Steering Wheel Finished!


Here it is, immortalised with my atrocious photography skills!

It's made mostly out of some old tongue-and-groove flooring samples, with some 4mm and 6mm ply in places.  What with the heavy-duty bearings and being screwed together, it's actually a really robust little thing!

I decided to have a composite axle so I could fit the button wires down the centre.

So I cut two long, thin beams of ply so they could fit through the very centre of the bearings.  Then I cut small sections out of the edges so that when pushed away from each other, they would lock into the bearings (i.e. not slide through them).  The other blocks you can see are holding the two long pieces apart so they can't fall out.

I swapped out the middle block with a spring mechanism.  I cut two bits of ply that I could slide onto the beams from opposite sides.  Then I inserted a section of bamboo skewer between those bits to hook the springs onto.  As you can see, I used screws to secure the other ends of the springs.  It makes a quiet creaky noise as the spring rubs over the edge of the rotating ply, but I can live with that.



The rotating beam links to a potentiometer by gears.  This allows the button wires to go straight out the end of the axle through a hole in the largest gear.  It also means a 90 degree turn on the wheel is a larger turn on the potentiometer, which (in theory at least) gives greater sensitivity.

I made the gears by modelling them in FreeCAD with a gears plugin, then printing them on my cheapo 3D printer.  Judging by the reviews, other people have had major problems with that model of printer.  Initially, mine died and refused to power up, but I figured out that's because the power-control relay failed.  I just bypassed it and it works fine (it just doesn't switch off when the print is finished).

Anyway, I decided to cast the gears in resin in the hope that would make them durable enough to withstand my race-loss-tantrums.  The cone/cylinders on top are so I can easily pour the resin into the resulting mold.

I forgot to take photos of the cast gears, but it turns out they look remarkably like the printed ones! ;)

I did screw up the first mold I tried to make because the silicone wasn't quite cured when I tried to take the printed gears out.  The weather had been so cold that the silicone had taken for ever to cure and the resulting gears were warped.  The second mold I made, I put a little extra catalyst in and left it curing overnight.  That worked a treat.

In the interests of protecting the potentiometer from my over-enthusiastic steering, I also put a full-lock-stop mechanism in.


The dowel hits the tacks to either side at full steering-lock.  Unfortunately, they have since managed to work loose, so I need to replace them with screws. 

And here's a rear-view of the final product!






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