2DOF Motion Simulator with truck wiper motor playseat

Mechanical part:

In Frex system, the seat is operated by electric actuators.
But the cost was too expansive for me: € 320 each (the only retailer here (https://miraiintertech.com/e-store/products/SCN5.html))

So, the actuators are advantageously replaced by wiper motors and a system of rods (just 10 times less expensive).

Wiper motors

Edit : finally, this bracket is too short : I couldn’t mount the 2 motors symmetrically .
If you can, make a DIY bracket with custom height.

Mounting with 3 screws M6 x 16 and washers

A steering rod (15 €):

A connecting rod:
– Center distance 65 mm (finally)
– 5 mm thick

With a file, try to file a 18° cone down : it has to go well on the motor shaft.
Tighten hard !


motors and rods final mounting
sanding the edges to remove the zinc coating of the bracket for a good welding

I checked the alignment of the motors with the platform (= I conterbalanced a small angular error during the welding of the platform)

Edit: the engine brackets are not stiff enough! they move under the constraints.
solution :

and I checked the rod could rotate freely at 360°
do not hesitate to do the same (one full turn may arrive more quickly than you think 🙂

here the assembly of the connecting rod with the movable platform :

Fixing rods on the platform:

we notice the hexagonal hollow: handy to tighten nylstop nut for example 🙂
it works well for top seat side.

On the other end, I shortened the length of the threaded rod so that it can rotate 360 ° without stumbling. There is a problem : the spindle mounted on ball, turns on itself when i tighten the nylstop nut : ‘(
So I made a hacksaw deep enough to insert a screwdriver while I clamped the nut.

Mounting potentiometers

wiper motor’s preparation = fixing the pot at the back of the engine

1 / tapping of the smooth hole of the engine
2 / a M4 threaded rod
3/ a 6mm diameter (like pot) spacer and M4 tapped

assembled with loctite:

then the parts for making a rotational connection adjustable to adjust the potentiometer
(The brass piece is … a 380V connecting block course!)

This solution is rather excellent!
it is tight enough to but if it goes too far: the pot is not damaged, it slips.

Making a light and flexible bracket for the pot: it should mainly prevent its rotation and absorb a bit of eccentricity.

thickness: 0.8 mm for soft and flexible
Overall un-folded dimensions: 50mm x 129 mm

the first bracket and the second waiting!

overview !

Engine and rods mounting :

– Make sure the platform is horizontal (spirit level)
– the 2 rods has to be perpendicular (red square on picture)


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"Enthusiastic Sim-Racer from the north of germany. I write here about web development, hardware, software and latest motion simulator technologies."