Electrathon America Forum

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Sequoia Electrathon Racer (2024)


Senior Member

Status: Offline
Posts: 159
Date:
Sequoia Electrathon Racer (2024)
Permalink  
 


I working on & planning to build another racer for 2024 biggrin

I learned a lot from building & testing Polaris

...but, I would like to try-n-upgrade many things like:

Roll over protection 

...so, the driver is more enveloped

Wheels

...properly designed for the "loads" that will be inflicted upon them

...a wider "foot print", for better traction

...stronger, no plastic

...bolt-on, for quick change ability

Brakes

...stronger, Hydraulic system & properly sized rotors 

Axles

...upgrade to 5/8" spindles, in the front

...& a 5/8" grade 8 bolt in the rear

Steering

...properly size the pitman arms, to the wheel diameter

 

Maybe something about like this:

SAM_1248.JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Ok
So, we have some goals
...& an idea, of what we would like it to look like
...but, where do you actually start?

The driver is the heaviest, most awkwardly shaped component in a racer

So, I usually start with the ****pit

Driver Accommodations

First, think about a Seat

I like the plastic racing style seats
...they kinda "wrap around" the driver & provide some side support

Then, think about things like:

Steering
...what kinda steering wheel
...how far should it be from the driver
...& how to mount it

Pedals
...what kinda pedals
...where are you going to put them
... how far should they be from the driver
...& how are you going to mount them

Roll over protection
...roll bar(s)
...or a full roll cage

Side impact protection
...what need to be where
...in what direction (vertical, horizontal, angled)
...& how high etc.
...& also, egress
...how does the driver get in & out
...& how easy is this to accomplish?

So, far this is all in thought or on paper

Now, actually set a seat up
...set a driver in it
...& start "mocking" things up (steering, pedals etc.)

Mapping things out, around an actual driver helps give a "real world" perspective of everything that's involved
...& the room that's required

Then, do lots of measuring
...& adjusting
...& making notes
...& even pics

Then, with this info
...you can start planning
...& building the rest of car (around the driver)

__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

After lots of trial & error, here are some of the specs that I have come up with.

Keep in mind that
...I'm ~5'5" tall & ~150 lbs.
...& these dimensions are based "around" a driver my size
...but, at this "planning stage" everything is adjustable

Chassis overall height: ~34"

Side impact protection height: ~18"

Dash bar/Steering support height: ~16"

C**kpit side to side: ~20"

Distance to pedals: ~34" - 36"

Leg Tunnel: ~14" x ~14"

Base frame rails: ~14" (apart)

* An easy mock up method is to use "real world" CAD (Cardboard Aided Design)
...just get a refrigerator box (or any big card board box) & re-configure it

Maybe something like have a ~14" x ~60" bottom
...leaving a ~24" area, for the seat/driver
...add a ~14" x ~14" x ~36" leg tunnel
...then, add some sides
...& go from there


* Also, keep in mind, the EA rule book (page 6.) requires a max overall width of 48" & a max overall length of 12" for all race cars


__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Specify parameters & work with in them

So, with the measurements
...& the diagram posted above, I started measuring, marking & cutting pieces

I started at the top, making the roll cage
...(2) pieces 1/2" Schedule 40 water pipe (actually 5/8"ID x 7/8"OD with ~1/8" wall) ~60" long
...marked at 3" intervals
...& then, bump bent 

* When making "stuff" where (2) matching pieces are required, I usually try to make both pieces, at the same time (it's easier to make matching pieces)

SAM_1225 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is a top view drawing of the top & mid layers, of the chassis 

...& a side view drawing, of the bottom rails


The top layer is the (2) curved top bars of the roll cage 
...the mid layer is mainly the upper side impact bars
...& the lower layer is the base rails 
SAM_1322 (1).JPG
* Notice, the highlighted 20" x 20" c**kpit area

...& 16" x 16" leg tunnel area

So, some measuring, marking & bump bending on a couple pieces of pipe (~78")

...& we have a couple of mid level "side impact protection" bars

...then, cut (3) ~14" crossmember bars

 

Then, after some squaring & aligning...everything, I tac welded

...the curved top bars

...to the cross bars

...& also, to the mid level bars

 

** Notice, I used the "work bench top" (old door)

...to screw down alignment boards

...& to "pin" the pieces "in place"

I also, used a ratchet strap to add "upper pressure" for holding the roll cage together, for welding biggrin

SAM_1262.JPG

Another view

SAM_1259.JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

I propped the rear of the "canopy" up at ~20"
...& the front at ~14"

Then, worked on dry fitting the base rails
SAM_1265.JPG
Then, added some "props" to mimic some of the "braces"

...to see if/how all of the measurements & everything was working out here "in the real world"

SAM_1268.JPG

I also, started thinking about how the front should look

...& bounced several options around

SAM_1276.JPG

But, we gotta keep the weight "in mind"

...because when adding pieces, it can "add up" pretty quickly furious

* Notice, I started curving the base rails upwards a bit (in the front)

...& the "hood" bars downwards a bit



Attachments
__________________


Senior Member

Status: Offline
Posts: 241
Date:
Permalink  
 

You have an interesting build going here. Keep it up. Don't forget to factor in your ballast location and retaining method.

__________________

Build something and race it!



Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Hey Archer,

Thanks!

If I may ask, how does the "weigh in" work, at EA races?

Does the driver actually hold the ballast weights
...& then, gets weighed, to make sure that they (together) weigh at least 180lbs.? (as per the rule book)

Then, the ballast (weights) get secured, in the car
...& the car then, gets inspected, just before the race?

__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

They say "If you can't take Mohamed to the mountain
...bring the mountain to Mohamed"

So, I brought the bender, to the chassis
...& did some more bending
SAM_1283.JPG
I bent the upper rails, downwards a bit more
...& the lower rails, upwards
SAM_1284.JPG
So then, I could just use (1) crossmember

SAM_1291.JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 241
Date:
Permalink  
 

Yeah. Weigh in works pretty much like you just described.

__________________

Build something and race it!



Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Now, it's time to double & even, triple check...everything

...by "eye" (eyecrometer)

...& using instruments (tools)

SAM_1295.JPG

Mainly checking for overall squareness

SAM_1296.JPG...& that everything is "about" where it should be (structurally)

SAM_1297.JPGA view from the rear 

SAM_1299.JPG

Then, start double checking that components "fit" about where they should

...like the seat

SAM_1300.JPG

...& the battery box area

SAM_1302.JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

So, with the seat "propped" in place I checked

* (reminder of our spec goals)

Chassis overall height: ~34" (check)
Side impact protection height: ~18" (check)
Dash bar/Steering support height: ~16" (check)
C**kpit side to side: ~20" (check)
Distance to pedals: ~34" - 36" (check)
Leg Tunnel: ~14" x ~14" (check)
Base frame rails: ~14" (apart) (check)

& also,

In the very last pic (in the last post) notice that the available area, for the battery box is
...~8" from the (front to back)
...the lower frame rails are ~13 1/2" apart (side to side)
...& there is at least 12" of vertical space available (up & down)


__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Hey Archer,

On the topic of ballast
...is there a preferred material (or thing) used as ballast?
...or a common (or recommended) retaining method?

__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

After most everything checked out "within specified parameters", I went ahead & made up & installed, a front seat mount (which also doubles as a mid-chassis, cross member)
SAM_1331 (1).JPG

Started working on & installing the "truss bars" 

* Notice the "truss bars" that "run" next to the seat, needed to be curved a little bit (to "clear" the seat)

I also, made up & installed a curved cross member, in the rear, that will also help support the driver's weight, while entering & exiting the car biggrin

SAM_1332 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

To help double check component locations & fitment, I added a few more "props" 

This pic mainly shows the pedal(s) location

...which is (~36") from the bottom/rear of the seat 
SAM_1349 (1).JPG
This pic shows a CAD "mock up" battery box, in relationship to the pedal(s) location

...to double check that there is adequate clearance, to actuate the pedals

 

I also, mocked up a potential spindle location with a "prop" steering shaft & tie rod

...to double check "swing" clearance, for these components too

SAM_1350 (1).JPG
Here is a pic with a wheel "propped" in place

...just to double check biggrin

SAM_1351 (1).JPG

This pic shows an old circular saw blade, used as a "prop" steering wheel (to help mock up it's location)

...to double check the distance, from the seat back to the "steering wheel" (~24")

SAM_1354 (1).JPG

This pic shows the steering shaft height, in relationship to the seat (~12")

SAM_1352 (1).JPG

This pic shows the mounting bracket height (from the floorboard up) which checked out at (~15")

SAM_1356 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

I found a (3) wheel hydraulic disc brake system, for Hammer Head go karts (~$75.00)

SAM_1139.JPG

It has heavier duty (more properly sized) components (thicker rotors & bigger calipers)
...& also, provides braking for all (3) wheels (for better control)

It comes with the Master Cylinder

...(3) Rotors 

...& (3) Calipers (already plumbed & the system bled)

* A couple of extra bonuses are

...the rear caliper has a parking brake feature incorporated

...& the Master Cylinder has an automotive style brake light switch, already built in biggrin

FYI: this video shows, this type of brake system, being mounted on a kart

* A couple of important factors to pay close attention to are:

1.) Check out the cast front wheel hubs, that are "normally" used with this brake system

2.) Notice where the master cylinder is mounted
...& how that mount is fabbed & installed

3.) Also, take notice of the size of the front rotors, compared to the size of the tires, they will be controlling
...& the size of the rear rotor, compared to the size of the rear tires, that it has to control 



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Well, I'm not going to use those China-cheap hubs, for a couple of reasons

1.) Those hubs are for use with metric bolt pattern (6") rims (tallest tires available ~15")

...& I would like to use (8") rims (with taller ~16"+ tires)

2.) This brake system is for a race car

...& will be controlling larger/taller tires

So, I'm thinking about using (3) of the larger 8" rotors (like used on the rear) in the front & rear (which should increase the stopping power)

...but, the smaller 5" rotors, have a 6-bolt pattern

...& the larger 8" rotors, have an 8 bolt pattern

Further explanation:

For comparison, here is an 8" rim/~16" wheel

...with an 8" rotor (sitting on it)

...& then, a 5" rotor (sitting on top)

SAM_1215 (1).JPG

This comparison makes it easy to see that

...the ~16" wheel would have a bit more than a ~3:1 leverage advantage, over the 5" rotor

...whereas the ~16" wheel would only have ~2:1 advantage over the 8" rotor

 

So, using 8" rotors (being more proportionately sized to control a ~16" wheel)

...plus, a Hydraulic system

...& (3) wheel braking

...& should provide this racer with better/superior stopping power biggrin



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

The wheels that I'm going to try, on this racer, are normally used on golf carts.

They are 8" steel rims that are 3.75" wide & have 4.80 x 4.00 x 8 Diamond Pattern Turf Tread tires

They are brand new "take offs" (meaning that the golf cart buyer wanted fancy wheels/tires installed)

I found a set of (4) of them on eBay for ~$75.00 & that's
...~$18.75 per wheel
...or ~$9.38 per rim
...& ~$9.38 per tire

* These are probably not the best tires for racing
...but, we have endless options available for 8" rims (when we get to that point)
...& for ~$9.00 ea. they are perfect for initial testing

FYI: these steel wheels weigh ~8lbs. (ea.) w/tires
...as opposed to ~3lbs. (ea.) w/wheels, that the plastic bicycle wheels on Polaris weigh

So, this "upgrade" comes with a ~15lb. "weight penalty"
...but also, has a (4th) wheel
...so we have a spare tire, that's all ready to go

For comparison, here is (1) of the (~16") golf cart wheels next to (1) of Polaris's (~20") wheels

 

* Notice the golf cart wheel is only a few inches shorter, than the bicycle wheel

...but, has almost double the width 

 

Plus = better traction

Minus = higher rolling resistance

SAM_1231.JPG

 



-- Edited by Functional Artist on Tuesday 2nd of January 2024 03:11:07 PM

Attachments
__________________


Senior Member

Status: Offline
Posts: 228
Date:
Permalink  
 

 

 

 

You wrote

"* Notice the golf cart wheel is only a few inches shorter, than the bicycle wheel

...but, has almost double the width 

 

Plus = better traction

Minus = higher rolling resistance

I do not think this is correct. Oddly, wider tires seem to have less rolling resistance. It has been discussed before in the tires section and there is some good test data comparing wider and skinner bicycle tires on the Internet. Here is what I posted:

 

The wider tire having lower rolling resistance is counter intuitive but it makes sense to me. Most rolling resistance comes from the tire deforming to create the contact patch-going from a round tire to a flat spot on the road. The more the rubber has to move, the greater the energy loss. This is why a larger diameter tire should have less rolling resistance than a smaller diameter tire. The greater arc of the larger diameter tire is closer to the flat line of the road and changes less.

 

The wider vs. thinner tire is due to the shape of the contact patch and geometry. The skinny tire contact patch is long and thin while the wider tire contact patch is short and fat. If everything else is equal, than the rubber in the center of the arc of the skinny tire has to move further than the rubber in the middle of the wider tire.

 

The key, of course, is 'if everything else is equal'. Different tire construction such as thicker rubber or inability to run higher pressures are going to weigh in too. We get our lowest rolling resistance just before the tire wears through. This makes sense since the rubber is very thin and it takes less energy to deform it. Not ideal for finishing the race though.

 



__________________

Cliff

www.ProEV.com



Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Hey ProEV,

That is some very interesting info.

Maybe (in the spring) I'll do some comparison testing between the skinny wheels on Polaris & these wider wheels.

Thanks for sharing

__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

I'm going to need a couple of dual flange hubs, to mount the wheels & brake rotors, on to the spindles

SAM_1329 (1).JPG

It's basically, just a piece of 1 1/2" OD steel tube

...that rides on a couple of #99502 bearings

SAM_1321 (1).JPG

...& has a couple of bolting flanges welded on (like this)

SAM_1310 (1).JPG

But, for this application we need custom bolting flanges, on each side

...an (8) bolt flange on (1) side to mount the rotor

...& a (4) bolt flange on the other side, for the (4) lug wheels

For fitment & measurement purposes, I made up a mock hub, out of wood & steel

SAM_1359 (1).JPG

Installed a couple of bearings, for mounting on a spindle

SAM_1361 (1).JPG

Then, drilled holes

...mounted a rotor

...& also, bolts for mounting the wheel

SAM_1417 (1).JPG

*The thickness of the wooden flanges isn't important

...the measurement from outer flange face to outer flange face, is the measurement that we need biggrin



-- Edited by Functional Artist on Monday 8th of January 2024 03:20:06 PM

Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is a look, at the back side of the "mock" hub, mounted on the spindle

SAM_1365 (1).JPG

Now, we can use the "mock" hub, on a spindle w/Rotor, to start working on a Caliper bracket

SAM_1366 (1).JPG

Back to the CAD (Cardboard Aided Design) biggrin

SAM_1368 (1).JPG

Added a Caliper, to the CAD bracket, to check fitment & clearance

SAM_1369 (1).JPG

Then, double checked fitment & clearance, from multiple angles

...& with a wheel

SAM_1370 (1).JPG

It looks like a bent "tab" (kinda like this) could used to bolt the Caliper bracket, to the arm on the spindle

SAM_1372 (1).JPG

This would securely attach the caliper bracket to the spindle

...& also, "act" as a "stop"

...so, the bracket can't "travel" around the spindle (especially when braking)

SAM_1374 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Next up, Caliper bracket CAD (template) to steel (~10g) 

SAM_1375 (1).JPG

Making (2) at once, helps to make them match biggrin

SAM_1381 (1).JPG

To cut out the (2) 1/2 circles, I first installed a notch, right in the middle

SAM_1382 (1).JPG

 



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

I put the (2) caliper brackets, end to end

...aligned the (2) "notches"

...clamped them down to a 1/4" steel, backer plate

 

...& then, used the (2) "notches" as a "guide" to drill a 1/8" pilot hole (in between the (2) caliper brackets & thru the backer plate too)

SAM_1387 (1).JPG

Then, drilled the 1/8" pilot hole, out to 1/4" (for use as a hole saw guide)

SAM_1391 (1).JPG

Then, used a 1 3/4" hole saw to, cut the (2) 1/2 hole(s)

SAM_1393 (1).JPG

Used a 5/8" drill bit to install the spindle hole

SAM_1395 (1).JPG

Now we have a couple of "rough" Caliper bracket(s)

...that "fit" on a 5/8" Spindle biggrin

SAM_1397 (1).JPG

 



Attachments
__________________


Newbie

Status: Offline
Posts: 2
Date:
Permalink  
 

are the two roll bar support bar at least 4 inches from the top of the roll bar??

__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Hey Babbydeers,

I have the lower section of roll bar supports installed

...but, winter has put progress on hold, for a bit

SAM_1348 (1).JPG

This is my work bench

...& our current temp is ~15* no

SAM_1460 (1).JPG

...but yes, when I get back at it, the roll bar support bars will come just about to the top (see drawing) biggrin

SAM_1248.JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is a rear view, of a whole front wheel unit

Caliper mounted on the bracket

...bracket mounted on the spindle

...with the hub, rotor & wheel

SAM_1407 (1).JPG

Side view, double checking clearance

SAM_1409 (1).JPG

It looks like each unit requires ~8" (from the outer edge of the wheel to spindle bracket)

SAM_1411 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 241
Date:
Permalink  
 

Looks like you're doing good work there. Keep it up!

__________________

Build something and race it!



Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Custom dual flange front wheel hub drawing

SAM_1426 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

SAM_1531 (1).JPG

The huge frontal area was driving folks nuts!

...just the windshield area was ~15"w x ~32"t

SAM_1534 (1).JPG

Thinkin' about it a bit more

...just a helmet & a couple of roll bars should dramatically reduce the aerial drag

So, she's goin' topless biggrin

SAM_1559 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Something like this should be rule compliant

SAM_1714 (2).JPG

...but, I don't totally "love" it confuse



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

DIY A-frames

SAM_1643 (1).JPG

DIY bushings

SAM_1703 (2).JPG

DIY CO shock & spindle mounting brackets

SAM_1709 (2).JPG

DIY front suspension

SAM_1716 (2).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Still not totally loving the roll bars

SAM_1822 (1).JPG

Re-calculating...re-calculating...

So, let's try something different

SAM_1825 (1).JPG

Maybe something like this

SAM_1828 (1).JPG

Another view

SAM_1829 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

This version passed this helmet clearance test pretty well biggrin

SAM_1830 (1).JPG

...but, it didn't seem to pass this clearance test

SAM_1831 (1).JPG

Here is a video with some info on an F1 Halo 

How The Halo Works | F1 TV Tech Talk | Crypto.com - YouTube

 



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Version 2

Raised the windshield "line" ~1"

...& added a taller rear roll "hoop" biggrin

SAM_1836 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

A couple of buddies brought to my attention

1.) The fact that the way the front Halo support, was attached to the center of the dash bar, that there was a potential for the dash bar to buckle.

Which could cause the steering wheel & column to collapse
...potentially injuring &/or pinning the driver in the ****pit, "if" the vehicle ever rolled over or flipped. Not good no

2.) A center windshield support could/would be irritating to try-n-look around &/or thru for an hour

Plan B: Let's try some A-Pillars

SAM_1906 (1).JPG

Another angle/view

SAM_1909 (1).JPG

Notice how this concept would transfer the "load" or force (in a roll over) down to the upper side frame rails

...& also/then, down to the lower frame rails (lower supports to be added)

&

How the dash bar & steering are now totally separate from the "load path" biggrin



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

The kool blue seat is from BMI karts (~$80.00)

Polyethene (not fiberglass) racing seats are a durable seat made of almost indestructible plastic perfect for racing go karts.

Racing Polyethene (Plastic) Sprint Seat | 660220 | BMI Karts And Parts

I made the rear seat mounting bars out of some 1/2" steel tube

I used a hydraulic press & a DIY forming die

SAM_1587 (1).JPG

After pressing, the end of the tube looks like this

SAM_1591 (1).JPG

After pressing (side view)

SAM_1589 (1).JPG

Made another, added some 1/4" holes & then, did some rounding & shaping 

SAM_1596 (1).JPG

mm



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is a drawing of the rear swing arm that I have in mind

SAM_1801 (2).JPG

The axle/spindle will be "open ended", to facilitate easy tire changes, without having to "mess with" the sprocket/chain & brake system biggrin

 

The axle/spindle will simply be a 5/8" x 7" bolt

...mounted thru/with a dual wall design 

...& the inner wall will double as the rear caliper bracket

Kinda like this (upper illustration shows the front spindle & the lower show the rear dual wall concept

SAM_1802 (2).JPG

Swing arm parts

SAM_1881 (1).JPG

After welding

SAM_1896 (1).JPG

The other side

SAM_1898 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is the other half of the rear swing arm

SAM_1931 (1).JPG

A "spacer" helps to space them apart & keep them parallel

...then, made sure everything was good-n-square (before welding)

SAM_1934 (1).JPG

Also, added a bushing holder

...made up a DIY bushing (a piece of 1/2" ID. reinforced rubber hose with a 1/2" OD. steel insert, for use with a 3/8" bolt) biggrin

...& a mounting bracket 

SAM_1973 (1).JPG



-- Edited by Functional Artist on Tuesday 26th of March 2024 02:16:01 PM

Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

To facilitate rear wheel "track" adjustment (if necessary)

I made the swing arm mounting bracket adjustable

SAM_1987 (1).JPG

This way shims/washers can be inserted in between the (2) brackets

...in the appropriate place

...which will affect/adjust the angle of the rear wheel biggrin

SAM_1990 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Lets get back to the roll bar or hoop 

...& according to the rule book


4 ROLL BAR
1. The roll bar must protect the driver's head/helmet in the event of a roll-over. It must be tall and wide enough to do this considering the full range of possible movement.
2. The roll bar structure must be triangulated with at least three legs or panel equivalent. Triangulated bracing can be either forward or rearward. With three legs bracing must extend from the top of the roll bar and securely attach to the vehicle structure, with four legs, each of the braces must extend to within 4" of the top. Any roll bar that is constructed from more than one continuous piece must be reinforced and braced triangularly from all junctions/joints in addition to the top.
3. The roll bar structure must appear to be sturdy enough to withstand the vehicle being dropped, upside down, from an altitude of one foot, with the driver inside without failure.
4. The drivers helmet must be below a straight line drawn from the top of the roll bar to the top of the highest
structural point when the driver is securely belted in driving position.
P A G E 6. E L E C T R A T H O N A M E R I C A

Before

SAM_1836 (1).JPG

After extending the rear

...& adding a "leg" or brace

SAM_1975 (1).JPG

 T

SAM_1976 (1).JPG

Another view

SAM_1978 (1).JPG

I also, added a 4" x 8" gusset

SAM_1981 (1).JPG

...across the 5-way junction for additional strength

...& to "lock' everything together biggrin

SAM_1984 (1).JPG

It looks to me like it will meet:

3. The roll bar structure must appear to be sturdy enough to withstand the vehicle being dropped, upside down, from an altitude of one foot, with the driver inside without failure.

 

What do you'all think? confuse



Attachments
__________________


Senior Member

Status: Offline
Posts: 241
Date:
Permalink  
 

Yeah I'd say you've built it sturdy enough. I like the frame design

__________________

Build something and race it!



Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Hey Archer,
Thanks!

I installed a coil-over shock, in between the chassis & swing arm

SAM_2001 (1).JPG

Another view

SAM_2002 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

A buddy of mine, used my drawing to make some custom wheel hubs (for use with Chinesium brakes/rotors & standard golf cart wheels) 

SAM_1751 (2).JPG

My "mock up" rear hub is on the left

SAM_2036 (1).JPG

Looks pretty professional

SAM_2038 (1).JPG

The rotors weren't "true"

...so, he "trued" them up a bit

...& included a "proximity pin" to ensure "if" taken apart it can only be re-installed (1) way biggrin

SAM_2039 (1).JPG

Here is the hub mounted on the swing arm

SAM_2041 (1).JPG

Caliper mounted

SAM_2042 (1).JPG

Clearance seems to be OK

SAM_2040 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

On this racer, I'm going to try a Boma BM-1024GD

SAM_2049 (1).JPG

It's 60VDC

...2,000W (brushless) motor (max RPM rating of ~5,600)

SAM_2097 (1).JPG

* The motor has a 10 tooth (drive) sprocket

...& the wheel has a 48 tooth (driven) sprocket

...which gives a 4.8:1 gear ratio

&

The 16" wheels that we are using, have a circumference of ~51"

 

So, let's say the motor has a "loaded" speed of ~5,000 RPM's

...& we are running a Gear Ratio of 4.8:1

...& the tires are ~51" in circumference 

 

Let's "do the math" biggrin

Ballpark Equation
MS/GR=ASxTC=IM/FT=FMxHR=FHxMM= MPH

Motor Speed/Gear Ratio=Axle Speed x Tire Circumference = Inches per Minute traveled/Foot (12) = Feet per Minute traveled x Hour (60) = Feet per Hour traveled x MPH Multiplier (.000189) = Miles Per Hour


5,000(RPM's) / 4.8(GR) = 1,041.67 (axle speed)
1,041.67 x 51 = 53,125.17 (inches per min traveled)
53,125.17 / 12 = 4,427.10 (feet per min traveled)
4,427.10 x 60 = 265,626 (feet per hour traveled)
265,626 x .000189 = 50.20 MPH smile



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Keep in mind that the Ballpark Equation doesn't factor in things like: rolling resistance, Aerodynamics, overall weight etc.
...it just gives us an idea of what "may be" possible with a specific set up (motor RPM's, gear ratio, wheel size etc.)

I used a straight edge to align the motor & wheel sprockets

...marked where the motor needs to go

...then, installed (4) 5/16" x 1" slots in the motor mount

SAM_2084 (1).JPG

I used (4) 5/16" x 1" Carriage bolts to mount the motor 

SAM_2095 (1).JPG

* Notice how the "square" under the heads "fit in" the slots

...so, the motor can be tightened down with just (1) wrench

SAM_2098 (1).JPG

I used the straight edge again to double check sprocket /chain alignment

SAM_2099 (1).JPG

...Another view (straight "down the line") biggrin

* Notice (after alignment) I used a couple of pairs of Vise-grips, to "lock the motor mounting plate "in place" for welding

SAM_2100 (1).JPG

A view with the chain installed

SAM_2102 (1).JPG



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Master cylinder & bracket 

SAM_2059 (1).JPG

Brake master cylinder linkage

SAM_2083 (1).JPG
Master cylinder mounted to the bracket

...bracket mounted to the chassis

...& the linkage connected too

SAM_2093 (1).JPG

Another view biggrin

SAM_2094 (1).JPG

 



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

I've seen F1 race cars that have switches & stuff on the steering wheels

...so, I was thinking maybe something like this biggrin

SAM_2085 (1).JPG

Let's start off making the steering wheel itself

...using a 1/8" x 6 1/2" x 13" piece of Aluminum (from old sign)

SAM_2113.JPG

Drilled some big 'ol holes

SAM_2127 (1).JPG

Added a couple of bends

SAM_2144 (1).JPG

Cut out the middle section(s) for hand grips

SAM_2149 (1).JPG

Did some trimming

...& even a bit of polishing (left side)

SAM_2152 (1).JPG

* Notice the "fancy" steering wheel mount?



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

To make the on steering wheel "instrument holder" for the gauges & switches, I harvested some ridged plastic from the back of an old TV

SAM_2206 (1).JPG

Cut out a piece & started marking for the cut-outs

SAM_2155 (1).JPG

Kinda like this

SAM_2160 (1).JPG

SAM_2170 (1).JPG

After adding some "hand grips"

...& polishing it up a bit biggrin

SAM_2205 (1).JPG

* The upper section houses the power meter & the control switches (On/Off, Forward/Reverse & 3-Speed selector)

...& the bottom area is for the speed-o-meter (cell phone w/speed-o-meter app)



Attachments
__________________


Senior Member

Status: Offline
Posts: 159
Date:
Permalink  
 

Here is the steering wheel, installed 

SAM_2218 (1).JPG

Another view

SAM_2219 (1).JPG

* Notice, to ease entry & exit, I included a "flip up" feature biggrin

SAM_2217 (1).JPG



Attachments
__________________
1 2  >  Last»  | Page of 2  sorted by
 
Quick Reply

Please log in to post quick replies.