Treadmill Dyno

[SparWeb]

She's real perrrrrty. 

[zap]

I love the overhead shot.

When are you going to apply the golf ball dimples?

[taylorp035]

If you had to hazard a guess, what kinda price tag you think this thing would carry if one were to eventually be able to purchase one at say, the local "TaylorP035's Custom Super Milage Cars" franchise

Well, if put it into production of one every two weeks and a decent profit, then maybe $5,000 - ish.  $1500 C.F., $1000-$1500 for the parts, $2000 for labor...

When are you going to apply the golf ball dimples? Wink

As I write this, I envision a trip to California from Virginia for less than $20.

With a few sets of tires and a gear ratio of ~4:1 good for 60 mph (which many of these vehicles have done before..... I even have a photo of one doing 55mph).  I'm not sure how the comfort level would be after 6 days.
This car got 3100 mpg 


Top speed with our 100 tooth big gear and our largest sprocket on the clutch should be ~48 mph.  Probably closer to 75 mph with smaller ring gears.  It would be awfully dangerous on the narrow 3 wheel setup.

I love the overhead shot.

I was kinda curious myself to see what the shape was.  The interesting part is that none of the cross sections actually look like a teardrop, just the over head view.  With no wheels or tail cone, the drag coefficient was a low 0.079.  It is currently calculated/estimated at 0.103, rounded up to 0.11.


It is also interesting to know that there is no center line in this car.  Definitely not symmetrical, not within 2"

[taylorp035]

Here are the videos in order of progress.


Engine running for the first time in the car with friction clutch:
http://www.youtube.com/watch?v=JFriwF1af4k

Up close with the servo clutch
http://www.youtube.com/watch?v=w_pifNUDjbo

Running engine with the servo working:
http://www.youtube.com/watch?v=XmMcVWxjgHc

Driving part 1:
http://www.youtube.com/watch?v=UebHghrXXIE

Driving part 2:
http://www.youtube.com/watch?v=J2jNBTJuIVo


Here is a photo with the logo on it 



We worked on the car from 2 pm on Friday til 3 am on Saturday. Then we came back did it again from 3 pm til 2 am.  In that time frame, we installed all of the windows (about 8 man hours), installed the engine plate, the engine, the electronic ignition, the cooled seat (not working very well right now), and the steering and wheel stops.

[Madscientist267]

"CLUTCH BEFORE ENGINE!!!" 

Hahaha there's learning to build a machine, and then there's learning to operate a machine... LOL

Then again, I guess 'RTFM' was not an option here... 

Very nice either way.

Maybe some kind of interlock... To keep the clutch from being engaged if the engine is already running... At least until the drivers have all had a chance to "RTFM"...

Steve

[taylorp035]

One issue was that we didn't have control of the throttle.  We still needed a crimp on the cable to connect to the valve, hence we opted to turn the idle way up (idle is good for 1.4 hp  ).

I'm surprised still that we didn't shear off any of those teeth on the clutch... only 2  8-32 bolts holding each tooth on.  And only one tooth actually provides the torque (the teeth are about 175 degrees apart).


Today I went back to the school and took some photos of the other side of the car that has more logos.  I also weighed the car, and it came in at 116.4 lbs, which is about 15 lbs heavier than I wanted.  Only the cooled seat, batteries, switches, computer, and seat belt remain to be added.  I predict a final weights of 123-125 lbs.

Making an 80 lb car is going to be tough next year.... ~ 20lbs less carbon fiber and glue, 10 lbs less Bondo, lighter starter motor, smaller batteries, lighter seat and no cooled seat, lighter computer(it weighs a few pounds), thinner windows, milled engine, maybe carbon fiber rims and steering handle, carbon fiber steering, aluminum bolts (with shear calculations), titanium axles (the old car had these), and a lighter big sprocket (hopefully I can get my workplace to wire EDM me a custom one for a Gates carbon fiber timing belt).

I believe the PAC CAR II only weighed 59 lbs...  Within our rules, we would be lucky to hit 70lbs with a million bucks... they probably spent more.

I sure hope someone can come up with carbon fiber based radial tires   Maybe rate for 300 psi... they make air tanks out of it for 10,000 psi.

[taylorp035]

The cooled seat cooling mechanism.
http://youtu.be/az0e2GBqiwA


We ended up bending and twisting the rear axle last week (not surprised after "dropping" the clutch at 4k rpm).  After some serious calculations, we decided to use last year's axle, which is ~5" shorter and hardened steel.


Gluing some mounting blocks in for the shorter axle.


Front with no wiring.  Took about 6-8 hours to wiring every thing inside of the car.  Used about 30 sets of Anderson Powerpole connectors.


Lightest weight chain guard ever!




The kill switches were tricky, because I had to wire up the lights too, so we could identify which switch was flipped. 

Testing in a half lit parking lot turned out pretty good.  Managed to miss the man-hole covers.  Top speed was recorded at 22 mph, but I probably didn't hit 3k rpm.  It was kinda rough to drive since the top of the engine was resting up against the firewall and we didn't have the cushion in at the time.  The steering was very good and easy to keep straight.  The brakes worked well to, as well as our very bright brake light.  It was interesting that the campus police didn't check us out.

The electrical system on the engine worked great.  The battery still had 25% left after running for ~ 10 minutes.  We will need about 2 minutes of run time at the track.  I still need to add a fuse to the circuit.

[REdiculous]

It may be light but the chain guard is kinda redundant since the chain can't grab hold of a pant leg...the back of the seat should be plenty of protection in case the chain breaks.

[taylorp035]

Actually, the chain guard is to protect the fuel line and bottle if it breaks.  Drivers generally have a difficult time exiting these vehicles (all of them are relatively air tight), and most are made of composites that will melt.  Plus, the drive may not be aware of a fire if the chain doesn't alarm them first.

The most dangerous thing though is probably a engine throwing a rod or a flywheel exploding.  0.032" aluminum is not going to stop either situation.  Ultra high compression test engines built by students may not preform as expected .

[REdiculous]

The chances of breaking a chain should be near-nil (especially once you're rolling) and the wheel-side chain shouldn't be moving fast enough to do any damage if it does break. Much more likely is throwing the chain and having it get tangled in the wheel, which the chain-guard won't help with.

[taylorp035]

True... In high school in my battlebots, we had a #35 chain on 4 hp doing 30,000 RPM (not a typo) on a 11 tooth sprocket .

Tonight I balanced the rear wheel and made some observations on how much friction there is.  At the fastest speed that I can spin the wheel by hand, it took 14 seconds to spin down, which is atrocious.  There is probably 0.5 in*lbs of torque in the seals, which comes to 5-10% of our mpg....  The seals will come out after we are done testing in the parking lot.

Sorry about the lack of driving video.  The camera did a poor job since it was so dark.  This time we will open the throttle all of the way.  Initially, we didn't want to break anything on the first major test run and the fact that is was so dark that we probably couldn't of seen any problems that would have developed.

[JW]

It's nice to see remotly hosted images display aswell as pictures attached to the forum. As an Admin, I work hard to make things like that, equal.

JW

[taylorp035]

It SOOOO easy.    www.tinypic.com   is where it's at.  Just select the photo, type in the scrambled code, and select the size (640x480).  When it's done, copy the "message board" code and paste in the reply.  It's kinda slow for people who have big pictures and slow internet, but it's worth it.

I gave up on uploading photos to otherpower.com b/c it didn't work half the time and I would have to manually re-size them in MSPaint.  As far as I know, all of the tinypic  pictures still work.

If I am really ambitious, I like to provide a link to a higher resolution photo for those who want more detail.

[JW]

I gave up on uploading photos to otherpower.com b/c it didn't work half the time and I would have to manually re-size them in MSPaint.

Yes thats true, I use MS Image Composer to resize and "save for the web". If you have a picture with over 150k you may have upload problems.

Did'nt I crop and save your Avatar to the OP/Board here?

JW

[Madscientist267]

For the Linux crowd, GIMP is good for resizing too.

Just open the pic(s), select 'Image -> Scale' and punch 640 in the X field, whack Tab, the Y field should automatically adjust (they are aspect-linked by default) and click Ok.

Save it, keep the default quality setting, and voila, you have your resized picture(s).

99.9% of the time, this pacifies the board's requirements for file size. Every once in a blue moon, I get one that is a little over (usually if there is a crap ton of detailed intricacy in the picture). In that case, I go back, re-save it with 5% lower quality, and it usually snaps right into place.

FWIW

Then again, those running Linux are probably already aware of all of this.

GIMP is however also available for Windoze.

... we now return you to your regularly scheduled thread ...

Steve

[taylorp035]

Did'nt I crop and save your Avatar to the OP/Board here?

You did.  I showed you guys the photos of me on Presque Isle, and at the same time, I was trying to get an avatar image.  I failed, but one of the admins (JW?) was really anxious to make it work.  He did all of the leg work.

[taylorp035]

Time for a video in the daylight 

http://youtu.be/fRXB8IkRB8o

Here is our first actual fuel economy run in the Erie parking lot at Penn State Behrend.  The result was ~400 mpg, which isn't bad when considering that the air drag is ~3x higher than it should be, and we are taking tight turns, which doubles or triples the rolling drag.  Also, the tires are only at ~75 psi, which will go up to 100 later.  Also the ground had a lot of tiny rocks and the bearings still had their seals in them.  Our goal is 1500 mpg.

Average speed was 12-13 mph in this test.  A total of ~8 miles was driven and 1.8 ounces of fuel was used.

Earlier, the driver decided to increase the throttle from rest and this is what happened....



A nice 25 foot burnout    This is why you put the cheap tires on the drive wheel.  The still looks good, but it demonstrates how thick the rubber is on the "low rolling resistance tires".  If we had our real low rolling resistance tires on there, it would of popped in 10 feet.

There was about 80 lbs of weight on the rear tire... pretty impressive for a 3 hp engine.

The lighter flywheel is very noticeable when compared to last year's car.

EDIT:  2nd video

http://youtu.be/pF-zJwCouxs

[Madscientist267]

Dang dood... that thing shizn'gits!

Very nice...!

Anybody track any G force measurements during the burn?

I know SOMEBODY has a Droid around there... haha

Steve

[ghurd]

The burnout looks like a classic case of bunny-hopping.
Get some ladder bars on it!
G-

[taylorp035]

I almost think that the unevenness in rubber is caused by the single cylinder. After twisting our axle, it was evident that the torque was at least 8-10x the rated torque (4 cycle, peaky explosion for that 1 cycle)...

Two kids coming to competition will have a Droid and an I-phone  8

I soooooo wish I had the camera when it was doing the burnout.  It was really awesome.  3.5k rpm easy the whole way.   

So much for going with a supercharged + 18:1 compression + OHV = 6+ hp next year 

[zap]

Too cool!

I'm working to get the Silverado above a 21mpg average

[taylorp035]

I finally figured out how to get you guys the photos that I have on our internal website   


http://behrend.orgsync.com/org/societyofautomotiveengineers22440/Pictures

[zap]

Nice pictures... that locomotive cab would look good in my backyard!

What was the "checkered" blue and white seat covering in the '09-'10 build?

[taylorp035]

It was a custom seat cushion that my mom made last year.  The fabric had a bunch of Penn State logos on it.  She made a new one this year (should be in the pics) that specially contours the crazy frame rails.  We also got it professionally embroidered.

[zap]

It was a custom seat cushion that my mom made last year.

Ahhh... Mothers... where would we be without them

[REdiculous]

Moms that sew are cool....mine owns a quilt/fabric shop so everyone in the family has a nice quilt.

[Bruce S]

Moms that sew are cool....mine owns a quilt/fabric shop so everyone in the family has a nice quilt.

OKAY that might be a problem, where are you located?
 I may need to make sure my wife doesn't know, we have more fabric from her old seamstress days than I can store in one closet 
Strange as it may be, quilts fell cooler than other blankets even during the summer, and there's no beating them for comfort.
AHhhhh

[taylorp035]

Yeah, she does quilts too, handmade, not with a machine.  She is located in NW PA.  She does here magic by working on altering bridal gowns (and the brides that come with them).

Hopefully we use the cushion this year.  Those of us who want every last MPG are willing to fore go the comfort for 40 minutes.  We weighed the car with everything in it (cushion, cooled seat..) and it came out to 127 lbs.  Without the fancy stuff, it goes down to 115 lbs.  12 lbs could mean up to 50 mpg.....

[REdiculous]

OKAY that might be a problem, where are you located?

We're in Oregon so probably nowhere near you. She has a site though, complete w/ an email newsletter.

Yeah, she does quilts too, handmade, not with a machine.

My mom uses machines but she kinda has to since she does so many. She not only quilts her own stuff but other people's as well and rents out the quilt machine from time to time. And she teaches several sewing classes and has her own line of yarn.

taylor, have you tried getting your mom to drive the car? You should totally try to get her in it for at least a lap.

[taylorp035]

She will not fit, even though she is not a big person.  The frame rails are only 13" wide where your hips sit... kinda a design flaw.

[Bruce S]

OKAY that might be a problem, where are you located?

We're in Oregon so probably nowhere near you. She has a site though, complete w/ an email newsletter.

Yeah, she does quilts too, handmade, not with a machine.

My mom uses machines but she kinda has to since she does so many. She not only quilts her own stuff but other people's as well and rents out the quilt machine from time to time. And she teaches several sewing classes and has her own line of yarn.

taylor, have you tried getting your mom to drive the car? You should totally try to get her in it for at least a lap.

I took a look at the website, then told wife about it while handing her a glass of wine  .
It has a nice layout.  There's nothing wrong with using those machines. They do make pretty paterns and if she's as busy as you say, can surely help her a lot.
Cheers
Bruce S

[taylorp035]

This is the big week!!! 

Testing with the body on it:
http://youtu.be/yz-zbT6U-9M

Here we got 674 mpg in the parking lot.  A lot of the energy was wasted in the corners (tire drag goes up by 2-3+ times for a 20-40 meter radius).  At 23 mph, the front end was sliding.    I was either turn hard or hit a whole row of orange cones.

Top speed was confirmed to be at least 31.5 mph, which translates to 4800 rpm.  Sure sounded good, but there was some really bad wheel shimmy, just like a bad shopping cart wheel.  We also had the rear tire lock up on us.  It was very sudden and caused the tires to squeal and the back end to whip out 90 degrees (sliding sideways in a 3 wheeled vehicle is never a good idea...).  The cause was dirt getting into our wheel bearings, after us taking the seals out 15 miles earlier.  About 3/16" of rubber was taken off a patch on our testing tire when this happened.

After all of the testing in the parking lot, the front frame holding the steering gave out.  Several cracks in the welds occurred, which caused the car to have only 1/4" of ground clearance and 15 degrees of toe -in.  Needless to say, we took 90% of the tread off our priceless radial tires in the process.

While looking at the university of Laval's website, they got 2909 mpg in Europe last week....  and took 13th.  First came in at over 8000 mpg set by a car named "Microjoule".

Thank goodness for extended wheel based mini vans


EDIT:

I was thinking of a new driving strategy.  Currently, we turn the coil on and then fire the starter motor.  Since she fires on the first revolution, the starter only gets to about 500-900 rpm.  Option two, which we haven't tried yet, is to turn over the starter at full speed (1000 rpm), and then turn on the coil.  According to our instructor, he doesn't think the engine sucks fuel until it fires.  We could swap in the lipo battery and boost it up to 1300 rpm and loose 0.4 lbs.  Together, my calculator says we gain ~40 mpg over our current set up.  I wonder though, which method is better?

 

[Bruce S]

What No windshield wiper 
Looking good. The line looks like a cute Cheshire cat style grin 
Thinking of the shimmy, is it possible there not enough camber in the front wheels? allowing the dirt to enter the bearing area?
it's always the little things.
My opinion would be to get the coil over firing RPM then shut down the starter.
Bruce S