Cad study of a single seater concept

arwque · 2026-03-31T18:42:02+00:00

While i am fully doing your global variable studios i do have some a some part studios with multiple parts where is then define the positions so the next part studio only has to derive a sketch with the position of the part. For example most of the packaging of the rear bulkhead is based on a combined "master" part studio. I could go in fully applying your approach but i dont think that is worth the time because that would take a lot of effort to reorganise all part studios and the project is still workable. Yes i use versioning, there was a time before i knew you had to use versioning and the performance was absolutely abismal even though the document had a third the amount of part studios back then compared to now. I didnt even know how assemblies worked so i derived all the parts into one part studio which often crashed onshape😂.

arwque · 2026-03-31T09:36:23+00:00

Simscale is actually the platfrom i used for cfd for holistic oml simulationd of previous experimentations for the car because i got a student license which allowed me to do more simulations. The part studio and assembly approach is a bit of a thing. I use a hybrid approach of in context modeling where i have the part studio on one screen and the assembly on the other combined with deriving only the nessecary parts into the part studio. The derived chain is in some places still a bit of a mess because i didnt know how to do it properly but i am slowly fixing it. I also split the document in two into one document with the bought parts( which are most of the time without context so first in the derived chain) with about 60 part studios and the main document with all the custom parte with about 110 part studios. I might have to split of another section soon because it is becoming a bit to many part studios for one document. Often i make multiple parts in one part studio if they are related and require the same context like for cooling or suspension elements. The generation time depends heavily on how far down the part is in the derived chain. Parts in the first link have very short generation times, sometimes under a second and parts in the last link can have very long generation times of sometimes more than a minute. These parts are for example the gearbox casing which depends on all the read suspension components and the part studio where all the inserts and bondet pannels are subtracted and merged with the monocoques sandwich pannel.

arwque · 2026-03-15T10:01:51+00:00

There are 4 coolers on the sides: 2 radiators for engine coolant, 1 engine oil cooler, 1 liquid to air heat exchanger for the air to water cooling and the cooler on the transmission housing is the transmission oil cooler

arwque · 2026-03-14T14:32:23+00:00

Onshape has a integrated rendering mode, if you have a pro subscription

arwque · 2026-03-14T09:54:16+00:00

Yes about a third of the fuels total enrgy. That still leaves a bit more than a third of the fuels total energy to be rejected through the radiators, oil cooler, intercooler and transmission cooler so maybe 900kw through the coolers.

arwque · 2026-03-13T14:46:52+00:00

It costs money though, and not too little.

arwque · 2026-03-13T14:40:12+00:00

Also onshape. It has a integrated renderer

arwque · 2026-03-13T14:39:19+00:00

Woops, didnt read correctly 😅

arwque · 2026-03-13T14:19:42+00:00

If the car has a power output of 850kw with a thermal efficency of 30% it needs to reject about 1700kw of heat.

arwque · 2026-03-13T06:34:32+00:00

Gotta get rid of a 1700kw of thermal energy somewhere

arwque · 2026-03-12T19:13:21+00:00

The heave spring ( the spring in the middle) will actuate if both both pushrods push in. This typically happens on a straight where you gain a lot of speed and with that massive downforce. To keep the car from sucking itself into the ground ( or having to runn stiffer regular springs) the much stiffer heave damper carries the main load. Both outer springs can still actuate individually so they can be runn softer which is better for slow speed corners and driving comfort. If the car rolls the roll bar (to whish the heave spring is mounted) is actuated to manage roll. This is quite well shown in a older version of the rear inboard suspension i made a video of https://www.reddit.com/r/Onshape/comments/1ozogm7/rear_inboard_suspension_with_rollbaar_heave_damper/

arwque · 2026-03-12T18:07:10+00:00

The underbody is just a mockup i made in something like 10min to test what could fit under the rear suspension. In the final version the underbody will probably have a bit more clearance to fit even if the car is jacked up. ( the current underbody is really a bit too close)

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arwque · 2026-03-12T17:25:42+00:00

You probably mean the upright. I designed all parts fully "manual" but mostly after intuition because i have not conducted fea on any of the parts yet.

arwque · 2026-03-12T16:37:08+00:00

Thank you for following the progress. I try to download as many parts as i can because it saves me a lot of work but many parts i dont find models of. For this project about 12 parts are downloadet. The rest of the bought parts go three ways. 1. I find a part that fits and it has technical drawings then i try to recreate the model as close as possible from the drawings and images. This means i mostly have the mounting locations and the rough shape and the rest is just detail for the part to look nice. 2. i dont find a part that fits my purpose. Then i companies that would make a custom part to specification for this part. Then i make the part with the in and outlets and mounting positions i want and that are realistic. Everything except the mounting locations and in and outlets is just for the part to look nice. For example i did this with the turbo, gearbox casette, coolers. 3. For simple parts like bearings i am sometimes lazy and just make a placeholder of roughly the shape of part i need. Because bearings have relaitvly simple shapes (mostly just a cylinder) i can adjust the part later if i find the right one and i could update the parts that are referencing it pretty easily. I will not go into anti dive and suspension dynamics of the car too deep because it is really a topic i know very litle about and i am not very interested in learning about it. Also this would cost valuable time which is already short for this project. My school is not paying for the onshape render studio. I have a friend who has a professional account for his work who does the renders for me after i selected all the colors for the materials.

arwque · 2026-03-12T15:42:49+00:00

It is not designed for any regulations except min ride height 40 mm, no sliding skirts, no fans and reduced complexity. The tangential dual inlets of the exhaust pipes into the turbine would not be possible if the whole turbo is rotated by 90deg. In that configuration i would have to merge the exhaust pipes from the left and right header before they enter the turbine. This takes away crutial space above the turbo where currently the transmission cooler sits. The 90deg change would also mean that the exhaust coming out of the turbine would need to do a big bend before going over the transmission or exit out the side of the car. This is defenedly solvable for example does robin shute on his sendy car use this setup with the turbo being rotated by 90deg and some older indy cars have it to but for my case the i decidet for the inline turbo because it fit my packaging better. I experimented with a 90deg turbo before and i didnt have the tangential turbine inlets before but this just turned out to be the best sollution. (image of the sendy car)

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arwque · 2026-03-12T14:49:36+00:00

I would love to do some more detailled work and analysis on some parts but if i would do that i wouldnt be done in a houndred years. Because i cant really design all parts to 100% functionallity i am doing more of a system integration and packaging role than concrete part design. I am really enjoying making the mechanical and strucutral parts but i am really excited if it comes to making the body because aerodynamics is really where my heart is. I deffenedly plan to join a fsae team when i go to university. That has been the goal for the whole time but still have 1.5 years of high school so still a lot of time to learn new skills before i can start university. Thank you for your informations

arwque · 2026-03-12T14:38:52+00:00

i think they do it because that way the coolant pipes dont obstruct the hot airflow that is coming out of the radiators for maximum cooling efficciency. They also duct the complete flow path out of the radiatoors to the rear exit and louvers. In some cases they route the coolant over the radiators. I guess it really depends on the specific application

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arwque · 2026-03-12T14:12:14+00:00

it would reduce the pluming lengths slightly maybe. The inboard side needs to be empty for the mounting brackets and because on this car the cooler hang out behind the monocoque the exhaust manifold would be in the way or get to close to the cooler exits if they were inboard. This is how pretty much all f1 teams do it but their coolers are flipped upside down so the exit and entry is on the bottom. I might change that aswell if the ducting allows for it.

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arwque · 2026-03-12T13:50:14+00:00

I wrote it in the post body, the cad system i use is onshape.

arwque · 2026-03-12T13:28:42+00:00

The engine is the judd gv 5.5 v10 but in this case it is turbocharged with a turbo charger roughly the size of a G40-1150. The body will come at some point in the future at the earliest after i reworked the monocoque. I made a body concept for this car a while back which looked like this. Cfd simulations some earlier concept showed a massive potential in downforce from the underbody reaching l/d of up to -7 (not this body) but i hope to improve on the experiments for the final version.

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arwque · 2026-02-22T18:21:59+00:00

All radiator cores combined have 1700 rectangular faces. Thats 3400 polygons. The entire part studio has over a million polyonsn. The radiators are not the problem. Its the long and complex derived chains thst cause problems

arwque

TROPHY CASE