Alternatives to the Kilktronic

[Gabriel Descamps]

Our team´s been doing research on the kliktronic for the past couple of years, however, we haven´t managed to make it work propperly, and we´re not really sure it´s worth it.

Anyone care to share other (better, cheaper, lighter) alternatives for automatic gear shifting? i.e. other solenoids, pneumatic or electric/magnetic systems?.

Thanks

[Gabriel Descamps]

Our team´s been doing research on the kliktronic for the past couple of years, however, we haven´t managed to make it work propperly, and we´re not really sure it´s worth it.

Anyone care to share other (better, cheaper, lighter) alternatives for automatic gear shifting? i.e. other solenoids, pneumatic or electric/magnetic systems?.

Thanks

[Cement Legs]

Our system is not quite ready for testing but we are going with a high pressure air system using bimba cylinders and microprocessor controlled soleniod valves. From what we have seen of other teams, this appears to be the most realiable system other than a mechanical linkage.

[CrazyDave]

We have a pnumatic shifter, with soleniod valves controlled by buttons on the steering wheel. It seems to be a good solution, lightweight, fast, and cheap. Although it makes me wonder what real benefit it has over a manual. how do the teams that use manual shifters like them?

[LCheung]

Exactly how reliable are the pneumatic shifting systems commonly used on FSAE cars? What provisions do most people use for detecting a positive shift engagment?

-Leon

[Colin]

Do a search there has already been some good threads on this subject. but to answer a few questions quickly

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Although it makes me wonder what real benefit it has over a manual. how do the teams that use manual shifters like them?
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I believe one of the biggest advantages is the fact that you don't need to take your hands off the steering wheel to change gears, also the shift time can be reduced (down to .1s) for a good auto system.

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Exactly how reliable are the pneumatic shifting systems commonly used on FSAE cars? What provisions do most people use for detecting a positive shift engagement
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How longs a piece of string? we had a great system last year, didn't fault once, but the year before had all sorts of troubles (don't underestimate the amount of electrical interference a starter solenoid can create), as for detecting shifts, a pot on the shifter drum works well

[syoung]

Our team has spent (wasted) considerable time in each of its four years of competing - with completely different people on the team every time - trying and failing to get Kliktronics to work.

My advice is not to bother, unless everything else is already working very well. If everything is working well, you've probably got engineers who are good enough to make a pneumatic system work instead, which I believe to be substantially better.

[ben]

My view on the matter is use a piece of steel tube to shift gears with and a bike clutch lever attached to the lever.

Spend your money on dampers and tyres.

If you insist on semi-auto use pnuematics but test it... a lot.

Ben

[nathan s]

In the past, our cars have had co2 pneumatic shifting. Very simple and cheap, but you have to consider bottle placement with CO2. We looked into NO2 and Air, but didn't see much of an advantage over CO2. We also have a guy looking into electronic. We are looking at it because we have had problems with running out of CO2. I think he may have it figured out, but am not sure at this point.

One thing I am not sure of is expansion chambers. Do any of you guys use them? Why or why not? I know that paintball guys use them to save gas and to keep the lines from freezing.

[kozak]

I might be able to answer that, i used to play paintball. really you only need X-chambers for rapid fire (or in this case shifts). so when you play if you have a co2 gun and you are really slamming the trigger the lines will start to freeze and slowly stat to draw more and more "liquid" co2 into the barrel reducing your projectile speed. an easy fix to this is switching to compressed air or nitrogen this is usually one of the first things that paintballers do when they get a new gun if it is set up for co2. so for shifting applications switching between the three should be no problem, and for expansion chaimbers unless you are shifting like 20 times per sec you shouldn't need an x-chaimber.

[nathan s]

Cool, thanks for clearing that up.

[LCheung]

I think they use rapid fire as a selling point for expansion chambers, but I think their real goal was to keep the liquid CO2 from traveling into the gun. (Although they also help with rapid fire, it's just that people care more about rapid fire than a functioning gun.)

If you want to run CO2, do like the paintballers that are serious about CO2. Run an anti-siphon on the tank to make sure the liquid doesn't get out and run a regulator that is known to handle CO2 well. Your regulators recharge rate is going to effect your consecutive shifts more than whether you are running CO2 or Compressed Air. Even if you run compressed air, if your regulator recharge rates are slow or spikey and inconsistent you're going to run into shift consistency problems.

[Charlie]

Everything on the car should have a purpose.

A pneumatic or electronic shifter should be a solution to a problem or a way to improve your system. Unless you have a clear reason for doing it get rid of it!

I know things like driver comfort, etc are hard to analyze objectively. But if that's the only reason for your shifter then I think it's a bad one; lots of drivers I've talked to would kill you if you took away thier shifter. Enough training will get that issue out of the way.

Can you get benefits from semi-automated shifting? Yes I'm quite sure of it. But you need to understand those benefits and your car system as a whole needs to exploit them if you go that route. Otherwise you are just adding complexity.

[peter_blais]

I've been running shifter karts for yeaaaars now, and recently been running van diemon FA chassis cars... Wanting an electronic shifter has never been an issue. A well sorted mechanical shift is just as quick (coupled with a flat shift feature) and gives a nice satisfying feel... On top of that, its just way less complicated.


Yes, the mechanical version takes some physical effort. Other then that, it makes no difference...

If your fiddling with a cable shift, make sure to keep it away from major heat sources, the cable on my van diemon is run literally through the exhaust manifold (between it, a frame tube, and the block) and has required LOTS of fiddling to keep it from "sticking"

http://fsae.com/groupee_common/emoticons/icon_smile.gif

[kufsae]

Too add to your shifter discussion.. this year on our car we used a system from england called quickshifter. The system worked excellent- easy to adjust, strong, fast shifts (less than .05s). the system also comes with all the harware to cut rpm automatically, so no lifting is required to change gears and no clutching is needed for downshifts. the only downside is the cost- about 1000 dollars for a complete system

[Garlic]

You guys spent $1000 on a shifting system?

How do you justify that?

[Colin]

kufsae
"(less than .05s)" sound's pretty quick, have you got any G-Force data to back that up?