Showroom DX - Compact Simulator

After lots of reading, planning, ordering, false starts and changing my mind as ideas evolved, I have finally commenced my DX Compact Sim, first as a 2DOF then my upgrade to 3DOF with assisted heave.

Motors http://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html
TGY-1270HV 40kg torque Metal gear Digital Servo w/ Heat Sink http://www.hobbyking.com/hobbyking/...igital_Servo_w_Heat_Sink_40kg_18sec_170g.html
Control boards http://www.pololu.com/product/1393/
Hall effect pots http://au.element14.com/bi-technolo...fs/sensor-hall-0-2v-20v-to-10v-pin/dp/2319662
HP Server PSUs: http://www.xsimulator.net/community/threads/how-to-modify-a-server-power-supply-for-12v.5774/

A sneak peak at the WIP results:





Version 2 with heave and surge - The 500x500 base frame houses 3 PSUs, 2 USB hubs, an amplifier and subwoofer down the middle, plus the Fanatec power supply, with the remaining small space used for the wiring loom and snap in loom connectors for the control box, which can be removed for easy servicing.




















Version 1 - Minimalist Compact design











Building my Compact Sim for VR

In the beginning planning phase I had a number of initial criteria for my project and those have grown.

The first is proper lumbar support. The seat from which my project takes its name, the first generation DX office chair, is incredibly well made, has a full frame and most importantly proper built in adjustable lumbar support. This has been my daily chair for many years and is still like new. The later generation DX seats did away with the proper lumber support and replaced it with a simple lumbar pillow.

In terms of other background criteria it is worth noting that I have come to sim building as a way to further explore presence (immersion) with the Oculus DK2 Rift, not the other way round. For me a motion sim is a giant haptic device. It is something that adds immersion and compliments a lot of other tech I am playing with in conjunction with the Oculus DK2 Rift. My aim is a compact but adaptable sim to test ideas related to Virtual Reality presence.

While I personally prefer cars and racing I have spent most of my rift/sim game tweaking with flight sims, as last year my 83 year old father was certified medically fit to fulfill his life long dream of learning to fly. He will inherit my current static sim once the DX project is complete but will likely continue to also use my more sophisticated motion simulator. Hence the DX compact sim will be easily configurable to be used for both flight and racing simulation, including easily converting between seat shaker and full frame modes.

Initially I had intended being sensible and follow in @bsft footsteps to basically replicate his brilliant Desk Racer. I actually started building it...



But then I thought 'hmm...what if' and things sort of got out of hand and followed on from there.

The first change was building materials, from steel to mainly aluminum, which I plan to polish when I am done.



My next bit of inspiration was to make the structural pivot post serve another function...by turning it into a built in subwoofer.









Sound deadening will be added later.

My next little trick involved adapting Big Block Chev billet alternator brackets as pivot mount points.




Next came the frame, which is 50x50mm box aluminum with 2 50x50mm angle caps either end.

Inside either end of the box section is 40x40x6mm aluminum angle, which braces the motor mounts and provides support for the anti-vibration feet on each corner, with other support feet mounted off the pivot post.





By this stage I had decided that while the DX sim was meant to be compact, small enough to remove the seat and fit in my Supra, why not try and squeeze in even more by adding a form of surge.

My aim is to trick the brain while using the Rift by slightly moving the controls to emulate surge. Below is the mock up so far, based on linear rails, which will incorporate height adjustable side panels for the HOTAS and wheel/pedals mounts.

I have ordered a couple of these 40kg servos to keep the control surge system compact, but as yet have no idea how I plan to set them up and drive them, so any suggestions are most welcome. I figure I can add more servos if needed. Please ignore the flimsy motor plates and arms in the pictures, they are just set up dummies.






At the moment I have some perspex as a base under the frame. It will be replaced by 6mm aluminum plate, once that arrives.

I have been collecting a bunch of other stuff to add further details once I finish off the basic frame and start on the electricals. While I am still waiting on some of it to be delivered, most has now been ordered so I hope I can continue the build without too many hold ups.

I will keep you all posted and look forward to you own 'hmmm...what if' ideas and observations

Yes @SeatTime the quasi surge is meant to simulate pressure on your feet and hands. I intend it to be used in conjunction with a sprung harness, as you have used on your sim.

I decided I would make the DX Racer a lightweight full frame but wanted to emulate what happens on a seat shaker, where the controls are separate from the sim and movement creates pressure via the controls. Will it work...I hope so, but it is an experiment.

I am also still toying with the idea of incorporating your innovative compact heave idea, I have everything I would need to do it but space is a bit tight.

Thanks @bsft ... it would not exist without your inspiration.

An action video is still a long way off @prilad as I am still messing with design aspects and won't even get to start on the electricals for a couple of weeks...but I promise it will happen!

I changed to aluminium for a number of reasons.

I am playing with the idea of a 'compact' and even portable design, so weight was one reason. My definition of 'compact' is can I design the DX Racer to fit in my Supra with a minimum of effort. I am a minimalist at heart!


Initially I planned 'neat and simple', as per @bsft original Desk Racer...but I just can't help myself when it comes to messing with stuff. So another reason for aluminium is aesthetics...I plan on polishing the frame to a chrome like finish, hide a lot of the wiring in the hollow frame and showcase it when I can't by using billet clamps and braided sleeves. That is despite the fact that I intend a removable cover, which means you wont see most of that until the cover is removed. Hence my focus has really changed from just putting a sim together as a practical experiment to compliment the Rift, to being a project in its own right. The downside, a delayed start, additional costs and a far more protracted build time.

The aluminium frame is actually bolted together and it looks deceivingly far more simple than it actually is. So the only welding was the centre post subwoofer and except for the universal joint I could have made that bolt together as well. It was just neater to weld it. I did need to fabricate the bar that holds the billet pivot points, but the bar itself is bolted to the rest of the aluminium frame. If I wanted to I could disassemble and actually flat pack the DX Racer frame into about 520mm x 380mm x 150mm.

Good question @ferslash, as I am currently pondering options.

I have both a Warthog HOTAS plus Saitek pedals and Clubsport wheel and pedals. While I really like all of them what I want to do is get away from my current unholy mess, where it is a real pain to swap between flight and racing sim controllers.




At this stage I plan having a quick release separate flight and racing wheel/pedal mount and may well end up with different pivot points for each, as the fanatec wheel/pedals are a good deal heavier. That way I could run the wires through each of the respective quick release posts and leave the respective pedals/wheel attached. I am mocking everything up as I am about to build both mounts later this week. Construction will be 40 x 40mm aluminum with a 6mm aluminium plate brace at the point where the wheel post would be and where the rail will be bent down for the pedal mount. The wheel mount plate will also be 6mm aluminium.

I am toying with the idea of the joystick being hinged on a second rail over the existing one, around the same distance a wheel mount post would be. I could then have a quick release to allow it to tilt up and to the front of the sim to aid getting in and out. I am a bit over swinging my leg around the fixed joystick in my current setup, but do still want a center mounted joystick. The only problem is that I won't be able to check out hinge options until next Monday. In the meantime I am just kicking ideas around using the bigger pin hinges I already had for a heave plate.

After kicking around different ideas for mounting controls I have gone with a movable center post that will mount the Warthog joystick when folded down and the Clubsport wheel when folded up. I will run USB cable through the main tube to make it simple changing control systems and pedals from flight to driving.

The pivoting center bar is rounded for clearance when folding, but also acts as its own stop when pushing it back to the upright position. The pivot hole has a 10mm aluminium reinforcing tube.



I then made up the main bar and 6mm brace. At the moment I have some steel washers on the pivot bolt between the folding bar and reinforcing plate, but will replace those with teflon.



Here is the center wheel post upright position. I still need to make the base for the Clubsport wheel but won't do that until later, as I have yet to determine the final length of whole moving assembly. I am still waiting on the servos to arrive that will drive the quasi surge system and have no idea yet how I will be mounting and attaching them to the control assembly, so have deliberately left the main and foldable bar a little long.



And folded down for flight controls, which will then support the Warthog joystick, I just need to cut the round base plate for it.



The 6mm aluminium plate that will form the inside base has also arrive today, so if I get time tomorrow I can ditch the temporary perspex I have in there at the moment and make up the permanent base plate.

Thanks @bsft, yes I have left the final post mounting and pivot point adjustments until I finish this part of the frame and balance it with the controllers/self in place. The Fanatac controllers are very heavy and further down the frame than the Warthog joystick, so I do expect two different balance points.

What time I had today was spent making the small but critical multipurpose bracket to mount the Clubsport wheel/shifter and allow quick release and change to the Warthog joystick, which pivots out of the way for ease of access.

Here is the post in the upright position with the new bracket attached.



And in the folded position.



I spent ages fiddling about with the Clubsport wheel/shifter bracket and attachment. The whole assembly is removed via two quick release screws.




Unfortunately the quick release screws I have are a tad too short, but I hope you get the idea, undo the two screws and remove the whole wheel/shifter assembly.




The bracket for the Warthog joystick was much easier, it is 6mm aluminium drilled and attached to the joystick via the original Warthogs screws. I added two 8mm tapped holes which is how it is attached to the pivot mount bracket. Again I will use long quick release screws but don't have them yet, so I have a couple of allen bolts in here at the moment.



Operational position.



And tilted forward for ease of access. The shape of the pivot post is such that it is its own natural stop and will not go further than in the picture.



I hope the whole idea of a pivot post with quick release controllers makes a whole lot more sense now.

Of course what I have done is sill provisional, as I don't yet have the servos to work out how much quasi surge movement to allow for. I think I have left enough but time will tell.

@ferslash I adapted billet alternator brackets made for a big block Chev motor.