Sean's Open Source Sim Racing Pedal set-

I designed these pedals because I wanted something better than the plastic boxes offered by logitech, fanatec, thrustmaster etc, without spending $1k USD for the high end pedal sets. These are a compromise between realism, complexity, available off the shelf parts and cost. They are a clean sheet design and 100% by me.

How much $, and who are these for-

If you are very handy, resourceful and can 3D print, you can put a set together for around $350. The steel parts were just over $200 shipped from sendcutsend.com in october 22'. These are not intended to just be bolted together from off the shelf components by a non-technical person like a lego set, these are quite DIY. You should be capable of figuring out the pinout of your wheel base pedal connector and how to make a simple harness to go from the pedals to your wheel base, or to a leo bodnar controller. You should know how to use a file and a tap and die, you will need basic hand tools and a drill or drill press. You should know how to solder and populate a simple circuit board with caps in the correct polarity.

The pedals-

All 3 are load cell based, but the clutch and throttle are positional, not pressure sensing as the brake is. They are designed around 10ga(0.135") laser cut steel parts, they are chunky and heavy. I designed them to be used with shoes-on, around my size US-12 feet. Between the pedal face adjustments and depending on where these are mounted in relation to your “car's floor” they should accommodate most everyone. In the middle pedal pad position, they are about 9.25" tall. All 3 are adjustable in spring rate, pedal travel, pedal tilt angle and pedal height. The clutch features a regressive spring rate swingarm to simulate a real life pressure plate spring rate curve. The brake uses a stack of polyurethane or silicone bushings with a take-up spring to simulate hydraulics. The bushing stack can be tuned to anything from long stroke mushy soft like an ancient pro-touring classic car to short stroke and rock hard like a modern GT or prototype, or anything in between. The brake uses a 200kg load cell, which with the angles involved and the pedal ratio, make the brake capable of measuring up to 342lbs at the pedal pad face, and you will not cause permanent deformation to the load cell until well over 450lbs. I have stood on the brake with my butt off the seat, they should be gorilla proof.

All pivot points ride on sintered bronze bearings and stainless steel shafts for reduced friction and longevity. I've included options for shim washers to tune every last bit of side to side slop out if that bothers you like it does me. Built correctly these pedals feel like they are welded to ball bearings, they are solid. They use all metric hardware(m3, 5, 6 and 8), but you can substitute SAE if you are a wierdo, everywhere except the heim joint and rod on the pedal arm.

Included in the files are gerbers and plans for a load cell amplifier for each pedal. The amplifier is a low power INA122 and requires as little as 2.2V to operate. Simply feed the board anything from 2.2-36v DC and a ground and it will output a DC voltage from 0-supply voltage based on cell load. The board outputs on either a 3.5mm headphone jack or a 3 pin header. You can purchase headphone cables on amazon and wire them to a common connector for whatever wheel base or USB board you are using, PS/2, RJ12/45 or DB-9 for example. The circuit has a built in low pass filter to eliminate noise from the cell, and has a 10 turn pot gain adjustment to dial in your output voltage.

I recommend 3D printed parts be done in PLA/+ or PETG. Lots of walls or completely solid. The parts were designed around 0.2mm layer height and a 0.4mm nozzle. There's no reason you can't print your own brake bushings in TPU although I have not tried it. Files will be included to print base and pedal arm spacers to save money on aluminum spacers but I have not tried them and cannot guarantee they'll hold up, although I don't see why they wouldn't. Printing at 0.5-0.6mm layer line width will help layer adhesion dramatically.

Sourcing tips-

The BOM I provided has links to the site(mostly mcmaster carr) with the most info for that part so that you have the info to find the best alternative available to you. I would not buy most of the parts from mcmaster, as they are expensive. You can find most of the hardware on ebay and amazon, or locally at the hardware store, see “alternative” column on the BOM. Most Ace hardwares have a surprising selection of springs.

Components are cheaper in bulk and a lot of the parts I used come in packs of more than you need. Maybe organize group buys on a forum. I may offer parts kits in the future.

Also the more of the same file you order from a laser shop the cheaper each individual part becomes. For example if you just order a single set of steel parts for yourself, order 2 left side base plates for each base instead of the left and right I've provided. The left side plate holds the load cell amp, and is otherwise identical to the right, and ordering 2 lefts is about $5 cheaper per pedal than a right and a left. The right will just have a few unused holes where the load cell amp goes.

If 10 people got together and ordered 10 sets worth from sendcutsend the price goes from about $200 a set to $140 a set, plus whatever shipping to distribute amongst yourselves.

The Bill of materials is a live document and will be edited as information and supplies change. Therefore it is not part of the downloads here and can be found on google documents. You can download it from there and add it to your files.

If you like my work, and want to help out, you can find a donate button at the top of the page.

While these are open source, they are not for commercial use. Remix culture and group buys are encouraged, build them for yourself, share pedal pad face designs, redesign for 11ga, redesign for pots, poly bushing sources etc. But do not not take my designs to build and sell. 

I will be adding things as I come up with them(instructions, workarounds, alternate sourcing), and some source file information for those looking to make their own pedal pads, etc as I get time. If you find any mistakes or information that doesn't make sense please notify me.

Zip file contains all the files in the V1.0 release.

Changelog-

12/2/22- V1.0 10ga uploaded

9/4/23- missing stls added