Motion Sim w/ Surge & Traction Loss

Hi guys,

I am looking at converting my current sim to 2dof motion



Currently looking at building a new base with pivot point under belly button position while racing. With 12v 200w worm gear drive motors either 50:1 or 60:1. Either attaching arms to rear of seat or rear of top sim itself. Will start getting parts soon but plan is to build this fully early in the new year. Shifter position will change aswell as removing the table and will need new brace put on it for pivot to attach too.

im trying to work out the gear I need but as far as I can tell I need

2x 200w Worm gear drives with either 50:1 or 60:1 ratio (not sure where I get these)
2x Pololu JRK 12v12
Universal Joint or Similar for Pivot
12v Power Supply to power the motors
Arms to attach between motors and sim
2x 4.7k or 5k ohm potentiometers with continuous turn

Anything else im missing?

I believe I need fans etc to cool the gear....does it matter if arms attach to back of sim itself or is it best to try attach to back of seat. Not sure if it really would but Id obviously like to get the best torque on it is possible

cool thanks a lot

Im getting a little curious about adding drift to it aswell. Is it quite simple to add? from what I gather I need a point at front and simply have the rear slide left and right from that point with an actuator pulling and pushing (to get the left and right).

Is that it? or is there a lot more too it haha

mount the motor connections as high as you can, if need be, make up a t bar behind the seat to shoulder height at least. You have a lot of weight to over come, so going up above centre of gravity is the key here.
I will find a link later for the motors, they can be found on eBay under crabpot saw mill motors. Try not to go of more than 45mm ctc levers as you need as much torque as you can use .he immersion factor will still be there, even if actual overall throw is not massive.
Best get the 2DOF sorted first and moving right, then look at 3rd DOF a bit later.

would it be much better to have a lighter frame? I could always start from scratch to try lighten the weight

it might help, however, a TV is between 5-10kg and thats quite a bit of weight up high. And also taking into account your actual weight as well. Your head may weigh near the same as a TV, but most of your weight is lower than the TV, so even 5-10 kg extra that high will move, but you need to consider re-enforcing the TV mount as well to stop flex.
I did built a PVC pipe full frame a while ago and motioned it.
The frame was lighter than steel and very sturdy, but again, I didnt have a TV on it .

As Mario found out as well as another guy , lee, screens , no matter how light can be moved, but the problem is that you are trying to move extra weight higher on the frame.
Both guys ended up taking the screen off and making it still.
That being said, again, frame design will need to be taken into account of how you plan to motion it.
If you use a really light seat like under 10kg, that will help.
I think maybe you could look at mounting the connecting arms at the front, again up as high as you can , like behind the TV.
Remember, with a full frame, it will flex under motion, and from experience I found it needs a LOT of extra steel to re-enforce it to support it.
You could support the whole thing on a bit of 19mm plywood to stiffen it up. Heres my suggestion

Mount the motors at the front but up right behind the tv, re-enforce the TV mount part and toss the whole frame on a sheet of ply, then pivot under that for balance point.
Maybe that helps a bit.
Cheers, David.

yes but Robs is a seat mover, not a full frame.

hmm okay that's a bit diferent to what I was planning. I was under the assumption the motors are always best behind the seat and add a T bar or such behind seat with arms connecting up high. Also the whole sim is welded together with steel and I would be very surprised if it couldn't handle the motion. However If you think it needs the ply then ill add it

with your frame, roll it on a broom handle and see how it flexes, if its sturdy enough on its own, you are set. If it flexes and bends, then you may have to re-enforce it somehow.
Any frame will handle motion, its how it flexes is the thing.
My suggestion about connecting to the TV is that the TV is the high point of extra weight. It may help motion it from that point as you are working with the higher point of weight.
You can put them behind the seat no problems as well. Just remember that the TV mount may flex and you may have to strengthen it.
I found from builds I have done, to overcome full frame flex, I cheat by putting motors at the front to help support the frame. But behind seat is best option overall.
I though with the TV being the extra high part in weight, it would make sense to motion it from that point.
I recall @nclabs , I think did that with a 3 screen rig, mounting the actuators at the front behind screens.
Anyhoo, prove me wrong!

@bsft

Thanks for your input. It might sound silly but are those worm gear drives going to handle moving me okay? Is it even possible to add more then 2 motors eg 2 at shoulder at rear and 2 at front as per your tv idea? Would this benefit in any way?

yes 2 of those motors will do it, heres Lees with 25:1 boxes, but internals are plastic. So under great strain they may fail over time. Although I have not had that issue.
Shoulder mount at rear.

however he chewed out gearboxes, so I suggest 50:1 or 60:1 with yours as the internals are metal.

these days he uses 3 projector screens, and really sets the profile to throw him around.

wow....that is AWESOME.

which video?
stronger gearboxes are cheap insurance for longer life sim action

well both to be fair. But love the 3x projectors for the lack of bezels etc while his actual motion from first video looks really cool as well.

Ive spent all afternoon reading posts on here and loving all the jobs. Every project seems to have their own differences of course and it's interesting seeing them all.

Ill definitely go for the stronger gearbox.

What is the Leaver CTC length? I mean what does that actually mean. Is it the movement the bracket off motor can move around?