Torsk (Backbone Chassis) Kart

[Functional Artist]

Placed the cockpit on the bench, over the backbone & double checked everything again

Everything still seems to line up pretty good

So, cleaned up the connections & welded a nice bead around both of 'em

Removed the "pin" screws & drilled thru the outer layer of pipe to a 1/4"

That way I could put a good "inner" spot weld, to help "lock 'em in from the inside"
...& fill up the holes too

Then, cleaned 'er up a bit

I'm likin' the way it's coming along

 

[Functional Artist]

Next, we gotta figure out where, exactly, is the cockpit gonna be positioned
...& how is it gonna be attached?

We know for sure (kinda) that it needs to be
...centered over the backbone chassis
...& as far back as possible but, still leaving adequate room for motor adjustment

As for attachment

I could just weld some short sections of pipe in between the backbone & the cockpit
(in all (4) corners)
...but, that's only a 2D (2 dimensional) connection & wouldn't be very structurally sound

There won't ever be very much weight pulling down on the cockpit
...but, without a 3D (3 dimensional) connection (some type of triangulation or structural back up) in a roll over situation & it would probably just snap off

Then, I thought about using a couple of pieces of 1/4" x 1" flat steel
...just welded to the bottom of the backbone
...extending out on each side & have the cockpit sit in top & welded to them

Again, not too structural, still only 2D

Then I thought, how about putting the cross bars on angles

In the rear across the backbone & the bottom of the seatback
...angled toward the rear
& in the front across the backbone & the bottom of the steering support
...angled toward the front

Yea, that looks better & stronger

It looks like this set up will
...give many good welding (junctions) on the backbone & the cockpit
...should allow the backbone chassis & the cockpit to twist/flex together
...& ain't gonna snap off on a roll over

 

[Functional Artist]

The pieces of 1/8" steel strips had 90* bends on one end

The bends wrapped around so nicely that instead of cutting them off
I wanted them on both ends

So, I marked both pieces ~1' longer than necessary & put 90* bends on the other ends too

Then, I drilled & used small screws to "pin" the bars in place for welding

 

[Functional Artist]

I started off by just welding the cross bars onto the cockpit
(they are "pinned" so I am not worried about them coming out of adjustment)

A quick bead (um blob) across the top & bottom on all (4) corners

Then, I removed the "pin" screws
...drilled the outer layer of steel out to 1/4"
...spot welded/filled them in
...& a little clean up

 

[Functional Artist]

Marriage time
...time to make two as one

The cockpit sits nicely on the backbone
...except for the trailing arms (remember they are a little wider than the backbone itself)

A couple of quick notches with the grinder & no more problem

Centered the cockpit, on the backbone chassis
...double checked the motor (rear) & battery (front) clearances (for the last time)
...this is where the "or forever hold your peace" part comes in

A couple of decent welds in the rear
...then a nice long bead in the front (I was on a roll)

 

[Functional Artist]

It's coming together nicely

Here is a video of progress so far

https://www.youtube.com/watch?v=Q9VBw-dMtZk

 

[Functional Artist]

Back to the tires, again

I finally got one of the 13 x 5.00/6 tires "blowed up" on the rim
...it was a total PITA

It looked like a wheel barrow tire
(imagine just mounting an inner tube on a rim & inflating it)

Yup, it looked kinda like that
(I thought I had some pics but, can't find them now)

So, I got a couple of 13 x 6.50/6 ribbed tires
...they look much better

The 13 x 5.00/6 ribbed tires should work in the front
...on narrower front rims of course

 

[landuse]

Looking good

 

[Functional Artist]

What do we do next? (on the chassis, that is)
...there is plenty of other stuff (the guts) left to do

So, we still need
...the steering (steering wheel, shaft, spindles etc.)
...& a seat

But, there are some variables, that need to work together, to consider or "keep in mind"

What type of steering wheel (style, dimensions etc.)
...which will affect, the steering shaft angle & help dictate it's mounting (above the steering support or below)

But, also what type of seat & it's mounting method
...because the seats dimensions will also affect or influence the choice of steering wheel & shaft mounting method

* The seat needs to clear (sit above) the rear battery so, we can't just "throw a cushion" on this one

More to come

 

[Functional Artist]

Have been workin' on/thinkin' about the seat situation

There is not much room behind the rear batteries, ~5"
...& the batteries stick up out of the backbone ~2"

So, maybe
...riding lawn mower style (with springs?)
...or just stuff some foam rubber back there

Naw, not feelin' it

How about a custom "wrap around the battery" seat
...standard plywood seat bottom/back
...a little bit of foam rubber
...& some vinyl

Yup, I like that better

Before padding & upholstery, I rounded & smoothed the edges a bit
...& the rear bearing spacers too

 

[Functional Artist]

First, tried a layer of 2" foam rubber padding
...but, when I sat on it, I could still feel the battery

So, I tried (2) layers of 2" padding
...could still feel it

(3) layers of 2" padding did the trick
...but, it was 6" thick

Then, I tried some of this 1" closed cell foam rubber stuff (like a pool noodle)

It is kinda springy
...but, it does not give (collapse) as much as foam rubber

The "white" layer on top of the plywood brings it up just about even with the top of the battery
...& a 2" layer of the foam rubber will top it off nicely

 

[Functional Artist]

I pretty much have the seat situation figured out
...placement, dimensions & such

Just have to make the cover
...but, it's kinda complicated
...& I wanna do it right
...so, I'm not gonna rush it

So then, I went back to workin' on the steering

First I boxed off the ends of the front axle with some 1/8" x 1 3/4" steel
...on a bit of an angle

 

[Functional Artist]

I started off with some 5/8" steel rod
...a couple of grease able nylon bushings
...a Craftsman riding lawn mower steering wheel
...a 1/8" x 3" "steering lever"
...& a mounting "foot"

The 'steering lever" seemed to have too much throw
...so, I made a few others (1/8" x 1 1/2" & 1/8" x 2 1/2")

 

[Functional Artist]

The steering wheel is NOT workin' for me
...too big? gawdy?
...plus I want/need to use a thumb throttle

Bounced around a couple of ideas
...but, I'm tryin' to stay away from "handle bars"

I liked the "butterfly style" steering wheel that I made for the !Arriba! kart last fall
...but, not the grip so much

So, I'm thinkin' an "open grip" "butterfly style" steering wheel

 

[Functional Artist]

I kinda liked the center part of the steering wheel
...so, I used it for (rough) measurements

To have ample room to "grip it good" & room to mount a thumb throttle
...it looks like we need ~6'

So, the "butterfly style" steering wheel is
...(2) 6" pieces of water pipe (marked & drilled to matching specs)
...(2) 12" pieces of 3/8" rod (custom bent to matching specs also)
...& a piece of 1/8" x 2" steel

Yup, that should work

 

[ezcome-ezgo]

What is you just cut away the red part of the tractor wheel?

 

[Functional Artist]

What is you just cut away the red part of the tractor wheel?

I thought about it

But, I would of had to leave a bit extra stickin' up & then whittled it down (to add a piece of pipe) for the thumb throttle & secure it

...& the mounting stub (coming off of the bottom of the steering wheel) was kinda wonky/wobbly

Plus, IMHO it just didn't go with the style of the kart

This one is much tighter & I think it looks "Bad Azz"

 

[Functional Artist]

Now, that we know the seat dimensions & steering wheel dimensions

Next, was to work on placement/aligning & getting the steering shaft mounted

I think, I'm gonna put the steering shaft inside of a protective tube
...in true backbone chassis style

It wont add much extra weight
...& it'll look kool

So, I bent a piece of 1/8" x 1 1/4" steel for the "foot" & welded it to the bottom of the steering shaft housing
...using a brass bushing to aid alignment (of the tube & the foot) during welding

Also welded the 1 1/2" steering lever to the bottom of the steering shaft
...leaving ~1/4" stickin' up (for "good" welding "penetration")

 

[Functional Artist]

Next is to get the steering assembly mounted on the kart

I drilled a couple of 1/4" "spot" welding holes in the "foot" (I'm kinda likin' this attachment method)

Also, I gotta keep it kool so I don't melt the lower nylon bushing, from the welding heat
...the way this is designed, the lower nylon bushing cannot be installed later

So, I slid the steering shaft & the nylon bushing down & as far away from the "foot" as possible (before welding)

First, welded (1) spot, securing the "foot" to the backbone
...then, checked temperature of the area around the bushing

Yup, still kool to the touch

But, I don't want to "push it"
...so, while that was koolin', I moved up to the top & double checked alignment

Then, plopped a weld on each side
...securing the steering housing to the steering support (left the nylon bushing out of the top 'cause it can be installed later)

Then, went back to the bottom & welded the other spot, on the foot
...again checking temperature

I kinda like the end result of these "spot" welds, it leaves an "industrial" but, "clean" look & seems like a very strong connection too

So, as a test, I not gonna weld along or around the edges of the "foot"
...to see if it holds up in this situation

 

[tgus3]

This is reallly interesting..it'll be "kool" to see how it turns out