I'm somewhat new to the group but have been studying mechanisms and mechanical devices for years. This video intrigues me very much...

https://www.youtube.com/watch?v=holIbm8Dnrg

the movement is described as opposite angular oscillations, but it appears to be a method to stir paint. At about the 15 second mark, 6 paddles rotate around the center in opposite directions, then reverse. This is accomplished by a single motor which rotates in only one direction. My ideas... Instead of paddles, how about a schools of fish, or turn everything upside down and the paddles are replaced by square dancers. Making this in wood or metal is well beyond my skill level. I am attempting to 3d print it and will post the results in reply to this message. So far, I have printed one gear, which took about 90 minutes.  

I'm somewhat new to the group but have been studying mechanisms and mechanical devices for years. This video intrigues me very much...

https://www.youtube.com/watch?v=holIbm8Dnrg

the movement is described as opposite angular oscillations, but it appears to be a method to stir paint. At about the 15 second mark, 6 paddles rotate around the center in opposite directions, then reverse. This is accomplished by a single motor which rotates in only one direction. My ideas... Instead of paddles, how about a schools of fish, or turn everything upside down and the paddles are replaced by square dancers. Making this in wood or metal is well beyond my skill level. I am attempting to 3d print it and will post the results in reply to this message. So far, I have printed one gear, which took about 90 minutes.  

Jim,
Thank you, that is very informative. I am now convinced that for this work, motor is the way to go. I will think of doing motor only with a removable hand crank assembly for construction, and using DC current. You use belt drives mainly, from what you have posted so far. For this work it has to be gears, since belts are not accurate enough for timing, what will probably be 11 cams. Plus, I really like making gears. Yet another personality flaw....

Regards,
Gus

Be Safe !

That's a great question... I wouldn't say that printing is tedious, but learning Fusion 360 gave me fits. I have used it for over a year and still consider myself a novice. There are plenty of youtube videos that will help and an active user community. The actual printing is typically error free. You can expect two common problems with any printer.  1) Bed leveling which in my mind is the most crucial step. Some expensive machines have a self-leveling feature, but mine does not. A level bed is not critical on small parts like the gears but it is very important on large parts like the bigger tornado rings. Leveling the bed takes maybe 5 to 10 minutes, but you won't know if it's necessary until your print fails!  2) bed adhesion: The first layer is critical. It must adhere to the bed. Otherwise, your print will fail. Sometimes, poor adhesion is caused by an un-level bed. Other times it is related to the print service being either too perfectly clean or too dirty. There are two common cures to poor bed adhesion. I use kids glue sticks. Before every print (while the bed is heating) I spread a thin layer of glue on the print bed. On the center of the bed, typically. Others use cheap hairspray, but I have never tried it. If you skip this step, the bed may be too clean and the first layer will not stick.  Two suggestions: Hang out next to the printer when you start every print. Stay there for up to 10 minutes and closely watch the first couple of layers. If there are ANY flaws or poor adhesion, corners rolling up, etc, then stop the print, scrape off the bad material, clean and level the bed, then add a bit of glue. Restart the print and wait again. Over time, you will learn how to spot problems early. I have printed at least 200 parts. Maybe one in 10 will fail to adhere early. Not a problem, since an early catch has used pennies worth of filament. I have had only two that failed mid-print. Both of those fails related to filament tangles. It is extremely important that you never let the end of the filament roll hang free or partially unwind. I can't stress this enough. In the 3d print community, nearly everyone would agree that tangled filament is a user error. If a tangle develops, your print will fail. My worst fail was 23 hours into a 30 hour print. This wasted maybe 25% of a roll, about $5 or $6. If you change a roll before it's all used up, you must hang on to the end and keep the filament tightly wound on the roll. It doesn't seem possible, but if you let go of the end, a tangle may develop several feet into the roll which you will discover when your next print fails. One other suggestion is that you set up an old cell phone or baby monitor so you can view your print remotely. 

Hope this helps. 

Jim

Yes. Very close. I switched phones and lost pictures of the guts. There are 4 vertical shafts each spring at different speeds, using a single DC motor in the base. There are 25 spinning rings. Each one has an offset hole and internal gear. Gears on the 4 vertical shafts mesh with the internal gears on the rings. The real ‘magic’ is not in the shafts, gears or rings. The center tube is made up of 25 different sections that interlock top and bottom. Each piece of the tube has a gear protruding through a slot in the side to meet up with the internal gear on the ring. I believe I have the drawings and will at least post a picture. 

Hi Jim,

Thanks for all that info. Have used DC motors, were they powerful, if so, guessing they can be speed controlled. What is a one way bearing ? Is it possible to label the photo you posted under Slip Ring ? I would like to know what the shown parts are .

Be Safe,

Gus

On 12 Jun 2020, at 12:51 am, Jim Coffee <jim@...> wrote:

Hi Gus...

I've successfully installed motor/hand-crank  combinations on several of my pieces and I'm always glad that I did.  I isolate the motor from the hand-crank using two one-way bearings.

This gives the option of hand cranking (which is really useful during the build!) and then operating under power when you simply want to stand back and let it go by itself.

I look forward to watching the progress of your politician.  Your work so far looks exquisite.

Cheers

-Jim-

On Thu, 11 Jun 2020 at 00:46, Gus <klekner@...> wrote:

Hi Jim,

I think a hand crank involves the observer more than motorised, so it will be manual. Though, in this case, given the size of the whole, it might be beneficial to stand back. Thanks for the question, I will keep the perspective in mind.

Hard to know how long it will take, there is so much inventing to do. My guess would be months, probably six at best.

Be safe,

Gus

On 11 Jun 2020, at 12:43 am, Jim Coffee <jim@...> wrote:

Hi Gus...

Thanks for posting.  I got out my converting calculator and see that this figure will be 31" high.  Very impressive.

I like the way that you have carved the head...nice shape and proportions and detail.  Good job.

Please do keep posting your progress.  These builds are very interesting.

Hand crank or motor?  What is your rough estimate for completion (month, year)?

Cheers

-Jim-

On Tue, 9 Jun 2020 at 21:16, Gus <klekner@...> wrote:

A politician is standing in front of the usual flag background, and an impressive foyer, behind an equally impressive lectern. He is delivering a message, as they tend to do. At the end, something happens, which I will keep secret until completion, no need to spoil a surprise.
The figure is 800mm tall, has eyes which turn side to side, up/down, the head turns, nods up, down, the arms move and he body turns from the waist and bows. All is dependant upon success of managing to achieve all of that.......
The first part is the carving of the head, from a 90x90 mm block of Huon Pine, an Australian semi softwood which holds small details very well. It was some 28 hours to completion.



The interior was carved out to make room for the eye mechanism, which is the next part to fabricate. That will be added to this post as the process continues.



Regards, keep safe !
Gus

Attachments:

• Carved Head.jpg
• Head interior.jpg

I highly recommend Fusion 360. The gear design function is a breeze and conversion to a 3D printer format is a snap. The gear shown printed in about 15 minutes and the PLA filament cost was probably less than a penny. I use a Creality CR 10 printer. There is a very large an active Facebook user group. Questions are usually answered within minutes. I don’t know if it can be considered automata but I designed and printed the kinetic tornado in the video below. It has over 200 parts. Fun project. I could have never done it without the printer. It has many gears inside which would have cost a small fortune to buy. The tornado rings spin in both directions at 4 different speeds  

Hi Jim,

Thanks for all that info. Have used DC motors, were they powerful, if so, guessing they can be speed controlled. What is a one way bearing ? Is it possible to label the photo you posted under Slip Ring ? I would like to know what the shown parts are .

Be Safe,

Gus

On 12 Jun 2020, at 12:51 am, Jim Coffee <jim@...> wrote:

Hi Gus...

I've successfully installed motor/hand-crank  combinations on several of my pieces and I'm always glad that I did.  I isolate the motor from the hand-crank using two one-way bearings.

This gives the option of hand cranking (which is really useful during the build!) and then operating under power when you simply want to stand back and let it go by itself.

I look forward to watching the progress of your politician.  Your work so far looks exquisite.

Cheers

-Jim-

On Thu, 11 Jun 2020 at 00:46, Gus <klekner@...> wrote:

Hi Jim,

I think a hand crank involves the observer more than motorised, so it will be manual. Though, in this case, given the size of the whole, it might be beneficial to stand back. Thanks for the question, I will keep the perspective in mind.

Hard to know how long it will take, there is so much inventing to do. My guess would be months, probably six at best.

Be safe,

Gus

On 11 Jun 2020, at 12:43 am, Jim Coffee <jim@...> wrote:

Hi Gus...

Thanks for posting.  I got out my converting calculator and see that this figure will be 31" high.  Very impressive.

I like the way that you have carved the head...nice shape and proportions and detail.  Good job.

Please do keep posting your progress.  These builds are very interesting.

Hand crank or motor?  What is your rough estimate for completion (month, year)?

Cheers

-Jim-

On Tue, 9 Jun 2020 at 21:16, Gus <klekner@...> wrote:

A politician is standing in front of the usual flag background, and an impressive foyer, behind an equally impressive lectern. He is delivering a message, as they tend to do. At the end, something happens, which I will keep secret until completion, no need to spoil a surprise.
The figure is 800mm tall, has eyes which turn side to side, up/down, the head turns, nods up, down, the arms move and he body turns from the waist and bows. All is dependant upon success of managing to achieve all of that.......
The first part is the carving of the head, from a 90x90 mm block of Huon Pine, an Australian semi softwood which holds small details very well. It was some 28 hours to completion.



The interior was carved out to make room for the eye mechanism, which is the next part to fabricate. That will be added to this post as the process continues.



Regards, keep safe !
Gus

Attachments:

• Carved Head.jpg
• Head interior.jpg

I've never seen that before. Very interesting. Although I'm completely new to automata, I find myself looking at mechanism animations and wondering which of them are within my skill level. The possibilities for movement are seemingly endless!  Here's my favorite channel with 1 or 2 new videos every week. 

https://www.youtube.com/user/thang010146/videos

thanks

jim

Jim, take a look at papermodelers.com for some backgrounds. There's also Fiddlers Green though they are 99% paid models.

Ron