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'wittle 'wesistor (Mini Jeep)

17061 Views 296 Replies 7 Participants Last post by  Functional Artist
For my next creation, I've been thinking about building a go kart sized jeep (mini-Jeep)
...but first, here is some Jeep info.

"The Jeep marque has been headquartered in Toledo, Ohio, ever since Willys–Overland launched production of the first CJ or Civilian Jeep branded models there in 1945. Its replacement, the conceptually consistent Jeep Wrangler series, remains in production since 1986. With its solid axles and open top, the Wrangler is the Jeep model that is central to the brand's identity.

At least two Jeep models (the CJ-5 and the SJ Wagoneer) enjoyed extraordinary three-decade production runs of a single body generation.

In lowercase, the term "jeep" continues to be used as a generic term for vehicles inspired by the Jeep that are suitable for use on rough terrain. In Iceland, the word Jeppi (derived from Jeep) has been used since WWII and is still used for any type of SUV.

Prior to 1940 the term "jeep" had been used as U.S. Army slang for new recruits or vehicles, but the World War II "jeep" that went into production in 1941 specifically tied the name to this light military 4x4, arguably making them the oldest four-wheel drive mass-production vehicles now known as SUVs. The Jeep became the primary light 4-wheel-drive vehicle of the United States Armed Forces and the Allies during World War II, as well as the postwar period. The term became common worldwide in the wake of the war. Doug Stewart noted: "The spartan, cramped, and unstintingly functional jeep became the ubiquitous World War II four-wheeled personification of Yankee ingenuity and cocky, can-do determination." It is the precursor of subsequent generations of military light utility vehicles such as the Humvee, and inspired the creation of civilian analogs such as the original Series I Land Rover. Many Jeep variants serving similar military and civilian roles have since been designed in other nations.

Development – 1. Bantam Reconnaissance Car
When it became clear that the United States would be involved in the European theater of World War II, the Army contacted 135 companies to create working prototypes of a four-wheel drive reconnaissance car. Only two companies responded: American Bantam Car Company and Willys-Overland. The Army set a seemingly impossible deadline of 49 days to supply a working prototype. Willys asked for more time, but was refused. American Bantam had only a small staff with nobody to draft the vehicle plans, so chief engineer Harold Crist hired Karl Probst, a talented freelance designer from Detroit. After turning down Bantam's initial request, Probst responded to an Army request and began work on July 17, 1940, initially without salary.

Probst drafted the full plans in just two days for the Bantam prototype known as the BRC or Bantam Reconnaissance Car, working up a cost estimate the next day. Bantam's bid was submitted on July 22, complete with blueprints. Much of the vehicle could be assembled from off-the-shelf automotive parts, and custom four-wheel drivetrain components were to be supplied by Spicer. The hand-built prototype was completed in Butler, Pennsylvania and driven to Camp Holabird, Maryland on September 23 for Army testing. The vehicle met all the Army's criteria except engine torque.

Development – 2. Willys and Ford
The Army thought that the Bantam company lacked the production capacity to manufacture and deliver the required number of vehicles, so it supplied the Bantam design to Willys and Ford, and encouraged them to enhance the design. The resulting Ford "Pygmy" and Willys "Quad" prototypes looked very similar to the Bantam BRC prototype, and Spicer supplied very similar four-wheel drivetrain components to all three manufacturers.

1,500 of each model (Bantam BRC-40, Ford GP, and Willys MA) were built and extensively field-tested. After the weight specification was revised, Willys-Overland's chief engineer Delmar "Barney" Roos modified the design in order to use Willys's heavy but powerful "Go Devil" engine, and won the initial production contract. The Willys version became the standard jeep design, designated the model MB, and was built at their plant in Toledo, Ohio. The familiar pressed-metal Jeep grille was a Ford design feature and incorporated in the final design by the Army.

Because the US War Department required a large number of vehicles in a short time, Willys-Overland granted the US Government a non-exclusive license to allow another company to manufacture vehicles using Willys' specifications. The Army chose Ford as a second supplier, building Jeeps to the Willys' design. Willys supplied Ford with a complete set of plans and specifications. American Bantam, the creators of the first Jeep, built approximately 2,700 of them to the BRC-40 design, but spent the rest of the war building heavy-duty trailers for the Army.

Final production version jeeps built by Willys-Overland were the Model MB, while those built by Ford were the Model GPW (G = government vehicle, P = 80" wheelbase, W = Willys engine design). There were subtle differences between the two. The versions produced by Ford had every component (including bolt heads) marked with an "F", and early on Ford also stamped their name in large letters in their trademark script, embossed in the rear panel of their jeeps. Willys followed the Ford pattern by stamping 'Willys' into several body parts, but the U.S. government objected to this practice, and both parties stopped this in 1942.

The cost per vehicle trended upwards as the war continued from the price under the first contract from Willys at US$648.74 (Ford's was $782.59 per unit). Willys-Overland and Ford, under the direction of Charles E. Sorensen (vice-president of Ford during World War II), produced about 640,000 Jeeps.

Jeeps were used by every service of the U.S. military. An average of 145 were supplied to every Army infantry regiment. Jeeps were used for many purposes, including cable laying, Sawmilling, as firefighting pumpers, field ambulances, tractors, and, with suitable wheels, would run on railway tracks."

I came across this drawing
...& it seemed like a pretty good guide

So, I'm thinking maybe ~50% should work for a mini jeep, I'll just have to calculate a ~2:1 reduction ;)

Wheel Tire Wood Font Rectangle
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281 - 297 of 297 Posts
While the paint is a drying, I looked into the wiring/connections for the (2) SC's
...& worked on installing the fuse box
Motor vehicle Bumper Gas Electrical wiring Automotive exterior

Mounting it right about there, leaves plenty of room for connections
Asphalt Electrical wiring Road surface Gas Electrical supply

These speed controllers from Alfa Wheels ALFA WHEELS have all of the wires/connections labeled
Fluid Finger Electrical wiring Gas Cable

...& they even come with all of the mating Molex connectors, that are necessary to connect the wires with/to all of the signals & accessories
Gas Wood Event Cable Plastic wrap

They are really easy to install, you just have to bare ~1/8" of the wire
...& insert it into the terminal (as such)
Gas Cable Wood Jewellery Nickel

Then, crimp the "upper" section of the terminal, to the wire
...& the "lower" section, to the insulation on the wire (for additional support)
Circuit component Wood Audio equipment Electrical wiring Electronic component

Then, simply insert the "wired" terminal into the Molex connector
...& connect it to the appropriate connector ,on the appropriate SC ;)
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All of the (small) signal wires coming out of the SC's are 18g. & use the small Molex connectors
...& the (big) power wires (from Batt pack & to Motor) are 12g. & use the bigger Molex connectors.
Electrical wiring Audio equipment Cable Electrical supply Wire

The bigger terminals crimp on the same as the smaller ones
Bicycle handlebar Wood Bicycle part Bicycle fork Sports equipment

The "tab" on the side is the "lock" that engages inside the connector
Finger Electronic component Thumb Cable Gadget

All locked in & ready for connection
Finger Cable Electronic component Thumb Electrical supply
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Working on the Battery Box
Output device Bumper Wood Automotive exterior Rectangle

Installed the (2kWh) 48V ~50AH Lithium battery module
...with 48V 50A Circuit Breaker
...with dual Positive (+) & Negative (-) battery cables (1 set of power cables to "feed" each SC)
...& a set of White (+) & Black (-) wires, for connecting the Charge Port
Bumper Gadget Electrical wiring Gas Automotive exterior

The Battery Cables are made of 10g. (pure Copper) Primary wire
...& the charge port wires are 14g. (pure Copper) Primary wire
Drinkware Cable Gas Electrical wiring Wire

I also made up & installed a remote BMS cable
Electrical wiring Cable Electrical supply Wire Gas

The long on top.
To be able to monitor the health of the batt pack (remotely) without having to remove it from the vehicle or opening it up
Automotive lighting Electrical wiring Circuit component Gas Electronic engineering

I triple checked it with a couple of other BMS connectors that I made up prevously
Handwriting Font Rectangle Gas Wood

All buttoned up & ready for installation
Hood Motor vehicle Vehicle registration plate Automotive tire Bumper

After closing it up, I re-checked on the pack remotely (Nice) ;)
Communication Device Gadget Gas Measuring instrument Font
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Front suspension assembly
...& steering assembly

All assembled & installed ;)
Motor vehicle Automotive tire Automotive exterior Bicycle trailer Gas

Another view
Bicycle Wheel Bicycle wheel Bicycle handlebar Motor vehicle

Another view
Automotive tire Motor vehicle Bumper Wheel Automotive exterior
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Rear Trailing Arm Assembly installed
...& we officially have a "roller" :)
Tire Wheel Automotive tire Motor vehicle Grass

Another view
Tire Wheel Vehicle Automotive tire Tread

another view
Wheel Tire Automotive tire Vehicle Tread
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Dry fit a CAD side body panel to check for fitness :)
Side view
Wheel Automotive tire Tire Motor vehicle Vehicle

Top view
Tire Wheel Automotive tire Tread Motor vehicle

* The left rear wheel has been "slid" inwards for this fitment test
...& while there, was used to mark the location of the rear wheel well ;)

Now, I can use this CAD side panel as a template, to make the "real" steel body panels :p
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I figured the Cowl should be next
...since we kinda need to establish the dash, for a place to mount the instruments & switches

So, back to the CAD templates (Cowl template, along with the rear edge of the hood template)
...& transferred the pattern(s) onto some of the 18g. steel

* I only wanted ~2" on each side (not the full width of the rear edge of the hood)
Wood Composite material Rectangle Bumper Tints and shades

Like this
Road surface Wheel Asphalt Tire Sidewalk

* I also, left ~1/2" on each end, for bendin' (body seam)
Tire Automotive tire Wood Road surface Wheel

Cut it out
Wood Motor vehicle Bumper Gas Automotive exterior

Then, marked the bending location(s), degree of bend & orientation
...& also, the location & orientation of the curve(s)
Plant Wood Gas Automotive exterior Automotive tire
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I installed a 1" double bend, on the dash side (to eliminate any sharp edges in the "knee area")
Automotive tire Wood Bumper Gas Cylinder
...& a 2' ...& left a 2" edge on the firewall side
Wood Bumper Gas Cylinder Automotive tire

Dry fit on the chassis (dash side)
Motor vehicle Automotive exterior Fender Grass Automotive tire

Firewall side
Furniture Motor vehicle Tread Table Wheel
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I harvested this black plastic from the back of an old big screen TV
Wheel Automotive tire Steering wheel Alloy wheel Vehicle

Trimmed it down a bit
...& then, installed some (old school) switches, voltage meter & speed-O
Gas Vehicle Automotive tire Bumper Auto part
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Since we can't mount the dash instruments & switches below the Cowl (limited knee &/or leg room) I figured I could/would just mount them, above the Cowl.

Notice there is an "area" above the Cowl, on these style Jeeps (outside view)
Analog television Automotive lighting Mesh Television set Gas

...& below the windshield (inside view)
Grille Rectangle Automotive exterior Tints and shades Electric blue

So, I figured that I could just incorporate the dash into that area
Wood Bumper Gas Tool Automotive exterior

...& maybe cover the "open sides" of the dash area with some windshield "side hinges"
Automotive lighting Hood Vehicle Motor vehicle Automotive exterior
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You can use a prism to read the instruments when you fold the windshield flat on the hood 😂
Many civilian Jeeps (CJ's) had partially exposed hood hinges
...but, they don't seem to be exposed (at all, in the last couple of pics that I posted) on the old flat fendered (M38's)

Here is an example of CJ hood hinges (1955 - 1995)

But, we need mini-hood hinges for our mini-Jeep, I got a set of (outdoor) gate hinges
...& trimmed them down a bit

...& did some rounding & smoothing

...& then, mounted them to the Cowl :)
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I checked & documented some of the component weights before installation

Battery box (~43 lbs.)

Speed Controller(s) & box (~8 lbs.)

48V 1,000W MY-1020 motor (~10 lbs.)

...& then, started on installation ;)

Right motor

Battery box
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As you can see the battery box will be mounted under the vehicle
...& hopefully doesn't have to be "messed with" for a long time
...but, we will still have "remote access" thru the BMS connector for monitoring & troubleshooting :cool:

The SC box will be mostly up under the body too
(the running board/fender will cover that exposed front portion, of the box), I set it up so the box is easily accessable

This way "if" there is ever an issue, you just have to unbolt the boxes, retaining bolts
...& lower the whole box, right down, to the ground (floor level)

...& pretty much everything (SC's, fuse box, connectors etc.) are right there & easily accessible ;)

Then, when done, just raise the box back up into position & secure (bolt) it in place :)
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I also "ran" the wiring harness up thru the floorboard via a rubber gromet

* Notice, I installed the gromet in a "slot", it's removable (if/when necessary) like for painting the body &/or replacing body panels
...without having to "mess with" the wiring or disconnecting components ;)
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If this thing is staying on pavement or grass, battery box may be ok. If it's going on a trail or offroad, though, you might think about bolting on a skid plate that'll support the machine if you high center on a rock, stump, or log, and not bend or rip it enough to get at the battery case.

Your design is excellent, love the packaging and weight distribution, just that the battbox positioning is in the most vulnerable spot if the Jeepette is driving over something.
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Your design is excellent, love the packaging and weight distribution, just that the battbox positioning is in the most vulnerable spot if the Jeepette is driving over something.
...& yup, I agree ;)

My Mini-Jeep has been designed for use as a Parade Vehicle
...& as such will be used mostly on pavement

It has dual (48V 1,000W ~1.2HP) motors, to give it some running thru the grass capability
...but, they only produce ~2.5HP (combined), it won't have much trail or off road capabilities

* Although, I may have to try to "Stack up" with a couple of other mini-Jeep's
...just to "show off" :cool:
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281 - 297 of 297 Posts