MicroTrac
- HABITAT: CEB Press - Sawmill - Living Machines - Modular Housing Units
- AGROECOLOGY: LifeTrac Multi Purpose Tractor - MicroTrac - Power Cube - Agricultural Spader - Agricultural Microcombine - Hammer Mill - Well Drilling Rig - Organoponic Raised Bed Gardening - Orchard and Nursery - Modular Greenhouse Units - Bakery - Dairy - Energy Food Bars - Freeze Dried Fruit Powders
- ENERGY: Pyrolysis Oil - Babington Burner - Solar Combined Heat Power System - Steam Engine Construction Set - Solar Turbine - Electric Motors/Generators - Inverters & Grid Intertie - Batteries
- FLEXIBLE INDUSTRY: Lathe - Torch Table - Multimachine & Flex Fab - Plastic Extrusion & Molding - Metal Casting and Extrusion
- TRANSPORT: Open Source Car
- MATERIALS: Bioplastics
MicroTrac is a small scale, walk-behind version of LifeTrac
Industry Standards
- The BCS Tiller is the main competition.
Tools
- Tiller
- Mower
- Chipper
-Laimet conical screw design. Makes nice big, uniform sized chips.
Engine
The engine will be a modular removable unit consisting of engine, fuel tank, hydraulic pump, hydraulic reservoir, and frame. The frame will be the hydraulic reservoir, made out of 4x4" square tube.
Specifications
Engine should be a 12-20 hp 1 cylinder diesel engine, with air cooling. The engine will run the hydraulic pump.
We have a 17.5 HP engine.
Dimensions: 18x16x13" Shaft: 1x?"
Turns CW from above. CCW from below.
Sourcing
- 14 hp 2 cylinder engine no starter $975
- 11 hp 1 cylinder generator $899.00
- 13 hp 1 cylinder silent $1300
- 13 hp $695 GAS
- 23 hp water cooled diesel engine with radiator $1000 - $1349
- 62 hp 4 cylinder tractor $1828
- 65 hp 4 cylinder tractor $710
- 40 hp 3 cylinder $1500 - $2300
- 35 hp 3 cylinder tractor $1185
- 90 hp 4 cylinder diesel 2000 vw beetle $2000
- 11 hp 1 cylinder $400
- 13.7 hp 2 cylinder $666
- Perkins 402C 13.7hp 2 cylinder Same as above, asked for quote 3/5/09 talked to jeff
Hydraulic pump
Specifications
- 12 GPM at 2500 psi, requiring 18 hp to drive it
Sourcing
Coupler
Sourcing
Wheels
- one set of drive wheels in the middle balanced with the engine so the Microtrac can be rotated easily, with a motor on the side
- doubled up for traction
- have support wheels on the back sides so it doesn't tip easily
- drive wheels the same as lifetrac, 30" high 10" wide
Bill of Materials
Engine Cage and Controls
| Part - Cage | Weight | Price |
| 12 gpm at 2500 PSI, 5/8" shaft 3/16" key - better | 9 lbs | $181 |
| NT filter or SC filter | 2 lbs | $17 |
| or type E coupler half 1/4" key 2.5" o'all long (2 of these,for | .65 lbs | $9.86 |
| Parts total | 12 lbs | $220.85 |
| Part - Controls | Weight | Price |
| 3 spool valve | 35 lbs | $200 |
| Parts total | 35 lbs | $200 |
Other choices, not used: |- |L095 coupler half 1" shaft 1/4" key 1-1/16" long || .65 lbs || $15.28 |- |L095 hytex coupler insert || .04 lbs|| $18.29 |- |L095 coupler half 3/4" shaft 3/16" key 1-1/16" long or 5/8" || .7 lbs || $15.28
- Note on 3 spool valve - about 1900-3400 PSI relief setting
Frame Metal
2x2x1/8" is 3.05 lbs/ft
Steel @ $0.70 per/lb
| Part | Weight | Price |
| 2x2x1/8" square tube 29" long, x 6 | 44.22 lbs | $30.95 |
| 2x2" square tube 24" long, x 4 | 24.4 lbs | $17 |
| 2x2" square tube 20" long, x 8 | 40.66 lbs | $28.46 |
| 2x2" square tube 7" long, x 2 | 3.55 lbs | $2.49 |
| 7x25" plate 1/4" thick | .83 | $0.58 |
| Parts total | 113.66 lbs | $79.56 |
Total: 125.66 lbs $300.41
+17.5 HP gas engine 60 lbs $?
+resirvoir 10 lbs $?
+battery 20 lbs $23
Total: 215.66 lbs
Power Cube (MicroTrac engine cube) Details
- The coupler halves and spider are shown in the pictures, from McMaster Carr page 1157
Power Calculations
Pump
- From [2] - Pumping = 1 Hp = 1 GPM x 1500 Psi - (linear relationship i.e. 2 GPM @ 1500 Psi = 2 Hp)
- For the above pump, 14.2 gpm with 3000 psi indicates 28.4 hp requirement
- Hp to drive hydraulic pump = Psi x GPM / 1714
- For the above .97 cu in pump, 3000*14.2/1714 = 24 hp
- If we run at 2200 psi => 18 hp required
- For .86 cu in pump, need 3000*12.6/1714 = 22 hp
- For the same with 2500 psi, 18.3 hp
Power Available
- Assuming 85% pump efficiency, we have 17.5*.85=14.8 hp power available to the machine
Wheel Motor Calculations
- 32 cu in wheel motor: 20 gpm, 5170 in lb torque, 145 rpm
- Using 12 gpm, 5170 in lb torque, at 87 rpm - uses 7 hp of the engine
Resource Map
Reviewers:
- http://www.tractorbynet.com/forums/build-yourself/140170-homemade-modular-hydraulic-engine.html
- http://forums.hydraulicspneumatics.com/eve/forums?a=tpc&s=4721063911&f=8641063911&m=74110526&r=74110526#74110526
Coupler info: