by "TheTurbochargedSquirrel" (thatsquirrel)
Published 04/12/2017 at 15:13
by "TheTurbochargedSquirrel" (thatsquirrel)
Published 04/12/2017 at 15:13
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STARS: 2
Time for race car CAD. I would show you the assembly but my laptop would probably get confused by the different drive letterings from the author computer and FUBAR everything.
"Dusty Ventures" (dustyventures)
04/12/2017 at 15:18, STARS: 1
Pssst!
Oppo Rally?
"RallyWrench" (rndlitebmw)
04/12/2017 at 15:20, STARS: 0
Dirt track car?
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 15:21, STARS: 2
Electric Formula car. There have been jokes about finding some dirt tires though.
"diplodicus" (diplodicus)
04/12/2017 at 15:27, STARS: 0
What size motor(s)?
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 15:33, STARS: 0
Pair of Lynch motors. Mechanically coupled but electrically separate. Should be good for something in the neighborhood of 74 hp and 114ft-lbs. Running at 120v through a Zilla 1k motor controller.
"diplodicus" (diplodicus)
04/12/2017 at 15:42, STARS: 0
That’s the kind used in the electric motorcycles that race at the isle of man right? It’s crazy how small those two motors are to me. I’m used to TEFC industrial motors.
"RallyWrench" (rndlitebmw)
04/12/2017 at 15:44, STARS: 0
Ah, from this angle it looked like the frame was staggered left.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 15:46, STARS: 0
I believe the IOM bikes tend to use 3-phase induction motors over a DC setup like this. These particular motors are marketed for use in electric boats.
"tromoly" (tromoly)
04/12/2017 at 15:49, STARS: 0
Estimated weight of 90 pounds?
IMO too much cross-bracing between the bulkhead and FRH, could probably remove two of those. Probably could remove two of the triangulations to the front suspension box, we ran much less bracing and never had a problem on the SES, through tech, or actually driving the car.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 15:49, STARS: 1
Yes? Maybe? I’m not 100% sure what my availability for this summer is going to look like so I’m only 90% sure I am going to be able to make it. I’ll shoot you an email registration anyway though.
"diplodicus" (diplodicus)
04/12/2017 at 15:50, STARS: 0
How much do those two weigh? We had to replace our 100hp DC testing motor. Its 1300lbs lol.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 16:14, STARS: 0
Don’t quite see where you are getting 90 lbs from but based on carrying it around I would say its about 150lbs.
I’m not 100% on what the frame rules are but from my understanding everything along the sides needs to be fully triangulated and removing any of those members would cause rules issues.
The rules are kinda funky when you read them. They are super strict in some places and loose in others. For example the bars bracing between the top of the front roll hoop and the main hoop doesn’t actually have to be there.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 16:16, STARS: 0
My guess would be 40-45 lbs. One person can easily move them around on their own. The power density of these is mind boggling.
"TorqueToYield" (torquetoyield)
04/12/2017 at 16:26, STARS: 0
Do any FEA optimization of that bad boy?
"tromoly" (tromoly)
04/12/2017 at 16:28, STARS: 0
The braces from the front bulkhead to the front roll hoop are only braces, they don’t necessarily need to have the suspension boxes triangulated up to them, our car 4 years ago didn’t anyways.
I agree the rules are funky, that’s why for my SCCA FSAE class build I’m working on I’m using the 1986 rulebook. Much more open and makes more sense.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 16:32, STARS: 0
I did not however my teammates did several FEAs on it before we moved to manufacturing.
"TorqueToYield" (torquetoyield)
04/12/2017 at 16:36, STARS: 1
Yea the best part of a model like that is how easy it is to optimize from a few simple FEA simulations (especially in SolidWorks). Simulate some quick and dirty loading, see what’s unloaded/unutilized then reduce, remove, or reconfigure those pieces so that every piece has a structural function.
Also, widescreen mode.
"Dusty Ventures" (dustyventures)
04/12/2017 at 16:52, STARS: 0
You should get your dad to enter too, that way you can beat him in a rally
"uofime-2" (uofime-2)
04/12/2017 at 16:59, STARS: 0
I know they kill you guys requiring the battery packs fully inside the cage.
our chassis typically are around 60 lbs fully welded with suspension mounts because those are the nodes and a part of the jigging (which your’s don’t appear to be though they really should be!!!! hint hint for next year), but no other tabs.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 17:21, STARS: 0
The batteries don’t have to be within the frame per say. They just have to have sufficient structure around them. We have run pods on the sides in the past. This car is getting a removable pack which mounts in from the bottom.
A lot of the weight comes from the wall thickness we are required to match. The main hoops have to be 1"x0.095" steel (or equivalent) and most of the structure has to be at least 1"x0.065" steel (or equivalent). This is a relatively large frame overall and it’s weight reflects that. In the past most of our frames have been close to the 100lbs mark.
"TheTurbochargedSquirrel" (thatsquirrel)
04/12/2017 at 19:38, STARS: 1
I kick his butt at virtual rally and the one time we shared a car at the Team O’Neil Rallycross test’n’tune in 2014 there was only 2 seconds between the fastest time set in the car and the slowest (it was close enough that we couldn’t tell who was driving for each run from the times though I wasn’t pushing at all and I am sure he wasn’t either). Now I really want to find a car we can drive at a rallycross to see how much slower than him I actually am.
I will ask him to see if he would want to co-drive with me. He has done a bunch of these over the years and would probably kick my butt.
"diplodicus" (diplodicus)
04/13/2017 at 08:08, STARS: 0
Ya that is impressive. How well do they hold up to abuse?
"TheTurbochargedSquirrel" (thatsquirrel)
04/13/2017 at 08:11, STARS: 0
Don’t know yet. This is our first year using these motors and we are still about a week from a driving car.
"DrJohannVegas" (drjohannvegas)
05/09/2017 at 10:35, STARS: 0
Dragging this up from the depths, but I gotta ask: Your region’s going to allow you to backdate the FSAE rules?
"tromoly" (tromoly)
05/09/2017 at 20:19, STARS: 1
Honestly I haven’t checked yet, I’m not far enough into the design for it to matter either, still working on fleshing out low-level lap sims before anything gets put in CAD. I’m mostly going off the rulebook not saying you can’t build to older rules, when I’m actually home for more than three days I’ll be contacting them.