I Added Shock Absorbing Feet to my Hexapod
Вставка
- Опубліковано 9 лип 2024
- I'm building an Arduino powered hexapod from scratch, and in this video I design a 3d printed compliant shock absorbing spring foot for my hexapod. I also update the tibia and femur with parts 3d printed by PCBWay!
Check out PCBWay Here! - pcbway.com/g/dPqG6Y
My existing foot switches were fine, but they had some issues. I also wanted to add some sort of shock absorbers to the legs to take some strain off of the servos. Because of this I decided to redesign the foot switches from the ground up, incorporating shock absorbers into them. I was able to make them fully 3d printed as well!
I also updated the tibia support, femur, femur support, bearing shaft, and friction pads.
Next video will be on the new design! I'm completely redesigning the hexapod from scratch in Fusion 360, and I'm printing the entire thing!
Discord Server - / discord
-------------------------------------------------------------------------------------------
0:00 - Intro
0:17 - The Footswitch
0:55 - Redesigning the Footswitch
3:41- Redesigning the Tibia Support
4:03 - Redesigning the Femur
4:24 - Redesigning the Bearing Shaft + Friction Pad
5:06 - Printing The Parts
7:29 - Assembly
8:25 - Testing!
9:03 - Outro
TikTok | / aecertrobotics - Наука та технологія
1:11 "The shaft was a bit too big, which to be fair, it's something I'm used to" 💀💀
lol
A solution for the feet that requires no moving parts is to use Force sensing resisitors (FSR's) in the foot to sense when the foot touches the ground. They are an analogue based sensor that gives a pressure reading between 0 and 1023 so you could even get the hexapod to walk gently and tiptoe around!
I think knowing how much force is being applied to each foot would be super valuable info! I wonder if I could replace the limit switch with one of those
@@AecertRobotics You could, definitely. You could even make it a multi-stage trigger to adjust the walking parameters. For example, a normal limit switch wouldn't allow you to have the hexapod adjust it's walking "animation" in reference to how heavy it is. With the FSRs, you could include that.
Which means no matter how much load you put on it (a big camera, a soda can holder, a 3D laser environment scanner, etc), with the correct algorithm, the hexapod would always "walk perfectly" adjusted to how heavy it is.
You could probably even implement a pid loop to actively dampen with the servos and stabilize the thing at high speeds and when jumping/landing.
The leg will still have momentum though, so that’s why the spring is necessary. Also force sensing resistors are apparently not very good.
@@thirtythreeeyes8624 that is hard to do with standard RC servos like this, it would be much easier with better servos with more feedback and control modes, like being able to control the motor current rather than position.
idk what any of this means but watching the robot improve over time is awesome, never stop
This has given me some ideas for a different version of the force sensitive feet I am building for my hexapod. They work with two opposing magnets, a spring and a hall effect sensor.
very elegant spring design
Thank you so much 🙂
Instead of making the springs thiner, you can reduce their width or remove a vertical strip in the middle.
Btw yea, springs should really reduce the impact force on the gears, definetly a good move.
Also the word you were looking for is impulse (Force * time).
Was für eine schöne und aufwendige Arbeit. ❤
Honestly just so cool, and ur such an inspiration
Awesome.
Really cool stuff. Cant wait for the next video!!
Itll be out sooner than you think!
Great work as always!
Thanks!!
Very nice and interesting work!!!👍
Again, really great video. Looking forward to the next one.
Thank you :) Next one is out!
Nice to see you again :)
I can't wait for the next video!
PS :You make me wanna build the same hexa"
I was wondering what these feet are for. Thought they are sensors for moving on uneven ground. Gonna add them once my hexapod is finished as well.
That's one use for them!
Glad to see the project is going well, I missed the videos!
I'm happy to be getting back into it 🙂
Good to see you again, project looks great, even if you are going back and redesigning from scratch. Like i said last time this 'and other vids like this' is why im researching 3D printers, also like i said last time programming all that is way beyond me. My first major project after I learn more about 3D printing/ modelling is going to be a M IV landship ww1 tank.
Thank you so much!
Trust me, a complete redesign in cad sorely was needed.
Oooh you'll love the next video! Robotics is such a fun way to get into 3d printing and coding 🙂
@@AecertRobotics Currently creating hobby room which will finally give space from a printer. Still trying to decide whether a resin printer or a 3d filament is better.
Not asking for advice as ofc your dont know all the parameters I need to take into account and there are plenty of reviews/ guides and such out there that I'm going to look into once I get a better idea of the space I have to work with as well as other constraints.
I seem to be rambling on. In short keep up the very interesting videos and maybe at some point I will have 'something' that can be controlled to show you :) .
@@Archtechnician If I can give some advice I own two fdm and two resin printers the resin never gets used. The detail is never needed even on small stuff since I only print structural items and unless using rather expensive resins fdm is always stronger and longer life of both raw material and finished part but, I only print in abs and tpu. There is also a big hassle with resin in that it has really bad fumes and is dangerous in liquid form making printing and cleanup a chore needing a quality respirator and large supply of gloves, paper towels, isopropyl etc. and the build volumes are much smaller.
1:12 HUH LMAO
unexpected xd
Ditch the on off switches in the shocks for hall effect sensors. That way you can incorporate a curve thru PIDS to slow the motors more smoothly and not slam full force or off. Then it would not matter what surface you were on.
I will look into this, knowing how far each leg is push down would be insanely useful.
Ooh it even sounds a lot nicer
Ikr!
Glad you are a Fusion convert now :D
Me too 😂
sell me the final project haha. i would love to buy the kit and 3dprint/build the whole robot.
nice project, what brand of pla do you use for printing, have you created a link on github to follow you?
Will this be shared with the maker community? Immagine making races or battles with the exapods, that would be amazing! Kudos for the excellent work!
I don't see why not!
Omg that would be so fun, and ty so much!
Are there still plans to create instructions for this? Would love to build it
100% yes
How was your process of calculating what load each spring should handle? I find it difficult to calculate myself. As there can be different number of legs grounded to support the weight of the robot at any given time.
are there still plans to release the CAD or a complete set of instructions/tutorial of how you made your hexapod?
100% yes. The current plan is that I'll be releasing the stls for free, but if you want the actual cad file you'll need to buy the kit (and maybe I'll sell it separately).
Email me and I'll send you the stls right now, but keep in mind they are still subject to change!
How did you decide on resin for the springs? While definitely more precise, my experience with resin has it being very brittle. Like almost no yield before failing. It is awesome for aesthetics and fine detail, but I am not impressed for structure or function.
Literally the only reason is because it wouldn't let me do petg for them.
Totally agree, but It was so cheap I figured I'd see what would happen
when did you add the switch and for what reason? curious to know
I added it a while back, it's so the hexapod knows which legs are touching the ground. It'll let it walk on uneven terrain if I code it correctly, it'll also be able to sense if a leg isnt doing what it should be.
Can you explain why you wanted the springs so soft? Surely you'd want to tune them to bottom out with just a bit less than 1/6 of the weight, maybe 20% less or something?
Exactly, ideally they should bottom out at 1/6th of the weight.
It's hard to get them exact though because of the additional friction caused by the design being made in blender, so I aired on the side of too soft because a spring not being fully pressed even when it should isnt good.
@@AecertRobotics cool! was also wondering about if the leg last section could be a parallel linkage, then there would be a mechanically easy way for the complaint spring to almost impact vertically regardless of extension? If the final part of the linkage was a spring, it'd be parallel when unloaded and collapse to a triangle when loaded?
I don't think most resin materials would work well for a spring. There are some resins that have some flex but it's not like FDM where you can make those kinds of parts. Generally a part like that would just snap and break if printed in resin.
You ever going to share the hexapod designs and code?
Email me and ill give you it, i just dont want it public yet because it isnt ready for multiple reasons.
How do you position the robot's steps?
I explain it pretty well here ua-cam.com/video/DKsyJYkdZ_o/v-deo.html
I hope to see the project soon. It would be good to test the code with my own design.
Email me and I'll send you the code
@@AecertRobotics Hey, thats awesome. Thanks for this.
I like the old design a lot. It looks very organic and spider-like due to the thin limbs, pointy ends and round middle part. Will you release those files too?
I don't see why not! Although maybe I should try altering the new design a bit to make it more edgy?
it's probably the product of the modelling method, blender is meant for digital art so it's easier to make something look more sci fi even if you didn't mean to. While in fusion you have to deliberately have aesthetic in mind because otherwise the path of least resistance will not look "fancy"
@@aronseptianto8142 That's actually well said dude. Forgot that he modeled in Blender. I've worked with CAD a lot and considering that he made all that in Blender is pretty crazy.
@@timotanzer322 yeah, my first few 3D printing projects was also blender at first, all of them required friction fit, it was not necessarily fun. Used fusion 360 after that and it was such an upgrade
Though now I've transitioned to freecad so it's not necessarily an upgrade, I kind of miss being able to do a master sketch
Any chance at pre-releasing anything. I can't wait to make one. Even if it's not complete?
Email me and I'll send you it
@@AecertRobotics I don't have your email
@@altf4thc it's on my UA-cam channel about page
Yeah I miss bullying you on stream, bring the good old days back
😂
HI, great job. seems to be working well. out of curiosity, which lengh are u using in IK ? foot pressed or extended ? it might have been the reason they exploaded on the first try
It exploded cause the shaft was wayyyy too thin, but I use the pressed in length in ik calculations
I recently discovered your project because i was searching for a hexapod design that i could make (mainly because i want to have a lil pet bot Spider like on Watch Dogs LMAO) and then found your videos and fell in love with your design. Can't wait to see the video of the re-design of the Hexapod!!!! (人*´∀｀)｡*ﾟ+
Can you please tell whose tutorial you watched to learn fusion360 or did was it a Coarse or something else??
BTW I have been following your Hexapod Build from the beginning and I love it
I think I just jumped right into it and then just looked up any question I had. And then this happened 😄 ua-cam.com/video/DKsyJYkdZ_o/v-deo.html
@@AecertRobotics I see , I will try to go by your approach too , one day
Love this work, I would consider not printing the springs. They won’t be super reproducible by others.
(Radio control car dampers are pretty great off the shelf dampers)
Can’t wait to see where you make it to with this.
Thank you 🙂
I agree that these springfoots are too hard to print, the new design though is a totally different story 😉
could this be printed in carbon fiber ?
I don't see why not
Hi i am Italian and i have an handicap at Job i lose an hand for me is inpossible made one please do you want sell your hexapod ❓
Only hexapod preprogrammed with controller please help me 🙏🙏🙏🙏🙏
Please let me know thanks have a good day
😚😚
☺️
I'd like to build a hexapod with your tutorials, but I'm a bit scared of the demand for servos. Do you really screw up servos that often to build this? Do I really need to invest that much in expensive servos to build a hexapod? I also imagine that not all 3 hexapod leg servos are required in such an extreme way, the servo glued to the body that moves the hexapod horizontally should be the least required, but the next servo that lifts the leg and supports the weight of the hexapod should be the most requested. It would save money with different servants thinking that way, correct?
I've lost about 10 servos so far, but you need to keep in mind I've been working on this thing for quite a while. I will not release this unless I am confident the servos won't be self destructing because of something I do (of course occasionally they can fail because they are cheap but that's unavoidable)
I'm working on getting the cost of the servos down. And you are spot on. The coxa servos take on the least amount of load, and the femur ones take on the most. Mix and matching servos based on need is not a bad idea at all.
Please let me know 🙏🙏🙏🙏🙏🙏🙏 thanks have a good day from Italy
"the shaft is a bit too big, which to be fair is something im used too" idk if you intended that or im just dirty minded
Not enough screen time of the robot :/
I considered putting more footage at the end of the video of it just walking around without me talking. Is that something you think I should do at the end of all the videos?
Yes, very much yes.
The video is very educational, and more progress update style.
But my short-attention span noggan ran out of entertainment.
protip: I know you probably like the look of the white but white filament is known for being weaker than other colors
Huh, that's good to know. I wonder how much weaker it actually is
@@AecertRobotics I had some issues in a design that held some bearings with a pretty tight fit. other filaments just stretched to accommodate and the white would always crack. White is mostly fine but I wouldn't be surprised if the friction pad you redesigned would work in a different color. plus black highlights look cool
0 maths. Bold.
.25mm its not a big deal for resin to be honest.
That was the size of the gap between the spring segments so yeah idk