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

autopilotjim
 

Neither a pilot or a sailor. By day, I create computer models that are used to automate repetitive tasks. Years ago, someone gave my that nickname. 


Re: Paper Modeling Lesson's Learned

Ron K
 

Additional note. I've used regular white glue for years and that's what Rob suggests. On another sit I found a recommendation for Aleene's® Quick Dry Tacky Glue™. It not only dries faster, but doesn't swell the paper as much as regular white glue. My experience with glue sticks has been that they aren't worth the extra trouble of the wide mouth.


Re: Paper Modeling Lesson's Learned

Sharon Fraser
 

Sorry I'm so slow with this reply Jim. You have shared some wonderful tips and techniques. I  have already cleaned out nail polish bottle and filled it with glue! So clean and precise!
Thanks so much, Sharon


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

 

Hi Jim...
Good job.  Thanks for sharing.  Your project reinforces my desire to acquire a 3D printer.
Now...looking forward to seeing what you do next.
Cheers from San Diego.
-Jim Coffee-
ps: Why autopilotjim (if you don't mind my asking).  Are you a pilot, or sailor?

On Wed, 24 Jun 2020 at 12:43, autopilotjim <jim7485@...> wrote:
After plenty of trial and error I have a working prototype. To get it right, I had to fiddle with the design and print a few parts more than once. 


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

autopilotjim
 

The most challenging thing is that the long gear rack binds at both ends when moving slowly. Perhaps a slow gear motor is needed. Currently, I can’t hand crank it slow enough. 


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

autopilotjim
 

After plenty of trial and error I have a working prototype. To get it right, I had to fiddle with the design and print a few parts more than once. 


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

 

Good job...
Keep going!
-Jim-

On Tue, 23 Jun 2020 at 11:55, autopilotjim <jim7485@...> wrote:
I was initially concerned that the file format would not allow for adjustments. However I was able to alter the individual pieces as needed. Example: I made the rack 0.2 mm thinner in 2 directions. I also made some holes slightly bigger to allow movement. Through trial and error, I am about halfway to a working prototype.  See video below. 


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

autopilotjim
 

I am not familiar with those settings. I adjusted the design instead. Thanks for the suggestion. I will check it out. 


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

autopilotjim
 

I was initially concerned that the file format would not allow for adjustments. However I was able to alter the individual pieces as needed. Example: I made the rack 0.2 mm thinner in 2 directions. I also made some holes slightly bigger to allow movement. Through trial and error, I am about halfway to a working prototype.  See video below. 


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

BiLL B
 

I've found that PLA is not the greatest with close tolerances and the design needs to be fiddled with a bit to get it right.
In cura you can increase/decrease the size of the design quite easily.

BillB


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

 

Hi Jim...
So I think that I understand that you are able to load the file up into Fusion360.
Keep in mind that I'm a neophyte with both Fusion360 and Cura.
I just did a bit of poking around and find that there are ways to adjust the tolerance on moving parts in both Fusion360 and Cura.  They are different methods.
Assuming that you know about this...could you briefly explain why it won't work...why you will need to redraw?
I can see how it could be complicated.  The rack, for example, cannot simply be shrunk.
Anyway, I'm learning from your problem and hope that you will continue to try to print this mechanism (and continue to share with us).
Cheers
-Jim Coffee-


On Mon, 22 Jun 2020 at 13:34, autopilotjim <jim7485@...> wrote:
It's supposed to look like this... but I can't get any of the interlocking parts to fit together, despite considerable sanding and filing. The tolerances in the original design are just not set up for 3D printing. Back to the drawing board, I will need to re-draw or alter the original files. 


Re: What's on my bench: The Peddler pedals

 

Hi Gus...
It's absolutely OK.  That's what this forum is all about.
Cheers
-Jim-

On Mon, 22 Jun 2020 at 14:30, Gus <klekner@...> wrote:
Thanks Jim for those answers ! Since I have already decided to motorise the Politician, I will be asking  you for other information as this proceeds, hope this is ok by you. 

Regards,

Gus 

Keep Safe


Re: What's on my bench: The Peddler pedals

Gus
 

Thanks Jim for those answers ! Since I have already decided to motorise the Politician, I will be asking  you for other information as this proceeds, hope this is ok by you. 

Regards,

Gus 

Keep Safe


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

autopilotjim
 

It's supposed to look like this... but I can't get any of the interlocking parts to fit together, despite considerable sanding and filing. The tolerances in the original design are just not set up for 3D printing. Back to the drawing board, I will need to re-draw or alter the original files. 


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

autopilotjim
 

Thanks!  I am often amused by combining two seemingly different things.


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

autopilotjim
 

for starters, I am attempting to construct it as is.  Once I figure it out, I will adapt it for other use as part of another project. 

Currently, the file is giving me fits! This has happened a couple of times in the past. I downloaded the file from the Youtube video and printed several parts. They were clearly designed to make a video... There is NO tolerance built in for movement of the parts. The attached picture gives just one example. There are two parts, which the designer called the rack (long piece) and the runway (bracket with slot and a hole).  The rack is supposed to fit into the slot in the runway and freely slide back and forth. However, I can't get it into the slot at all. I'm hopeful that I will be able to update the design using Fusion 360. Alternatively, I will need to re-design the whole thing from scratch and I'm not sure my skills are up to the task. 


Re: What's on my bench: The Peddler pedals

 

Good morning Gus...
Yes, you are correct.  The slip-ring is to avoid twisting cables.
The reason that I've got ten leads is that I ordered three slip rings with 10 leads.  You are correct...I only need three.  Each circuit is rated at 2 amps.  The motor uses .15 amps. The reason I combined the leads to make three circuits was simply because that's what I did.  I could have left the leads "idle".  But since I had them I thought I would use them.
The whole thing is about 15" high...13" diameter.
Yes, the two pins on the motor simply slid into two female holes and the power is transferred to the automata.  I believe that I've seen this called a "dirty coupling".  Yes, the three tires (o-rings) carry the entire weight of all except the base.
I've not got a customer for this yet.  The way this has unfolded is that I had one part for the first one that I had to wait for (it came from China).  So I had already started this second one and now I find it almost done.  When I start making my 'sales calls' to see if I can rent these I'll have two with me (at least initially).  I hope that there is a market.  I would love to create automata that are actually seen and that are useful.  We'll see.
Thanks for your comments.
Jim Coffee
creating automata in San Diego.

On Sun, 21 Jun 2020 at 15:32, Gus <klekner@...> wrote:
Hi Jim,

The slip ring seems to be a method to transfer current to a rotating element, overcoming the twisting of the cables, is that so ? Ten cables go to the motor ? So many leads,  merely for redundancy, no other purpose ? A small motor doesn't draw a lot of wattage, does it ? How big is this whole assembly ? The two pins attached to the motor connect with the driving wheel is made by you for the purpose I assume. Is the weight of the display wholly borne by the three tyred wheels ? 
You made this whole assembly in a hurry, did you manage to get a business to hire it ? Well done.
Regards,
Gus

Keep Safe


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

Gus
 

Hi Jim,

Are you constructing an automaton, or the mechanism as in the animation ?

Gus


Re: What's on my bench: The Peddler pedals

Gus
 

Hi Jim,

The slip ring seems to be a method to transfer current to a rotating element, overcoming the twisting of the cables, is that so ? Ten cables go to the motor ? So many leads,  merely for redundancy, no other purpose ? A small motor doesn't draw a lot of wattage, does it ? How big is this whole assembly ? The two pins attached to the motor connect with the driving wheel is made by you for the purpose I assume. Is the weight of the display wholly borne by the three tyred wheels ? 
You made this whole assembly in a hurry, did you manage to get a business to hire it ? Well done.
Regards,
Gus

Keep Safe


What's on my bench: The Peddler pedals

 

I'm getting the Peddler assembled.  There was a conversation recently about slip-rings.  In the 1st image (lower center of the image) is a slip-ring assembly.
First, let me explain what I am building:
  • It is a product spinner.
    • The base remains stationary and contains the electrics assembly.
    • The drive assembly rotates on top of the base.
    • A product display platform rotates on top of the drive assembly.
  • The Base
    • contains the electrics assembly.
      • an hour meter
      • a on-off toggle switch
      • a 3 amp circuit breaker
      • the slip-ring assembly
    • Feeds power for the motor up to the rotating drive assembly through a slip-ring.
    • You can see the slip ring in the 1st image.  It's lower center. The bulk of the slip-ring assembly is fastened to its base via stand-offs.
      • 10 wires go out the bottom over to the terminal strip.
      • The 10 wires that go up to the motor leave the slip-ring through a hub in the center that rotates.  It's good to 300 rpm.  I'm going at about 4 rpm.
    • I only need 3 active leads to go up.  Because the slip-ring comes with 10 leads I've connected them together...two 3-wire and one 4-wire.  This will give me redundancy that I'll probably not ever need.
    • You can see these wires coming up through the center of the drive assembly.
    • This electrics assembly slips into a slot in the base and is screwed in place.  The base contains only this electrics assembly.  You can see this assembly fitted into the base in the second image.
  • The Drive Assembly
    • Rotates on top of the base.
    • Contains the motor (center-right)
    • Contains the biped that pedals (the pedals are center-left). The biped is not shown.
    • Holds the rotating product display platform (not shown).
    • Contains the 3rd wheel, an idler.
    • The exterior of the drive assembly will be finished in a manner similar to the base.
That's it.
I would love to see what's on your bench.

Cheers from San Diego
-Jim Coffee-

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