I'd like to share what I've done in making my own rudder pedals, having made the mistake of buying what I considered to be a "cheap" pair of Thrustmaster Elite pedals.
I modified the Elites as far as I could - gave them toe brakes, greased and freed up the mechanisms, re-fitted all the supports with bolts and spacers but the centring system on all plastic pedals looks awful to me - the centre detent and overall complexity of the systems on all plastic pedals made me long for the smooth response the much more expensive custom made pedals.
So I decided I'd try my hand at making my own metal pedals using materials I can easily get off ebay and local hardware shops and online.
Having bought all the parts in several different places, the total cost is a bit of a grey area, especially as I had one part refunded on ebay for damage, even though I was still able to use it and didn't need to return it. Anyhow, total cost is around £150 for the mechanical parts. This could be a lot less depending on prices for some parts on ebay - I could see some of the most expensive bits on sale in the US for just a couple of dollars but with lots of shipping, and the bearings I used could be purchased from China very cheaply.
I used Sketchup as a kind of virtual lego/mecano to piece this together. I'm no CAD or mechanical design expert, so the .skp file I have is a bit of a mess - more like a sketchbook of the design, with few bolts placed - but the main structure and dimensions are all correct.
I decided to use Unistrut as the frame because parts are really cheap, and they're easy to model in sketchup with a lot of parts already downloadable from 3dwarehouse. Another main component of the design is four CBR600 motorbike steering dampers. I got these off ebay for ~£15 each, but as mentioned, in the US they're *really* cheap. I scanned these in 3D using Autodesk 123D Catch, then imported them into Sketchup to help with working out the dimensions required.
I toyed with the idea of a cam based centring system but I couldn't come up with an easy way of making the cam myself so I tried a different method using a spring extended between the two arms of the steering dampers which move away from each other when the pedals are moved. This works to an extent - there's not much force in the middle, so there's no distinct centre. But there is a very smooth response of the spring at the ends of the movement, and I feel this will work well for aircraft control.
I think pictures will explain a lot more than I can in words, so here's a couple:
Still to do - connecting up the electronics and hall sensors. I'll be using a BU0836X (or one of the joystick boards I have lying around), and the sensors will be based on
LocNar's excellent looking Bic pen hall sensor pots
If anyone wants more pics or explanations of particular parts, feel free to ask and I'll take more pics.
e: oh yeah, the bottom struts are asymmetrical - for some reason the company cut me 550mm lengths in stead of 500mm. No bigge.