no barrel sensor

[prince sharma]

there is no barrel sensor in cbr600 so can we use pneumatic ram in this case??

[prince sharma]

there is no barrel sensor in cbr600 so can we use pneumatic ram in this case??

[PatClarke]

Sharma, I bet no-one who reads this forum has any idea what you are talking about!

I think you should rephrase and expand your request.

Pat

[Jon Burford]

I normally tap the barrel and listen to the sound to know how much is left..

But in all seriousness, you can do whatever you want. what problems do you foresee?

[Rex Chan]

We can guess though:

He wants to run pneumatic gear shifting, using fancy paddles. However, he has no way of figuring out what gear he's in, due to a lack of gearbox drum barrel sensors. Thus, he's wondering if it's even possible.

Short answer: yes, but you need to open up the gearbox to install a sensor (AFAIK, never done it myself).

But, it has already been covered why you should not do this.

What I'm more interested in is this: why does every new (Indian) team want to do paddle shitfers? They have the internet, so can see what other FSAE teams are running, and paddles are not a required item to build a car that scores well. Yet they persist. I saw photos of the new Pakistan team installing a gear sensor; why don't you ask them how it went? More to the point, did you see how slow the Indian team was at the FSAE-A enduro?

[Jon Burford]

Why would the system need to know what gear it's in?


Presumably you could still make it shift up and down?

[Nicky]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rex Chan:

What I'm more interested in is this: why does every new (Indian) team want to do paddle shitfers? They have the internet, so can see what other FSAE teams are running, and paddles are not a required item to build a car that scores well. </div></BLOCKQUOTE>


To this I can only say that, like any other ambitious team(around the world) we've had concepts tested since the last 4 years for a quick shifter. This doesn't necessarily mean we put it on and expect it to run at the event. We've done our bit of engineering.

This was in 2006, with the bulky components that we had from FESTO. This includes a 15kg dual 1.5ltr canister which could only be charged to 5Bar. Needless to say, we ran a manual shifter at the event that year.
Using Pneumatic muscles provided by Festo, 2006 (http://www.youtube.com/watch?v=Q_z0cW_roNA&t=0m40s)


This was in 2010 when we wanted to check for feasibility of a paddle shifter, it was ever worth the effort. This included an onboard compressor. All this was done parallel to the construction of the car. Again, this forum did provide insight.

We didn't have the cash for a 400bar system, nor the local facility to charge it here or at the event. Also, that would mean expensive testing as you have to keep getting the canister charged. So, we used an onboard compressor(consumes 3A for about 2.5-3seconds to refill air consumed in a shift).
Testing on the engine stand (http://www.youtube.com/watch?v=19CU3ULvgk0)

This was a few weeks post the last test, when we integrated the system. What you see just infront of the muffler. This includes a 1.2kg double solenoid from Festo, an accusump canister and an onboard compressor.
First run with pneumatics on the car (http://www.youtube.com/watch?v=68pnCCbDVfQ)

On proving the concept, we integrated it to the Motec M800 and ran ignition kill. We initially blew a clutch thanks to running an aggressive kill strategy. Correctly sized the piston, canister and got a double solenoid that weighed in at 250gms. The whole system now weighs in a little over 1.2kgs. We ran the 2011 event with this setup.

Conclusions: Shift times dropped from 500-600ms to about 80ms, no clutching due to the ignition kill. Eases effort for the driver; no packaging of a stick shifter; this with about 15 shifts a lap, saves close to 6sec/lap. Now tell me Rex, if that's not a good enough reason to go for paddle shifters!!

When it comes to knowing which gear you are on, train the drivers. A well accustomed driver while know instinctively which gear he is in without even looking at the dashboard.

PS: This is what happened while testing, immediately changed the t-joint with a steel one. Works great ever since.
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/375216_230246997043362_123943224340407_516231_9474 57143_n.jpg

[nowhere fast]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Nicky:
Conclusions: Shift times dropped from 500-600ms to about 80ms, no clutching due to the ignition kill. Eases effort for the driver; no packaging of a stick shifter; this with about 15 shifts a lap, saves close to 6sec/lap. Now tell me Rex, if that's not a good enough reason to go for paddle shifters!! </div></BLOCKQUOTE>

The shifter will not save 6 seconds per lap. The car stops accelerating during a shift, but it doesn't stop moving.
Combining a power cut with a manual shifter will give similar shift times to a paddle shift, the only real benefit in my opinion is ease of use for the driver.

However, it's good to hear you developed the paddle shift in parallel with the car and only used it in competition when it was suitably developed.

[Bemo]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by nowhere fast:

Combining a power cut with a manual shifter will give similar shift times to a paddle shift, the only real benefit in my opinion is ease of use for the driver. </div></BLOCKQUOTE>
And that is something you shouldn't underestimate. Especially if your drivers aren't too experienced everything what makes the car easier to drive will save you a lot of time. You will hit less cones and still be faster. During an endurance that can be quite a lot.

[prince sharma]

what m asking is if there is no barrel sensor who can we know in which gear car is running..?

[Jon Burford]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
what m asking is if there is no barrel sensor who can we know in which gear car is running..? </div></BLOCKQUOTE>

Why do you need to know? your driver will know.
All you do is go up and down

[Fyhr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jon Burford:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
what m asking is if there is no barrel sensor who can we know in which gear car is running..? </div></BLOCKQUOTE>

Why do you need to know? your driver will know.
All you do is go up and down </div></BLOCKQUOTE>

Alternatively if you really need to know and don't want to modify the engine block for some reason, perhaps you know the engine speed and perhaps you know the wheel speed.

Assuming also, as this is an engineering competiton, you know some math.

[prince sharma]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Fyhr:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Jon Burford:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
what m asking is if there is no barrel sensor who can we know in which gear car is running..? </div></BLOCKQUOTE>

Why do you need to know? your driver will know.
All you do is go up and down </div></BLOCKQUOTE>

Alternatively if you really need to know and don't want to modify the engine block for some reason, perhaps you know the engine speed and perhaps you know the wheel speed.

Assuming also, as this is an engineering competiton, you know some math. </div></BLOCKQUOTE>


how can we program microcontroller to display gear on dash using engine speed and wheel speed?

[kcapitano]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Assuming also, as this is an engineering competiton, you know some math. </div></BLOCKQUOTE>

Hmm, an invalid assumption perhaps?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> how can we program microcontroller to display gear on dash using engine speed and wheel speed? </div></BLOCKQUOTE>

That would depend on what microcontroller you're using, what programming language, how you are going to display the gear number on your dash, and probably more things...
Only you can figure out how to put it all together!

[Nicky]

Alternatively, I know I'm spoon feeding a troll now, but anyways.

Find the tailshaft rpm from the wheel rpm based on the final drive ratio you are running.

From the engine rpm and this tailshaft rpm, you can back calculate a ratio. This ratio includes the primary and secondary reduction from the crank to the clutch. You arrive at a ratio. Match this to the various gear ratios and you'll be closer to a given gear's ratio. Add a little tolerance to that and voila, you have which gear you are in.

Read the engine manual for the various reduction ratios. If you still do have a doubt after the handout I just gave you, I suggest you try this link
Basic Learning (http://kindergarten.com/)

[prince sharma]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Nicky:
Alternatively, I know I'm spoon feeding a troll now, but anyways.

Find the tailshaft rpm from the wheel rpm based on the final drive ratio you are running.

From the engine rpm and this tailshaft rpm, you can back calculate a ratio. This ratio includes the primary and secondary reduction from the crank to the clutch. You arrive at a ratio. Match this to the various gear ratios and you'll be closer to a given gear's ratio. Add a little tolerance to that and voila, you have which gear you are in.

Read the engine manual for the various reduction ratios. If you still do have a doubt after the handout I just gave you, I suggest you try this link
Basic Learning (http://kindergarten.com/) </div></BLOCKQUOTE>

dude!! i am doing this first time so its little confusing.. stop making these pathetic comments..

[Rex Chan]

This reply is to Nicky.

First off, I want to say that I agree with Nathan about how it's good that you developed your system over time. I wish we had the time and patience to do this. However, this raises the question: is it worth it to spend the time to develop?

I also agree wtih Bemo that, all things being equal, a paddle shifter is a benefit (easy, consistant, fast shifts). But the important point is that things should be pretty good (i.e. your car is very fast) before paddles are worth it.

Onto the real question: you have clearly laid out the path it took to get paddle/pnuematics working for your team. Now I will do the same for mine (MUR Motorsports 2011 - mechanical solid linkage gear shift, cable hand clutch).

Timewise: it took 2 people a few hours to work out how to run a solid rod from the cockpit to the gear selector thing, through a bellcrank.

Weight: I weighed the rods and bellcrank, and it was less than 150g. I would guess the whole system weighs 300-400g, but def less than 0.5kg.

Cost: We already had the materials in our workshop, but if we had to buy it all, would cost not more than $50.

In summary, our system took a lot less time, weighs a lot less, and cost a lot less than your system.

However, you claim a significant time benefit (~6s per lap). If you have data to show this amount of time saving, I think most of us would very keen to see it. Or if you wouild rather not share, can you at least confirm this time saving? In my opinion, a paddle shifting system would save us in the order of 1 second per lap. This would not make such a system worth it for us.

Now, back to my previous question: "Is it worth it to spend the time to develop?" I think that it woud only make sense for a team to develop paddles is they were at the front of the pack in laptimes, where such a system would make a important difference. At both FSAE-A 2010 and 2011, MUR was 6 seconds behind the fastest teams. Thus, we have a long way to go before we are close to the fast teams, and the biggest gains for us are to be had in drivers and car setup (IMO).

May I inquire as to how off the fast teams your team is?

PS. A mechanical shifter does not depend on any other car system to work. And it works all the time (paddles have more moving parts to go wrong/fail).

PPS. We don't clutch on upshifts either, nor on downshifts (unless they get it wrong).

[Bemo]

I have to agree with Rex that 6s sound very optimistic as the time saved per lap by pneumatic shiftig. Including to propably less cones etc. I'd also go with 1s per endurance lap in average.

That's quite a lot. But without wanting to offend anybody, I have to say that Indian team usually have big troubles to get their car running at all. Adding an pneumatic system doesn't make it any easier to get it running.

Back to the original topic. There is a reason the CBR engine has only a sensor which detects wether it is in neutral or not - because in the motorbike you don't have a display which tells you which gear you're in. You just shift up and down and have to count or to know it by intuition / feel it. Same works for FSAE cars. The 2011 car from Stuttgart was the first one with a working gear sensor, but we were able to win quite some competitions.
As you mentioned it is the first time you're doing this and you're asking very basic questions my advice to you is to build a very simple and reliable system.
Compared to the usual performance of Indian teams it would be quite a big step to pass scrutineering without bigger issues and to finish endurance. Focus on that before you invest your time into the fancy stuff.

[prince sharma]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bemo:
I have to agree with Rex that 6s sound very optimistic as the time saved per lap by pneumatic shiftig. Including to propably less cones etc. I'd also go with 1s per endurance lap in average.

That's quite a lot. But without wanting to offend anybody, I have to say that Indian team usually have big troubles to get their car running at all. Adding an pneumatic system doesn't make it any easier to get it running.

Back to the original topic. There is a reason the CBR engine has only a sensor which detects wether it is in neutral or not - because in the motorbike you don't have a display which tells you which gear you're in. You just shift up and down and have to count or to know it by intuition / feel it. Same works for FSAE cars. The 2011 car from Stuttgart was the first one with a working gear sensor, but we were able to win quite some competitions.
As you mentioned it is the first time you're doing this and you're asking very basic questions my advice to you is to build a very simple and reliable system.
Compared to the usual performance of Indian teams it would be quite a big step to pass scrutineering without bigger issues and to finish endurance. Focus on that before you invest your time into the fancy stuff. </div></BLOCKQUOTE>


so bemo what you suggest what type of transmission we should use..?? and regarding other issues of car running we will take care of that..

[shark.ashwa]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bemo:
I have to agree with Rex that 6s sound very optimistic as the time saved per lap by pneumatic shiftig. Including to propably less cones etc. I'd also go with 1s per endurance lap in average.

That's quite a lot. But without wanting to offend anybody, I have to say that Indian team usually have big troubles to get their car running at all. Adding an pneumatic system doesn't make it any easier to get it running.

Back to the original topic. There is a reason the CBR engine has only a sensor which detects wether it is in neutral or not - because in the motorbike you don't have a display which tells you which gear you're in. You just shift up and down and have to count or to know it by intuition / feel it. Same works for FSAE cars. The 2011 car from Stuttgart was the first one with a working gear sensor, but we were able to win quite some competitions.
As you mentioned it is the first time you're doing this and you're asking very basic questions my advice to you is to build a very simple and reliable system.
Compared to the usual performance of Indian teams it would be quite a big step to pass scrutineering without bigger issues and to finish endurance. Focus on that before you invest your time into the fancy stuff. </div></BLOCKQUOTE>


so bemo what you suggest what type of transmission we should use..?? and regarding other issues of car running we will take care of that.. </div></BLOCKQUOTE>

Facepalm! http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif
Please read Bemo's post again! I don't think you understood what he said......

Sharath

[Fyhr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by shark.ashwa:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bemo:
Pass scrutineering without bigger issues and finish endurance. </div></BLOCKQUOTE>
Asks for transmission advice
</div></BLOCKQUOTE>
Reread Bemo
</div></BLOCKQUOTE>

I'm not saying it's a good solution, but running a CVT would remove ALL the issues stated in this thread http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Bemo]

Lol, except keeping it simple http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Fyhr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Bemo:
Lol, except keeping it simple http://fsae.com/groupee_common/emoticons/icon_wink.gif </div></BLOCKQUOTE>
Very true, I didn't think through the availability of snowmobiles in India. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[PatClarke]

http://www.amazon.com/2011-201...-India/dp/B004W9N97G (http://www.amazon.com/2011-2016-Outlook-Snowmobiles-India/dp/B004W9N97G)

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

Pat

[Nicky]

@Rex: I do agree that this rather took a lot of time to develop, that's cos we pretty much abandoned the idea till 2009 and had none working on it. In essence if you look at it, was about 8 scattered months where some time was spent in this in all, but time to event-ready system over 4 long years!!

Again, whether it was worth this system, yup, our accel times went down by 0.2s. My bad with the 6s/lap. But paddles eased driving a lot for us. When it comes to the components, we shelled out about INR4500(USD 100) in all for the system. Wouldn't you do anything to make your car go a tenth faster? Isn't that what racing is about?


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by prince sharma:
dude!! i am doing this first time so its little confusing.. stop making these pathetic comments.. </div></BLOCKQUOTE>

I thought I just handed out to you how to find which gear you are in. So what about the comment did you find "pathetic"?

[Jon Burford]

The CVT remove no comlexity with regards to anythihg, just for the record...