Astro Skeleton clock.

[Buchanan]

Here is the next installment. http://www.my-time-machines.net/astro-09-18.htm Saturn is complete and Jupiter nearly so.


Kvom, yes. You are correct. The clock is not stopped or interfered with during a demonstration. So the accuracy of the clock is not affected.

 

[Buchanan]

Here are a few photos of progress to date, Jupiter is complete 64 of the 105 gears in the Orrery.

 

[bazmak]

Your skill and craftsman ship is beyond belief,it makes my head spin just looking and thinking about it
PLEASE DONT DROP IT

 

[kvom]

Doing some rough math: 4000 parts made over 10 years = more than one part made per day. You really keep your nose to the grindstone.

 

[bazmak]

Putting it like than gives it more wow factor

 

[LorenOtto]

Thank you for sharing so we can all learn a new thing every day. It helps to keep our brains alive.

 

[Buchanan]

Here is the next installment:http://www.my-time-machines.net/astro_10-18.htm

 

[kvom]

Gets better and better. I enjoyed reading how the 17mm spacing as drawn turned out to be 17.005mm in actuality. 2 tenths off.

I assume that the "clutch" on the moon arms is to allow them to be positioned manually if adjustment needed.

 

[CFLBob]

There really are no words for how awesome this. I've been reading your updates quite a while and it never ceases to leave me breathless.

 

[nel2lar]

Buchanan
I have seen this for years and it keeps me amazed at the magnitude of talent and perfection. I can not say it enough how much I enjoy your build. I have one question that has been on my mind for years, How do you keep the brassy parts bright and shiny? I have made parts with brass and can not keep that polished look for very long. I use William R. Smith's Rub N Brite polish and love how nice it makes the brass look. I am open to any suggestions.
Nelson

 

[Buchanan]

Kvon you are dead right. I polish with Brasso and Lacquer with an Australian product called Like Armor. We have not made a decision what the final finish will be, but if you polish brass and leave it undercoated, just don,t touch it. (why do we want to hold that part when it is beautifully polished?)

 

[burkLane]

I recently started to read the complete linked page from start to finish. This project quickly fell into the wow this is crazy complex mechanical engineering art. I was in awe of the detail for any single part of this. As kvom mentioned the amount of engineering and mechanical detail put into accurately tracing the movement or path of a moon is extraordinary. Then adding artistic constraints of proportion , scale and style put into 1000's of parts made over years in time puts this in category of its own.

 

[Buchanan]

Here is something others might find useful. I first read about in the M.E. many years ago. In this project space is tight. Especially in height in the Orrery. With the main center bearing assembly. the available height is 29mm. into that space we must fit 6 concentric sleeves or shafts and 12 ball bearings.

Standard miniature ball bearings are far to thick so this is how we thin them down. First remove the seals or shields with a small screwdriver

Then gently push out the cage taking care not to distort it.

Encourage the balls to one side with a sharp thin probe or screwdriver

The center race will then be free to remove.

Hold in a collet or step chuck. I use both when holding in a straight collet , care must be taken to clamp it true.
I usually clamp it lightly and then run the lathe in reverse and push it back into the collet while the lathe is running with a lathe tool. This removes any wobble.
then reduce the thickness by the required amount with a carbide tool. Here I use a broken 1/8th inch carbide drill as a blank. cutting angles are not critical but it will need to be sharpened a few time during machining down an inner and outer bearing. Negative top rake and minimal clearance gives a strong edge. In n this photo I did not remove the shield, it fell out when I have machined away enough of the outer race. This saves time picking away with a tiny screwdriver. The step in the inner edge of the outer race, for the shield, is a good indication of how much you can thin down a bearing, before you get clearance issues with the cage.

The outer race is removed from the lathe and measured for constant thickness.

If necessary, the thickness is adjusted in a 100 grit diamond lapping plate until it is of constant thickness and to size. I leave a about 5 hundredths of a millimeter for adjustment,about a thou.

Then I replace it in the lathe and turn a radius /chamfer on the inner and outer edge.

Repeat the procedure on the other side of the race. I don't chamfer the second side until it is lapped parallel, as is is a way to identify which side I am lapping. .
Repeat the same procedure for the inner race. More to follow.

 

[Buchanan]

Clean everything and apply a little grease on the inner side of the outer race. Replace the balls all on one side .

Put the inner race back in place. The thinner components make this a relatively easy process.

Spread the balls equally around the bearing and gently encourage the cage back into place.

You now have a reduced thickness bearing that has a much better scale appearance.
the process takes about 1/2 hour with a little practice on a bearing this size. It pays to have a spare bearings in case you drop something.

 

[ShopShoe]

Buchanan,

I'll never make a masteriece even approaching a fraction of what you can do, but I appreciate the description of this bearing-thinning process. I can see getting into a situation where a thinner bearing is needed, but not available.

Thank You for sharing your project and your expertise.

--ShopShoe

 

[Buchanan]

I have now altered the 12 ball races require for the center bearing assembly and made all the associated parts.

These make a set of 5 concentric sleeves
.

.


Here they are all assembled.

I do appreciate all the compliments. Please take into account that this is a commercial project and I get to spend all my time working on it. I also have luxury workshop equipment It makes it much easier than trying to do something like this in spare time with a limited budget,

 

[petertha]

Again very impressive.

Do you have certain favorites among brass alloys like this one for turned shafts & bushings vs. that one for milled gears vs. flat stock with profiles & fretwork?

Do you have a favorite technique / materials for fine lapping brass say in the simplest example like an ID to a known shaft to achieve a target fit? My limited experience is using brass itself as a lap against something harder like steel. In the case of your tiny gears & bushings, what works best to remove material but not stay embedded?

 

[Shopgeezer]

I am new to the forum and just found this topic. After reading through the entire thread and picking my jaw up off the floor I am curious as to the motivation of your client. Is the goal to produce the most complex mechanical clock in history? You say that the client is designing the clock as you build it. I can only imagine the Solid Works files. He must have considerable mechanical design experience, as well as very deep pockets.

Maybe once it is done you should take on a replica of the Antikythera mechanism. You would be the most experienced person on the planet to do this.

 

[nel2lar]

Shopgeezer
The Antikythera mechanism would be a back step for this master has been. Talent and real masters come together in projects like this.

 

[nel2lar]

Shopgeezer
The Antikythera mechanism would be a back step for this master has been. Talent and real masters come together in projects like this.