PDA

View Full Version : solenoid shifter



Dude
10-03-2002, 10:24 AM
I just want to know if any university ever used electric solenoid shifter on their formula... we're looking forward to put one on our car this year and it would be nice to have any feed back about it!

Thanks

Dude
10-03-2002, 10:24 AM
I just want to know if any university ever used electric solenoid shifter on their formula... we're looking forward to put one on our car this year and it would be nice to have any feed back about it!

Thanks

David Money
10-03-2002, 12:57 PM
We haven't really done any work with it but have found one from Dale Walker's Holeshot Performance. It uses a huge solenoid and can do both upshift and downshift (which is really hard to do). The incorporation of downshifting just came out. /infopop/emoticons/icon_eek.gif

Cats
10-04-2002, 07:40 AM
We used a Kliktronic system last year. Their system worked fine. With the exception that some of our drivers have problems down shifting, but I think that is because most of our drivers don't use the clutch. We also built a circuit board to work with our ECU to cut the spark and fuel during shifts. This became a much larger task than expected, because we ran into electrical noise problems, that made our car want to shift when ever it wanted to. But I guess those are just the problems you run into with a ME doing an EE's job. If we can ever get rid of the noise, it is going to be a great improvement.


Dan
Bearcat Motorsports

Duke of URL
10-17-2002, 01:13 PM
Electronic shifting is possible.
You also don't have to be an EE to do it right.

I'm in ME and I'm doing an electronic shifter for our vehicle.

I'm using hobby servos and I've proven the concept with a prototype.

Its fully electronic with up/down and neutral find capabilities.

Clutching is still manual
No clutch this year because of the time involved.
Can be easily made so its like F1

J. Tway
10-17-2002, 11:52 PM
We have used electro-pneumatic for years now. I would like to drop the pneumatic. However, I have yet to find a solenoid, servo, steppermotor etc. to actuate the clutch without weighing or costing a ton. Has anybody found anything out there yet?

J. Tway

Duke of URL
10-18-2002, 09:24 PM
I might have.
It depends on what you consider costing and weighing a *ton*

For us, a ton is around $300 US
If that's cheap for you then I have an answer.

Also, how much is weighing a ton
I'm guessing you can spare a pound or two at most...

Finally, what kind of speed and torque do you need?

Angry Joe
10-21-2002, 01:08 PM
We ran pneumatic paddle shifters in our car last competition and anticipate doing so again this year. The car still uses a foot clutch. We played around with electric servos but the best we could find were barely strong enough and too slow for our liking.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

Duke of URL
10-21-2002, 04:05 PM
If you don't mind my asking, what kind of servos did you use?

What is the make, model, etc?

I've found servos that are small (about the size of a deck of cards), light (1/4 pound), fast (1/4s), and strong enough to handle clutching.

Send me email at umchuang@yahoo.com

Andres
10-24-2002, 07:42 AM
Are everyone using a clutching system that is operated manually, or anyone has incorporated the clutch to the electric actuator, or anything similar?? any thoughts on this??

Richard Lewis
10-24-2002, 10:10 AM
We're going with a seperately actuated foot clutch with our pneumatic shifting. We were considering clutch by wire, but are not entirely convinced of its advantages. Also, launch control to use a clutch by wire system scares me a bit after watching F1 struggle so badly with it last year. I'm sure it can be done, and has been done... the question is if the gains are worth the costs.

-------------------------
UVIC Formula SAE Team
http://members.shaw.ca/drax77/UVICFSAEcar.jpg
http://fsae.uvic.ca

Dan B
10-24-2002, 10:46 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Andres:
Are everyone using a clutching system that is operated manually, or anyone has incorporated the clutch to the electric actuator, or anything similar?? any thoughts on this??<HR></BLOCKQUOTE>

We use a pneumatic cylinder for the clutch to down shift as well as the up/down shift cylinder. We also use a hand clutch for starting and stopping.

Duke of URL
10-25-2002, 09:31 PM
Clutch by wire is one of those things that requires a few years to develop properly.

Ideally, it would be developed using a previous vehicle to test it on.

Once that's done to everyone's satisfaction, then it can be grafted onto the current car.

Problem is, everyone wants to work on the new car (at least here anyways).

Also need to make sure that the previous car is left intact to play with.


As for the clutch, we are also using a manual clutch. Mostly to shorten the development time (we're very impatient).


One thought about the clutch by wire is to use an analog clutch control.

In that, the there would still be a clutch pedal, but it would send a proportional control signal to some kind of actuator on the clutch.

All that does is simplify the clutch cable routing. Simple is good.

DC

EliseS2
11-05-2002, 11:49 AM
We ran a soleniod shifting mechanism on a previous year car. It was heavy and drained power from the engine. With our new rear end we do not have room of a large soleniod. Our pneumatic system seems to working alot better.

Duke of URL
11-09-2002, 04:22 PM
I can't quite figure out why people keep using solenoids if they have so many problems.
Everybody that I've talked to complains about weight for the power you get.
Leave solenoids for power door locks.

Pneumatics and hydraulics are good, but full electronic motion control is better. Servos are the way to go.

DC

Travis R
11-14-2002, 07:16 AM
This is the same thing I posted in the other thread.
We used a kliktronic with our f4i in 2002. I like it, but finding neutral was a little tricky at first. It's become a lot easier as the tranny got broken in (sloppy) and we got better with the buttons.
The other problem is grabbing neutral on your way to second. But if you hold the button down just a hair longer it isn't a problem. Our ECU will do ignition cut for shifting, but I like it better turned off. But that's just me.
We're also looking into servo actuation.

Travis Rouse - Test Pilot - The University of Texas (Austin)
http://www.ls1power.net/RX7/autox4_slide.jpg

Christopher Chow
11-14-2002, 01:24 PM
Ok, this may seem off topic but...
My Mini-Baja team uses a manual trany. The tranny is from a atc 200 from 1981 and has an automatic clutch. Ie. the shifter is linked to the clutch so that when you shift (up. or down) the clutch is disengaged. Heres the interesting part, Im trying to go with an "electronic" shifting system that can comply with the Baja rules, and i belive that this rules out pnumatics. So the system must be totally electronic. Where can I find servos that are powerful enought to shift and disengage a clutch? I figure is about 30 lbs of force over 1.75 inches of travel.

Thanks!

Chris

Duke of URL
11-17-2002, 06:43 PM
Is the 1.75 inches travel or lever arm?
The servos that I've been looking at are spec'd in torque, not force.
What is the peak value for the torque to execute a shift?