Shraddha
New member
someone please tell me on which basis i should select chain for our go-kart. there are options like #35, #40, #41, #420, #219 chains
please suggest
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OzFab
Well-known member
It depends on the sprockets you have; first, accurately measure the distance between the teeth on the sprockets...
Shraddha
New member
we are designing totally new kart using briggs and straton 500 series engine (127 cc), speed of engine = 2600 rpm, speed of axle = 80 km/hr. can we keep velocity ratio 3 and no. of teeth on small sprocket = 12, on large sprocket = 36
crazykart
Crazy member
If you dont have sprockets as of yet then the selling points of those chain sizes is price, strength, and weight.
35 is cheapest, and also weakest.
40 is a step up in price and strength, and weight
41 420 etc etc etc.
While the weight of the chain is really negligable the main things youre wanting to look at is price and strength.
You dont want to try and push 1,000 pds of kart and driver with 35 chain. You also dont want to strap 420 chain and sprockets on something that will only have a yotal weight of 300 pds, unless you have money to blow.
Sounds like your kart will be fairly small, may I suggest 40 or 41 sprockets and chain/clutch?
Just my general understanding
35 is cheapest, and also weakest.
40 is a step up in price and strength, and weight
41 420 etc etc etc.
While the weight of the chain is really negligable the main things youre wanting to look at is price and strength.
You dont want to try and push 1,000 pds of kart and driver with 35 chain. You also dont want to strap 420 chain and sprockets on something that will only have a yotal weight of 300 pds, unless you have money to blow.
Sounds like your kart will be fairly small, may I suggest 40 or 41 sprockets and chain/clutch?
Just my general understanding
Shraddha
New member
thank you for your useful reply. but may i ask for more help? actually i didn't found calculations for axle designing. where can i find it?
crazykart
Crazy member
Calculations for axle designing? You mean a gearing ratio calculator?
OzFab
Well-known member
Sorry but, there's absolutely NO WAY to achieve that with what you have described; yes, a 3:1 gear ratio may give you a 80kmh top speed but, you will never reach it because you will destroy any clutch you can find before the kart even moves &, also, the engine simply will not produce enough torque...
My lightweight kart has a mildly worked Honda GX160, 5:1 gears & 10" rear tyres & I get 50kmh; if I lower the gearing any more I risk damaging the clutch...
Shraddha
New member
see i'm 3rd year mechanical engineering student. i'm new to go-kart designing with little knowledge. the requirements are - The wheelbase of the vehicle must be between 42-55 inches and the smaller track width
(front or rear) must be no less than 80% of the wheelbase of the vehicle. kart should be clutch less and have only monolithic suspension. i don't know how i will gonna make it
(front or rear) must be no less than 80% of the wheelbase of the vehicle. kart should be clutch less and have only monolithic suspension. i don't know how i will gonna make it
You say the kart must not have a clutch. This means that you will never be able to stop without the engine dying. Think of it like a motorbike that has gears. If you do not pull the clutch in when you want to stop, the engine dies. You will also always need to start it either with the wheels off the ground, or you will need to push start it like a car that doesn't want to start .
I also have no idea what monolithic suspension is. I tried to google it, but google doesn't know either. You will have to show us a picture or describe what it is
As for the sprockets, gearing sort of remains the same even without a clutch. You will still need a sprocket on the engine output shaft, and a sprocket attached to the axle using a hub and a keyway cut into the axle. You can google "key and keyway" if you are not too sure what they are. If it were me, i would try get a 10T sprocket and a 60T axle sprocket. This means a 6:1 gear ratio. This all depends on the size tyre you are going to use. If you use something bigger than about 13 -14 inches, then you will need to gear lower like a 7 or 8:1 gear ratio. This means that you will go a bit slower, but you will have more torque.
I would have a look at karts that others have made in your school, or use google a lot. You can also go to a gokart racing place and ask if you can look at a few of their karts for research. Test them out too
.I also have no idea what monolithic suspension is. I tried to google it, but google doesn't know either. You will have to show us a picture or describe what it is
As for the sprockets, gearing sort of remains the same even without a clutch. You will still need a sprocket on the engine output shaft, and a sprocket attached to the axle using a hub and a keyway cut into the axle. You can google "key and keyway" if you are not too sure what they are. If it were me, i would try get a 10T sprocket and a 60T axle sprocket. This means a 6:1 gear ratio. This all depends on the size tyre you are going to use. If you use something bigger than about 13 -14 inches, then you will need to gear lower like a 7 or 8:1 gear ratio. This means that you will go a bit slower, but you will have more torque.
I would have a look at karts that others have made in your school, or use google a lot. You can also go to a gokart racing place and ask if you can look at a few of their karts for research. Test them out too
crazykart
Crazy member
Wow, didnt see you wanted a 3:1 ratio. I thouhht you were just asking about the differences in the chain and such, maybe I should read all next time lol.
Actually there is a way to do a clutchless system, BUT (couple big buts actually) you can only do it with belts and stay light, and 2 you will burn through a LOT of belts if it ever does work. At a 3:1 though, no not gonna work so just nevermind.
Actually there is a way to do a clutchless system, BUT (couple big buts actually) you can only do it with belts and stay light, and 2 you will burn through a LOT of belts if it ever does work. At a 3:1 though, no not gonna work so just nevermind.
Even if you use a belt tensioner clutch...it is still a clutch
crazykart
Crazy member
Im sorry but when I think of a clutch, and a belt tensioner I think of two completely different things.
I suppose it will be up to the teacher to make the final call
crazykart
Crazy member
True true. I'm not saying I'm either right or wrong either, just to me they are two seperate devices.
Then again the teacher may have meant a clutch as in something that operates multiple gears... who knows except the teacher as it wasn't exactly put out very clearly.
As far as monolithic suspension, basically it means no big huge suspension, if any at all. No huge shocks or coil iver springs, no swing arms, no a-arms or trailing arms... the only non monilithic suspension I can think of at this moment is fabros clever little micro spring suspension for his 2013 build off winner kart...
Then again the teacher may have meant a clutch as in something that operates multiple gears... who knows except the teacher as it wasn't exactly put out very clearly.
As far as monolithic suspension, basically it means no big huge suspension, if any at all. No huge shocks or coil iver springs, no swing arms, no a-arms or trailing arms... the only non monilithic suspension I can think of at this moment is fabros clever little micro spring suspension for his 2013 build off winner kart...
It it sounds like they are basically not allowed to use any suspension
Shraddha
New member
one of my friend told me that monolithic suspension means which we provide just below the seats of bicycle and motorbikes to absorb shocks
crazykart
Crazy member
No, sorry had to reread it. It has to.only have a monolithic suspension. There is two deffinitions of monolithic, first is basically big, huge. Second is: made from one piece...so idk Im guessing a one piece suspension...?
Ah ya that^^^^ makes sense now lol. One poece suspension, seat only suspension...
You need to ask your teacher some questions before we can help you. What does the teacher mean by no clutch exactly, and do they consider a tensioner to fall in the family of clutches? Does it HAVE to go 80kmh? One set of gears or are multiple allowed?
Thats what I want to know.
Ah ya that^^^^ makes sense now lol. One poece suspension, seat only suspension...
You need to ask your teacher some questions before we can help you. What does the teacher mean by no clutch exactly, and do they consider a tensioner to fall in the family of clutches? Does it HAVE to go 80kmh? One set of gears or are multiple allowed?
Thats what I want to know.
Shraddha
New member
okay let it be. i'll clear my doubts about suspension some other time. i have calculated gear ratio as 3 and calculations are with me. please check it out and tell me why we can't go for it.
Speed of engine = 2600RPM
Speed of axle = 80 kph = 22.22m/s = speed of the wheel
V=ωr
R = 9 inches
= 9×2.54cm =22.86cm
= 0.228m
V=22.22m/s
22.22=ω× 0.228
ω= 97.456rad/s
1 Revolution = 2��Radians
? = 97.456 Radians
=15.51Rad/s
=930.6362Rpm
Velocity Ratio = 2600/930.636 = 2.79
The velocity ratio is 2.79~3
this calculations are done by the referring one gokart project report. their calculations are as follows.
Speed of motor = 2670 RPM
Speed of axle = 60 kph = speed of the wheel
23
V=ωr……………………………………………….…………………………………………………………………………………….... (3.4.2.2)
R = 6 inches
= 6×2.54cm =15.24cm
= 0.154m
V=16.67m/s
16.67=ω× 0.1524
ω= 109.361rad/s
1 Revolution = 2Radians
? = 109 Radians
=17.41Rad/s
=1044.32Rpm
Velocity Ratio = 2670/1044.32 = 2.6
Speed of engine = 2600RPM
Speed of axle = 80 kph = 22.22m/s = speed of the wheel
V=ωr
R = 9 inches
= 9×2.54cm =22.86cm
= 0.228m
V=22.22m/s
22.22=ω× 0.228
ω= 97.456rad/s
1 Revolution = 2��Radians
? = 97.456 Radians
=15.51Rad/s
=930.6362Rpm
Velocity Ratio = 2600/930.636 = 2.79
The velocity ratio is 2.79~3
this calculations are done by the referring one gokart project report. their calculations are as follows.
Speed of motor = 2670 RPM
Speed of axle = 60 kph = speed of the wheel
23
V=ωr……………………………………………….…………………………………………………………………………………….... (3.4.2.2)
R = 6 inches
= 6×2.54cm =15.24cm
= 0.154m
V=16.67m/s
16.67=ω× 0.1524
ω= 109.361rad/s
1 Revolution = 2Radians
? = 109 Radians
=17.41Rad/s
=1044.32Rpm
Velocity Ratio = 2670/1044.32 = 2.6
Shraddha
New member
hey i'm really sorry if i sound stupid to you guys... but i have to do this anyhow that's why asking such questions. sorry
hey i'm really sorry if i sound stupid to you guys... but i have to do this anyhow that's why asking such questions. sorry
Don't worry about it. There are no stupid questions here.
With a gear ratio of 3:1, you are still going to have a problem, even though you do not use a clutch. That is just too high for the kart to move. You are going to have to gear lower (have a bigger number like 5 or 6). This means the sprocket on the axle must have lot more teeth than 36
Do you have to go 80km/h/ That is really too fast for a home made kart in my opinion
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