MicroTrac
From Open Source Ecology
HABITAT PACKAGE: CEB Press - Sawmill - Living Machines - Modular Housing Units | AGROECOLOGY PACKAGE: LifeTrac Multi Purpose Tractor - MicroTrac - 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 PACKAGE: Pyrolysis Oil - Babington Burner - Solar_Combined_Heat_Power_System - Steam Engine Construction Set - Solar Turbine - Electric Motors/Generators - Inverters & Grid Intertie - Batteries | FLEXIBLE INDUSTRY PACKAGE: Lathe - Torch Table - Multimachine & Flex Fab - Plastic Extrusion & Molding - Metal Casting and Extrusion | TRANSPORTATION PACKAGE: Open Source Car | MATERIALS
MicroTrac is a small scale, walk-behind version of LifeTrac
Contents |
[edit] Industry Standards
- The BCS Tiller is the main competition.
[edit] Tools
- Tiller
- Mower
- Chipper
-Laimet conical screw design. Makes nice big, uniform sized chips.
[edit] Design
[edit] 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.
[edit] 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.
[edit] 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
[edit] Hydraulic pump
[edit] Specifications
- 10.1 GPM at 3600 RPM and 2500 PSI, requires 17.3 hp to drive it - best match to available engine - [2]
[edit] Sourcing
- .677 cu in, 10.1 gmp @3600 RPM, 3000 PSI max, 4000 RPM max, $180 - [3]
[edit] Coupler
[edit] 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
[edit] Bill of Materials
[edit] Engine Cage and Controls
| Part - Cage | Weight | Price |
| [.677 cu in, 10.1 gmp @3600 RPM, 3000 PSI max, 4000 RPM max, $180] | 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
[edit] 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 | ||
| Tubing total | 125 lbs | $94 |
Total length of 1/8" tubing - 37 feet, or 4 sticks of 10' lenght.
+17.5 HP gas engine 60 lbs $?
+resirvoir 10 lbs $?
+battery 20 lbs $23
Total: 215.66 lbs
[edit] Power Cube (MicroTrac engine cube) Details
- The coupler halves and spider are shown in the pictures, from McMaster Carr page 1157
[edit] Power Calculations
[edit] Pump
- From [4] - 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
[edit] Power Available
- Assuming 85% pump efficiency, we have 17.5*.85=14.8 hp power available to the machine
[edit] 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
[edit] Spider Torque Rating
The Hytrel coupler spider has a 401 in lb torque rating. This is at 3600 rpm. If this pump is driving a hydraulic motor at 87 rpm (wheel motor at 12 gpm fluid flow, at its rated torque), what would be the maximum torque that the 87 rpm could have? 401*3600/87 = 16600 in lb. That is well within the 5130 in lb torque of the wheel motor. Coupler spider will hold up.
[edit] Resource Map
(could use more review)
Reviewers:
- http://www.tractorbynet.com/forums/build-yourself/140170-homemade-modular-hydraulic-engine.html
- No response as of 4.28.09
- http://forums.hydraulicspneumatics.com/eve/forums?a=tpc&s=4721063911&f=8641063911&m=74110526&r=74110526#74110526
- Useful response, including hydraulics primer, Mr. Hanson's contact as a consultant, etc.
- The response claims need for 30 hp if we want 15 gpm at 2200 psi. We have 12 gpm at 2500 psi.
- CadTrac uses 16 gpm pump and 18 hp engine, at 2000 psi for 1/2 of the flow (to wheels) and 1000 psi to rest of flow (loader)
Coupler info:
- http://www.lovejoy-inc.com/uploadedFiles/Catalogs/jw.pdf
- http://www.ohiobelting.com/pdfs/lovejoycplg.pdf
[edit] Notes
- On calculations (right picture) - formula for horsepower to drive pump (with 1714 factor) includes the efficiency of the pump (about 85%)
[edit] Parts Buildout
