Honestly super smooth to use I'm amazed they worked with my rush job replacement wheels I think the dual wheels on each motor helps, as they push the shaft equally so it keeps contact on both
the tire shredding, from my experience, is just from not enough engagement with the drive shaft. You could probably get away making the wheels 1mm dia larger and it would most likely shred a lot less.
That might be the case here, but also these wheels are old old I got them for free, from someone who'd had them for nearly 20 years I believe they are natural rubber and are getting close to the end of their usable life I want to make proper polyurethane ones, if they start sheading too I'll definitely increase the diameter of them
back when i was making motorised bikes, i learnt early on that FD only worked if you had a fairly large rubber roller... like a small scooter wheel. and due to the nature of gears, the tyre diameter doesnt matter, as it acts simply as an idler gear... what matters is the roller diameter. pretend its the part that rolls on the ground. teh first attempts were using star washers clamped on a shaft, they gave the ideal roller diameter for direct drive, and were easily replaced. yet they still couldnt deal with water, the smallest patch of dew in the morning was a nightmare... and the small diameter just shredded tyres, with stupid high pressures to try and keep them gripping. most of the power was absorbed in simply overcoming the inevitable tyre deformation. inflate them to silly high pressures, and it was catch 22 as the contact patch was reduced... swapping to a small scooter tyre, with a reduction ratio suited to that tyres diameter, allowed for use in all conditions... with relatively low contact pressure. rubber on rubber, with a reasonably large contact patch making all the difference. at that point though, already having had to use some type of reduction, it proved easier to just drive the wheel directly. ie, chain drive all the way. and then they got banned here at least a decade ago so i havent done one since... anyway... with this approach, youre better off using the case of the outrunner itself as the rolling surface, hence use relatively low KV motors... rather than a fixed mount, pivot it and use a spring to achieve the required pressure. or just use the motor itself as the wheel. its not like you are worried about unsprung weight?
Very good explanation and description of your process, a shame the camera failed. Maybe next time consider putting a sheet of grey paper or something down, when assembling white HDPE parts on a white table :)
This is so cool! Have you tried making a walking robot? I’m designing one now and it’s really fun - the best example I’ve seen at ant weight class is “revolve” by Broken Link Robotics.
It is a bit front heavy I dont have much weight left to put into the back, but I'm thinking of adding wedges or at least some bumps to the front armour to stop the weapon hitting the floor when it rocks forward
Tangent drive is so much fun. It took me awhile to get used to, but I really love the power-to-weight ratio. I can't wait to see how it works out on this bot!
I doubt that the PU wheels would have worked as well as the RC car tires because PU wears down faster than rubber I'm interested to see how it does with PU tires next event.
It's always good when there's a new team panic video
wow! this was a fast comment
Thanks for the kind words!
Wouldn't be team panic video without the pre-event panic of getting everything together last minute.
I never thought I'd see the day you'd build a 4WD vert. Welcome to the club! 😄
I can't wait to see Stickers perform.
Hahaha yep, i've come to the dark side
But honestly I've always thought this style would be fun to drive
I was planning on a design that will use these motors so it's nice to see this. I look forward to seeing how the event went
Honestly super smooth to use
I'm amazed they worked with my rush job replacement wheels
I think the dual wheels on each motor helps, as they push the shaft equally so it keeps contact on both
10/10 vid
Thanks!
I'm trying to up my editing game
the tire shredding, from my experience, is just from not enough engagement with the drive shaft. You could probably get away making the wheels 1mm dia larger and it would most likely shred a lot less.
That might be the case here, but also these wheels are old old
I got them for free, from someone who'd had them for nearly 20 years
I believe they are natural rubber and are getting close to the end of their usable life
I want to make proper polyurethane ones, if they start sheading too I'll definitely increase the diameter of them
back when i was making motorised bikes, i learnt early on that FD only worked if you had a fairly large rubber roller... like a small scooter wheel.
and due to the nature of gears, the tyre diameter doesnt matter, as it acts simply as an idler gear... what matters is the roller diameter. pretend its the part that rolls on the ground.
teh first attempts were using star washers clamped on a shaft, they gave the ideal roller diameter for direct drive, and were easily replaced. yet they still couldnt deal with water, the smallest patch of dew in the morning was a nightmare... and the small diameter just shredded tyres, with stupid high pressures to try and keep them gripping. most of the power was absorbed in simply overcoming the inevitable tyre deformation. inflate them to silly high pressures, and it was catch 22 as the contact patch was reduced...
swapping to a small scooter tyre, with a reduction ratio suited to that tyres diameter, allowed for use in all conditions... with relatively low contact pressure. rubber on rubber, with a reasonably large contact patch making all the difference.
at that point though, already having had to use some type of reduction, it proved easier to just drive the wheel directly. ie, chain drive all the way.
and then they got banned here at least a decade ago so i havent done one since...
anyway... with this approach, youre better off using the case of the outrunner itself as the rolling surface, hence use relatively low KV motors... rather than a fixed mount, pivot it and use a spring to achieve the required pressure.
or just use the motor itself as the wheel. its not like you are worried about unsprung weight?
This bot would love a just cuz robotics all in one weapon I bet!
Some forks to stop the endos too
Great video again tho
Very good explanation and description of your process, a shame the camera failed.
Maybe next time consider putting a sheet of grey paper or something down, when assembling white HDPE parts on a white table :)
This is so cool! Have you tried making a walking robot? I’m designing one now and it’s really fun - the best example I’ve seen at ant weight class is “revolve” by Broken Link Robotics.
Hmm...looks like the bottom is front heavy. Either put some scrapping forks on the front to prevent that, or put more weight in the back.
It is a bit front heavy
I dont have much weight left to put into the back, but I'm thinking of adding wedges or at least some bumps to the front armour to stop the weapon hitting the floor when it rocks forward
Tangent drive is so much fun. It took me awhile to get used to, but I really love the power-to-weight ratio. I can't wait to see how it works out on this bot!
I doubt that the PU wheels would have worked as well as the RC car tires because PU wears down faster than rubber I'm interested to see how it does with PU tires next event.
true, which is why I opted for a 60 A PU, basically an attempt to get the grippiness of PU while not shredding a set every fight