Well I just had the pleasure of talking to a Unisport distributor who was there at the end of the company. He said total production reached about 1500 kits before the 70's economy and a large stock of improperly stored firewalls took the last of the company's resources. Apparently the machine shop making the forward firewalls - the 1/4" steel plates that mounted the linear actuators & centered the tilting parallelogram & steering & lined up the frame, pretty much the linchpin of the design - at the end of production was storing them leaning at an angle instead of stacked flat. A slight bend started showing up and finished cars were wearing out tires quickly. The expense of dealing w/ this problem was the straw that broke the camel's back.
The linear actuators are military issue, from airplane landing gear (sorry not sure which plane), and even have a clutch that's plated off here:
I haven't had much time for the project this summer, but now I have a line to the original circuit diagrams and build manuals - once I've got them I'll get as much info online as I can, & I'll have an easier time replacing the broken old switches.
Have you thought about automating the leaning?
ReplyDeleteOne of these http://en.wikipedia.org/wiki/Arduino with interfaced to a wiimote could hand the leaning for you.
Just an idea for improvement
Yeah, it's looking likely that the "snap switches", which are limit switches to set the tilt boundaries, are obsolete and could be replaced by an arduino w/ rubber stopper backup. From there I may experiment w/ auto tilt, but I'm really looking forward to having a stable 3-wheeler with optional tilting, where the tilt is manual and controlled by a large joystick where the shifter would be. This will let me experiment w/ tilting timing and forces. The big thing with auto-tilting is ideally you initiate tilt just before you turn, which is much much harder settup-wise than tilting just after you turn. Tilting just after you turn is much more energy-intensive and less sure-footed.
ReplyDeleteC.
ReplyDeleteThe steering-wheel mounted thumb switch was just about the easiest method of lean control one could imagine. Perhaps you recall the it was 'left-on/off/right-on', and not unlike paddle-shifting. With the 'push-me/pull-you' linear-actuators the tilt was extremely fast for a machine with a track of five feet and an over-all length of fifteen feet. After crushing the micro-switch limiter on one side in downtown Portland, Oregon one afternoon, I had the foresight to install a 1/2 inch piece of fuel tubing over the plunger on each micro-switch on both UNISPORTS back in 1972. those pieces of tubing are still on the one I bought, but have hardened over time. I never crushed a micro-switch and neither did the owner of the 450cc powered UNISPORT.
The main purpose for my responding to these entries after all this time (I almost died and have been rebuilding my heart and limiting my projects to the point of eliminating many) deals with the tilt suspension/steering/brake design. Recently I decided that, rather than restore the unit, I might apply a hot rod dropped tube front axle with wish-bones absorbing braking stress and spring-wrapped shock absorbers replacing the tilting-parallelogram 1/2 inch steel axles. Newer disc-brakes and an easier to maintain later model 650 twin, rather than the Yamaha TX750.
What all this appears to be leading up to is my slow realization that I have reached the end of this project, among others I have already forfeited, and am about to see if the LeMay Transportation Museum in Tacoma, Washington wants it.
EarlWizard
Hi we found one in a garage in excellent shape. m wondering what it is worth. I have been researching for days but cannot find much information on it. Thank you.
ReplyDeletehttp://earlywiz.smugmug.com/VEHICLES/1972-UNISPORT/21375642_zN64PF
ReplyDeleteHi I have one its in mint shape never been used I was very lucky to buy it from one of the factory workers . I have the top all lights it's not ever been used or has been in sun. It's white and green stripped
ReplyDeleteWow, would love to see pictures and hear more details, thanks for your reply.
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