Floating Sprocket Concept

[Denny Trimble]

Well, it's not quite working out...
http://students.washington.edu/dennyt/fsae/floating_sprocket.avi

Man, our car just about fell apart today, on our first drive since SVSU. We also discovered a broken front swaybar, which explains our handling at SVSU a little bit http://fsae.com/groupee_common/emoticons/icon_smile.gif

I guess we'll have some work to do this week before the Northwest FSAE Shootout!

[Denny Trimble]

Well, it's not quite working out...
http://students.washington.edu/dennyt/fsae/floating_sprocket.avi

Man, our car just about fell apart today, on our first drive since SVSU. We also discovered a broken front swaybar, which explains our handling at SVSU a little bit http://fsae.com/groupee_common/emoticons/icon_smile.gif

I guess we'll have some work to do this week before the Northwest FSAE Shootout!

[BeaverGuy]

Wow, we were just talking about whether those heavily machined sprockets failed very often.

Replacing a sprocket and sway bar? It isn't like you had to pull the motor to fix your exhaust valves. http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

Have any other teams confirmed their appearance next weekend?

[Denny Trimble]

Well, this one is a little puzzling, given that we've run the same sprocket for 100 hours on a previous car before it cracked. We then made the replacement thicker, and this new one thicker, but it failed after less than 20 hours. We haven't determined what caused this one to fail so early yet. It could be our new guy used a program for a larger sprocket, or that we somehow received a sprocket blank that wasn't 7075.

Mostly I'm whining because we're in summer mode, and hope to do only about one day a week of work http://fsae.com/groupee_common/emoticons/icon_smile.gif

As far as I know, UW and OSU are the only confirmed teams for the NWFS. WWU and UBC are still tentative.

Today we also worked on making sure the parking lot was decorated properly in advance:

http://students.washington.edu/dennyt/fsae/everett_decoration.jpg

[rjwoods77]

Hey Denny,

Sorry for asking this but what is the point of doing that. Wont it increase chain slap on sprocket teeth? Looks cool but I was just wondering about the performance gain of doing that.

[Denny Trimble]

It was a joke, our sprocket self-destructed today. It used to be one piece, now it's five plus five teeth missing (found one).

[rjwoods77]

Oh. I was gunna say.

[buddy]

Denny,

Maybe the problem was the 7075, It typically has low fracture toughness, any surface or material imperfections will result in a "pre-cracked" condition leading to early fatigue failure.

buddy

[Didier Beaudoin]

On a similar note, we've destructed a rear brake disc 2 days ago. It will make a nice clock. I should post a picture sometime.

[Jersey Tom]

I agree with Buddy. 7475 might be a better option.

[Rob.C]

nice lookin sprocket!

we have run 7075 rear sprockets for the last 2 years, last years car did student plus a load of testing, then went over to aus and competed over there, we necer had a problem with it, however, that was annodised (admitadly it didnt do much testing, but still a good 100/ 150 hours!)

this years car has a hard annodised sprocket, that has dome a lot of testing and student! (although we spapped a new chain in enduro http://fsae.com/groupee_common/emoticons/icon_frown.gif but that car is going to aus this year.

do you annodise your sprocket at all?? or maybe thought about leaving a little more material there!??