3DOF or 5/6DOF race/fly sim

I am starting this thread to kick around some ideas and have the community perhaps help me decide which route to take.

I want it to be a racing sim first and a flying sim second, traction loss is optional but welcomed. I have also been looking into platform sims since that is basically what my desing would be.

The best sim for racing and flight would be a 5/6 dof without a doubt. But it really comes down to your ability to build it and your budget. 3/4 dof is all you really need for racing though and its okay for flight as well, just not the best.

3DOF platform?



@SilentChill 3DOF with moving pedals and steering

I personally use a fast moving 3dof platform with heave. I could easily implement traction loss too but have yet to do so because I don't really feel its necessary for me. The feel of the sway of the platform along with the sound of the tires loosing traction is enough for me to tell when I'm loosing it.

Thank you, this is what I wanted to hear, what motors are you using and what is your payload capacity.

I am still not sold on the shakers , don't get me wrong I would like to have them but my priority is the movement in the Sim and want to save all the money for that, later I can add it to the Sim.

I’m using dc motors I think are somewhere between 600 and 1000 watts on a gearbox that reduces the rpm to 68. I say I think because the place I bought them from claimed they were 1500 watts but there’s no way. I have a motor that is exactly the same dimensions from the same manufacturer on a different gearbox I bought from someone else where it’s claimed to be 825 watts. The manufacture states 900 watts is the largest motor they put on them though so I really don’t know for sure what mine are since they do customize them somewhat to their customers needs. My guess though is they are 825 watts if that seller was correct in his statements.

What I do know for sure is that they are 12v motors and I can run them fine with sabertooth 60x2 motor controllers that are capable of 120 amp peaks. However, the motors are no longer available for sale in the United States from the only distributor I found that carried them. I had to replace the gearboxes output shafts with my own machined shafts anyway that ran me over $100 each.

I use a proprietary compensation system for the heave weight that greatly increases the speed of heaving the platform. However, I can still only use my rig for a little more that an hour or so on average (with Dirt3 for example, only 30 to 45 minutes) and then I must let the motors cool down for 20 or 30 minutes. I’m already using water-cooling on them so I really need them to be 24v motors.

If my dreams and ambitions come true, I am going to start importing some myself in a 24v version with the correct gearbox shaft in the future for use on a commercial simulator. I must make a substantial minimum order though so I’m not quite sure how to proceed. I have been considering a kickstarter campaign as a possibility.

My thinking is similar to simexperience where they sell starter kits to full-blown simulators. I think I will be able to sell a 3dof starter kit for half the price or less of a competing dBox system and it will have substantially better specifications. It is capable of producing fine tactical vibrations as well as 200mm heave, +- 15 degrees sway, and +20 and –15 degrees of surge (actual max heave from end stop to end stop is 275mm but you must use less). I believe the actuators speed is greater than 600mm per second but I have not done exact testing as of yet. Unloaded the math says they will do almost 1200mm per second. However, due to my proprietary weight compensation system and my actuator design, tactical vibrations are not tied to the maximum actuator speed.

Attempting all this has not an easy endeavor however so don’t start holding your breath waiting on me.

Btw, with me on it the total platform weight is 300lbs but it should be capable of 350lbs or more (just haven’t had anyone larger than my 185lbs on it yet) at a slightly reduced speed.

Edit: I forgot to mention that I can use full heave, full sway, and full surge at the same time. One doesn't impact the others motion.

Do you think this place http://www.wms1.com/wms1/index.html will have a motor I can use?

Probably but you will need a gearbox also. When it comes to heaving its more about a strong gearbox or actuator than the motor itself. Worm gear motors just wont do the job from my experience.

If you come across a DC motor and gearbox that is readily available for purchase that can be used for such platform sim, let me know.

Look here for a gearbox (reducer) http://www.surpluscenter.com/shop.axd/Search?keywords=gear+reducer&page_no=30
There should be something there that should work for you according to the specs. although I use something different which, like I said, is no longer available (probably because of complaints from customers because the specs stated were not true). I would probably try one that accepts a standard 56c frame motor that you can find almost anywhere.

ps. It looks like you will have to run them at double there rated speed however in order to get something close to what I use. You would need a 3600rpm motor instead of 1800 and I recommend you go with 24v if at all possible also.

If I went with a platform sim, what advantages would 4 motor setup in a square pattern be over a 3 motor in a triangle besides perhaps faster response and ability to hold more weight.

Since you only ask for advantages the only one I can think of besides what you mentioned is that your platform wouldn’t have to be quite as strong as far as twist is concerned. I can think of several possible disadvantages however.

Hi @BlazinH , don't want to drag this too far off subject, but have you measured the current to your motors under load to maybe get a better idea of their size/quality? As I have been getting some surprising load carrying results from just 350W rated motors.

No I haven’t. I have a millimeter that is capable of 10 amps but I have never bothered to get a shunt to test with. I don’t know why I haven’t just ordered an amp meter/shunt combo from ebay because they don’t cost much.
I will order one so I can see what amps I’m drawing since I have been telling people I don’t think smaller motors would be large enough for a platform assuming mine are 800 watts or more.

2DOF wasn't included in the title but i'm about that start on a 2DOF rig and wonder if i should build it with the option to add yaw later?

i personally don't think yaw is a big deal for fixed wing planes (my main interest) but i could see it been nice on helis and cars. what do you all think? is yaw a big deal or is 2DOF enough?

thx

sorry, what is 'reaching traction loss '?