grimsel - Technical Tour

See what technical details and features make grimsel a world record breaking car!
World Record video:
• AMZ - World Record! 0-...
What is AMZ and Formula Student video:
• What is AMZ? What is F...

[@Seekerofknowledges]

Theses guys created a mini Rimac Neverra almost a decade ago. This car is an engineering marvel and the team behind it should be really proud of themselves.

[@profrex1858]

I was certain you'd worked through the options and clearly you chose well. I think it was my professor Socrates who said "it's a poor professor whose students don't surpass him." My compliments to your excellent professors as well as your team.

[@xilw3r]

Oh my god the motors are pieces of art. 3.4 kg.... props to the designers! probably some serious expenses went into those little satan's pills :D

[@Casskario]

btw. now we are under 2kg :)

[@fnky143]

Excellent video guys and well done on the 0-100km/h record achievement! Things have certainly moved on since my time in Formula Student back in 1998 ;)

[@cryo4o]

"First race car worldwide to implement adaptive dumping" ... of course, if you don't consider what was done in Fomrula 1, 25 years ago from Williams.... Except this statement, great job and keep it going

[@cokbagus23]

and you know, magnetic suspension on high end production cars.

[@rahulmaity2136]

fantastic stuff , alot to learn for teams who r beginners

[@justinwang7616]

Awesome video! Cheers from Berkeley Formula Racing (FSAE West)

[@roelende9670]

You guy are amazing and what a job! Very interesting, all together it is making so much more sense than a ICE.

[@diegobula4597]

Such a masterpiece of engineering!

[@NoanatorTV]

1:05 form mono 2:11 alu honeycomb 3:43 dämpfer 6:45 sidepods nur kühlung/weniger cw 10:11 mono fußraum

[@AustinBartz95]

Did I hear that right? 50HP/motor? 3.4kg/motor?

[@javelchamp]

yes, that's correct. the car has over 200hp in total and 1700Nm of torque at the wheels.

[@FirstLast-tx3yj]

@@javelchamp whats the weight of the car??

[@javelchamp]

@@FirstLast-tx3yj 168kg offical weight for formula student competitions... a bit lighter for the world record attempt due to some further weight improvements

[@christianh8073]

What CAD software do you use to design your cars? Solidworks, PT Creo or something else? How do you merge all the designs together since every member works on something different? Do you use grabcad or something similar?

[@FabioWidmer]

We are using Siemens NX as this is the software being taught to all engineering students at ETH.

[@comptegoogle511]

How old were you guys in 1999? That's the year that I was the composite team leader for the S.A.E. formula at E.T.S. Montreal. Back then We've hand-made the plugs, the molds, and the parts for the fairing, the bench, and the motor air duck. I was advocating for a fiberglass S2/kevlar (best cost report) or carbon fiber (best weight saving) monocoque but unfortunately back then the non-metal mechanical engineering students were not in majority so the 2000 team went once again for a Chro-mo tubular frame.

[@bradrogers3881]

Fantastic work guys. Congratulations!

[@jamesrrodgers]

thank you, exceptional accomplishment and video. your team is proving to world the great potential of electric cars.

[@maheshpadmanabh6564]

amazing work. all the best from 4zeRacing Team.

[@kyun6856]

Hello, I'm a student currently studying SAE Inwheel Powertrain. 1. I'd like to know the material and module value of the planetary gear being used. 2. Using the inwheel motor method is expected to deliver a lot of shock to the gearbox, how did you solve it?

[@yogeshsai]

Hello brother I am a student currently studying fsae

[@yogeshsai]

Can please give some technical information about fsae ev

[@profrex1858]

Furthering jayfulf's query about unsprung mass, wouldn't inboard motors allow lower center of gravity since gear train design would be more flexible? Similarly, distributing weight of batteries would allow also allow lower CoG and reduce cooling and polar moment issues, where driver weight/vehicle balance becomes a significant and relatively inflexible (really!) variable.

[@AMZFormulaStudent]

Hi Profrex, thanks for your interest! You're right that inboard motors could be positioned in a way, that they minimize CoG (Ka-Raceing actually is a perfect example for maximizing this concept). Still in our concept evaluations the lower CoG and lower momentum around the z-axis together with the lower unsprung mass still do not outweigh the gains made by lowering the overall weight, and friction as well as the packaging advantages. Regarding your question about different accumulator packaging, you might be eager to hear, that we actually split the accumulator in two separate boxes, putting one below the feet of the driver and thus lowering CoG!

[@2troke]

Great question and answer here, I wondered this myself. I want to be a student again, we got to make a wood bookcase at school!!! That is some serious design and manufacturing, something I would expect from a specialised low volume car builder for millionaires and the like. Just awesome. 50HP for 3 KG, X 4 sounds like TNT. Your 0-100 time is faster then a Formula 1. How much does the car weigh in a typical or average set up, IE with the wings on it, with or without driver? What sort of speeds are achieved in Driving? Do you use different reduction ratios for different conditions/events?

[@Kletterhaus]

Enough downforce to drive at the ceiling? We need a stuntman.

[@NikolaosSkordilis]

And a _very_ long ceiling.

[@DraganKrstic]

Can you tell more about motors itself? Their type, voltage, current...

[@duttaarjun1453]

Hi, could I know the motor specifications, thanks. Loved the video btw !

[@ezb77]

Is it correct that you use Lipo cells of about 3600 mAh? 112 cells in series and 4 parallel? What is the max. current draw on the battery while driving?

[@AMZFormulaStudent]

Hi Eugene! Yes that is correct. We're drawing nearly 400A during acceleration!

[@FabioWidmer]

It was 3.9 Ah cells in grimsel to be precise. The regulated maximum power during the race is (was) 85 kW. Divide that by 3.5 V per cell (which corresponds to a low SOC) which is 392 V battery voltage. You get 217 -ish A. Of course, for the WR, this must have been a little higher, but this was not exactly design spec ...

[@TestinDaCable]

looks like an awesome job guys! well done!

[@Javierm0n0]

not sure if i missed it, how hot do the motors get during the 0-62 (0-100) runs?

[@bruderrudiger9574]

Javierm0n0 About 250 degrees

[@DeepakPatel-nu3bm]

Can you explain how we can change the position of dampers like horizontal ,straight etc with reason

[@hankbluebullr4661]

My god you guys are awesome i started developing my electric engine with more less the same dimensions of those 3.4 kg 50hp engine but mi one Will weight like 6-7 kg and i gues i will not have even 5 hp i don't know you gli guys did that but you have made the future😀

[@AMZFormulaStudent]

Thank you for your kind words. We do our best

[@hankbluebullr4661]

AMZFormulaStudent i would like to see the next project 👍

[@AMZFormulaStudent]

We are working on it. Write a message to our social media channels with your email if you want to get the newsletters and be up to date.

[@jaeheich2240]

Such a informative video!

[@ksriram1997]

How can we regulate the four wheel drive system? So that they can adjust theirs rpm at the time of need...

[@lightmens]

how long that motors live? and how do you cool them ?

[@chiragshetty3231]

By any chance do you guys use 3D printing for some of your parts?

[@TheLordinio]

Yes the watercooling Jacket for the motor is 3D printed

[@Toxition]

Chirag Shetty And also the Prototype Modells

[@shalvami]

RIP to Internal combustion engine

[@LoanwordEggcorn]

Excellent work ladies and gentlemen! Is there a technical paper about the motors? Given their small size and high power density, I assume they're permanent magnet.

[@AMZFormulaStudent]

Hey Loanword, unfortunately there is no paper about the current motors. But you're right, they are permanent magnet synchronous in-runner motors.

[@wabisabi6802]

Is it possible to remove the reduction gears and aim for top speed?

[@krazed0451]

Given peak torque as stated in the video is achieved up to 1/2 of the potential RPM I imagine the motors would run out of necessary torque w/o the gear reduction. A top speed electric car would need a complete redesign.

[@mostlymessingabout]

You need torque to accelerate from stand still. A variable or multiple speed gear box can potentially give higher top speed but this is a race car with high acceleration.

[@jsautosolutions]

What kind of hardware do you run for the control unit?

[@saltyman37]

I was wondering the same

[@javelchamp]

ETAS ES910

[@twomonocoques2551]

Did I see correctly that you have build two monocoques for Gotthard (one behind Grimsel, one assembled in the rear)?

[@danrees100]

They look similar don't they but in fact the one they are building is gotthard (2016 car) and the fully assembled car lined up is fluela (2015), whereas the main car here, grimsel is from 2014.

[@surplusstock8778]

Anyone know the brand of hub motors?

[@michaborski7383]

how the hell did you get so good power/ratio in engine? Any more details?

[@cokbagus23]

their secret?

[@abhijiths4399]

hi could you share the design file

[@amigodesigns]

I know it could be confidential, but I would like to know if you use aluminium honeycomb or other materials for the inner core of the wheel, because I think is the only way to achieve better weight on a wheel of this kind... Thanks in advance

[@javelchamp]

the core material for the rims is not aluminium honeycomb but a foam called "rohacell". Its a high temperature foam that has a very good compressive and shear strength (at about the same density as al. honeycomb) and it can be machined to a desired geometry.

[@amigodesigns]

+luciens okay! thanks :)

[@alonsofangio6247]

i am a new teammate in a new fsec team ,intrested in the battery system

[@ivanbaric8618]

Super-Bravo!

[@Pinguthreads]

Where did you get these motors?

[@javelchamp]

they are developed and assembled by the team, manufactured by sponsors

[@yadhukrishnan1279]

whats the grimsel's wheelbase and trackwidth

[@javelchamp]

approx wb: 1500mm, approx tw avg: 1200mm

[@chriscon5036]

what is the range of this gokart?

[@brynclarke1746]

"22km in race mode" from the video, don't know what that'd be if you drove at road pace

[@JustinCrediblename]

when are you going to have carbon nanotube electrical wiring?

[@jayfulf]

Two questions: 1. Why didn't you mount the motors inboard to reduce unsprung mass? 2. I could be wrong but it looks like there's almost no caster or camber angle. Why not have positive caster and negative camber?

[@AMZFormulaStudent]

Hi jayfulf! Thanks for your interest in our car, great questions! You're right, that one could achieve lower unsprung mass with chassis-mounted motors. However the overall weight increases as you need to account for all parts connecting motor an wheel. Also the friction of the drivetrain is higher, decreasing efficiency. And finally the packaging in and around the chassis gets more complex. Our cars have to fulfill a certain minimal template inside the chassis, so you would have to "find" the space for the motors. However, there are teams who indeed use this concept (i.e. KaRaceing). In the end it's a question where you put your priorities and where you expect the higher gains. Regarding your second question the caster angle is indeed positive but hardly visible in this video. Camber and toe, however, are zero (under load) since since that's where these tyres reach peak longitudinal grip.

[@jayfulf]

AMZFormulaStudent Hey, thanks for the detailed response. That answers my questions perfectly.

[@llavero5]

Engines and gearbox in wheels increase unsprung weight... maybe in track is less important than strret?

[@bobloblaw1636]

unsprung mass shouldn't matter on perfectly smooth tracks, as only the sprung mass is moving relative to the wheels. The tracks used in Formula Student are generally smooth.

[@chriscon5036]

build those but a lot bigger

[@w0ttheh3ll]

I'm sure there's something I am missing here. Why can't you just re-wind the motors and leave out the gearbox?

[@brynclarke1746]

I feel like a torquier slower motor for the same power would be bigger and heavier, moreso than you'd gain by dropping the gearbox, but I don't know a lot about motors.

[@Cynyr]

you'd need more amps to get the same wheel torque at lower speeds. more amps would mean thicker winding wires, a different battery arrangement, and thicker conductors. given the low weight of a single stage planetary gear system, the the troubles of getting even more amps (they claim above they are pulling 400A during acceleration) out of the batteries this seems like a sensible solution to the issue.

[@w0ttheh3ll]

thanks, that makes a lot of sense. 400A is mind-boggling already.

[@Rottensteam]

What about ground effect? Lots of downforce, very little drag.

[@AMZFormulaStudent]

Front wing and undertray are of course operating close enough to the ground to make use of the ground effect. If you're referring to active ground effect devices like in the Brabham BT46, we would love to use them but they are prohibited in Formula Student.

[@Rottensteam]

I was thinking more like the Lotus 79 with side skirts rubbing along the ground containing the low pressure. But if the undertray makes the same effect then same, same :P I'm not an engineer like you guys, thought just popped into my head. Awesome to follow your development!

[@AMZFormulaStudent]

Sliding skirts are prohibited as well, as the cars are not allowed to touch the ground with anything else but their tyres. Otherwise you would definitely see them on our cars ;)

[@Rottensteam]

AMZFormulaStudent That's some strict regulations haha! Awesome

[@tr0yyy]

so much science

[@w0ttheh3ll]

this is engineering. science is if you come up with a theory, then try to disprove it.

[@황남주-n7u]

wow

[@TheBegby71]

Are you using stepper motors for drive?

[@adan3598]

:)

[@Warrow74]

about the downforce: "..at a speed of 110Km/h it can drive on the ceiling... theoretically." :-)

[@cokbagus23]

maybe it produces downforce bigger than the weight of the vehicle itself?

[@michaelcorcoran3942]

Skeptical hippo eyes....

[@cpnoshow8264]

not bad..

[@dylandesmond]

Start building bigger cars