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464 Posts
Discussion Starter · #24 ·
Next, I did some grinding
...because the trailing arms are 2 1/2" & the backbone is only 2" & the trailing arms are centered on the backbone so, they stick up ~1/4" above & below.
(which is no big deal except where the motor mounting plate sits)

The motor mounting plate needs to set level with the backbone
(across from the backbone to the trailing arm)
...which (in turn) should also ensure it's squareness with the rear axle

I made sure that
...the backbone chassis was sitting level on the workbench
...then ground the edge of the trailing arm down
...checking progress several times
....until the motor mounting plate was sitting nice-n-level

Before assembling & aligning everything, I drilled (2) 1/8" holes near the inner edge of the motor mount plate so, once the motor mount plate is where it needs to be
...I can mark the (2) spots & drill them out (to use as alignment points)
...& also to install small screws (so, I can "tack it down" in "that exact spot" for testing & then welding)

Reassembled everything again, each time adding a piece to the puzzle
...bolted the bearings in place
...slid the axle thru 'em
...installed the sprocket on the right side
...bolted the motor to the motor mount plate (at lowest adjustment)
...added a piece of #35 chain
...& adjusted/aligned everything (with the square, straight edge & the level)

After triple checking ALL of the alignment points
I drilled out & added the (2) small screws to "lock 'er in place"

Gave 'er a spin by hand (gripping the axle)
Yup, spins pretty good

I also, hooked up (1) 12V battery, just to quadruple check the alignment of the propulsion unit (motor) with the drive unit (axle) before welding the motor mount in place.

464 Posts
Discussion Starter · #26 ·
Moving right along (or forward)

Now that the backbone is pretty much established
...& the rear axle housing
...& the motor mount

Next, would be the "Cockpit" or the operator compartment

I figure signature rollbar/seatback ~40" tall
...the floor should be ~16" from the bottom of the seat to the bottom of the steering support
...& the steering support should be ~16" tall

So, I got the bender out
...& a 10' piece of water pipe

I started off by measuring & marking the piece of pipe right in the middle, 60" from each end
(this will be the top of the rollbar)
...& also @ 40", each way, from the center mark
(these will be where the seat back will curve into the floor)

So, it's marked at 20", then at 60" then at 100"

Then, put 'er in the bender, lined up @ the center mark & bent 'er to the max
(to help bring the bottom, seat back area, as close together as possible)

When the pressure is released it springs back pretty good
...but, we can work with that

Once we had the rollbar/seatback next, was the (2) side bends @ the 20" mark
...& the other @ the 100" mark

Before each bend, I angled one side up a bit & the other side down a bit

The idea was to get them to angle inwards, toward the backbone because, the bottom of the seat back (rear part of the cockpit) should be ~16" wide

Where as the steering support (front part of the cockpit) should (nearly hug the backbone) only be ~8" - 10" wide (quite a bit narrower)

They didn't angle in as much as I had in mind but, should be able to work with 'em

464 Posts
Discussion Starter · #27 ·
Steering support (front part of the cockpit) is next

I had a ~48" piece of water pipe

Measured & marked it in the center (~24") then, marked it @ ~14" each way from the center mark
...which should leave ~10" going back, on each side, from the lower bends

Put it in the bender, lined up @ the center mark & bent 'er to the max
...then, bent each side (~35 pumps) @ the 14" from the center marks
...but, only this time, with each side angled outward away from the backbone
(to be able to (hopefully) meet up with the (2) ends of the rollbar/seatback bar)

The floor of the cockpit needs to be ~16"

Set the backbone on the workbench
...positioned the cockpit over it
...& aligned the floor bars @ 16" apart (just on one side for now)

First thought about splitting the difference & just cutting them both @ 8" (8" from the front & 8" from the rear)

The front section is about where it needs to be, it's the rear section that needs to be worked a bit

I figured that I should leave a few inches more, on the rear section
(longer arms should give additional leverage, for workin' it)

So, I wacked the rear sections arms off @ 10" & @ 6" for the fronts

There is gonna be some pressure on these "floorboard" connection joints
...not really structural but, more from my bends being a little off
...& having to do some "tweakin" to bring 'em together

So, I'm not gonna just butt weld 'em together
...I'm gonna pin 'em
...then, butt weld 'em

5/8" rod (like for steering shafts) fits nicely inside this water pipe & will make good strong "splints"

I wacked off a couple of 3" pieces (should give us ~1 1/2" inside each end)

Drilled an 1/8" hole ~1" from the end of each pipe end (on the inside edge as to not be so visible)
...then inserted a "pin" ~1 1/2" into the ends of both of the front sections pipe ends
...then, drilled an 1/8" hole about 1/4" into the 5/8" rod & inserted a small screw to "pin" the pin in place

Slid the left end of the front section onto the alignment pin of the rear sections left side
...still a bit off

Wrapped a ratchet strap around the lower part of the rollbar/seatback help draw the sides together (in a precise & controlled manner)

It took a little tweakin' but, I got 'er together

Inserted the front pin/screws to lock 'er in place
...& double checked everything

Looks pretty good
...all of the bends came out deicent
...all of the rails (seatback, floorboards & steering support) are mostly even
...& it even sits nice-n-level

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 so, it's ready to be installed onto the backbone chassis

464 Posts
Discussion Starter · #28 ·
Next 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

I like this set up, 'cause it will
...look better & be stronger
...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

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

Then, I centered the cockpit, on the backbone chassis
...double checked the motor (rear) & battery (front) clearances (for the last time)

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

Here's another video of progress :D

464 Posts
Discussion Starter · #29 ·
Been working on the kart here & there, from time to time :D

Once I got the steering assembly finished up
...then, the chassis is pretty much done

Cleaned everything up "super good"
...& gave it a good coat of "self etching" primer seal up all of that "bare" metal

I made a custom seat for it too :cool:

Here is another video of progress so far

464 Posts
Discussion Starter · #30 ·
Most of the main components are now installed & connected :D

The speed controller & most of the wiring is inside of the backbone chassis for protection

I also made a dash board, it has on/off switch (DPST) (it switches the meter & speed controller on or off @ the same time) dual purpose :cool: amp/volt meter (indicates the amp draw & battery pack voltage but, also doubles as a "system activated" light) dual purpose :cool:
(when the meter is on it tells the operator the speed controller is on too)
...a charge port (right there visible, so the kart cannot be driven off with the charger still attached)
...& a 50A circuit breaker (resettable fuse "earth friendly" & doubles as a main power cut-off for maintenance or storage) dual purpose :cool:

Here is a video of progress, so far

464 Posts
Discussion Starter · #33 ·
It rolls out pretty good

Next, on the agenda
...battery covers/hold downs
…& eventually, a paint job

...steering seems "heavy" (bottom) seems kinda small
...the Amp/Volt meter readings seem "jumpy"
…& the thumb throttle acts "weird", it seems to have a "dead spot"

When running at full throttle, I noticed a "miss" (I guess you would call it)
...I can physically feel & can audibly hear, the motor is NOT running at full speed

but, if I "back off" just a bit
...I can hear the motor "smooth out" & feel 'er speed up

Maybe a throttle issue?

I got the brakes hooked up
...& also added a Speedometer (~$10.00)
(it's just a little thing, like they use for training & on workout bikes)

So, if it's accurate, (I'll have to check) looks like our top speed was ~24 MPH
…& it says that I logged ~5 miles on this run

The meter showed (~51V) toward the end of the ride
…& it wasn't showing/indicating any signs of slowing down)

I can't post pics
… so, here's another video

464 Posts
Discussion Starter · #35 · (Edited)
I've been doin a little more to the Torsk kart.

I added brakes (we don't need no stinkin' brakes)
…& a small speed/odometer (~$10.00)

It's "actually" for exercise bikes &/or for bicycle training
...but, should work great for our purposes

It displays & records the current speed that your going, the average speed of a ride, the top speed & distance traveled also

Here is a video of my second test ride gather some speed & distance data


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