C02 Dragster

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Calibre11
Calibre11
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Joined: Sun Jan 26, 2020 7:25 pm

C02 Dragster

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Hey everyone, I'm currently working on a CO2 dragster project in high school. I came here to ask for some suggestions on how to make my dragster fast. (I want to be a racing car designer after college and am really interested in this field) Any suggestions?

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flynfrog
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Re: C02 Dragster

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Cut weight and reduce friction. I think back many years ago I found aluminum for the axles and built a shell car. It's still on my workbench.

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hollus
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Joined: Sun Mar 29, 2009 12:21 am
Location: Copenhagen, Denmark

Re: C02 Dragster

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Search the “F1 in schools” projects. Force google to search within this site. Lots and lots of good discussion around the subject here in the past.
¡Puxa Esportin!

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Big Tea
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Re: C02 Dragster

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flynfrog wrote:
Sun Jan 26, 2020 8:05 pm
Cut weight and reduce friction. I think back many years ago I found aluminum for the axles and built a shell car. It's still on my workbench.
And the best grip you can have on driving tyres
One test is worth a thousand expert opinions

Calibre11
Calibre11
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Re: C02 Dragster

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What's more important, weight or aerodynamics? Because I'm conflicted between building a very aerodynamic bullet-shaped body and literally a tiny wooden rod to save weight.

Scorpaguy
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Re: C02 Dragster

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Calibre11 wrote:
Mon Jan 27, 2020 2:07 am
What's more important, weight or aerodynamics? Because I'm conflicted between building a very aerodynamic bullet-shaped body and literally a tiny wooden rod to save weight.
Weight is the enemy of the start...drag is the enemy of speed. Not knowing the race rules it is hard to say, but I cannot imagine length and sustained speed being important enough to add aero fixtures that add significant weight.

AJI
AJI
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Joined: Tue Dec 22, 2015 8:08 am

Re: C02 Dragster

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Big Tea wrote:
Sun Jan 26, 2020 9:25 pm
flynfrog wrote:
Sun Jan 26, 2020 8:05 pm
Cut weight and reduce friction. I think back many years ago I found aluminum for the axles and built a shell car. It's still on my workbench.
And the best grip you can have on driving tyres
???
It's a co2 dragster. There are no driving tyres (unless he's building a compressed gas piston engine)

My question, what are the co2 emmissions like :lol:

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Big Tea
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Joined: Sun Dec 24, 2017 7:57 pm

Re: C02 Dragster

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AJI wrote:
Mon Jan 27, 2020 6:59 am
Big Tea wrote:
Sun Jan 26, 2020 9:25 pm
flynfrog wrote:
Sun Jan 26, 2020 8:05 pm
Cut weight and reduce friction. I think back many years ago I found aluminum for the axles and built a shell car. It's still on my workbench.
And the best grip you can have on driving tyres
???
It's a co2 dragster. There are no driving tyres (unless he's building a compressed gas piston engine)

My question, what are the co2 emmissions like :lol:
I was kidding. I assume it is a 'jet type'?

Guys, I freely admit I know nothing about it, but a strange question just occurred to me.
Would 'upforce' be any use? The 'weight' would be insignificant, but would it reduce rolling resistance?
Also, can the 'jet' be directed over or under a plane?
(sorry if its stupid, but just asking)


Edit
I got quite interested in this while looking it up.


some good advice here
http://www.meprogram.com.au/wp-content/ ... -Folio.pdf
One test is worth a thousand expert opinions

Rodak
Rodak
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Joined: Wed Oct 04, 2017 2:02 am

Re: C02 Dragster

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Interesting project. My first thought was, as was immediately posted, minimum weight and friction. It would also seem important to have the axles perpendicular to the line of travel so there was no wheel scrubbing. Also, there is no mention of requirements for the cartridge housing; would it be possible (or beneficial) to house the CO2 cartridge so that an expansion nozzle could be added after the cartridge, to better control gas expansion to atmospheric. Possible some way to insert the cartridge vertically into a housing that incorporates a nozzle. I doubt aerodynamics plays much role in final speed, but smooth is good....

Stu
Stu
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Joined: Sat Nov 02, 2019 9:05 am

Re: C02 Dragster

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I recall having to build something similar whilst at university many years ago, however that was elastic band powered and required a brake. With my team we ended up building a lightweight aluminium monocoque with a single rear wheel on a ball-bearing mounted axle (drive on one side, brake on the other), the front axle had individual spigots with ball bearings mounted in the wheels.
Rear wheel was very groovy, and light. Large diameter, thin tri-spoke made from Perspex. We HAD to fit a ‘tyre’ (rubber band), as it would spin up... with the tyre on it generated enough grip to pick up the front wheels....😄
We ended up with a variable ratio gear on the drive side.
Vehicle was required to cover a 12m track as quickly as possible, with points for accuracy (hence the brake). Great fun!

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Big Tea
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Joined: Sun Dec 24, 2017 7:57 pm

Re: C02 Dragster

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Stu wrote:
Tue Jan 28, 2020 8:15 am
I recall having to build something similar whilst at university many years ago, however that was elastic band powered and required a brake. With my team we ended up building a lightweight aluminium monocoque with a single rear wheel on a ball-bearing mounted axle (drive on one side, brake on the other), the front axle had individual spigots with ball bearings mounted in the wheels.
Rear wheel was very groovy, and light. Large diameter, thin tri-spoke made from Perspex. We HAD to fit a ‘tyre’ (rubber band), as it would spin up... with the tyre on it generated enough grip to pick up the front wheels....😄
We ended up with a variable ratio gear on the drive side.
Vehicle was required to cover a 12m track as quickly as possible, with points for accuracy (hence the brake). Great fun!

As it seems to be guided by a 'line' could it be beneficial to have the wheels with a high caster and no actual fixed alignment? No need to steer and as long as there is little friction with the line there would be no scrub from the wheel.
From what I see of the rules it does not seem to prohibit steering by using the line

(I have no real idea, just asking)
One test is worth a thousand expert opinions

Stu
Stu
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Joined: Sat Nov 02, 2019 9:05 am

Re: C02 Dragster

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If it is guided by a string line, I would be looking to build something as close to a guided missile as possible....

Calibre11
Calibre11
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Joined: Sun Jan 26, 2020 7:25 pm

Re: C02 Dragster

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I was looking at a few F1 in schools designs and they all have wings and fairings. Are these worth their weight?