Frame design

Millwright

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A little more work tonight with a bit of success and a few lessons.
I got a functioning drive in place. Belt installed and chain in place. Did a test run on Jack stands.
 

Millwright

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A reliable throttle control is proving to be a bit of a pain. Need to pick up just the right spring. Still fiddling with that.
Getting my brake set up right is a bit of a tedious operation too.
When installing the chain I thought I had lucked out on my sprocket spacing, fit so nice. Under power it is flopping around more than I like. I will have to go with a tensioner.
The belt seamed really loose, I know it's supposed to but wow, that's loose. Regardless, wheels spin at idle!
I'm a little worried about heat on the belt. For the short run I did, it heated up a lot. I'm thinking it might be due to the close proximity to the cylinder?
 

Millwright

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First "on the Pavement" run today.

Steering is very stiff and extremely touchy!!
Brakes are just a vague suggestion of stopping.
Throttle ended up being hand control for now, but actually works pretty good.

I started out with 4.8:1. Loads of torque.
Spins and kicks gravel.
I have no idea of speed or RPMs, just holding on for dear life!!!
Need to fix the steering right away.
 

Functional Artist

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First "on the Pavement" run today.

Steering is very stiff and extremely touchy!!
Brakes are just a vague suggestion of stopping.
Throttle ended up being hand control for now, but actually works pretty good.

I started out with 4.8:1. Loads of torque.
Spins and kicks gravel.
I have no idea of speed or RPMs, just holding on for dear life!!!
Need to fix the steering right away.
"just holding on for dear life!!!"...That's the spirit :thumbsup:

Glad you got 'er going :cheers2:

Keep up the good work ;)

Progress, I love it :bannana:
 

madprofessor

"Loose Cannon Creations"
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Shortening up the pitman arm would be most folks' first thought about that touchy steering, but I'm wondering how that'd affect the turning radius on a kart with a 6' wheelbase, even a narrow one like yours.
Had to address that same thing on my 8' wheelbase, decided anything at all that reduced the lock-to-lock angle would be a bad thing. Has to practically track sideways to make me completely happy, found that at a certain point it just skids forward. Got my tightest turning radius possible though. Depending on the chain-drive steering gears reductions to smooth the rest of the twitch out.
If that 420 will let the tires break loose into an asphalt doughnut, then you know it's geared short enough. Should only go taller from there to get that top end you want. Shame to sacrifice that sweet smell of burnt rubber for speed though.
 

Millwright

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So I fixed my steering, a little bit.
I extended the arms on my spindles from 2.5" to 5" long. The next issue with steering may be the steering wheel. I think I went a bit heavy on castor, and I don't have the leverage I need at the steering wheel. It's a 10" wheel.
It's a lot more manageable now, but still a bit of a wrestling match.

I did a bit of a speed test today.

16" wheel, 4.8 gearing, 3900 RPM
Chart says 38mph, I clocked 33.

I had a lot of throttle left, but still not comfortable enough with the steering to push it beyond that.
 

Millwright

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I started out this kart project with visions of perfection and performance.
Now I'm cutting and hacking and Jerry rigging parts together!!!
I'm going to chalk this build up to "a learning experience"
The next one can be perfect. Lol.
 

madprofessor

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Don't sweat the learning, you'll finally get it completely the way you want it. You're just doing it the way I am with my steering, trying different things to reach the desired goal, and learning from each new rigging.
Did doubling your spindle arms' lengths still leave you with sufficient lock-to-lock angle for a tight radius?
 

Millwright

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I had to adjust the length of the rods, but it did not effect the radius.
Lock to lock is 10 to 2. (clock face)

I can do a u turn on the road using both lanes but not touching either shoulder. That's good enough for me.
 

Millwright

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I changed up the gearing slightly. I have the 48T paired with a 13T for a 3.7 ratio.

There is no noticeable difference in torque from the 10T I started with. It's still pretty good and kicks up some gravel.

The speed calculator says top speed at 4500 RPM will be 58 mph. My GPS clocked me at 50.
If the tach reading is true, I guess the loss must be in the torque convertor?

I tried to attach a 30 second video clip. Too large!
What are the rules on file size?
 

Denny

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You will always be making changes to it until you figure out a formula you like. Then just keep following it on the next ones.
 
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