Awesome ideas with pulleys,I didn’t think of that. I ride bikes so I do it the way bike brakes & gear shifters system works,which means I have the cables with its housing along the arm to lighten the arm load without motors n wires.Thanks for sharing your ideas ❤
Something to note: you do not appear to have any fillets in your parts. The pulleys especially suffer from this. Fillet the ends for what amounts to free additional durability, as those sharp angles are going to lead to stress concentrations. Also, your wire force appears to go mostly into the channel walls or into the tensioning area, this will lead to rapid wear and induce failure under high loads, as the majority of your pulley surface is not utilized, also having sharp turns in your wire where they transfer forces inside that pulley will lead to fatigue. Instead of this, try to get friction across the wire length, such as perhaps with an outer disc on your pulley that can have its radius reduced. Also consider using a helical structure instead of a flat pulley, though be warned that shrinking this structure is easy (and works well due to exponential friction with multiple windings on the pulley), but will cause rapid fatigue of steel wire if the radius is too small, be sure to not go below the minimum pulley radius for your wire diameter, and consider using string with a low stretch factor instead to shrink your transfer pulley as the wire is not the limiting strength factor in your design. Edit: upon reading another comment, you mentioned that shrinking your pulley makes the tension mechanism hard to fit. Consider raising the height of your pulley with a second portion that you can rotate independent of the first. This "upper" portion of the pulley will be able to hold the wire ends. You can attach the wires, then twist the upper portion and glue to the main pulley, holding the tension. I find that hot glue on PETG works well, use some glue channels on the tension pulley for a flush fit.
@@Gaaaaaame wow a lot of good info here. Thanks for the comprehensive notes -- good for future reference 👍 And yeah this is a constant problem in building the various components in this larger framework github.com/andrewfrueh/PowderOfLife ... getting into so many domains simultaneously always seems to carry the risk that I'm missing critical domain specific information, so thanks again.
@@Gaaaaaame also, do you have any recommendations for good low stretch string or cord? I've tried waxed polyester but I have a hard time finding something that has the power transfer of Steel cable. I'd love a recommendation
@androofroo i know of one but forgot its name. Ill attempt to find the name of it, keep in mind that it is not the easiest to find unless you are in europe based on what i have heard, but it is still attainable in the US. Ill check out your github, links are often scrubbed from comments on youtube, so if you have an email address that isn't listed on your channel, providing me with one here will allow me to throw some part files your way. Also do tell me what file types you can open, as i operate using sldprt but can export to several others.
Rope notes: Paracord creep factor is high "DM20" (which I believe stands for Dyneema m20) has extremely good creep factor but is hard to find outside of Europe Vectran is not terrible but weakens and loosens over time.
How are you planning to use this on the robots? You mount one of the sides to a motor? What king of motor and how do you do it? Would love to see your next steps. Great video!
I am using this pulley system in the wearable that I'm currently posting as "Doug" (the large yellow finger mounted on my shoulder). I've had to go through several iterations as I keep tearing up the pullys with all the force. Thanks for your comment 🤘
Thanks. This is really interesting. Though, when I'm going to try this I will attempt to make the wheels smaller and maybe go with a double pulley (block and tackle) like here ua-cam.com/video/M2w3NZzPwOM/v-deo.html since I want the joints to be smaller.
OMG I love Destin and SED! And yes you should totally try that. My one issue with making the wheels smaller is it makes it hard to pack that tensioning trolley inside. I'd love to see what you come up with.
You have action at a distance, now throw a ghost on the end for *spooky* action at a distance.
@@Gaaaaaame 👻
Awesome ideas with pulleys,I didn’t think of that. I ride bikes so I do it the way bike brakes & gear shifters system works,which means I have the cables with its housing along the arm to lighten the arm load without motors n wires.Thanks for sharing your ideas ❤
@@Jim_One-wl4ke bikes would be a terrific source of inspiration so much mechanics packed into such a lightweight frame... thanks for your note
@@androofroolove your idea of tensioner on the wheel👍
Something to note: you do not appear to have any fillets in your parts. The pulleys especially suffer from this. Fillet the ends for what amounts to free additional durability, as those sharp angles are going to lead to stress concentrations.
Also, your wire force appears to go mostly into the channel walls or into the tensioning area, this will lead to rapid wear and induce failure under high loads, as the majority of your pulley surface is not utilized, also having sharp turns in your wire where they transfer forces inside that pulley will lead to fatigue. Instead of this, try to get friction across the wire length, such as perhaps with an outer disc on your pulley that can have its radius reduced. Also consider using a helical structure instead of a flat pulley, though be warned that shrinking this structure is easy (and works well due to exponential friction with multiple windings on the pulley), but will cause rapid fatigue of steel wire if the radius is too small, be sure to not go below the minimum pulley radius for your wire diameter, and consider using string with a low stretch factor instead to shrink your transfer pulley as the wire is not the limiting strength factor in your design.
Edit: upon reading another comment, you mentioned that shrinking your pulley makes the tension mechanism hard to fit. Consider raising the height of your pulley with a second portion that you can rotate independent of the first. This "upper" portion of the pulley will be able to hold the wire ends. You can attach the wires, then twist the upper portion and glue to the main pulley, holding the tension. I find that hot glue on PETG works well, use some glue channels on the tension pulley for a flush fit.
@@Gaaaaaame wow a lot of good info here. Thanks for the comprehensive notes -- good for future reference 👍
And yeah this is a constant problem in building the various components in this larger framework
github.com/andrewfrueh/PowderOfLife
... getting into so many domains simultaneously always seems to carry the risk that I'm missing critical domain specific information, so thanks again.
@@Gaaaaaame also, do you have any recommendations for good low stretch string or cord? I've tried waxed polyester but I have a hard time finding something that has the power transfer of Steel cable. I'd love a recommendation
@androofroo i know of one but forgot its name. Ill attempt to find the name of it, keep in mind that it is not the easiest to find unless you are in europe based on what i have heard, but it is still attainable in the US.
Ill check out your github, links are often scrubbed from comments on youtube, so if you have an email address that isn't listed on your channel, providing me with one here will allow me to throw some part files your way. Also do tell me what file types you can open, as i operate using sldprt but can export to several others.
Rope notes:
Paracord creep factor is high
"DM20" (which I believe stands for Dyneema m20) has extremely good creep factor but is hard to find outside of Europe
Vectran is not terrible but weakens and loosens over time.
Love the hotglue cable coat idea!
Hot glue is the best!
After recently studying some of Leonardo da Vinci‘s inventions, I noticed that his automaton used pulleys and it seems that he had the right idea.
Yeah that guy really was a terrific engineer
How are you planning to use this on the robots? You mount one of the sides to a motor? What king of motor and how do you do it? Would love to see your next steps. Great video!
I am using this pulley system in the wearable that I'm currently posting as "Doug" (the large yellow finger mounted on my shoulder). I've had to go through several iterations as I keep tearing up the pullys with all the force. Thanks for your comment 🤘
Love this robust design.
Thanks! I love things that take a lickin' and keep on tickin'
Very helpful! Thank you so much! 😎🤖
my pleasure 🤘
Amazing, great! Congratulations!!
A complicated process, but you made it clear 👍🏻
pretty cool
thnx
wlcm
great!
thanks
Thanks. This is really interesting. Though, when I'm going to try this I will attempt to make the wheels smaller and maybe go with a double pulley (block and tackle) like here ua-cam.com/video/M2w3NZzPwOM/v-deo.html since I want the joints to be smaller.
OMG I love Destin and SED! And yes you should totally try that. My one issue with making the wheels smaller is it makes it hard to pack that tensioning trolley inside. I'd love to see what you come up with.
@NoidoDev ,Thanks, reminder snatch block ideas, that really takes away lots of gearing for torque,cheaper too😊❤
Not that complicated, cable does what tendons do in the human body, roughly...
ikr? That's what I was thinking while designing it. And that is certainly what I am trying to emulate/steel from... no need to reinvent the wheel 😉