April 2011 Production Run BOM
Update as of Sep. 7, 2010:
Extreme Traction from Marcin Jakubowski on Vimeo.
Download open source tractor 3D source code
Cut List
Square tube:
- 4 × 76"×4"×4" tubes for base (shortened by 16")
 - 3 × 5'×4"×4" under base tubes.
 - 2 × 52"×4"×4" vertical chassis centre tubes.
 - 2 × 55"×4"×4" vertical chassis tubes for front corners.
 - 2 × 59"×4"×4" vertical chassis tubes for rear corners (PC mounting area).
 - 2 × 68"×4"×4" top chassis tubes.
 - 3 × 44"×4"×4" top chassis tubes.
 
Rounds:
- [4] 28" × 1-7/8" axle shafts (22" before; turn gussets around for easy wheel takeoff)
 - [1] 56"×1-7/8" loader shaft.
 
Rectangle:
- [2] 100"×6"×3" 3/8" tubes for front loader arms.
 - [4] 6"×4" 1/2" angle-iron to attach re-enforcing tunes to Loader arms.
 - [44] 5"bolts+nuts + [88] washers to suit to attach re-enforcing tubes, angle-irons & H/cylinders to Loader arms.
 - [4] 4-1/2" 1-7/8" DOM to mount shafts through the frame.
 - [4] 3-1/2" 1-7/8" DOM to mount loader shafts to loader arms.
 - [8] thrust bearings - in the form of large washers with 1-7/8" hole to go between frame-shaft-DOM-mounts and loader arm mounts.
 - [4] 6" bushings/DOM to weld in gussets and wheel mounts.
 
Plate:
- [12] 10"×8"×0.5" steel plates to mount flange bearings and hydraulic motors to frame.
 - [4] 6"×8"×1/2" QA-plate to mount motors to QA-motor plate.
 - [2] 12"×12"×1/2" plate to mount H-cylinders to frame base.
 - [4] 12"×4"×1/2" plate to weld to H-cylinder base plates.
 - [16+] 1"diameter-hole nuts to weld into above plates.
 - [1] 1/4" 4or5"×36" plate to mount Valves too.
 - [4] 10"×12"×3/8" plate to connect Rear H-cylinders to loader-arms.
 - [4] 8"×12"×3/8" plate to connect Front H-cylinders to loader-arms.
 - [4] 12×10×1/2" plates to make wheel mounts.
 - [8] 4"×4"×1/2" plate cut diagonally to make [16] gussets.
 - [4] × 32"diameter × 9" wheels.
 
P.C. & Seat mounting metal:
- [1] 144" 4×4" 1/4" thick angle Iron
 - [1] 88" 2×2" 1/4" angle iron
 - [1] 192"×4" 3/8" plate
 
Other
- [16] thrust bearings - in the form of large washers with 1-7/8" hole - torch these on torch table from 1/8" stock
 
Bolts
Functionality list:
- [40] 3/4x5-1/2", with [40] washers for one side and [40] metal lock nuts for the other side. For wheel plates & cylinder plates.
 - [42] 3/4"x9" bolts, [80] washers, and [40] metal lock nuts. This is for the assembly of the main frame.
 - [16] 1/2"x2" bolts + [16] nylon lock nuts + [16] lock washers to suit. Motor attachment to motor QA/interface plate. These could be 2" studs, as these are welded to the motor QA/interface plate.
 - [8] 3/4"x2" bolts for motor; [8] nuts to weld; [8] lock washers. Attachment of motor interface plate to frame.
 - [32] 5/8"x2"bolts + [32] metal lock nuts, [32] lock washers to suit. Mounting of bearings to frame.
 - [32] 9/16"x2" fine thread bolts, [32] washers, [32] nylon lock nuts. Attachment of wheel to wheel hub. Includes studs, nuts, and washers.
 - [4] 3/4"x4.5" bolts; [8] nuts; [4] nylon lock nuts. Mounting of wheel bushings to wheel shafts.
 
TOTALS:
- [40] 3/4"x5.5" bolts
 - [42] 3/4"x9" bolts
 - [4] 3/4"x4.5" bolts
 - [8] 3/4"x2" bolts
 - [120] 3/4" washers
 - [80] 3/4" metal lock nuts
 - [16] 3/4" nuts
 - [4] 3/4" nylon lock nuts
 - [8] 3/4" lock washers
 
- [16] 1/2"x2" bolts
 - [16] 1/2" nylon lock nuts
 - [16] 1/2" lock washers
 
- [32] 5/8"x2" bolts
 - [32] 5/8" metal lock nuts
 - [32] 5/8" lock washers
 
- [32] 9/16"x2" bolts
 - [32] 9/16" washers
 - [32] 9/16" nylon lock nuts
 
Hydraulics
Note that the following list involves 2 loaders. For a simpler version, a single front loader is sufficient. Two loaders are used for extreme flexibility.
(download Blender file here)
Main
Parts from Surplus Center:
Functionality list:
Note: Green indicates finalized shopping list from Surplus Center. Blue indicates list from McMaster Carr. Red is Dalton Hydralics. See Parts Sourcing for contact information.
- [8] 1-7/8" Flange Bearings - [1] or 2-1/2" Flange Bearings [2]
 - [2] Front Loader cylinders - 36" - $174 - 48 5/8" retracted length - [3]
 -  [4] 3/8 NPTM x 1/2 NPTF 90 SWIVEL [4] for Front Loader Cylinders up to hose
- 4.9 square inch area at 2500 PSI implies 12000 lb of force for each cylinder
 
 [0] Rear loader cylinders - [5][0] SAE 8M x 1/2 NPTF 90 SWIVEL [6] for Rear Loader Cylinders- [4] QA plate hydraulic cylinders 
& 2 Rear Loader[7] [0] 3/8 NPTM x 1/2 NPTF 90 SWIVEL [8] for Q.A. Plate Cylinders- [4] Motors - [9]
 - [2] 1-1/4 SHAFT COUPLER W 5/16" KEYWAY - [14]
 - [2] 1-3/8" 6T fully splined shafting - [15]
 - [2] Female 1-3/8" 6T spline coupling - [16], $30 each
 - [12] 1.875" double split shaft collars - [17]
- got 10 double split
 - got 2 single split - [18]
 
 - [1] 1/2" male QC tip, which already have female part [19]
 
Valves
- [1] 3-spool motor valve, 25 gpm - [20], $288
 - [4] 1/2" Quick Couplers [21] - for motor valve work ports
 - [4] 1/2" NPT M to NPT M 90deg Elbow for Motor Valve working ports [22] - for 2 sets of work ports to wheel motors
 - [4] 3/4" NPT quick couplers - Dalton Hydraulics - 2 for in/out, 2 for auxiliary work ports
 - [2] 1/2 NPT hex nipples [23]-for auxiliary pair of motor valve work ports
 - [2] 3/4 NPT hex nips [24] - in and out of valve
 - [2] 3/4 NPT to 1/2 NPT bushing [25] - auxiliary work ports
 
OSE Danfoss Black 2 Spool
- [4] SAE 8M TO 1/2" NPTM CONNECTOR for working ports [26]
 - [6] 1/2" NPT QUICK COUPLER F/F S20-4 [27]
 - [1] SAE 10 PLUG for OSE BLACK 2 Spool [28]
 - [2] SAE 10M TO 1/2" NPT CONNECTOR [29]
 
3 Spool Husco
- [1] 3/4" NPT quick couplers - Dalton Hydraulics - 1 pair for inlet
 - [1] 3/4" NPT nip - [30] - for inlet
 - [3] 1/2" nip for return cross [31]
 - [1] 1/2"-1/4" bushing - to accept case drain return [32]
 - [2] quick coupler pairs for return line - [33]
 - Pipe cross fitting on the return line to accommodate case drain return - [34]
 [1] SAE 12 M to NPT 3/4 M Connector [35][1] SAE 10M TO 1/2" NPT CONNECTOR [36][1] 1/2 X 1/2 X 1/2 NPTF TEE [37]
2 Spool Prince Valve
[1] 3/4" Quick Coupler for outlet (already included in central 3-spool motor valve)- [2] 3/4" NPT nip for inlet/outlet - [38]
 - [1] 3/4" NPT tee (already have these) for inlet
 - [2] 3/4" to 1/2" bushings - [39]
 - [1] 1/2" NPT male elbow - [40]
 - [2] 1/2" quick coupler pairs - [41]
 
Cushion Valves
- [2] 1/2 NPT 30 GPM 1500-3000 PSI HYD CUSHION VALVES - [42]
 - [4] 1/2" male QC tips to plug into valves, which already have female QCs [43]
 - [2] 1/2 NPTM x 1/2 NPTF swivel [44] for cushion valve to mount tees, for separating to right and left cylinders; only one swivel needed per cushion valve
 - [4] 1/2" nip - [45] - going from between swivel and tee.
 - [4] NPTF Tee [46]- 4 for loaders only, not QA plates
 
Power Cube
- Note: pump is already obtained
 
- [1] Coupler half, 5/8" - $10
 - [1] Coupler half, 1" - $10
 - [1] Solid spider - $14
 [1] Breather cap - [47] - $8- [1] 3/4 NPT coupling - found at big box hardware stores
 
- [1] Suction strainer, 2" to 1-1/4" - [48] - $23
- Use for dual Power Cubes
 - [1] Use 2" coupler from bix box store to thread into Power Cube frame
 
 - [1] Pressure relief for power cube bypass- [49]
 - [1] 20 GPM return Line Filter - [50]
 - [1] 3/4" NPT Swivel for return line filter going into frame - [51]
 - [2] 3/4" NPT hex nip on both sides of filter - [52]
 - [1] 1"-3/4" NPT reducer bushing for frame receptacle for return filter - [53]
 - [1] 3/4" quick coupler for return line to filter
 - [2] 1/2" quick couplers for main power lines
 
Hoses:
- [1] 2 foot hose from pump outlet to return line filter - [54]
 - [2] 10 foot hoses, already have these - [55]
 
Pressure Bypass:
- [1] 1/2" NPT Bypass valve - [56]
 - [3] 1/2" Quick couplers - 1 complete for tee near pump, one going from return filter to tee, and male tip for return line. This gives one extra female quick coupler left over. This set of 3 QCs does not cover hoses going from and to the PowerCube.
 - [4] 1/2" NPTF hex nip for one and other side of tee, on both tees - [57]
 - [2] 1/2" NPTF tee - from outlet of pump to pressure bypass, and from bypass valve into return line filter - [58]
 
Hoses
Between Motor Valves & Motors
- [4] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for in/out of the valves [59]
 - [4] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for in/out of front motors [60]
 - [4] 1/2 X 1/2 X 1/2 NPTF TEE [61]
 - [4] 1/2" X 48" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for rear motors [62]
 
Motor Case Drains
- [2] 1/4" X 72" NPTM 2750 PSI HYD HOSE to run parallel with tractor sides [63]
 - [1] 1/4" X 30" NPTM 2750 PSI HYD HOSE from Tee to Tee in return hose [64]
 - [1] 1/4" X 36" NPTM 2750 PSI HYD HOSE to Rear Motors [65]
 - [3] 1/4 X 1/4 X 1/4 NPTF TEE [66]
 - [3] 1/4 NPT hex nipples [67]
 - [4] 1/4" NPT quick couplers are already with the motors
 
Front Loader
- [2] 1/2" X 12" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE from Valves to Cushion [68]
 - [2] 1/2" X 36" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for left front loader cylinder [69]
 - [1] 1/2" X 48" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for right front loader cylinder [70]
 - [1] 1/2" X 60" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE for right front loader cylinder [71]
 
Front loader QA Cylinder Hoses
- [4] 3/8" NPTM x 1/2" NPTF swivel - [72] - swivels for QA cylinders
 - [2] 1/2" nips - going from cylinder swivels to tees - [73]
 - [2] 1/2" NPTF tees - from cylinder to hoses - [74]
 - [2] male QC tips - for plugging into control valves - [75]
 - [2] 1/2" X 48" NPTM 3000 PSI HYD HOSE [76]
 - [1] 1/2" X 120" NPTM 3000 PSI HYD HOSE [77]
 - [1] 1/2" X 144" NPTM 3000 PSI HYD HOSE [78]
 
Rear Loader Hoses
- [2] 1/2" X 12" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE to Cushion Valve [79]
 - [1] 1/2" X 60" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE [80]
 - [1] 1/2" X 96" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE [81]
 - [1] 1/2" X 84" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE [82]
 - [1] 1/2" X 120" 1/2 NPTM X 1/2 NPTM 3000 PSI HYD HOSE [83]
 
Rear loader Q.A. Cylinder Hoses
- [4] 3/8" NPTM x 1/2" NPTF swivel - [84] - swivels for QA cylinders
 - [2] 1/2" nips - going from cylinder swivels to tees - [85]
 - [2] 1/2" NPTF tees - from cylinder to hoses - [86]
 - [2] male QC tips - for plugging into control valves - [87]
 - [2] 1/2" X 48" NPTM 3000 PSI HYD HOSE [88]
 - [1] 1/2" X 120" NPTM 3000 PSI HYD HOSE [89]
 - [1] 1/2" X 144" NPTM 3000 PSI HYD HOSE [90]
 
Seat
- [1] Tractor Seat [91]
 
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Total Weight
- Frame 4x4x1/4" square tubing - 1277 lb
 - Loader arms (2 sets), 3x6x3/8" tubing - 900 lb
 - Loader arm shafts, angles - 150 lb (even)
 - Loader arm cylinder mount plates (base (66lb) and top(80)) - 146 lb
 - Loader arm bottom eyes - 46
 - Hydraulics, wheel bearings - 811 lb
 - Wheel mounting plates, gussets, tubes - 112 lb
 - Bearing and motor plates - 160 lb
 - Wheels - 200 lb
 - Wheel tracks (140 lb chain, 209 lb rebar (2.6 lb/ft for 1" rebar)) - 349 lb
 - Bolts - 75 lb
 - Pins - 30 lb
 - Power Cube (1) - 420 lb
 - Quick Attach Plates (2 sets) - 234 lb
 
Total weight of tractor with 2 sets of loader arms, 1 small Power Cube, and wheel tracks 4910 lb dry weight, with 2 Power Cubes - 5330 lb. Weight of loader arms with cylinders and Quick Attach plates: 940 front, 900 back, for total of about 1840 lb. Weight of 2 Power Cube version with only front loader - 4430 lb.
Cost
Basic Structure
This is about a buck fifty per pound of the 2214 lb machine, or about the going price of tomatoes. That is without the PowerCube. If you use an off-shelf 18 hp engine – the price may be $1225 ($500 for 18 hp engine + $200 pump + $225 frame + $300 balance of system). The total is then $4808.
Front Loader
- Heavy duty front loader arm metal (3/8″x3″x6″ rectangular tube) – $500
 - Cylinders – $600
 - Control valve – $200
 - Hoses – $100
 - Couplers and fittings – $100
 - Quick Attach plate – $150Cushion valve – $66
 
TOTAL FRONT LOADER COST – $1716
Rear Loader
- Rear Loader Cylinders – $520
 - Heavy duty rear loader arm metal (3/8″x3″x6″ rectangular tube)- $340
 - Selector valve (4) – $180
 - Quick attach plate – $150
 - Cushion valve – $66
 
TOTAL REAR LOADER COST – $1256
Steel Tracks
- Chain - 80 feet - $270 at $3.37/foot
 - Links - $28
 - Rebar - 140' at $1.57/foot - $220
 
TOTAL for Wheel Tracks - $518
Quick Attach Plates
(See Open Pario for design)
- [6]1"x5" pins (30") - $10
 - [129"] 3/16"x3" sq tubing - $46
 - [113"] 1/2"x3" flat - $34
 - [6"] 1" DOM tubing - $15
 - [24"] 1" rebar - $3
 - [66"] 1/4"x2" flat - $6
 - [6"] 1/2" rebar - $1
 - [15"] 3/4" threaded rod - $3
 - [8] 3/4" lock nuts - $1.60
 - [2] 3/4" nuts - $0.40
 
MATERIALS FOR EACH QA PLATE - $124
Overall cost for a dual loader tractor – wheel base of about 7×7 feet, designed to handle 3 Power Cubes, for a power limit up to approximately 150 hp – $6550 without the PowerCubes. Design is absolutely scalable, such that a half-size version – or MicroTrac, may be made – and it can be designed readily from our Blender model drawings.
Package Options
Package 1
- Basic 4 wheel drive tractor - $3583
 - Tracks - $520
 - Front loader with quick attach plate- $1840 (with quick attach plate)
 - Power Cube - $1236 for 18 hp
 
Total cost is $7179 in materials. The 18 hp may be undersized, so we recommend 2 PowerCubes for 35 hp
Package 2
- Basic 4 wheel drive tractor - $3583
 - Tracks - $520
 - Front loader with quick attach plate- $1840
 - Quick Attach plate - $124
 - Front loader bucket - $400
 - 2 Power Cubes - $2472 for 35 hp
 
Total cost is $8815 in materials fpr 35 hp.
Package 3
Now here’s the good part. We aim to develop the induction furnace within 2 years, with which we will be able to produce all tractor structure and components, minus the rubber parts, from scrap steel. This means that we will demonstrate how to build a tractor at the cost of scrap metal plus rubber, plus energy to run the induction furnace. This should be about $1k in materials such as hoses and hydraulic seals, plus labor. This indicates a possibility of closing the industrial divide between the developed and developing worlds.
