and repeat the process until things are running smoothly. If stopping continues I'll check the pendulum is swinging correctly and the pallet is aligned correctly and increase the weight if needed. I don't normally alter bob weights.


Quartus only needs winding once evey two days so your frequent winding issue isn't a problem. I think the use of a pulley sound ingenious and I'll log it for future use.


Regard. A

Hi Walesey.

I don't see how the pulley on top of the weight is increasing the run time. Surely if the weight starts at 1000mm above the floor then it can only unspool 1000mm of cord.
Wouldn't it be the case that the only way to increase the run time is to increase the distance the weight has to drop?

Philip.

Dean,
Did the PDF of the diagram come through?

Yes, but if the weight is at the top (fully wound) then there is effectively zero unspooled (make this our zero point.) When the weight drops 1000mm, then there is 1000mm of cord on EACH side of the pulley, ie 1000mm from the barrel down to the pulley and 1000mm from the pulley back up to the clock again. so if the weight to drop 1000mm, that requires 2000mm of cord to spool off the winding barrel, hence twice the running time.

You could set up a simulation (just so you can see how it works) using a cotton reel on a pencil as your winding barrel. Tie the end of the cotton to a fixed point next to the pencil (or get someone to hold the pencil/cotton reel, and also the end of cotton at the same level) and use your finger as the pulley. As you pull your finger away from the cotton reel, you will pull twice as much cotton off the reel and the reel will spin twice as fast as it would if you just pulled on the end of the cotton, without the "pulley"(finger)

Or, you could just try it and see!

cheers
Walesey

I have just finished my afternoon glass of wine and still like the idea but agree with huon-pine with the fact that the weights only have the same height to fall. I hope this idea works in reality.
Yea I got the diagram and am spending some time on trying to sort it out!
cheers

Dean.

It's not the height the weight falls but the number of turns the weight imposes on the shaft. Twice the cable length = twice the number of turns of the shaft. I think. And I haven't had any wine It should take the weight twice as long to fall the same distance.

I must admit, I hadn't realised why clockmakers use pulleys until now. Attached is a picture of Simplicity with the dial removed. A piece of red wire indicates the route of the weight cord - fixed to the frame on the right at the top and also winding its way round the spool to the left. Does this help - for every 1cm the weight drops - 2cm of cord need to come off the spool (1cm for the down side and 1cm for the upside).
Apologies for using red wire but I've used fishing line for the weight cord here and it doesn't show up on photos. Bye for now - I need to put the face back on before the kids use it as a frisby!!

Kind regards. A.IMG_2621_1.JPG

I was struggling with the idea but, yes, I can see it now.

Philip

Good on you Eastgate!

I was looking for a photo like that to more clearly demonstrate the idea that I was trying to get across, but could not find one!

Thinking about it, I think that the more upmarket "Cable wound" grandfather clocks use pulleys the same way too.

Anyway, thanks for helping to clarify the issue.

Dean, I had a look at the photos of your clock. That is a BEAUTIFUL piece of work. Well done! I particularly like the "jigsaw puzzle" effect. How was that done?

cheers
Walesey