Protohippus 2
and further development (Protohippus 3 and 4)
The construction of the first prototype, Protohippus 1, was strong, but quite complicated to build because of many small Aluminum pieces, that were welded together. There are over 70 small Aluminum pieces. The pipes of the front part are not aligned.
Next I tried to plan a frame, that is as simple and cheep as possible, made of aluminum. Aluminum makes less overweight than steel, when designing is not very accurate. I thought to connect the frame parts with rubber blocks, but I was not sure, if the rubber parts should withstand all the forces. That's why I decided to design the new prototype changing the front part of Protohippus 1, which has been strong and rigid.
Hipparion Protohippus 2, the first idea of the second prototype.
Simple frame made of common Aluminum profiles, welded joints.The second protoype, Hipparion Protohippus 2 was ready in June 2001. The construction is as follows:
- Aluminum frame, made of standard 6063-T6 profiles (40 x 40 mm˛ x 2/3 mm ja 18 x 100 mm˛ x 2 mm), sheets (2, 3, 4 and 10 mm) and seat frame of round pipe (22 mm x 1,5 mm)
- distance from seat to pedals adjustable ±75 mm
- 20" (406 mm) wheels, wheelbase 950 mm (37.5") and wheel gauge 870 mm (34"), biggest width 900 mm (35.5")
- adjustable Flevo-bottom bracket (steel, SKF-bottom bracket)
- Shimano Nexus Intern 7-Speed hub with Roller Brake
- Shimano cranks (length 170 mm), two front rings (52/42), no front changer (yet)
- Shimano changer as chain tightener
- the tilt of rear wheels about 5 degrees
- Magura Race Line hydraulic brake as second brake in the fornt wheel
- seat height about 300 mm (12")
- height of the bottom bracket 400 mm (16")
- road clearance about 80 mm (3")
- big trunk under and behind the seat
- yellow Greenspeed mesh in the seat
- weight of the frame and seat about 8 kg
- weight of other parts about 12 kg
- total weight is now about 20 kg (plus new mudgards missing); total weight is about 3 kg less than in Protohippus 1.
Protohippus 2, 3-dimensional virtual model (VRML 2.0) (305 kB, enclosed), needs an 3D browser plug in, e.c. Silicon Graphics CosmoPlayer), but with Firefox CosmoPlayer does not work well (in my computer). Zip-comressed model: B158.ZIP, size only 26 kB, open with UNZIP. – The model is simple, stearing damper, mudgards and some other datails are missing. Turn the model upside down and round and round!
The seat is rigid. Adjustment for different drivers is made by moving bottom bracket cassette (Flevo). The distance from the seat back corner to the middle of bottom bracket can be 750...900 mm. Protohippus 1 has moveable seat, and the distance is 850...870 mm in my use and I have NOT long legs. Protohippus 2 is thus meant for quite short legs (for my wife; now Hipparion is in my use and is OK).
The painting is made with car paint with brush instead of spray. Only little acrylic paint was needed. Spraying wastes most of the paint.
I have not constructed front changer, there is no space for normal changer. I think, tube aroud the chain and manual change should be enough.
I use now Schwalbe Marathon Plus tires. They are good against punctures. In the next photos there are still Nokian tires with white sides.
Hipparion Protohippus 2 in front ja three years old Protohippus 1 on the right
I have made the drawings with computer and plotted on paper in scales 1:2 and 1:1. Parts are welded togeter with MIG. The angles are quite easy to get right when the 1:1 drawing is under the parts. My drawing program is simple and I can not get exact dimensions of other than straight pipes. A good 3D program would cost more than 15.000$ (for instance ProEngineer).
After 15.000 km test drive Protohippus 2:
- is as stabile as Protohippus 1
- is as comfortable as Protohippus 1
- has as good loading capacity as Protohippus 1 under and behind the seat
- moves similar way or little better than Protohippus 1
- is smaller and lower than Protohippus 1
Hipparion Protohippus 2 and morning coffee (2001)
A short video of Protohippus 2 in YouTube (2008-10-11) 
Protohippus'es on a ferry in Turku archipelago (2001)
Protohippus Two was made for my wife: she has shorter legs than mine. I thought it to be ergonomically not optimal; the seat is too far to front. The drivers "hindges" and the hindge of the trike are not on the same line (as should be). But, in fact, Protohippus Two is better than One. Protohippus One was stolen in August 2006 and after that I have driven my wife's Protohippus Two and found it little better than Protohippus One. My average speed is better with Proto 2. The differense is - expect the seat position - the weight and small rear wheels. I have drawn some new versions, Protohippus 3, where both, the bottom bracket and the seat, are moveable and the back axle is on the same level with the frame tube. In this case the seat is changeable; it's possible to use reinforced plastic seat box or a normal Aluminum tube seat or whatever. Beneath is a sketch of Protohippus 3. It is very similar to Porotohippus 2 but it is 50 mm longer and few hundred grams heavier.
The width 900 mm is too big for trains in Europe. If the total width could be less than 600 mm, it will be possible to pull the vehicle into the train wagon without taking any camping gear off of the rack. I have thought telescopic rear axle, but with Aluminum construction, it is quite difficult to realize. That's why it's still an idea.
Enclosed you see a picture seen above Protohippus 4. The seat width is 320 mm and total width little less than 600 mm.
Plan of fairing for Protohippus 4. The fairing could be foam plastic.
Wolfgang Bion has made good rules to make a fairing:
Fairing
Design4
Design5
Design6
Hipparion Protohippus 4, virtual model. Look with Cortona-plug-in (Cortona now seems to crash Firefox!).
Hipparion protohippus 4, moving parts, three small AVI-animations:
Hipparion Protohippus 4, animation 1.
Hipparion Protohippus 4, animation 2.
Hipparion Protohippus 4, animation 3.
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