Second offroad kart build

[amx1992]

Hi all. I'm building a second kart after the first was a massive disaster. Things i've learnt from the first kart: ackermann matters, steering is good and better engine mounts.

Im in south of England, so measurements are generally milliliters and centimeters and money in pounds. I'll try and keep a log of costs and take as many pics as possible.

The plan is independent front suspension and rear swingarm, with a geared four stroke powering it

Ive got hold of a motorbike which is fire damaged, £40, which is great because my main ride is one of these, so plenty of spares

Engine is a 5 gear, 150c, four stroke, air cooled, electric start and gear indicator. im also planning on using the rear suspension, mirrors, exhausts and brake system. I also had to get a wiring loom, £20.

 

[amx1992]

Im using mainly 2mm wall 25mm box section for the majority of the frame and 20mm box for the struts. I used a jig to make building it a bit easier and i'm using a flux cored welder (they're not that bad!). Metal was £50 (for whole project), total so far £110.

 

[amx1992]

Next is the engine mounts which are made out 5mm steel plate. Cut them out with an angle grinder ( of a job).

 

[OzFab]

Next is the engine mounts which are made out 5mm steel plate. Cut them out with an angle grinder ( of a job).

That they are...

Nice work so far. Here's another thing to consider: The chain drive cannot go forward from the sprocket; have you considered this as part of your engine/axle placement?

 

[landuse]

Next is the engine mounts which are made out 5mm steel plate. Cut them out with an angle grinder ( of a job).

Nice work so far!

I hear you with cutting plate with a grinder! Been there, done that....nearly burned out my grinder.

 

[amx1992]

Ive mounted the engine so that the engine sprocket is level with the bar running across the back, then it'll go to a swing arm.

Stupidly, Ive welded one side of the engine mount supports right across where the chain will go so it'll be out with the angle grinder again

 

[Jim-L-L]

Next is the engine mounts which are made out 5mm steel plate. Cut them out with an angle grinder ( of a job).

Not trying to teach you to suck eggs but try doing lots of shallow sweeps so the grinder does not bog down and RPM stays up also metal does not overheat. you will be through it in no time

 

[landuse]

Not trying to teach you to suck eggs but try doing lots of shallow sweeps so the grinder does not bog down and RPM stays up also metal does not overheat. you will be through it in no time

Thats how I did it, but it is still a mission

 

[fowler]

Ha need to get a better grinder

mysteryboy will tell u how awesome cheap grinders are

But yea
Loads or shallow sweeps
If the one spot heats up too much then
A it becomes harder to cut once its heat affected
B there is a chance the disc can over heat and explode

U have made a decent start

 

[amx1992]

B there is a chance the disc can over heat and explode

Ive had that happen before, i'm glad i was wearing goggles

 

[loud1]

Next is the engine mounts which are made out 5mm steel plate. Cut them out with an angle grinder ( of a job).

Ha.. Yea, i cut my triple tree plates with a grinder, that stuff was 1/4in, a little more than 6mm. nice job so far.

 

[OzFab]

Ive mounted the engine so that the engine sprocket is level with the bar running across the back, then it'll go to a swing arm.

Oh, there's a swingarm beyond that, cool.

It does, however, bring up anther point: The swingarm pivots need to be on the same axis as the sprocket shaft or you will have chain tension problems...

Man, I gotta stop raining on this poor guy's parade...

 

[loud1]

Or you need a spring loaded tensioner.

 

[amx1992]

It does, however, bring up anther point: The swingarm pivots need to be on the same axis as the sprocket shaft or you will have chain tension problems...

Ive been thinking about that. On the motorbike the axis of the sprocket and swing arm are different, so im going to hope it works ok. Failing that i'll try make a chain tensioner

 

[OzFab]

On the motorbike the axis of the sprocket and swing arm are different

True but, the pivot is in a direct line between the drive shaft & the axle so, keep that in mind...