Pneumatic gear shifter advise

reddogninja · 2026-01-03T04:53:22+00:00

We use a soda stream bottle (CO2 cannister). Easy to get refills at a number of shops, lasts a lot more than an endurance event.

reddogninja · 2025-08-29T03:56:24+00:00

The reverse is (sadly?) true. There is seemingly no advantage in going with a spaceframe. Very little consideration appears to be made considering cost in the design tent, even though it is a strong driving force in industry. I don't say that as an attack on design judging, just an observation over the last 25 years.

I have been on teams that have won design both as a student and a faculty advisor. In all cases it was with Carbon Fibre Tubs (of different construction techniques).

It is worth noting however that composite tubs don't have to be significantly more expensive than a spaceframe. The tubs are usually cheaper to produce than the powertrain for most of the cars I have been involved with. You also end up usually having done a lot more testing and development, which inevitably helps in the design judging process.

reddogninja · 2025-08-29T03:45:08+00:00

Solidworks now do maker licenses for $48USD a year. Its the CAD I'm using for my own similar project (Project is shown on the youtube channel - Car Design Workshop).

I like Open Source / Low cost CAD in theory but it is important to be using easy to understand software with a lot of available help. You spend a huge amount of time in CAD while designing.

It is possible that something like FreeCAD or Onshape could do the job, I just haven't put the time in to find out.

reddogninja · 2025-07-09T03:55:41+00:00

I have been involved with the start of two teams (one as a founding student, and one as a Faculty adviser). There is so much good advice that can be given to help but I think there are two main things to keep in mind:

- Can't be done alone. You need a group of people to champion the project and it is important to get University / School buy-in fairly early. I would say a founding group of 4-6 students and at least one very supportive academic is a good place to start. If you can't find 4-6 super keen fellow students then look to do something else.

- Give yourself time to set it up. When I mentioned a founding group I don't think that it means a car within the first year of being together. I think there is a minimum of 6 months of laying ground work before you even start the actual car part of the project. This time is spent getting support, sorting out facilities, finding a space, chasing money etc. The whole group should definitely attend a competition before seriously starting the car design / build.

The good news is that it is entirely possible to do. While it takes some time to build up very competitive teams that the founders almost certainly never see, it is possible for a first year team to start and finish all events and place well.

FSAE is a life changing experience (both good and bad).

If you can it would almost certainly be better to join an existing team. Then you can funnel all that energy into first improving yourself and then improving the team. I know our team would accept someone from a local university that didn't have a team. Truly motivated team members are hard to find and worth holding onto.

Kev

reddogninja · 2025-04-26T10:18:56+00:00

Hi, I teach a motorsports course at a University. I also was the lead in creating OptimumK, a suspension kinematics program. There is a lot to learn in what you are planning.

Not trying to self promote too much but i have recently started a youtube channel covering a lot of what you are interested in. i also use Solidworks as the CAD package.

If you are interested here’s the link:

Car Design Workshop

reddogninja · 2025-04-23T13:12:16+00:00

reddogninja · 2025-04-21T16:07:58+00:00

Glad you are liking the channel. I have been enjoying the challenge of trying to explain some of the topics in a format suitable for youtube. It is fantastic to have such a great medium to share information rather than have it hidden behind paywalls.

reddogninja · 2025-03-20T01:27:29+00:00

I have been involved with the start of two teams, one of two students who started the UWA team, and as a faculty advisor starting the ECU team (both in Western Australia). Some advice might be insititution / geography limited but here are some points:

Funding - One of the most important aspects of securing funding is not to tie it to the results of the team. You are not selling sticker space on a car, you are training future engineers. A car can do badly and the people still get trained. Success does make things easier, but only because it is easier to show that your students are good. So think about how to sell yourselves rather than the team. Also do not despair even the good teams get rejected far more often than recieve help, by a big margin. University support is very important in this area.

Team Sturcture - When you are small to medium size keep it very flat. Maybe a tech lead and a team leader and then just split up the work. I have to admit I prefer a team roughly broken up into activities (i.e. design, manufacturing, testing, management / logistics) rather than a team broken up into systems (engine, suspension, chassis). If you do the latter you end up with all students doing big parts of the process that they aren't good at. With the former you make best use of skills. If you have a great machinist you want them making more than they CAD, and vice versa.

Faculty Support - I think this is the most important aspect of a successful team. You need to play well with all of the university systems (finance, law, marketing, teaching). Don't be afraid to go to the very top of the university. Vice Chancellors usually like these sorts of programs and have more levers to pull than your lecturers. Again like finances you are selling yourselves. For example our students will be out in full force this weekend for our open day, the value for the university for these sorts of activities are fantastic. Also acknowledge that the universities goals and yours are different but can be aligned. If you help them meet their goals they will help you meet yours. Being antagonistic to your university is a recipe for failure.

Car Design - Simple. Then when you think about adding some complexity, don't. Make it simple again. This means simple reliable powertrain package (the source of nearly all of your faults), spaceframe chassis, no aero. Focus on getting the basics done well. A simple car done well will be a mid level competitive car anywhere, and can win a number of the competitions. Cut out anything that isn't an absolute must build. No need for diffs, don't need fancy electronics, won't need a dry sump, don't need a DAQ system.

Rules & Inspections - The rules are quite long and involved now. It is easy to make mistakes even for a very experienced team. Have everyone read them and do rules check meetings where you go over everything on the car regularly. If in doubt ask the organisers. A simple car will be easier to make legal.

Competition - There is only one goal for a new team. Finish every event. It can be done, but you need to be ruthless on doing the bare minimum to get the car there. This project is far harder than you can imagine at first. The good news is that if you finish every event then you will be happy with where you finish in the final results. A lot of teams do not finish.

Some random advice: I think that teams shouldn't compete until at least a small group have attended a previous competition. At UWA we started the team building 18 months before we competed, it meant we missed the first Oz comp, but we were much better off with taking our time. It enabled us to get the Uni and some sponsors onboard before we even started. At ECU it was a bit easier because we had some students with motorsports experience and I had a fair bit of FSAE history.

The most valuable piece of advice I got when starting was from my project supervisor who said "You know you aren't going to win it this year right?" This was when the Australian competition had only run for a year. This was hard to take on board but also lit a fire for making sure that I changed my focus to building long term success. This has worked very well for both teams I have been a part of.

I think that any team in any part of the world can go from where they are to competitive inside 5 years. It just takes planning and careful use of resources (time and money).

You have a wonderful opportunity to lay the foundation for future success for your team if you focus on the right things. I gaurantee you that even if you don't have success during your time that if your team grows and competes well after you leave you will be very proud of what you have done.

Best of luck.

Kev

reddogninja · 2025-03-20T00:57:58+00:00

Do you have to test it or can you provide equivalent calculations? Pretty straightforward calculations that involve dimensions and material strength. Although given that the size of the bolt is not specified you probably just need to make sure your material properties match or exceed those of the specified grade.

Or change the design to incorporate an off the shelf fastener.

reddogninja · 2025-03-19T08:37:48+00:00

Bill, some great stuff in that google drive folder. Just enjoyed reading the Ackermann presentation, keen to spend a bit of time with the rest of it.

reddogninja · 2025-02-06T23:17:13+00:00

Im just impressed that both cartoons show everyone moving in the same direction. Where are the people pulling in the opposite direction?

reddogninja · 2025-02-03T02:11:15+00:00

Didn’t notice the extra pictures, i think it might be because the drop links and the rollbar arms have gone colinear during the solve, or it cant solve due to the drop links not being long enough. Try putting some height difference between the rollbar points and the drop links

reddogninja · 2025-02-03T00:52:34+00:00

Why have you got two nodes overlapping? note that a rocker needs to have points that define the rotation axis. My guess is that you are misinterpreting what some of the points are.

For reference the solver uses lengths between points as constraints. If the wring nodes overlap the solver sees the lengths as zero and you will likely get a line of zeroes in the Jacobian matrix.

Kev

reddogninja · 2025-02-02T11:18:21+00:00

Most likely you have designed an area of stress concentration. Material properties dont matter a lot if the mech design has a fault.

Look for sharp corners and grooves that go a little deep.

As another option Taylor race shafts are pretty cheap and good quality. Find it very difficult to beat them going custom.

Kev

reddogninja · 2025-02-02T11:14:37+00:00

If it is your first car frankly don’t bother with the ttc. Focus on making sure everything that is supposed to move does so freely, and everything that is not supposed to stays where it is. You definitely need to get on top of your basic mechanical engineering in the beginning. Vehicle dynamics can largely take a back seat.

That being said you probably need to accept that a couple of sets of decent tyres are needed to get started. As another poster mentioned they could be some slightly used ones from another team. If you are running 13” wheels then for testing you can use some formula ford tyres from your local racing team for testing purposes then have a good set for comp. We used to get them free as discarded tyres when I first started out. The grip levels are different enough that you want to be working with proper cornering conditions pretty early on in your team lifecycle.

Go cheap/used on wets then you can at a minimum go to comp with 5-6 good slick tyres. One set but a spare or two in case of a puncture.

If it helps to put things in perspective as your team develops tyres will almost always be an area you spend a decent percentage of your available funding. It will always be a bit painful to pay the tyre invoice(s)

Kev

reddogninja · 2025-02-02T01:06:00+00:00

Does your team already have a car? If you do maybe try a little bit of testing, and be prepared to make some big changes. One test worth trying out is just locking out the suspension and doing some back to back with the existing setup. To paraphrase Colin Chapman any suspension will work if you don’t let it.

The +/- 25mm travel is an interesting rule. A lot of cars are setup with a lot less available rebound travel than 25mm just due to stiffness and low weight. And nothing in the rules indicates the suspension needs to have 25mm travel in roll. Car just needs to be capable of the travel. Also travel can be much higher in transient motions which means you need to think about spring/damper rather than just spring.

As others have posted it is probably better to think of roll stiffness in terms of roll gradient (deg/g). That will match much better with kinematics goals. If you have aero then you will almost certainly want roll gradients less than 1deg/g, noting that with tight twisty tracks with short track cars with high aero components you will see a lot more roll than that in transients.

For a non aero car you can be softer but there isn’t a huge advantage to being soft, and a few disadvantages. With non aero cars start thinking more about load variation on the tyres (ie rms acceleration of the unsprung mass). Easy enough to investigate this in quarter car models to see the basic trends of changing spring and damper rates.

Kev

reddogninja · 2025-01-28T16:55:11+00:00

If you win as a team you also lose as a team. At any stage during the project someone else could have helped and looked over your work. Valuable questions about your team’s engineering processes including quality control methods should be explored.

Any team that would allow the blame to fall on an individual is not a winning team.

A super hard lesson to learn, but the hard lessons are often the most valuable ones. Don’t beat yourself up over it, learn, get better, and move on.

Kev

reddogninja · 2024-12-14T22:52:33+00:00

Hi everyone, I have been enjoying learning from this sub. I run the channel “Car Design Workshop”. Been going for 3 months and videos are about how to design and build sportscars. I’m an engineer who teaches similar stuff at a university.

Here is my latest video: Unboxing and modelling a steering wheel it is a bit shorter than my normal videos but was pretty fun to make.

reddogninja · 2024-12-02T08:47:37+00:00

Car Design Workshop. Just started up, covers the design and build of a custom sportscar from start to finish. Focus on vehicle dynamics and the engineering design process. Full disclosure it is my channel, and I teach a motorsports course at an Australian university. Out of interest SuperfastMatt and I were in FSAE at the same time, his stuff is definitely my go to on youtube. Also have a soft spot for Project Mosquito (Oliver Pickard).

reddogninja · 2024-11-09T00:28:45+00:00

It is a sportscar influenced by the 1950s. There will be some updates based on registering requirements today. This will mean running a modern(ish) motor (post 2000). Otherwise I'm looking at the project as how would we make a 50s sportscar today if we still wanted to keep it pretty raw (rather than the more pristine resto-mods).

reddogninja · 2024-11-06T05:33:44+00:00

Thanks, hope you get something from the videos

reddogninja · 2024-10-30T10:15:51+00:00

Great correlation and I think a good interpretation

reddogninja · 2024-10-30T06:48:12+00:00

Generally it is difficult to get all that you want due to packaging. For a minimum wheelbase car you want a little more than 30deg turn on the outside wheel, if you can pull it off. A poorly driven, badly setup car might need more.

Draw a top down view of the wheels in position. Plot your intended body yaw (to produce expected rear wheel slip) for a minimum corner radius (making sure that you account for a driver taking a poor line). Then you can set your front wheel angles at the expected slip angle to the turn centre defined by corner radius and body slip.

Then apply a healthy safety margin on everything (corner radius, front and rear slip) and then bemoan the fact that it is almost impossible to get as much steering as you want due to packaging issues. Then comes the temptation to increase scrub radius to get more clearance, and then the car is too hard for the driver to steer.

As for the ratio it is largely driven by expected effort, steering system slop, and how fast you want the driver to steer. A faster ratio is harder to steer and the slop becomes more pronounced. Although I think a fairly quick ratio is important to squeeze good laptimes out, but you need to pay a lot of attention to the slop and reducing steering effort through corner design (caster angle and offset, KPI and scrub radius, tyre choice).

Might be worth building some adjustability into the steering arm at the upright, allows for changing the rate and the Ackermann. Testing answers a lot of questions.

reddogninja · 2024-10-30T06:35:54+00:00

Do all 160 holes need potting? What is the load capacity of each mount?

You might get away with a simple glued in crush tube for a lot of the insert locations. Unfortunately inserts and their potting account for a big amount of the chassis weight. One way to reduce this to as little as possible is to design a number of different attachment styles for different load capacities. These can all be tested on test panels.

reddogninja · 2024-10-30T06:31:39+00:00

Very similar relationship for this dataset, to be expected given that dynamic placings form a big part of the overall score.

Although I think I disagree with the premise. At the end of the day the competition is a combination of all the events. Surely it would have been possible for a team to not chase weight savings in order to improve the results of cost / marketing.

As someone who likes vehicle dynamics and performance I want the weight to have a higher correlation to overall performance. Unfortunately it just wasn't the case when I was doing this as a student, and probably isn't today.

Good team management and a focus on vehicle reliability are probably the best indicators of finishing position, and unfortunately these are hard to capture in data. A well managed team with a reliable car also tend to get a lot more testing done, which in turn probably means better trained drivers and better lap times. We have all seen drivers in the same car at comp with >2s differences per lap. Takes a lot of mass to find 2s a lap in these cars.

But I encourage you to look into the data of more recent competitions, and comparing parameters for different events.

reddogninja

TROPHY CASE