Homemade Modular Hydraulic Engine

   / Homemade Modular Hydraulic Engine #1  

Jeremy Maso

New member
Feb 3, 2009
Maysville, MO

Thanks to everyone that helped out in the previous threads! We've decided to focus on only one project for now to get it to production, and we're refining our development strategy, analyzing the feedback from the progress on the previous projects.

Our current project at Open Source Ecology is a modular hydraulic engine to power the next version of the compressed earth block press. The engine is part of the MicroTrac, a walk behind tiller.

We're using a 17.5 HP "OHV" engine from a ride-on lawn mower to power the pump. Here's the BOM and some pictures:

|[Prince SP20 Series Hydraulic Gear Pump .976 Cu. In., CW, Model# SP20B16A9H4-R | Pumps | Northern Tool + Equipment pump 3/4" shaft 3/16" key] || 8 lbs || $155
|[Buyers Return Line Filter 20 GPM Capacity | Hydraulic Accessories | Northern Tool + Equipment filter] || 2 lbs || $17
|[Power Transmission > Couplings and Collars > Jaw Type Couplings > Shaft Coupler Body : Grainger Industrial Supply L095 coupler half 1" shaft 1/4" key 1-1/16" long] || .65 lbs || $15.28
|[Power Transmission > Couplings and Collars > Jaw Type Spiders > Insert, Hytrel : Grainger Industrial Supply L095 hytex coupler insert] || .04 lbs|| $18.29
|[Power Transmission > Couplings and Collars > Jaw Type Couplings > Shaft Coupler Body : Grainger Industrial Supply L095 coupler half 3/4" shaft 3/16" key 1-1/16" long] || .7 lbs || $15.28
| Parts total || 12 lbs || $220.85

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: about 215.66 lbs

In the pictures the black box is the battery, the yellow thing is the hydraulic reservoir, and the tan thing is the gas tank.

The idea is that the engine is counter-balanced on the other side of the wheel by the implement. We're also planning on putting wheels on the back sides of the engine cage in case it comes back too much or when there's no implement.

Right now we just need it to be used for the two hydraulic cylinders and auger of the Compressed Earth Block Press Prototype 2. Does it look like it's going to work for that?

And when we get to the garden tractor phase, is it going to be manageable to handle? We're looking at it being like the BCS tiller.

Thanks for any feedback, and thanks to everyone that helped in the earlier threads!