One possibility is "Kong" rubber dog toys. They are actually modeled after air springs (the inventor was a car mechanic whose dog liked to play with them) and they come in a wide variety of sizes and also several levels of hardness.
Squash balls have been successfully used in home built microlight undercarriages, the extra bonus of squash balls is they come in three levels of hardness so you can tune it to your vehicle, they are also smaller than tennis balls. Keep up the videos, I’m really enjoying them.
some bike seats use the squash ball principle, in tandem with coil springs. they are good when the weight of the suspended load is low and you don't need more than 1.5" travel
nice, i think i am fan of the tennis ball solution more for its durability. Once appropriate angle and contaiment are sorted than it sounds like they should work better than the cord solution. This Tim is just excellent, had he been born 2 centuries ago he could have done his true calling and make some headway on these new fanagled railway ideas.
You can salvage a lot of free extension springs from a worn out/broken kids trampoline. Compression springs are easily found in old cilinder heads. Cool project!👍
For recording the springs around 11:00, mounting the camera directly to the bar show would give a clearer view, especially if recording at say 60fps & then slowing the footage while editing.
if you want to mimick car shocks you could add in a squash ball or two to even out the springiness. Remember to mill a monroe decal into the plywood for added performance
Tim, if Wimbledon doesn't go ahead we'll know why. 😂 I think the bungy idea looks better than the tennis balls, if you go into production they'll be easier to change if you need to. I think keeping things simple is the best way to go, as would be easier to repair if you had too. 👍🤗
The bungie only allowed movement in one direction, it would end well when force is transfered direct to the frame on the up stroke. Otherwise I would agree.
Great job but another idea is coiled rope like a roman balista or mangonel catapult could be a better alternative that's also cheap. Love the ingenuity. Cheers J
This took me back to the war years when many kids built trollies with salvage from damaged properties. What you are doing Tim is ingenious and also great fun. Well, for me anyway. And you seemed to be enjoying yourself. Will you make a warning device or just shout 'Olly! Olly! Olly! as we did? Great stuff.😀
@@wayoutwest-workshopstuff6299 The mind is willing but the flesh is weak. But there is one under the house that I made for my son a few years ago. It's a pity at my age, 90 this year maybe, that I wouldn't be able to bend down to get into it. I just enjoy watching you playing on your one. A great job.
How about wooden leaf springs. May need to steam some pieces of wood to get a bend in the leafs. May work better than bungee cords. As others have said, rubber likes to be relaxed most of the time.
The arms off of an old recurve bow and arrow mounted under your lower control arms bolted to the frame rail in the center would work as leaf. Springs. These videos are fun to watch. Thank you for sharing.
this lil thing is gonna be delightful when its complete and rolling around. Watching the mock up frame go just with gravity makes the image much clearer in my head. Excited, even though I'll never ride it myself.
I think the bungee system is more or less how the wheels on world war 1 aircraft were sprung. It worked for them. It is so nice to find an engineering project with technical jargon that I can follow!
This is just brilliant 👍. You're approach to "Research and development" in a complex field with practicable on hand materials is something that should be encouraged to all budding engineers. A true, easy to follow inspirational creator. Well done 👍. Cheers Pete' New Zealand.
*@Way Out West - Workshop Stuff* 7:40 Bungee cord is probably a bad idea, because they contain rubber. I have learned from *JoergSprave* (The Slingshot Channel) (and he REALLY knows rubber), that rubber looses it's elasticity when stored in a stretched out way. Rubber works best when it gets stretched out for as short amount of time as possible, then is stored in a "relaxed" state.
@@wayoutwest-workshopstuff6299 If you cut bungee apart, you will see that its just a lot of thin rubber strands. Just like any rubber bands.. they eventually elongate, and even break apart. This is why Bungee Jumping stations, have to constantly check and test the bungee cords... and even then, there have been tragic cases of the thing snapping. You could probably solve the tennis ball issue, by making pivoting joints. They will certainly hold up better, than Bungee.
OMG ! this is genius, where were you when i was a kid, you would have revolutionized kids into engineering, as i child we used to build go-karts just for fun, no internet, nobile ment you had to use your imagination and the scrap yard never minded a few of the kids going over and picking a few old wheels and pipes, now it's called the soapbox challenge lmao. fantastic job.
I've found the elastic properties of the rubber in bungee cords doesn't last very long if it's constantly under tension. The tennis balls are probably a better idea.
Reminds me of Sir Herbert Austin and his draughtsman drawing up the Austin7 on his billiard table. We all know where that project went! Keep up the good work. Best wishes.
I was thinking about the same design. One end could have a glued on cap and the other end could have a screw on cap so it could be opened up to change the balls if needed.
Got 11 minutes in as I was looking for the suspension from a crop duster for you and you got there yourself. The AgCats and like had bungee cord shocks.
Wonderful R&D. Note how in your test rig, you had a rigid rear suspension and things went fairly well: backs up my earlier point about keeping your rear suspension arms on the stiff side. An air ride suspension is a neat idea: you probably could bodge one of with innertubes and some lathe turned parts, but I don't suppose you've got a lathe handy (the tools you do have access to are amazing, things I don't have and don't think about, but I've got a lathe) and while it would be more refined and tunable with air pressure, your design with bungee cords is just a little more low teach and obvious to the user should anything start to fail (making repair and service easier). Keep going I say and thank you for making and sharing these videos.
@2:03 - There are people who own electronic drum kits in apartments make platform risers out of tennis balls to prevent their downstairs neighbors from complaining about the bass pedal. Pretty crafty.
We used to make these when we were kids. Old planks of wood and pram wheels. The were called ‘Weans Bogies’ in Scotland. I loved flying down hills at breakneck speeds. 😊
We sometimes used tennis balls to support vibration isolation tables. Wheel barrow sized inner tubes worked too. Neither was perfect but for the price to performance ratio it was pretty good. Air tables are quite expensive.
I would go with springs if they are free combined with rubber balls. The springs holding the majority of the weight. Ive had no luck with bungees lasting any length of time. I imagine you'll have them in the rear to protect your backside 😂 and was testing concept for now. Great job by the way
I must say that is a very unique way of solving that problem. Perhaps the blocks putting tension on the balls could have an adjustable rail so you can tweak how low the wheels should be, but also you could add on slots for an adjustable amount of bungee cords as a combination along with the balls to adjust the dampening. Your videos are great, inspiring, and I hope you continue to do this, but no matter what this community will support you if you need to take a break from video making.
Reminds me of the rubber cone suspension of the classic Minis, my own is hydrolastic but they switched to rubber springs after a while due to production cost.
Great stuff Tim! As an alternative to bungee cords I use old bike tyre inner tubes for various jobs. My son used to compete in a cycling team that was sponsored, so punctured tubes were always being replaced rather than repaired. You might get free scrap tubes from a bike repair shop. Inner tubes should be stronger than bungee cords, and you can easily inspect for wear. Whatever expansion spring system you choose, it occurs to me that you could have some adjustment system built in (turnbuckles?). If this was via rope and pulleys, then each front axle could share the same tension spring, keeping them equally balanced. All the best, Chris.
It would be interesting to see a comparison camera view for 1/ mounted firmly on the body with suspension and 2/ mounted firmly on part of the car without suspension. This could give a comparison of the with/out suspension and show how the ride is improved with suspension.
The answer is yes, here in outback Australia as a young lad. Depending on if it was wet or dry or if the roads had been graded, we used to shove tennis balls inside the springs to improve the drive. Made the bumps better for spotlighting.
I've also seen other rubber balls stuffed in springs and inflated for a firmer ride. Put it in flat, then inflate it. Way easier than pre-pressurized balls.
on a more serious note, this is most excellent! A proof of concept that rolls comfortably down the laneway! I'd just like to suggest that you put at least one wrap of "bungee cord" ('s what they're called here) above the axle, to prevent massive uncontrolled droop. Cheers!
Bungee cords rot and/or stretch way too easily. Especially if they are left outdoors. I suppose they would work as long as you had them oriented in such a way as they could be replaced very easily. Honestly I like the tennis balls better. Well, the fancy ones that don't go bad as quickly as regular ones, anyway. You could probably soften the tennis balls further by not containing them sideways with a baked beans can. Allow them to stretch more. Roll a piece of sheet steel into a tube with 2 or 3 layers. Add hose clamps to keep it cylindrical, and place the clamps at the centers of the balls inside the tube. Then, adjust the hose clamps to let the balls squish more or less. And make a pivot for the tube on the bottom, and a pivot for the ball squisher (lol) so you don't need to worry about angles.
It would be interesting to see a side by side stress test of the two different ideas. I feel like the tennis balls would be a better option for longevity. Especially if you could contain it as you described.
ICE trike uses short cylinders of elastomer for their suspension. It comes in soft, medium or hard. They work very well on my recumbent ICE trike. You might look into using elastomer as it’s a very simple solution.
Have I seen you using those coiled tines off a hay rake on something recently ? I bet you could incorporate one each side to do your springing ? You could mount the coil on that central bar, with the tines going out to the wishbone and could use them "trailing arm style" for the rear axle too ?
In the 1960s there was a sprint motorcycle that used bungy cords for front suspension. I think (memory!) it was called “Ag’s Barra”. The bungies were used in tension via rocking links at the base of the front forks. I would have thought that a small fat inner tube (scooter?) squashed between two plywood boards would be viable too. Have you looked at Citroen 2CV suspension? And surely those bicycle suspension units could be modified (softer plus longer travel) by using the principles of leverage.. Les in UK
Belville spring washers?. (maybe try the "plastic hats" , that are frequently used for sports training) They are Usually metal disks with hole in middle, that have been bent to form a cone shape. Under a compression load, the cone tends to flatten. Add more washers in same orientation to stiffen spring. Flip orientation of some washers to weaken spring and increase travel. Or otherwise adjust spring characteristics.
If those tennis balls are filled with an aerated rubber foam and not pressurised, then you can probably drill and run a rod straight through them with stops at either end like a shock absorber.
One thing to think about might be failure modes. I'd be concerned with the bungee cord snapping under tension and turning into a very dangerous whip right as you lose control
In my opinion you definitely be fine leaving a solid rear axle like on the four-wheeler, it would flex with the frame and it's highly unlikely that you would reach rough enough terrain to get the wheels off the ground. Also neat idea with the tennis balls😊
Could make some air shocks from some small rubber tires and a couple of metal squash plates with a holding groove on the inside (kinda like a rim on the outside instead of the inside) with a valve for inflating or deflating for the desired squish. Don't know how well it would work or if it would even hold air but it's another avenue to explore if you so choose.
Cool I can't wait to see the final product I have an idea 💡 for the final product suspension use go kart suspension of course it would be expensive at frist but you could sale the production versions at different build stages from chassis and body to complete car.
Race cars use push-rod or pull-rod suspensions. Basically a pivoting lever to transfer the motion laterally into the middle of the chassis. Maybe that could help?
If you do decide to go back to compression springs, perhaps a coiled up bike inner tube in a can? Less sideways spring because it's not a sphere, and the springiness is adjustable with just a bike pump
I bought a score of pound shop tennis balls. Most of the bounce was gone, so I suspect that the reason they were cheap was that they were long past their sell by date. As you say, they worked fine as dog toys!
Tennis balls are a bit similar to the rubber cones used on the classic Mini. Not sure on your bungy idea as from experience they don't survive well when left outside. Fascinating project.
This would be a separate project of course, but whenever you get around to doing more on making a loco for the railroad if these would work for suspension there? Of course, you don't have to have suspension on a loco, but it would help smooth out the ride a bit with any imbalance as the pistons shift position.
I would have recommended going to the scrap yard and salvage some scooters for their suspensions. Costs next to nothing and better than most self built stuff, but this is very good work you did.
I work with old ww1 era aircraft (in this case a sopwith-pup), and they actually use bungee cords as suspension just as you said here. Converging development!
The tennis ball suspension, in particular your setup of it, reminds me very much of the Formula 440 (now Formula 600) racing cars. They use rupper pucks in tubes, under a plunger, for their suspension. If you decide to go the tennis ball route, Ihighly recomend looking at how it was implemembeted on these racing cars.
You can also make a suspension out of Wood: Hazelnut is extremely flexible and doesn't wear out (quickly) when bent continuously back and forth.. You can make bows out of out.
love your experimentation. noted the toe in or cant is bad. not see how bungee is adjustable. tennis ball is somewhat better. but still need method to adjust the toe-in or cant. probably threaded wooden screw rod with cup on end (to massage the ball).?
I'm sure that bungee suspension featured on WWI aircraft. By the way, when British POWs at Colditz built a glider in order to escape, they incorporated tennis ball suspension into the design of the simple skid which served as undercarriage. When a replica of the glider was tested, half a century later, the tennis ball suspension worked perfectly.
maybe use the heavy rubber tarp tie down bungees big trucks use (EPDM Tie Down) they come in various lengths, they are available in a in lot of places in the US, Im sure lorries use something similar
While there are many potentially useful ideas offered by readers, all seem to be low hysteresis, meaning you may need some form of shock absorber. My garage door used to slam shut when it finished closing because it uses a low-overhead closer that pushes the uppermost segment straight into the header at the end of the closing stroke. I found a pair of snowmobile friction shocks and installed them to cushion the closing. And they are wrench-adjustable.
instead of bungy cord you could use (old) bicycle inner tyres. I dont know if they are longer lasting than bungy cord but they are abundant in my country (Netherlands) and very versatile. Also if you have an undamaged one you can partially fill them up with air to change the properties. I use half inflated ones to fasten fragile loads to my bike, gives a bit more cushioning and protection.
You might be able to use just one ball if you increased its "squishyness" by drilling some holes through it. Since those special tennis balls arent hollow, but have foam in them, you should be able to get any level of squishyness you want by drilling holes thru them. But yeah, i think i like the bungie system better too.
Cut a disk / use washers the same diameter as the top of the can tin. Attach disc to pieces of wood, the wood then irun vertically. You could use a round pieces if wood and not have the disks, attach the same way, put a bolt though middle of wood and bolt at the end. Bolt feds through to spring plate, runs through piece of wood and is bolted fully other end
have you noticed how an air spring looks like a pneumatic wheelbarrow wheel on its side (or stack of wheels), i thought about using them a compensating bolsters on 7 1/4 gauge railway articulated wagon bogies, never got to testing Going a little further; my old mid 90s kawasaki motorbikes rear shocks (old twin shock swing arm) are a pair of air bladders in a cylinder style housing, linked by hose filled to about 3-5psi, forks are similar but 10-15psi, food for thought
You could use old bicycle tires. Here in Russia a guy named Данник build a solar powered carriage from junk with both front and rear suspension build using old tires used as bangee cords
One possibility is "Kong" rubber dog toys. They are actually modeled after air springs (the inventor was a car mechanic whose dog liked to play with them) and they come in a wide variety of sizes and also several levels of hardness.
Brilliant! Thanks - I'll look into them
funny i've had several dogs that had kongs and i'd never heard that. quite a fascinating tidbit, thanks for sharing mate!
Great idea! Those things are tough and will likely way outlast the tennis ball.
@@LazloNQ I wonder if I could use those to replace the bump stops on my old vw. It could use new ones.
@@WikiSnapperprobably the wrong size and stiffness, but only one way to find out. FOR SCIENCE!
I love the tennis ball pivot arm idea. The bungee cords seem to work very well also. Nice to have multiple options!
so the tennis ball is air suspension with a bit of rubber the bungee cord is a tendon as in animals.
Squash balls have been successfully used in home built microlight undercarriages, the extra bonus of squash balls is they come in three levels of hardness so you can tune it to your vehicle, they are also smaller than tennis balls.
Keep up the videos, I’m really enjoying them.
some bike seats use the squash ball principle, in tandem with coil springs. they are good when the weight of the suspended load is low and you don't need more than 1.5" travel
Sounds pretty painful
nice,
i think i am fan of the tennis ball solution more for its durability. Once appropriate angle and contaiment are sorted than it sounds like they should work better than the cord solution.
This Tim is just excellent, had he been born 2 centuries ago he could have done his true calling and make some headway on these new fanagled railway ideas.
You can salvage a lot of free extension springs from a worn out/broken kids trampoline.
Compression springs are easily found in old cilinder heads.
Cool project!👍
Great suggestion but I don't know if the cylinder head spring would have enough travel
Stack them, and you could run a bolt on the bottom that runs through as a guide
this is going to lead to some very disappointed neighbours' kids the next time they go out to play on their trampoline, lol
@@tomslastname5560 The springs and frame always outlast the trampolene, are often fouind as salvage.
@@highnoonsmallenginerepair increase the leverage then. Old farm cultivators have compression springs same as a pelletgun
For recording the springs around 11:00, mounting the camera directly to the bar show would give a clearer view, especially if recording at say 60fps & then slowing the footage while editing.
if you want to mimick car shocks you could add in a squash ball or two to even out the springiness. Remember to mill a monroe decal into the plywood for added performance
Tim, if Wimbledon doesn't go ahead we'll know why. 😂 I think the bungy idea looks better than the tennis balls, if you go into production they'll be easier to change if you need to. I think keeping things simple is the best way to go, as would be easier to repair if you had too. 👍🤗
The bungie only allowed movement in one direction, it would end well when force is transfered direct to the frame on the up stroke. Otherwise I would agree.
Really?
I think just swapping out the tennis balls would be much easier than re-tensioning the bungee cords.
Great job but another idea is coiled rope like a roman balista or mangonel catapult could be a better alternative that's also cheap. Love the ingenuity. Cheers J
This took me back to the war years when many kids built trollies with salvage from damaged properties. What you are doing Tim is ingenious and also great fun. Well, for me anyway. And you seemed to be enjoying yourself. Will you make a warning device or just shout 'Olly! Olly! Olly! as we did? Great stuff.😀
It is fun! Perhaps you should make another one yourself, Ron?
@@wayoutwest-workshopstuff6299 The mind is willing but the flesh is weak. But there is one under the house that I made for my son a few years ago. It's a pity at my age, 90 this year maybe, that I wouldn't be able to bend down to get into it. I just enjoy watching you playing on your one. A great job.
How about wooden leaf springs. May need to steam some pieces of wood to get a bend in the leafs. May work better than bungee cords. As others have said, rubber likes to be relaxed most of the time.
This would be cool
Or just pull a trailer leaf pack apart and use a single leaf
Ie. Bed slats. They’re as wide as a single mattress though but are preformed to be curved.
@@locouk
Brilliant !
Don’t for get Alex Moulton and his rubber suspensions for the Mini and many Bicycles. All great stuff to think about. Thanks for exploring,
I second that. Alex Moulton...we'll worth investigating
The arms off of an old recurve bow and arrow mounted under your lower control arms bolted to the frame rail in the center would work as leaf. Springs. These videos are fun to watch. Thank you for sharing.
this lil thing is gonna be delightful when its complete and rolling around. Watching the mock up frame go just with gravity makes the image much clearer in my head. Excited, even though I'll never ride it myself.
You might though : - )
I think the bungee system is more or less how the wheels on world war 1 aircraft were sprung. It worked for them. It is so nice to find an engineering project with technical jargon that I can follow!
This is just brilliant 👍. You're approach to "Research and development" in a complex field with practicable on hand materials is something that should be encouraged to all budding engineers. A true, easy to follow inspirational creator. Well done 👍.
Cheers
Pete' New Zealand.
*@Way Out West - Workshop Stuff*
7:40 Bungee cord is probably a bad idea, because they contain rubber.
I have learned from *JoergSprave* (The Slingshot Channel) (and he REALLY knows rubber), that rubber looses it's elasticity when stored in a stretched out way.
Rubber works best when it gets stretched out for as short amount of time as possible, then is stored in a "relaxed" state.
Joerg Sprave is definitely the good guy to consult on nutty and dangerous wooden contraptions.
True, but with enough of it, and a very light body, there may be very little stretch most of the time?
I liked the tennis balls rather than the bungees the bottom of the cylinder needs to be canted at the mid angle of the swing arm - I think.
@@wayoutwest-workshopstuff6299 If you cut bungee apart, you will see that its just a lot of thin rubber strands. Just like any rubber bands.. they eventually elongate, and even break apart. This is why Bungee Jumping stations, have to constantly check and test the bungee cords... and even then, there have been tragic cases of the thing snapping.
You could probably solve the tennis ball issue, by making pivoting joints. They will certainly hold up better, than Bungee.
OMG ! this is genius, where were you when i was a kid, you would have revolutionized kids into engineering, as i child we used to build go-karts just for fun, no internet, nobile ment you had to use your imagination and the scrap yard never minded a few of the kids going over and picking a few old wheels and pipes, now it's called the soapbox challenge lmao.
fantastic job.
I've found the elastic properties of the rubber in bungee cords doesn't last very long if it's constantly under tension. The tennis balls are probably a better idea.
they recommend changing it every four years in light aircraft suspension
Reminds me of Sir Herbert Austin and his draughtsman drawing up the Austin7 on his billiard table. We all know where that project went! Keep up the good work. Best wishes.
I believe the tennis ball idea is preferable. Three balls inside a sealed pvc tube with piston arms through the pvc caps. Worth a trial anyway.
I was thinking about the same design. One end could have a glued on cap and the other end could have a screw on cap so it could be opened up to change the balls if needed.
Gotta love this channel, reading the comments is almost as fun as watching the video, so many people have cool ideas.
Got 11 minutes in as I was looking for the suspension from a crop duster for you and you got there yourself. The AgCats and like had bungee cord shocks.
Well one thing is for sure it is giving plenty of enjoyment along the way bro. Safe travels. Ken
Looks like fun! I had great fun with simple go-carts as a kid.
Wonderful R&D. Note how in your test rig, you had a rigid rear suspension and things went fairly well: backs up my earlier point about keeping your rear suspension arms on the stiff side.
An air ride suspension is a neat idea: you probably could bodge one of with innertubes and some lathe turned parts, but I don't suppose you've got a lathe handy (the tools you do have access to are amazing, things I don't have and don't think about, but I've got a lathe) and while it would be more refined and tunable with air pressure, your design with bungee cords is just a little more low teach and obvious to the user should anything start to fail (making repair and service easier). Keep going I say and thank you for making and sharing these videos.
I was questioning everything, now I'm convinced. This awesome
@2:03 - There are people who own electronic drum kits in apartments make platform risers out of tennis balls to prevent their downstairs neighbors from complaining about the bass pedal. Pretty crafty.
Your car is really interesting and I am amazed at all the clever ideas you have. Great job, Tim!
We used to make these when we were kids. Old planks of wood and pram wheels. The were called ‘Weans Bogies’ in Scotland. I loved flying down hills at breakneck speeds. 😊
We sometimes used tennis balls to support vibration isolation tables. Wheel barrow sized inner tubes worked too. Neither was perfect but for the price to performance ratio it was pretty good. Air tables are quite expensive.
I would go with springs if they are free combined with rubber balls. The springs holding the majority of the weight. Ive had no luck with bungees lasting any length of time. I imagine you'll have them in the rear to protect your backside 😂 and was testing concept for now. Great job by the way
I must say that is a very unique way of solving that problem. Perhaps the blocks putting tension on the balls could have an adjustable rail so you can tweak how low the wheels should be, but also you could add on slots for an adjustable amount of bungee cords as a combination along with the balls to adjust the dampening. Your videos are great, inspiring, and I hope you continue to do this, but no matter what this community will support you if you need to take a break from video making.
Pretty cool! You'll get it working the way you need. You always do!
Really like your video’s and especially your humor. Please carry on! 👍😁
Get four old bicycle pumps and connect the outlets in an X (when seen from above) with a pressure rated pipe/tube for suspension. :)
Great idea - except they'd just break sideways : - (
@@wayoutwest-workshopstuff6299 okay? Thats bad :/
Reminds me of the rubber cone suspension of the classic Minis, my own is hydrolastic but they switched to rubber springs after a while due to production cost.
Great stuff Tim! As an alternative to bungee cords I use old bike tyre inner tubes for various jobs. My son used to compete in a cycling team that was sponsored, so punctured tubes were always being replaced rather than repaired. You might get free scrap tubes from a bike repair shop.
Inner tubes should be stronger than bungee cords, and you can easily inspect for wear.
Whatever expansion spring system you choose, it occurs to me that you could have some adjustment system built in (turnbuckles?). If this was via rope and pulleys, then each front axle could share the same tension spring, keeping them equally balanced. All the best, Chris.
It would be interesting to see a comparison camera view for 1/ mounted firmly on the body with suspension and 2/ mounted firmly on part of the car without suspension. This could give a comparison of the with/out suspension and show how the ride is improved with suspension.
I'm in awe! That looks so steady! And so, so fun!
Fantastic job!
The answer is yes, here in outback Australia as a young lad. Depending on if it was wet or dry or if the roads had been graded, we used to shove tennis balls inside the springs to improve the drive. Made the bumps better for spotlighting.
I've also seen other rubber balls stuffed in springs and inflated for a firmer ride. Put it in flat, then inflate it. Way easier than pre-pressurized balls.
@@nobodynoone2500 pretty sure a 16 year old isnt a. Going to think of thst and b. Thats what they had at the servo
on a more serious note, this is most excellent! A proof of concept that rolls comfortably down the laneway! I'd just like to suggest that you put at least one wrap of "bungee cord" ('s what they're called here) above the axle, to prevent massive uncontrolled droop. Cheers!
Bungee cords rot and/or stretch way too easily. Especially if they are left outdoors. I suppose they would work as long as you had them oriented in such a way as they could be replaced very easily. Honestly I like the tennis balls better. Well, the fancy ones that don't go bad as quickly as regular ones, anyway. You could probably soften the tennis balls further by not containing them sideways with a baked beans can. Allow them to stretch more. Roll a piece of sheet steel into a tube with 2 or 3 layers. Add hose clamps to keep it cylindrical, and place the clamps at the centers of the balls inside the tube. Then, adjust the hose clamps to let the balls squish more or less.
And make a pivot for the tube on the bottom, and a pivot for the ball squisher (lol) so you don't need to worry about angles.
I have considered using solidly mounted plywood arms that are also the springs. Old fiberglass skis might work too.
It would be interesting to see a side by side stress test of the two different ideas. I feel like the tennis balls would be a better option for longevity. Especially if you could contain it as you described.
If I remember right in a old combine they use leaf spring made of hickory wood in some part of the mechanical function
These are the people that make the world go round.
Looking good Tim.
The most wonderful voice I’ve heard!
When you get to the shock absorbers, look into how Austin 7 friction shock absorbers worked, very simple and they work too as a bonus.
Brilliant! Keep it up Tim.
Looks good. Plus your having fun. Cant beat that. You might even end up in casualty but lets hope not.
Very clever idea; having the ball holders & squashers moving would eliminate quite a few problems.
ICE trike uses short cylinders of elastomer for their suspension. It comes in soft, medium or hard. They work very well on my recumbent ICE trike. You might look into using elastomer as it’s a very simple solution.
Really? Thanks. I will.
Have I seen you using those coiled tines off a hay rake on something recently ?
I bet you could incorporate one each side to do your springing ?
You could mount the coil on that central bar, with the tines going out to the wishbone and could use them "trailing arm style" for the rear axle too ?
I'm really liking those tennis ball air springs myself. A little more refinement, and I think those would be cool!
In the 1960s there was a sprint motorcycle that used bungy cords for front suspension. I think (memory!) it was called “Ag’s Barra”. The bungies were used in tension via rocking links at the base of the front forks. I would have thought that a small fat inner tube (scooter?) squashed between two plywood boards would be viable too. Have you looked at Citroen 2CV suspension? And surely those bicycle suspension units could be modified (softer plus longer travel) by using the principles of leverage.. Les in UK
Try rubber surgical tube. The type used in sling shots. Very stretchy and very strong.
Belville spring washers?. (maybe try the "plastic hats" , that are frequently used for sports training)
They are Usually metal disks with hole in middle, that have been bent to form a cone shape. Under a compression load, the cone tends to flatten. Add more washers in same orientation to stiffen spring. Flip orientation of some washers to weaken spring and increase travel. Or otherwise adjust spring characteristics.
Wonder what the insurance will be on this one 😂 . Love the tenisball suspension! Always looking forward to your videos. Cudos from Norway.
If those tennis balls are filled with an aerated rubber foam and not pressurised, then you can probably drill and run a rod straight through them with stops at either end like a shock absorber.
great idea
I thought only the dog toy ones were made like that.
Did the Brompton use a Squash ball in the prototype? I seem to remember a documentary about it on the cathode ray tube, wireless tv.
One thing to think about might be failure modes. I'd be concerned with the bungee cord snapping under tension and turning into a very dangerous whip right as you lose control
In my opinion you definitely be fine leaving a solid rear axle like on the four-wheeler, it would flex with the frame and it's highly unlikely that you would reach rough enough terrain to get the wheels off the ground. Also neat idea with the tennis balls😊
Could make some air shocks from some small rubber tires and a couple of metal squash plates with a holding groove on the inside (kinda like a rim on the outside instead of the inside) with a valve for inflating or deflating for the desired squish. Don't know how well it would work or if it would even hold air but it's another avenue to explore if you so choose.
Cool I can't wait to see the final product I have an idea 💡 for the final product suspension use go kart suspension of course it would be expensive at frist but you could sale the production versions at different build stages from chassis and body to complete car.
You can run the bungee cords from the bottom of the arms near the wheels, across and under the center rod, and attached to a frame on top.
Race cars use push-rod or pull-rod suspensions. Basically a pivoting lever to transfer the motion laterally into the middle of the chassis. Maybe that could help?
Interesting stuff. Bungee cord worked on early airplane landing gear for years.
If you do decide to go back to compression springs, perhaps a coiled up bike inner tube in a can? Less sideways spring because it's not a sphere, and the springiness is adjustable with just a bike pump
Nice work so far, keep going…
Excellent work Tim!!
Best to keep it simple :) much less to go wrong and easier to fix!! :)
I bought a score of pound shop tennis balls. Most of the bounce was gone, so I suspect that the reason they were cheap was that they were long past their sell by date. As you say, they worked fine as dog toys!
Tennis balls are a bit similar to the rubber cones used on the classic Mini. Not sure on your bungy idea as from experience they don't survive well when left outside. Fascinating project.
This would be a separate project of course, but whenever you get around to doing more on making a loco for the railroad if these would work for suspension there? Of course, you don't have to have suspension on a loco, but it would help smooth out the ride a bit with any imbalance as the pistons shift position.
I would have recommended going to the scrap yard and salvage some scooters for their suspensions. Costs next to nothing and better than most self built stuff, but this is very good work you did.
I wish that was possible here!
@@wayoutwest-workshopstuff6299 I have no doubt that it was the best solution available that you came up with.
If you haven't already, you should try radius arms and tennis balls as the rear suspension. :)
I have learned a lot about tennis balls thanks
I work with old ww1 era aircraft (in this case a sopwith-pup), and they actually use bungee cords as suspension just as you said here. Converging development!
The tennis ball suspension, in particular your setup of it, reminds me very much of the Formula 440 (now Formula 600) racing cars. They use rupper pucks in tubes, under a plunger, for their suspension. If you decide to go the tennis ball route, Ihighly recomend looking at how it was implemembeted on these racing cars.
You can also make a suspension out of Wood: Hazelnut is extremely flexible and doesn't wear out (quickly) when bent continuously back and forth.. You can make bows out of out.
love your experimentation. noted the toe in or cant is bad. not see how bungee is adjustable. tennis ball is somewhat better. but still need method to adjust the toe-in or cant. probably threaded wooden screw rod with cup on end (to massage the ball).?
Have you considered a double spring tine off of an agricultural hay rake or baler?
I did that in the last video - too heavy
I think the tennis balls is a brilliant idea. After a bit more of experimenting, I'm sure you will make it work.
It seems that the bungee cords are working better!
I'm sure that bungee suspension featured on WWI aircraft.
By the way, when British POWs at Colditz built a glider in order to escape, they incorporated tennis ball suspension into the design of the simple skid which served as undercarriage. When a replica of the glider was tested, half a century later, the tennis ball suspension worked perfectly.
maybe use the heavy rubber tarp tie down bungees big trucks use (EPDM Tie Down) they come in various lengths, they are available in a in lot of places in the US, Im sure lorries use something similar
That oversized dog @ 8:19 is quite lovely, you should make sure it's paid in apples for it's role in this video ;)
While there are many potentially useful ideas offered by readers, all seem to be low hysteresis, meaning you may need some form of shock absorber. My garage door used to slam shut when it finished closing because it uses a low-overhead closer that pushes the uppermost segment straight into the header at the end of the closing stroke. I found a pair of snowmobile friction shocks and installed them to cushion the closing. And they are wrench-adjustable.
What about a torsion spring connected to the centre shafts. Or a spring tine connecting the arm to the main shacy
both heavy steel though
There was once a single seater hill climb car called a Terrapin that had rubber webbing suspension with moderate success. Built by Alan Staniforth.
instead of bungy cord you could use (old) bicycle inner tyres. I dont know if they are longer lasting than bungy cord but they are abundant in my country (Netherlands) and very versatile. Also if you have an undamaged one you can partially fill them up with air to change the properties. I use half inflated ones to fasten fragile loads to my bike, gives a bit more cushioning and protection.
You might be able to use just one ball if you increased its "squishyness" by drilling some holes through it. Since those special tennis balls arent hollow, but have foam in them, you should be able to get any level of squishyness you want by drilling holes thru them.
But yeah, i think i like the bungie system better too.
Cut a disk / use washers the same diameter as the top of the can tin. Attach disc to pieces of wood, the wood then irun vertically. You could use a round pieces if wood and not have the disks, attach the same way, put a bolt though middle of wood and bolt at the end. Bolt feds through to spring plate, runs through piece of wood and is bolted fully other end
with the bike suspension you can find different rated springs for your needs ive seen them as low as 150 lbs 68kg and as high as 600 lbs 272kg
I'll keep looking!
have you noticed how an air spring looks like a pneumatic wheelbarrow wheel on its side (or stack of wheels), i thought about using them a compensating bolsters on 7 1/4 gauge railway articulated wagon bogies, never got to testing
Going a little further; my old mid 90s kawasaki motorbikes rear shocks (old twin shock swing arm) are a pair of air bladders in a cylinder style housing, linked by hose filled to about 3-5psi, forks are similar but 10-15psi, food for thought
You're right - I'd need something quite a bit smaller than a wheelbarrow wheel though. Hmmm..
You could use old bicycle tires. Here in Russia a guy named Данник build a solar powered carriage from junk with both front and rear suspension build using old tires used as bangee cords
Will it be wide enough to drive on bike paths tho? that would be neat
what a great idea! (to use tennis balls).
Yesss new video❤❤