2DOF Full Platform Flight and Racing Rig

Take 3 and all in.

The last thing I wanted to do is build a rig from scratch but alas, I've been unable to find anyone in the US to build one. The commercial options under $10K are limited and include the Blue Tiger ($7500) and the Atomic A3/A3 ($6500) but compatibility is questionable and there is very little information available for these rigs. If I were only looking for just a racing simulator, the SimExperience Stage 2-3 (starting at $3899) would have been a winner. I’m a bargain hunter but in the interest of time, I’m attempting to use parts and methods clearly documented at this forum. I believe I’ll come in well under $3K.

Thanks to bsft, yobuddy, and a ton of talented builders here, I "think" I'll be able to build a 2DOF platform rig for flying\racing. I've ordered the bulk of parts needed but no doubt, assembly will require some serious time.

I’ll try to include links and details to all parts used for this build along with enough information to duplicate the project. So far:

Static rig: I really liked the rSeat RS1 but its heavy at ~100lbs as is the VRC 1000. The Human Racing GT chassis seems to be one of the lightest and stable static rigs without an annoying center bar. For anyone considering the GT Chassis, buy it from Thailand (humanracing.com) and save $400 over the US distributor and it might even arrive sooner. ($1200 shipped). I’ll need to make a mod to add a HOTAS but should be easy enough.

Motors: 2 x 200w 12V motors from motiondynamics with 2 x 50:1 gearboxes ($610 shipped to US):
http://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html
http://www.motiondynamics.com.au/worm-drive-gearbox-to-suit-industrial-motors.html
I’m hoping no regrets on not buying these 32w 12V motors ($229 each): http://www.motiondynamics.com.au/12v-dc-worm-drive-geared-motor-320w-60n.m-54-rpm-clone.html
Controllers: 2 x JRK 12v12: http://www.pololu.com/product/1393 ($209 shipped)

Potentiometers: 5K Pots http://www.digikey.ca/product-detail/en/6127V1A360L.5FS/987-1393-ND/2620662

Power supplies: I bought 2 used HP DPS-600PB B power supplies. ($30 shipped for both)
($30 shipped for both)
Reference for using these power supplies: http://www.xsimulator.net/community/threads/how-to-modify-a-server-power-supply-for-12v.5774/

Unijoint : Found a pre-made unijoint for motion sims on ebay for $75.Driveshaft was my backup but would have required more work.
Controls : Thrustmaster Warthog HOTAS and Logitech G27. These are sunk costs and don’t count towards price - the G27 steering wheel is a bit loose and small though

To do :
Frame: I’m definitely building a platform and hoping to squeeze out maximum angle from the motors. Wood or steel is the question. I’ve already determined I’ll be learning how to weld for this… I’m more concerned about getting nice clean cuts of square tubing.

Display: I'll be using an Oculus Rift DK2 which is what drove me down this rabbit hole! With that said, I'm considering a large lightweight monitor with fast refresh (ideas?)

Rumble: Possible Buttkicker mini LFEs which are impossible to find right now.

All the stuff I haven’t thought about yet:

fusednova,
I'm going to order mine this week for my ckas type platform - it's in the build section...............with the RS1, 42" TV, Logitech Surround, mines going to come in a little under 7000.00 us.
the RS1 added another 1600.00 - expensive but beautiful unit....
I'm going to post more pictures as soon as I get the RS1 mounted and finished up.....I'm putting in on a diamond-plate platform top...going to look good.

Stay with it friend.

Tom

sit the frame on a length of pipe and roll it back and forth at the same time try to bend the frame, If it flexes, get is reinforced or make a frame to go under it.
With that much weight planned, its a curly one.
As you are using a rift, the immersion factor will be there and you will not need that much throw.
For 12v, I suggest 12v 200 watt worm gears with 50:1 boxes at least and maybe 45mm CTC lever, shouder mount at rear.
And the JRKs to run them.

There are many cheap 0.37kw gearbox motors on Alibaba that you can get for 300Usd the pair. Is better that the wiper motors jejeje

Im starting my 2dof sim like yours, and I bought SEW motors for a lot of money , but any brand of motor with 0.37kw, helical-worm gearbox with 30rpms output and a good VFD will do the job.

Thanks for the input - revised first post with all the latest changes since I've been unable to have one built.

The unijoint was just a leftover "made" part being sold by another rig builder ( http://www.paragalactic.com). Seems like a market for DIY kits may be emerging and no doubt, the Oculus will accelerate this movement. Even today, I think someone could make reasonable profit by selling kits for $1500 for frame, motors, controllers, etc.

It's very hard to find large monitors with a fast refresh rate. I guess racing doesn't require 2ms response?

Agreed. To give you an idea, I run 12v motors and jrks. They run at 20 ms refresh rate to match the simtools rate of 20ms. I get about vibrating changes 25-30 times a second on the motors with the heave force , thats a good vibration , feel the gravel, every single slat in the wooden bridge, the pothole on the left hand side of the road.
You will be fine with that. If needed, put some bass shakers on it to get real noise feedback
With construction, I use steel for the frame and wood for the seat and base pivot mounts.
I do recall someone ages ago had a static frame, then sat it of a big sheet of thick ply and motioned that. It worked well, but has some bad design errors with motor placement.

Ahh. - I was talking about a large monitor. Im hoping to mount a 32" to the platform (15-20lbs) but finding gaming monitors at 2ms isn't easy. Maybe screen refresh isn't as important for racing?

The Human Racing GT Chasis arrived today. Super easy setup. The rig is compact. Steady, and very comfortable. My only complaints are the lack of cable management and no options for mounting HOTAS. Easily solved but will take time to make mounting plates.

oh sorry, refresh rate good but not vitally important, depends how fussy you are. I run 50hz LCD tv with no problems, 8.5ms refresh I think.
And as for mounting TV with frame, mount motors at shoulders at rear as even with a balanced 2DOF, the tv adds quite a bit of high centre of gravity weight.

Thanks for the info on the monitor. For this first rig, I've decided to weld up a single monitor stand on wheels and not attempt to press my luck with the motors. It will be the first welding project and will certainly be nasty looking!

I've already hit my first snag of sorts. My motors and 50:1 gearboxes arrived from Motion Dynamics. The new gearbox seems to fit well enough even though the motor has 2 screws but the new gearbox has 4 holes. I assume using just the 2 screws is fine but my question is regarding the plastic "coupling connector" that sits between the gearbox and the motor. Is the plastic connector a problem or should I attempt to swap it out for metal?

Thanks for anyone's input!

That plastic Flex connector or what ever you want to call it is fine, Only if your doing thing's WRONG will those break. (so ive been told)

Ha - well there is only a 50% of me doing this wrong But I may not get that far with this motor\gearbox:

The holes don't actually line up enough to seat the gearbox by at least 2mm (it looks worse in the picture). Ideas? Widening the hole on the gearbox seems too risky.


Another problem is how do I attach a rod end to the solid bolt? Drilling and tapping the opposite side for the pot seems easy but I cant tap this 20mm bolt for 10mm threaded rod.

not the easier to do.
I made a lever and ran a bolt through it, on and I drilled the holes out a bit more so they lined up.
With the plastic couplers, worry if they break. Then look for metal

The pot I just glued into the back in a drilled out hole, but in hindsight, I should have tapped a thread into it and then attached the pot on that

whats the diameter of that shaft on the gear box ? Any chance a large Flex coupling would fit over ?

20mm on the ones I used, The back of the shaft is almost flush with the gearbox housing , making it a tad difficult to adapt a pot to it.

I just welded a coupling for my pot onto the 60:1 gearbox (it is a steel gearbox unlike the standard motor 25:1 ). Drive shaft on the other side is connect via a fitted pipe with a key-way welded in and a threaded hole for a bolt.

Thanks guys! I'll definitely use one of these methods depending on what I can find.

Just welded today for the first time. It's an art to be sure. I'm not having a problem getting a solid weld (I hope!) but pretty is another story! I can draw a straight line but getting solder in a straight line is harder than expected.

This week I've managed to take the 50:1 gearbox apart, swap the bolt, and mount to the motors. For anyone using the same motors and gearboxes:

- Tapping out the rivets was proving difficult so I drilled them out with 3/16" drill bit (5mm will work). Fast and easy. Use some can air to remove the shavings before taking the drive apart.
- Once apart, the bolt slid right out and I reversed the direction to make it a left angle drive. This was 10x easier than I thought it would be.
- I purchased extra rivets from motiondynamics but I didn't even try using them in case I need to get back in the gearbox. I used #10 x 1.5" screws. 5mm x 35 or 40mm screws will work.
- A 5/16" drill bit (8mm will work) was used on two of the gear box mounting holes and now it fits perfectly on the motor.