3DOF on a budget

Getting there slowly. I currently have the 2dof working and tested using LFS.

In the beginning



I have used two cruciforms for the base.

The swivel is accomplished with a heavy duty marine steel boat swivel plate.






The seat base is a 3mm galvanised steel plate with a 2mm stainless steel plate acting as a leaf spring. Whether or not I needed the latter is debatable but it was in my workshop (big shed), so I decided to use it, notwithstanding I needed to add a spacer to overcome a lip on the universal joint.






The motors are 150w golf trolley motors I sourced from a manufacturer who has stopped using them, got them at a good price!
The potentiometers for the feedback are 10k high quality wire wound I sourced from RS Components.
The flexible couplings are off eBay.




This picture shows some testing of the linkages. I used JRK's as they will provide 150w no problem with more briefly if cooled well enough, as you will see later.



Full back.



Full forward.



Full left.



Full right.



The JRK's, heat sinks applied to both sides of the circuit board. The logic being that heat will be emitted from both sides and thus it will help with cooling.



These are the server power supplies I am using. One for each dof, over the top maybe, but they are cheap and easily modified, without opening them, by connecting several pins together to activate them.



I have since modified the linkages as I was getting different angular movement between fore/aft and side to side. I have reduced the output arm to 20mm from centre and the input to the seat base is 160mm. This gives an 8 to 1 reduction in movement and a corresponding increase in torque. By modifying the seat base hook up point I now get +/- 10 degrees all round.



The motor cooling fans, a bit of bling, unintentional as I order them off eBay without looking carefully.



Here I show the back of the housing for two of the JRK's. The holes allow air to enter just over the cooling fins.



The other side of the housing showing the extractor fans and incidentally the usb hook up cables.

I am using a small notepad for the Game Engine connected to the Game Manager computer via crossed Ethernet cable. The main reason to ease the load on the main computer as I will be using Oculus rift for better immersion.

This is still work in progress as I have to do the third dof and tidy up the wiring etc.

A bit remiss of me not to give some background thinking and requirements for the seat. I have built and flown radio controlled helicopters, jets and all manner of conventional aircraft. I have flown paragliders, so you would be correct in thinking I am a frustrated pilot. Due partly to age and mostly to cost the idea of learning to fly for real is a non-starter. Having purchased an Oculus Rift and entered the world of VR flight and then visited a simulator show and experienced a motion seat, I had to have one. The cost of the seat I tried was prohibitive so next step was t0 search the web for DIY and behold the this site. So the requirements for the seat is Roll, Pitch and Yaw for flight primarily with the added benefit of driving simulators. I weigh in at 110kg and the seat weighs in at 12kgs. I have yet to attach a means to mount steering and pedals so that will add weight. With the current limit set to 20amps on the jrk's it seems to work fine so far, time will tell.
Back soon!!

Some information on the kit I used.
Motor:
Model MY6812 12v 150w DC Motor & Gearbox
Motor rated at 2500rpm on load with a no load speed of 3400rpm
Gearbox17 to 1 ratio, to fit 12mm axle
Overhaul length 190mm, max dia 150mm

Motor Mounting:
Heavy Duty U-Bolt Clamp (exhaust clamps) along with 2cm square tubing.

Linkage:
Track Rod Ends Female Right Hand R/H 8mm
8mm threaded rod along with 8mm i/d steel tubing.

Potentiometer hook-up:
Flexible Shaft Coupling CNC Stepper Motor Coupler Connector

Motor output arm:
Mild Steel Flat Bar
Bright Mild Steel Metal Rod 12mm
The bar was turned down to mate with the couplers
This is where welding facilities come in to attach them together.

More to come, when I have a minute.