4 corner D-Box style rig with wiper motors?

So I keep throwing around ideas in my head of how I might like to make a sim rig and I keep coming back to a D-Box style setup that moves the 4 corners of my full frame. Seat movers seem less complex on one hand (only two actuators), but more complex on another (u joint at base, balance important, etc). My rig is super cheap, but fairly rigid. It only cost me about $5 for the few bolts I didn't have as I had the spare 2x4s and karting seat already, so there was no cost there. It seems like it would be very well suited for actuators on the 4 corners, but the D-Box setup is prohibitively expensive for what I'm willing to spend.

My current idea is putting a wiper/window motor or something of the like at each corner like a D-Box actuator. I realize this would normally be an issue as 4 window motors would typically not like supporting the ful weight of me and the rig off the ground, but then I got the idea of "why does it have to?" My thought is that the rig would normally rest on the ground and the motors would only lift it during telemetry events. They might have to fully support the weight for brief periods (like hopping a bump or something), but these would be fairly short transient events. I would likely lose resolution for high frequency events and things like road noise, but I have a bass shaker on the seat to help fill that gap.

Is this idea crazy? Has anyone tried anything like this before? Seems like the worst that could happen would be reduced feeling on bumps so I only really get roll and yaw, but I think that might be enough for me at this point.

For what it's worth, I'm guessing the full rig with me included is probably only ~250 lbs. Though I agree wiper motors aren't the most powerful thing ever. I was hoping to find some specs to see what I could come up with regarding their strength. Maybe a wiper motor wouldn't be the best solution either, but some kind of motor/gearbox combo at each corner was the idea at least. I was thinking of SCNs originally, but they would be right on the edge of their ability if I got high power ones. I find it odd that there is no real alternative actuator to a D-Box. Not sure what sort of magic dust they sprinkle on them to get the power and speed they have over just about anything else out there.

Take a look at the Frex HyperAxis 100 actuators. These will lift 100kg. A good deal more expensive that wiper motors but also a good deal less expensive than the D-Box route. Look at making up a Prosimu type motion rig.

Hmm, that motor setup is probably even way overkill for what I need to lift, but definitely the idea I had. Out of curiosity, have you ever sourced a motor and gearbox like that for rough price/power estimates or have you just done the math?

All told I'd like to try to stay as much under $1000 as I can. I think I can do a 2 actuator seat mover for around that, so my target was to see if I could beat it. I had some window motors around the house already, so that was why I started kicking this idea around. I realize u-joints aren't that expensive, so I could potentially do a dual window motor seat mover, but I felt like a rig mover would be a little easier to work with due to the seat I have. The karting seat isn't really well suited for attaching things as it has a pretty low back and no mounting to speak.

Edit: As a side note, I also have an Oculus Rift, so a rig mover vs. a seat mover makes dealing with the relative motion a lot easier. I can mount the camera sensor to the rig and have it move with me easier than I can mount it to the seat.

Hmm, those are a slick setup in a nice little package. Does yours actually "float" off the ground so to speak? Seems like with high ratio gearboxes and powerful motors you could actually support the load of my rig fairly easily without burning up motors that bad.

As a reference, not that it's a terribly good picture, but this is what I'm working with. Thrustmaster TX wheel with the T3PA pedals and TH8A shifter. I think it was maybe 4 12 foot 2x4s to make the whole thing, so super cheap but pretty dang sturdy.

Have you got a picture of your setup? Does it "float" at the neutral position? I would think with the kind of power you have that you'd have no problem support the weight. I could probably use motors half that size and still move mine around fine.

Okay, I think I found your rig by using some common sense and looking through your posts. That is one compact setup! I think my plan this weekend is to corner weigh my setup to see what each motor would theoretically have to lift. As I have the advantage of a pretty long lever arm, I'm not sure I'll need as much force. Though I'm not sure how balanced my setup is either. I'm fairly sure it will probably be a touch rear heavy, but total gut feel would be maybe 60/40 split to the rear as the pedals and wheel are fairly heavy.

In scaling it out over the weekend, the bare rig looks to be around 60-75 pounds. I'd add another ~170 to that, so 250 is a pretty reasonable guess for the total weight. The rig itself is close to 50/50 weight distribution, but I realize it might change more significantly with me sitting in it and I didn't have a good way to check it at the time (need an analog scale for continuous reading, not a digital one).

I may have found another interesting motor source as well, though I need to do some more research on it to see what they are really capable of. Was getting some tools out of the garage the other day and saw an old garage door opener. Not sure if it's an AC or DC motor though. I know they run both directions, so I'm more leaning toward it being a DC motor despite the system plugging into a standard AC socket. Need to try to pull some part numbers off it when I get the chance. They are fairly strong motors to be able to lift a garage door (lifting one by hand even with the spring assist isn't trivial), so I'm optimistic it would handle the load, just not sure if a JRK would have enough juice to power it.

I could be totally wrong but i don't see how the 4 motors on the corners will provide any enhancements to the motion over putting a ujoint under the platform and using two motors. If you want to use the extra electronics and motors my personal thought is that adding the 3rd for traction loss and a 4th for heave or surge would give you much more immersion that the 4 motors, one on each corner.

Again, never tried a DBox setup but just my musings as to what you would get from that vs something like @noorbeast 's compact racer or @RacingMat 's platform style and i think you would achieve the same result with half the equipment and less power requirements.

For sure interested in opinions and thoughts as I dream up my next project...

I wasn't necessarily thinking of it in terms of better motion than other systems, more just that this one would be easier for me to implement with my setup. My seat isn't really well suited to a seat mover and with my Oculus headset moving the seat around without moving the camera that tracks the headset at the same time presents some new issues. If the seat moves relative to the camera it will cause my view in game to bounce around and tilt with the seat. Some people have managed to get around this with software tweaks that adjust the position in the code with offsets based on the sim rig's commanded movements, but that's pretty far above my skill level. The easier solution is mounting the camera to whatever is moving so my head stays in the same position relative to it (in this case the whole rig).

As for using just two motors and a pivot, I agree that that method would likely be cheaper, though slightly more complex in a certain sense. It would be easier because you have pretty direct control over your two axes of rotation, but at the expense of having to have an elevated rig that is well balanced on a single pivot. I need to look over the math options in x-sim and sim tools, but on the surface it seems like a four corner setup should be easy to program, just assign each motor to correspond to wheel travel on a car and tweak sensitivities from there (assuming the telemetry is present to do this in your game of choice).

The motor controllers seem to be the big expense at the moment. At $100 apiece they add up quick. If the garage door opener motors work out, they seem to be nice and cheap (~$30-40 for a 1/2 hp one), so I can get 4 for the price of 1 motor gearbox combo I have seen elsewhere. I have a few PC power supplies still sitting around the house I might be able to use to reduce the cost even further, but worst case if I have to go the server power supply route those are still only ~$30 each. Rough numbers would put me around $750 with all of that if I can't reuse anything I can find at my house.

A lot of this is just testing the waters too. I keep seeing stuff and getting ideas, but figure it's a good idea to see if anyone has ever tried anything similar before wasting time and money on it. Seen plenty of seat movers, but not many rig movers. I'm not sure I'd ever really seen a "4 corner motor rig" as opposed to a "4 corner actuator rig", so I got to wondering if there was a reason.

hey thanks for the detailed response.

I still think that...
1. your platform will need to be elevated to fit the motors under one way or another
2. a ujoint is $20-$50. Two extra motors a lot more. I cannot see the extra complexity. I can see it with the 4 corners
3. you need more power at the motors to actually lift as opposed to tilt
4. With a platform mover you can mount the oculus camera to the moving part of the rig. it would move with the motion just as it would with your 4 corner style
5. programming for wheel travel on track will not give you vehicle pitch and roll, or acceleration(surge). Basically only heave

again just brainstorming. Lots of room for error in my comments

I see what you mean. There would be a little more "programming" involved to get more of the forces involved, though I think that would be fairly straightforward (again, I definitely need to look over the software some more to really understand its capabilities before committing to buying anything). I had the same problem with bass shakers where I wanted independent channels for two different shakers, but it seems that's not nearly as readily available in the form I wanted in any software out there (ie. program X telemetry to this bass shaker channel and Y telemetry to that bass shaker channel).

As far as elevating the platform I had a few ideas. Originally I was thinking about it mostly being a tilt rig where the platform would sit on the floor with the motors beside it and it would only have upward motion (so sitting level would be my zero point and negative motion would be excluded), though I realize this would remove quite a bit of the motion. My plan is still to mount them on the side of my frame though, so I would still be quite low to the ground. I picture almost a direct couple between the motor lever arms and the frame, so no extension rods like a seat mover for instance.

I mostly don't like the u joint setup just because I have such a long frame and I'm just not that keen on the whole thing sitting on one point. It's hard enough to get in and out of the thing now (I know, it's my own fault since I built it), but having the whole thing leaning when "off" just seems like it would be a hassle. I suppose gas shocks or springs could help with that some though.

Motor power is certainly my main concern. If I was just tilting the rig (zero at the floor) I'm not sure I'm that worried, but if I try to support the full weight so I have bi-directional travel I can see why this idea isn't very often used. Sitting 4 motors at stall essentially to hold the weight up is a good way to burn them up, but I'm also wondering if I can't take a lot of that load off with clever gearbox selection. If I can get a gearbox that locks against back-driving with enough ratio then the motors would see next to no load for static weight suspension, though they would still have a moderate amount to move when commanded.

To make a platform mover I'd pretty much have to redesign my whole setup, so that's one reason I'm avoiding it as a first plan of attack. I've been trying to do baby steps to figure out what is "enough" for my taste (which will probably ultimately never happen shy of driving a real car, lol). Started with just a frame to hold the controls in a "car-like" setup, then added some bass shakers to get a little feedback. Added the Oculus hoping that would be the magic bullet, and while it has made things much better, I still wonder what it would be like with actual motion. Would be great to try one out before committing to anything, but not sure there is anything around me to demo (Kansas).

So you think this is the same as a seat mover?

I don't think so...

I'd Tried seat mover noorbeast style and foot mount, both with dk2. I prefer the sensibility of the foot mounted sim.

well yes i,m sure with the D box actuators it is good. I never suggested a seat mover but what i suggested was a u joint under a platform. I still from that video don't see what extra motion cues you'd get from d-box which would be absent from the same thing built with two motors and a ujoint . from what i can see in the video the range of motion would be very similar. I also still think that a more immersive use of the extra motors would be traction loss. Also this was a question of a wiper motor sim which i think will have a hard time lifting that weight.

I also said I could be totally wrong. Which is really likely.

Anyways can't wait to see what you end up building one way or another I like seeing new designs. I was only throwing out musings so i did not mean to imply something was better.

There is no way to do a dbox style sim with wipers. The more similar diy sim I saw was made with winches:

The prosimu t1000 works likely plus traction loss.

Check elevation of the seat on that kind of sims
Anyway, it is a question of personal taste, I prefer heave over TL, also I like to feel what is happening in the 4 wheels and it would be more sensitive with 4 motors than a cv and 2 motors.

Sorry if I sounded harsh, it wasn't my intention at all. English is not my first language so it can be difficult to communicate sometimes.

super cool and something to watch for. I'm planning to build something more elaborate in the future so I'm for sure interested in the outcome. Id really like to sample a DBox style sim so that i could compare against other designs. Anyways, lots of room for preference and opinion when choosing a style.

@mariano68 - Your sim looks like what i was thinking so if you've tried both the 4-corner dbox and yours i say you have much more experience than me on this topic.

cheers

So what exactly do you mean by there's no way to do a D-Box style setup with wipers? This is what I had in mind. I would build a perimeter frame to hold the motors and have the lever arms between the two frames. I would likely still have to do some kind of tie rod instead of the direct connect I was picturing originally due to needing some misalignment to allow the frame to articulate without binding, but that seems easy enough.