If you’ve been to the right events, you’ve seen them before – the cars with an external cage that let the car complete a somersault in the forward direction under heavy braking. They’re impressive, but it’s possible to take things even further. Enter [mastermilo82] and the RollKa.
The RollKa follows on from the RollGolf, which was a straightforward roll car build. Built around a Ford Ka, it eschews the external cage for a more radical design. The Ka has been shortened, and designed to fit within two enormous steel rims which wrap around each side of the car. Additional idler wheels have been welded to the Ka’s roof to enable it to effectively roll within the outer steel rims.
It’s a rather eccentric design, known as a diwheel. We’ve seen impressive electric versions before, but at least at this stage, this project appears to lack any advanced control systems and gets by on sheer luck and welding prowess. The build is still at an early stage, with episode three starting some early movement tests under power. It’s a testament to what can be achieved with a spacious garage and some imagination, and we can’t wait to see what happens next! Video after the break.
[Thanks to Baldpower for the tip!]
Mooi, beste Noorderburen. ;)
Nice build.
This one is also very fun ;)
https://www.youtube.com/watch?v=RfFvzDzW2Ww
Wow. If that doesn’t make working through the motion-control math that much more palatable.
how about anti-torque to make it derivable at lease?
I just don’t know enough about Auto leasing, calculus, or how they relate to each other, to help with your question.
Pretty sure the lease has terms that prohibit welding wheels on the roof.
I’m getting a strong Scrapheap Challenge vibe from this
Before or after it’s been driven? :-)
I loved that show. Amazing what a junkyard, some tanks of oxy acetylene and unlimited creativity can accomplish!
There were some great commercials for the Ka back in the day.
If they had welded two of those Fords together,
they’d have a Ford KaKa,
and in Boston, they’d call it a KaKa cah (car).
Take me for a Ride in Your Ka Car? https://www.youtube.com/watch?v=8RtaCYzk5VQ&list=RD8RtaCYzk5VQ&start_radio=1
If they slightly increased the space between axles, they could install the tires while mildly underinflated and then adjust tension by changing the air pressure. Then they wouldn’t need all the extra wheels.
The extra wheels aren’t about the tension. His concern was that the large unsupported arcs between the wheels might buckle if you hit a bump. He wanted to provide more points of support to prevent this possibility.
So how does it steer? I see him working something that looks like a brake lever, but it’s not covered in the build videos.
it uses the differential as a steering device. If you brake one wheel, the other goes faster.
He has one brake lever for either side. If you slow down the left side while rolling forward, you’ll turn left, etc.
Cars often have a handbrake cable to each rear wheel, joined just under the centre console with a balance bar. Remove the bar, add a 2nd handbrake lever and away you go – fiddle brakes on the cheap!
Lewin, you say it’s an eccentric design but those wheels appear circular to me! ????
B^)
“…this project appears to lack any advanced control systems and gets by on sheer luck and welding prowess.” I hope it wouldn’t be more appropriately called a die-wheel!
Not surprised this came from mastermilo82, there rolGolf was great: https://youtu.be/OTfiAmuOp5c
Awesome. But having spectators, especially kids that close to an stunt with little to no control is not ok.
Kinda like a Russian Zorb.. with a car in it.
Car engines don’t like to run upside-down. That could be problematic. ????
It’s a Ford Ka, they don’t run any better right-way-up.
There only seem to be two issues: having the gas tank feed still take in gas, and having the oil pump still take in oil. Without switching to a dry-sump, this car can only handle momentary inversion.
I love the image. Thanx for sharing.