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Crazy Gear Pendulum Clock

Just finished the beautiful Crazy Gear Pendulum clock and have it running flawlessly.

I did make one minor change, it is battery orperated. I designed and printed a battery powered weight. I replaced the fish line with a endless loop of 1/8 " ball chain. The weight is powered by a 1000:1 N20 gear motor to operate a small ball chain sprocket with idlers inside the housing. When the weight hits it's lower limit it activates a rack and pinion that tilts a mercury switch. That powers the motor and sends the weight to the top limit where the motor is turned off. I designed a chain sprocket that snapes on to gear 8 (no modifications to that stl file). However, after making a few chain sprockets for gear8 I ended up with a sprocket that was 4.5 inchs in dia. That required that I make a small change to the gear7 ratchet so I could get clearance for the sprocket.

All in all I am very happy with my latest pendulum clock. My daughter saw a photo of it and wants me to make one for her.

Thank you Steve for your beautiful creations and your acute attention to detail.

Leon

44 comments

44 Comments

hoppy

I have made one more change to the battery operated weight. The chain has slipped on the motor gear on one of my clocks concerning me about the design. So I made a change to the motor gear that allows the ball chain to make a complete rap around the sprocket. This greatly improved the dependability of the sprocket. For those that may be thinking or have built this project, please let me know and I will make the STL file available. If you have completed this project I would highly recommend this update and it can easily be retrofitted .

hoppy

Replying to

Here is the new sprocket in action. This is an early photo I have added a lip to the sprocket to help direct the inside chain. I have not had trouble with that but just precautionary measure.

Hoppy

ksmietanski

Replying to

Hi Hoppy.

Am currently on leave but will be back home soon.

One of the first things on my list is to start your build. If it is OK with you, I will make contact with you upon my return to get the file for the new gear.

hoppy

Replying to

Great, just let me know.

Hoppy

hoppy

Aug 19

The switch in held in by 2MM screws all the rest are 2.5mm

woodwaker_dave

Aug 07

I was looking at the design and what it will take to get this started and came here. Steve is there any way to add the self winding mod to the download? or post it somewhare, as it would only be useful if you have purchased the original design. I have finished my 9th Crazy gear desk clock and am ready to try this.

hoppy

Aug 13

Replying to

Thanks Steve,

Will be experamenting with with the gear7 modification soon.

I have reverted back to using a micro switch and abolished the idea of a snap action switch using the mercury switch. Just have not come up with a design that I was happy with. And as a safety for the small contacts of the switch I have added a kickback diode on the motor.

Leon

woodwaker_dave

Aug 13

Replying to

Will be interesting to see what you come up with. I had problems with the reed switch on the coup perdue clock. I think two limit switches might be a good solution

hoppy

Aug 16

Replying to

I know that the motor does not draw much current but a diode across the motor will help with the EMF that is produced. This will help the arc on the switch and increases the life of the switch. The diode I use is a IN4002 and put the white bar on the diode to the positive side of the motor or what ever side the positive battery.

Hoppy

ksmietanski

Aug 07

Hi Hoppy,

Have now built Steve's SP12 and it is evident that Steve has put lot of effort and it can be seen where he has used the good bits from all of his previous designs. SP12 went together flawlessly and just started ticking away as soon as I put a weight on it.

Now that it is running, I will want to recheck everything and try and get the friction as low as possibe.

Anyway, the thought of making this clock battey operated is extremely interesting to me.

I have a few questions.

I have built a number of Steve's SP8s (Coup Perdou) with the N20 motor. I purchased the motors from a number of different supplier from ebay as well as alliexpress. I have found that the quality of the motor/gearbox is variable. A couple of the builds are still going strong, but one in particular required a motor/gearbox change as one of the gears stripped.

Why did you go for the N20 motor. Is this a good option for long term usability and longevity?
Why did you go for a ball chain option. I would have thought that the winding option that Steve used for SP8 would be more efficient with the weight around the bottom gear.

Krys S

woodwaker_dave

Aug 07

Replying to

Could you post your mods and send a link? Steve has given his blessing to post. See his response.

hoppy

Aug 08

Replying to

Hi Dave,

Yes, I see that Steve has allowed me to post the files. But as I mentioned to him, I am still working on the design. There are a few things that I was not totaly happy with and have made changes to the design, these changes are now under testing. I hope to have a final design in a week or two. For those who may want to take on this project I have to warn, I do not intend to make instruction sheets. However, I may provide detail photos of the assembleys.

Hoppy

woodwaker_dave

Aug 08

Replying to

Thaanks. I appreciate the conversation, as now I have premission from Steve to post my mods to the Crazy Gear Desk clock. I jsut orederd some more motor kits and am planning on build more. I will publish my files and instructions as I make the new clocks.

Steve

Jul 28

Very nice. I always enjoy seeing modifications made by other builders. Adding an endless loop ball chain probably makes the mechanics inside the shell easier. This clock is fairly efficient. Any idea how long the batteries might last?

You have spurred my interest in this style of self winder. I am curious if bicycle chains would make good chains. They are relatively cheap and the larger sprockets might be easy to print.

woodwaker_dave

Aug 20

Replying to

That's my problem also, my wife if not a fan of the wall clocks, so am limited to where I can hang them

hoppy

Aug 21

Replying to

Thanks Krys,

Let me know if you have any questions or find any errors in the printed parts.

Hoppy

hoppy

Aug 23

Replying to

Hi Steve,

I looked into buying a tool for splicing the ball chain and you are right, very expensive. So I did like you and used flush cut cutters and pliers to do the job.

I had a failure on the motor gear sprocket and did some redesign to thicken the walls and added an additional set screw. I also printed the sprocket at 100% fill to help the strength. I am adding the file to this message. One other thing I printed the sprocket with the small end to the build plate, less stringing on the inside of the gear box cavity.

Hoppy

MotorSprocket14v2

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