33 replies to this topic

[cmcraeslo]

 Hey all.

I'd like to share with you guys the project I was working on for the last 2 years. It's fully pneumatic paddle shifter system for any cable driven H gearbox.
The ECU is controlling the valves and can also control the clutch so one this could be used on a syncro gearbox also. Average shift I get with the dogbox is 0.08s which I'm looking to improve.

 

Video:

https://www.youtube....h?v=JPRZ0MhzCuc

I'm constantly trying to improve the system so comments/Ideas are welcome.

More pictures & videos of the car on my facebook: https://www.facebook.com/mmemotorsport

 

p.s.: sorry for bad video at the beginning of the movie. I'm an engineer, not a professional camera guy

 
Thanks!

Marko 

 

[Canuck]

Is everything on the passenger side floor, part of the paddle shift mechanism? Looks like a very interesting bit of kit though - very cool.
I did wonder whether you might see a shift time decrease by using hydraulic instead of pneumatic by virtue of eliminating any compression of the motion transfer fluid. But then I wondered if the inertial increase of moving a heavy fluid vs. air would negate the benefit or even make it slower. At a guess, I would think you could reduce the size of the required cylinders and supply lines with hydraulics, but I don't know. I'm a senior student, not an engineer.

[cmcraeslo]

Hey there. Thanks for the reply.

 

As to your question about the kit: Paddle shift mechanism uses one ecu (the small black box), compressor & bottle. Everything else is either engine ecu management, or power distribution unit (this alu box replaces all fuses & relays & extra wiring in the car), or something else ;)

 

I did study the hydraulics.. but I find it inconvenient: it needs high pressure pump and bottle (more expensive than pneumatic), it needs fluid (possible leak in the car - not good), oil would need to be heated in cold environment or it would not move very fast.. and again, it has fluids, which is pain in the ass to mount, remove the air and so on I'd say overall, the hydraulics would be heavier, more complicated and much more expensive.

[Kelpiecross]

As a simpler alternative to pneumatic and hydraulic is possibly  the good old solenoid.   I was considering using solenoids  in a motorcycle-powered car -   two solenoids - attached directly to the gear lever - one to yank the lever back and one to yank it forward.   I was using 6 volt solenoids running on 12 volts.  On 12 V  the action of the solenoid snaps instantly and powerfully like a rattrap.   I never actually tried it in anger (never finished the car) but in testing it seemed to work OK.  The solenoid takes a lot of current but the action is so quick that the solenoid doesn't tend to overheat and doesn't take too much energy out of the electrical system.    

    Also -  you can get kits now to convert an H-pattern  to sequential (still manual though)  -  maybe solenoids could be attached to the lever to convert it to paddle-shift?    

[cmcraeslo]

Hey.

 

I actually tried that too. Problem with solenoids is that they're not strong enough. Under load, there's actually a lot of force required to shift a car. It's ok for motorcycle, but on a regular turbo engine that just doesn't work. I did once a regular sequential shifter on a big turbo car. We needed to get 700N to shift reliably (problem is usually 1st to 2nd, or 2nd to 3rd). I tried few different options. Nothing beats pneumatics in term of speed and power. If you need speed/power, you just increase the pressure

Also, for this kind of system (without the lever) I would still need 7 different positions together. I don't know how would I do that with solenoids (and that it wouldn't weigh 100 kg )

 

On my car I primarily had H-pattern to seq. converter and then pneumatic shifter on it. But, the mechanism itself takes some time to shift (there are afterall moving mechanical parts) + pneumatics delays. The result was somewhat slower shifting and stronger requirements.

 

The cylinders I use at the moment are too strong for my application, but that's just a prototype, it's not fine-tuned yet

[Lee Nicolle]

While I will never be a fan of paddle shifts the problem is that on a dog box they will smash the dogs and on a sychro box just tear the synchros to pieces.

Any gearbox designed to be manually shifted generally requires the drivers 'feel' to get the gears to change. And either at least a 'lift' of throttle or rev matching on the way down.  Something many drivers really do not have. Accentuated by  shift mechanisms that allow the gears to be pulled through to quickly. Oil quality too will accentuate this. Heavy oils always make shifting harder on dogs or sychros.

That is where a GOOD [many are not] H pattern beats anything else. Sequential, read straight line shifts often tear boxes to bits,, unless they are built for them.

Drag racing has been using air shifters of various forms for decades.

Edited by Lee Nicolle, 15 November 2015 - 22:11.

[Nathan]

How did Toyota do this job with the 3rd generation MR2 automatic?

[gruntguru]

A great alternative to solenoinds is the good old electric motor. The internals of a 12v battery drill include reduction gearing. Response time and torque available are impressive. The chuck of a small battery drill is easily able to direct drive the rotary shifter input on most motorcycle sequential boxes.

[gruntguru]

A great alternative to solenoids is the good old electric motor. The internals of a 12v battery drill include reduction gearing. Response time and torque available are impressive. The chuck of a small battery drill is easily able to direct drive the rotary shifter input on most motorcycle sequential boxes.

[Kelpiecross]

I have never actually operated a V-8 Supercar sequential gear change (not many people have)  - but - on TV the driver seems to exert very little pressure on the lever - and the lever seems to have a very short movement. 

[cmcraeslo]

Hey all. I think that properly designed paddle shifting is actually safer than manual. While looking at the gear position sensor (datalogging feature) you can easily see which part of the shift is struggling and you can adjust the parameters or reduce the speed of the shift. Naturally auto blip/rev matching needs to be used in a cloosed loop setup with careful tuning. But when set up correctly.. I think it makes minimum gear wear.

As i said before, gcu i designed also has capability to press the clutch and you can set different speed for up and downshift (downshift requires somewhat smoother release) so basically one can use the system on a syncro box also.

Also using electric motor doesn't come near the performance of pneumatics. Either it is powerful and slow, or fast and weak. I dont think it's good solution for cars.

Marko

[Kelpiecross]

Actually that is a pretty good idea - I must keep it mind for future use.  More available, cheaper, more adaptable than a solenoid. Good idea. 

 

The above is referring to GG's electric drill idea - for some reason my "quote" button doesn't work.   

Edited by Kelpiecross, 16 November 2015 - 12:32.

[Sisyphus]

One comment I will add from bitter experience of using powerful actuators in another context is that you should provide a hard, external stop on the actuator rather than letting the internals of the gearbox provide the actuator motion stop.  Given a little thought, you should be able to make an adjustable travel stop on the actuator so that you don't bash whatever it is inside the gearbox that will stop the motion if you don't (and it will typically be something expensive). 

 

I learned this from using air actuators to bang a valve back and forth--without the external stop, an internal shaft got a big shock torque and failed in fatgue.

 

 

Gerry

[cmcraeslo]

Hey Gerry.

 

That's correct and the only correct way to do it. That's what "properly designed paddle shifter" means

 

Marko

[Canuck]

How portable is the application, meaning how easily can it be utilized by units that are not the specific transmission it seems to be developed on? How flexible it is in terms of gears (4,5,6,7)?

[cmcraeslo]

Hey Canuck,

 

I'm afraid I don't understand the question about the 4,5,6,7 parts. The system is designed to have 4 positions to select the gear pair and 3 positions to shift into a gear. With that in mind, you can shift any gearbox with proper adapter.

For my vw for example, the 4 position cylinder selects pairs: R (has no pair), 1-2, 3-4, 5-6 and 3 position cylinder selects gear in a pair, or neutral (middle position). I don't have any other setup configured at the moment (this is a prototype) but if there was some need for it in the future, It's not really a big job, just few lines of programming codes in the control unit.

 

I hope that answers your question.

 

Marko

[ray b]

Hey.

 

I actually tried that too. Problem with solenoids is that they're not strong enough. Under load, there's actually a lot of force required to shift a car. It's ok for motorcycle, but on a regular turbo engine that just doesn't work. I did once a regular sequential shifter on a big turbo car. We needed to get 700N to shift reliably (problem is usually 1st to 2nd, or 2nd to 3rd). I tried few different options. Nothing beats pneumatics in term of speed and power. If you need speed/power, you just increase the pressure

Also, for this kind of system (without the lever) I would still need 7 different positions together. I don't know how would I do that with solenoids (and that it wouldn't weigh 100 kg )

 

On my car I primarily had H-pattern to seq. converter and then pneumatic shifter on it. But, the mechanism itself takes some time to shift (there are afterall moving mechanical parts) + pneumatics delays. The result was somewhat slower shifting and stronger requirements.

 

The cylinders I use at the moment are too strong for my application, but that's just a prototype, it's not fine-tuned yet

700n= 500+footpounds

I would like to see a manual shifter that needs 500f/p input

or could survive 500f/p input even once

or a driver who could do 500f/p with one arm

when younger I could move 500lbs with both feet 1 foot [football teams weight rig ]

 

I think somebody missed a digit in that formula

[Greg Locock]

700N is about 180 pounds force. Carry on...

[cmcraeslo]

Hello ray.

 

As mr. Locock said..it's actually 157 lb. However, I'm talking about the force when you shift a fully loaded turbo car with a dogbox from 1st to 2nd without releasing the clutch (that is by using engine management to release the load) and you also need to know that you're using a gear lever when shifting by hand, which is 1:5 ratio for example. So, we're looking at 31 lb of force.

[ray b]

'' 1 joule is equal to 1 newton meters, or 0.737562149277 foot pounds.''

 

from this site via google  http://www.convertun.../to/foot pounds

 

their calculator said 516.2935044939 f/p =700n

 

you guys may be correct as I don't have a clue in newtons

that is why I googled it

[gruntguru]

ray you are confusing N.m with N.

 

http://www.convertun...ewton/to/pounds

 

 

[Kelpiecross]

On the subject of hydraulic actuation of paddle shifters etc. - the F1  drivers and designers seem happy with hydraulic actuation. 

[cmcraeslo]

True, but paddle shifting is not the only hydraulic component in the F1 car, so if you have a high pressure hydraulics already in the system it only seems natural that you use that ;)

[kevins]

Hi Marko,

 

Bit late to this topic but this was something I toyed with (just in my head) many many years ago. I was thinking of using stepper motors, did you even consider them?

 

Does your system "learn" the clutch bite point?

 

[cmcraeslo]

Hi Kevin.

 

I did. If I had a clutch only system they would probably work just fine, but with this dogbox operation it needs to be fast and powerful, and steppers aren't (enough). Would love the control though

About the clutch point.. unfortunatelly not. That would be pretty awesome.

At the moment I can only control how fast the clutch releases (so for up shift I get faster release than the down shift).

 

Clutch is ignored on a dogbox (like the one in the video).

 

Marko

[kevins]

I was thinking of this back in about '93 - at that time I had just got myself an '88 Sierra Cosworth (4 door road, not race) and thought it would be cool to have one of these new at the time F1 paddle shifts. And if I was going to make one have it so it can fit any car. So idea was to use steppers and sensors to learn both the H pattern and clutch of any car it may be fitted to. Idea never got any further than my head.

 

So well for actually doing it, love the video. What did you use for the ECU of the shifter, something off the shelf that you can code yourself?

[cmcraeslo]

Hey. 

I designed the pcb/firmware and the software myself from scratch. I've been doing paddle shifting for some time now, I just added the H-paddle compatibility to it. I have a software that goes with it too.. it took me quite some time ;)

 

 

 

[kevins]

Hi, thanks for the pics! I'm very impressed you did all the mechanical, electronic, embeded and application software yourself! And I suppose that's you driving too?

 

I see you have a company, if I may ask did you build this to sell commercially? I'm not in the market for one so just courious. I ask because you are using surface mounted chips in the ECU. I've not been involved with hardware since about 1991 and back then SMD was only available to OEMs and the like. Is it now avaliable to a very small company or individual for prototypes and very small runs? What equipment do you need?

 

I guess that big chip is a CPU and peripheral on a  single chip and the big box is a 12V driver array? What did you code in, assembly or somthing higher level and a cross complier?  Did you have to get an ICE for the chipset?

 

For comparison (and LOLs!) here is my prototype lap timer/stopwatch I did (and gave up on) in about '92 using an Intel 8085 CPU

 

Edited by kevins, 02 December 2015 - 13:21.

[cmcraeslo]

Hey there.

 

Yes, that's me driving it too..

 

Electronics has changed a lot since 1991, that much is true. SMD is standard now, it's much easier to build things and it's also cheaper. You don't need any special equipment. Just a small soldering iron, steady hand and maybe a heat gun. And that's it.

 

That big box is actually a relay that cuts the ignition if you wire your coil directly through my ecu. It's not the preferred way, but some people don't have other options.

 

Everything was built as a hobby project (I've been racing with cars sincer year 2000) and I built stuff for myself primarily. Hopefully, one day I can make a living off of motorsport products. I need to make some website eventually and sell something, but that wasn't the primary goal.

[cmcraeslo]

Sorry, forgot to answer about the chipset. I'm using atmel avr studio and xmega chip, it supports in system programming and debugging and runs at 70 mhz.

[MatsNorway]

Everything was built as a hobby project (I've been racing with cars sincer year 2000) and I built stuff for myself primarily. Hopefully, one day I can make a living off of motorsport products. I need to make some website eventually and sell something, but that wasn't the primary goal.

 

Have you been contacted by Cody Loveland from Lovefab, inc.? he was very interested in this for his Pikes Peak car.  Check out the facebook page. www.lovefab.com

Edited by MatsNorway, 02 December 2015 - 15:37.

[cmcraeslo]

Hey Mats.

 

No, I havent heard from mr. Loveland. I checked his products and they look awesome though. That turbo exhaust.. That's how it's supposed to be done

[Fat Boy]

While I will never be a fan of paddle shifts the problem is that on a dog box they will smash the dogs and on a sychro box just tear the synchros to pieces.

Any gearbox designed to be manually shifted generally requires the drivers 'feel' to get the gears to change. And either at least a 'lift' of throttle or rev matching on the way down.  Something many drivers really do not have. Accentuated by  shift mechanisms that allow the gears to be pulled through to quickly. Oil quality too will accentuate this. Heavy oils always make shifting harder on dogs or sychros.

That is where a GOOD [many are not] H pattern beats anything else. Sequential, read straight line shifts often tear boxes to bits,, unless they are built for them.

Drag racing has been using air shifters of various forms for decades.

 

Have you ever ran a paddle shift on a road race car? I have on several, and they're brilliant. Once you get the upshift ignition cut dialed in, they're perfect. If you've got a blipper, once dialed in, the downshift side is perfect as well. I only started mileaging dog rings after changing to paddle systems. Prior to that, with any manual box (H or Sequ.) dogs were more of a wear/maintenance item.

 

Sensor failure can be a bitch as can air solenoids, lines, fittings, etc., but the present professional systems that are common right now are pretty damned nice.

[cmcraeslo]

Fat Boy -  exactly