Date   

Re: First Attempt... mechanism animation video to working model

 

Jim...
Regarding the link...I want to applaud you for seeing a mechanism and then seeing an automata on top of it (within it).
Have a good weekend.
-Jim in San Diego-

On Wed, 17 Jun 2020 at 18:50, autopilotjim <jim7485@...> wrote:
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.  


Re: First Attempt... mechanism animation video to working model

 

Hi Jim...
Well, that video certainly fills the brain, doesn't it?
3D printing to the rescue.  I love it.
Looking forward to seeing the finished assembly.
Thanks for sharing this.
Cheers
-Jim-

On Wed, 17 Jun 2020 at 18:50, autopilotjim <jim7485@...> wrote:
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.  


Re: WIP "The Politician"

 

Hi Gus...
Glad I could help.
I do use chain (usually plastic (Delrin)) occasionally when I need to maintain timing.  And occasionally I make gears.  I suspect that I've not made near enough gears to be good at it.  I really admire a quality gear maker.  It sounds like you've achieved a high level of gear making competency.  I have the ultimate respect.  I think that you will be pleased that you've decided to add a motor.  
Please keep us informed with the build process...it sounds very interesting.
Cheers from San Diego
-Jim Coffee-

On Wed, 17 Jun 2020 at 18:43, Gus <klekner@...> wrote:
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 !


Re: 3D printing...some random thoughts

 

Good morning Jim...
Thanks for the info.  Your post makes me more comfortable with my pending purchase.
Yes, Fusion 360 is complicated...but it's capable of most anything...so worth the investment.
I'm a photographer.  For years I avoided using Photoshop because it's complex.  Then I bit the bullet and am now a comfortable photoshop user.
Thanks again.
-Jim in San Diego-

On Wed, 17 Jun 2020 at 18:26, autopilotjim <jim7485@...> wrote:
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


First Attempt... mechanism animation video to working model

autopilotjim
 

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.  


Re: WIP "The Politician"

Gus
 

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 !


Re: 3D printing...some random thoughts

autopilotjim
 

I have only ever used PLA and it is strong enough for moving gears.  


Re: 3D printing...some random thoughts

autopilotjim
 

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


Re: 3D printing...some random thoughts

 

Jim...
This is all very interesting.  
Tell me, when 3D printing a project such as this...is it a tedious process?...or do things simply print correctly?
If in the end, you needed 50 parts...how many parts do you typically need to print?  50?   60?  ??
And I think you said PLA.  You must find it strong enough for drive trains?
Thanks in advance.
-Jim Coffee-


On Tue, 16 Jun 2020 at 16:04, autopilotjim <jim7485@...> wrote:
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. 


Re: This concept tickles my automata fancy

autopilotjim
 

What a great idea!


Re: WIP "The Politician"

 

Hi Gus...
Regarding motors:  I have only used AC synchronous gear motors.  They run at a specific speed.  I use the 10 and 20 rpm most often.  
The photo you mention is a bunch of things that are going to be assembled.  There is no slip ring in the image.  I was waiting for it to arrive.  I'll post about slip rings one of these days soon.
Regarding One Way Bearings:
IMG_20200616_200634-1000.jpg
  • Here is a hand sketch that shows basic components.
  • Assume that you want to hand-crank:
    • Rotate the hand-crank counterclockwise.
    • This drives Bearing B counterclockwise.
    • Bearing B locks onto the shaft and causes the shaft to rotate counterclockwise.
    • Bearing A freewheels.
    • The motor does not feel the rotation of the shaft.
  • Assume you want to operate with the motor:
    • Turn the motor on.  It rotates counterclockwise.
    • This drives Bearing A counterclockwise
    • Bearing A locks onto the shaft and causes the shaft to rotate counterclockwise.
    • Bearing B freewheels
    • The hand-crank does not know that the motor is running.
  • Assume that you want to rotate the output shaft clockwise
    • Try to rotate the output shaft clockwise.
    • (Assuming a gear-motor) The shaft that runs through Bearing A will attempt to turn clockwise.  
    • The motion will be prevented (because the gear-motor will not turn backward).
  • Assume that you want to rotate the output shaft counterclockwise
    • Rotate the output shaft counterclockwise.
    • The shaft that Bearing A and Bearing B are mounted on will rotate counterclockwise.  
    • Neither the motor nor the hand-crank will know that the shaft is rotating.
  • Here is a link to the One Way bearing that I use.
I hope this helps folks understand how I am able to both hand-crank and use a motor on an automata.

Cheers from San Diego
-Jim Coffee-



On Sun, 14 Jun 2020 at 23:44, Gus <klekner@...> wrote:
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:





Re: 3D printing...some random thoughts

autopilotjim
 

Please forgive me if this post gets duplicated.  


Re: 3D printing...some random thoughts

autopilotjim
 
Edited

Yes. Very close. I switched phones and lost pictures of the guts. There are 4 vertical shafts each spinning 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.


Re: 3D printing...some random thoughts

 

Good morning Jim...
Thanks for your response.
Yes, Fusion 360 does look good.  I've got it loaded up and I work with it occasionally.
Covid-19 has caused a delay in my printer purchase.  I had been planning on a FLSun delta but as time went by and I became aware of online support, etc. I've changed my mind.  At this time I think it's going to be a Creality 3 V2.  We'll see.  It's a moving target.  The actual decision will be made just before I purchase it.  
Would you mind explaining the basic mechanical concept of the Tornado?  In my mind's eye, I see vertical shafts side by side that counter-rotate, with geared collars at each blade that capture one direction or the other and perhaps modify speed?  Am I close?
The 3D printing world is very interesting.  And I love the filaments!!!!!!!!! 
Cheers
-Jim-

On Mon, 15 Jun 2020 at 20:21, autopilotjim <jim7485@...> wrote:
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  


Re: WIP "The Politician"

 

Morning Gus...
Give me another day or so to respond to this.  One way bearings are interesting...and I want to respond with some graphics.
Cheers
-Jim-

On Sun, 14 Jun 2020 at 23:44, Gus <klekner@...> wrote:
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:





Re: 3D printing...some random thoughts

autopilotjim
 

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  


Re: WIP "The Politician"

Gus
 

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:





Re: Almond coupling

 

Good morning Jim...
Nice referral.  These are quality animations...sort of like a modern-day 507 Mechanical Movements.  I'll add this link to the group video page later today.  Nice animations.  Many thanks.
Cheers
-Jim-

On Thu, 11 Jun 2020 at 09:23, autopilotjim <jim7485@...> wrote:
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


Re: Paper Modeling Lesson's Learned

 

Hi Ron...
Thanks for the links.  At papermodelers.com I note this automata and toys link.  I'm going to bookmark this URL and study over the next few weeks.
Cheers
-Jim-

On Thu, 11 Jun 2020 at 15:12, Ron K via groups.io <peter.pilot=yahoo.com@groups.io> wrote:
Jim, take a look at papermodelers.com for some backgrounds. There's also Fiddlers Green though they are 99% paid models.

Ron


What's on my bench: I'm waiting

 

I've got a slip ring on order...it's shipping from China.  Actually, I ordered 3.  I ordered them on 7 May.  According to tracking, they have arrived on the east coast of the US.  I'm guessing that I'll see them sometime next week.  It is not unusual for me to order something from China. It's sort of the "good news/bad news" situation.  The bad news part is always the month or so of transit time.
Anyway, in the meantime, I've been working on my second product spinner, which I call The Peddler.  A biped pedals in a circle which causes a display tray to rotate next to him.  In the image, you can see the parts that I've created thus far...all stacked together.  The slip ring will allow the motor to be installed within the part that rotates...which will permit me to have a much simpler drive train.
And just this afternoon I finished installing an Hour Meter in my first product spinner (which I had previously completed).
I ordered two Hour Meters.  The first one is installed and working and I'm disappointed to 'hear' that it makes a noise.  I was expecting an Hour Meter to be silent...but these two make a 'choooo' noise, once per second.  Sort of distracting to me...but my wife likes the noise...so go figure.
Anyway...that's what is on my bench at the moment.
What's on yours?
Cheers from San Diego
-Jim Coffee-
IMG_20200611_153839-1000.jpg

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