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Various 2 DOF motion sim builds with 12v12 JRKS


Heres some of the DIY motion sim builds I have done over the years
Using Wiper motors
Joyrider style build

Compact rear motor wiper mount compact frame , full moving frame

Front motor mount wipers, full moving frame

12v 200 watt DC motors , full moving frame

200 watt motor “foot motor mount” full moving frame

Then I built a frame for it, with PC, screen, PSUs, etc

Some shoulder mount seat movers, 200 watt DC motors

Desk racer 200 watt motors

2 Desk racers converted to “all in one” sim builds

Converted Brick spreader actuators sim, seat mover, using 12v 4500 rpm motors 1:1 drive, home made feedback system, 2 DOF.

Feedback is using a 5 Kohm pot in various ways
Cut out slider lever

direct on back of motor shaft

Feedback system for actuators was a bit tricky, but a combination of gears and levers fixed that

Videos of the sims in action

And if people are curious to find out the difference in motion between full frames and seat movers, heres a comparison]

Heres what I came up with, didnt record lap times. No frame made made me faster or slower, so times were about the same.

Comparisons between simulators. Other people will of course differ with this comparison, so please add your thoughts.

First things to consider, angle of actual swing of the frames and the profile written. Also, its a brain trick.
If you want a big swinging frame, go hard, the biggest swing I have had is 14 deg total, but others have frames up to 25 deg. And thats for race, not just flight.
Both frames use same motors and JRK control boards

Seat mover with shoulder mounted motors.
Generally ,a seat mover can give more precise motion detail as it has less over all weight to move than a full frame. However, too much movement can make it hard to hang onto the wheel or mash the juice pedal. And yes, the wheel and pedals are stationary, so proper placement to allow you being pulled away and pushed around has to be taken into consideration. But as said, it does give you the feeling of being moved around in a seat in a vehicle, even with a race seat to hold you in more. You tend to shift your body around to compensate for movement and also what your brain thinks you are moving like. You can still feel pitch and roll of track, but maybe a bit less as legs are still.
Some SCN seat movers on videos have HEAPS of throw. It might look like fun, but can be too much and eventually make it tiring to drive the game.
As mine is DIY and has 70mm travel of motor lever and at 600mm from the pivot , total angle is 6.5 degrees. Not much, but then again, too much may make it too hard. Other people will of course differ with this comparison.
I had a seat mover of 12.5 degrees at one stage, so with a good profile, it was nice, but a harsh profile and WHOA! Fun but hard to hang on.

Full frame with motors mounted near feet
Full frames allow you , wheel and pedals to move with you. You dont really get sensation of being pulled, pushed around from pedals and wheels. Obviously not as much as a seat mover, but still there. You tend to feel a bit more of the motion of roll and pitch , when your whole body is getting moved around, I find.
Seat mover can lose this a bit, but not really much.
Motors mounted at feet on the frame in question, may take away some of the finer vibration and motion that shoulder mount gives, but then again, shoulder mounting motors would return that finer detail due to higher leveage point. It may lessen a bit due to the fact that a full frame requires a bit more power to move. But hey, just change the profile and increase the motor power a bit more.
Although, I must say, once again, a good profile can give the same sensation in motion, be it from a different spot. Feet or knees instead of shoulders.
Full frame is about 8 deg total swing. May not sound like much considering 4 deg from centre, but again, throw a decent profile in it and you feel like you are moving a lot more.

After a while I get the same sort of feeling from both my frames, even though they are different in design.
In your choice of motion sim build, It will come down to watching videos of other frames, opportunity to play on sims when they are around to do so. Taking a look at pics, seeing what takes your fancy. Heck, even a seat mover can be converted to full frame later, add the extra bit, move pivot, and off you go. 2 seat movers I have sold, the owners have since converted them to full frames, their choice of course. They enjoy both frames they tell me.
I have only played on a $40,000 VRX dbox with 3 screens, impressive rig, but motion was lousy I though. Although others whom have such rigs wind it up and get great results. Mind you, I dont have that sort of money to get one.
I have been through 10 different 2DOF designs, starting with joyrider design with about 9-10 deg total swing with screen on it. Good fun, but I found it a bit difficult to focus ona screen moving with you. But thats just me.
Then I moved onto development of more compact designs, with motors under rear, at knees, out the side, shoulder mount, at feet. Still 2DOF. Screen static.
So thats how I go here. Each frame design is a new learn to drive experience I find. Nothing makes me go faster I think. I am slow regardless.
I may have missed something and please add your thoughts as well. Its always good to compare notes.

Cheers, David.


Hello, David.

Thank you for sharing; these look great! I have not personally built one of these systems yet, but they look like a lot of fun (both to build and use). Your comparison between the two different systems is really interesting too, especially with all of your experience with them.



Thanks Brandon, they are a tough little board, considering a mate of mine introduced them on the simulator forum about 4 years ago.
They are a hit and myself and Nick Moxely promote them heavily to new users for their simplicity and power.
Despite their small size with a heatsink and fan cooling of the big chip, we overdrive them to 30 amps continuous and 40-45 amp spikes peak. never fail.
So the 200 watt motors get overdriven to about 550+ watts in motion.