Hopkins Baja Design / Build Thread

Originally posted by Old Greg Adam, all I mean is that correlation is not causation.  62 inches may be the end all, be all of wheelbases, I don't know.  But don't mistake the fact that a lot of fast cars are in that ball park with the idea that it was their wheelbases that made them fast.

Right, there are other things at play that make the fast cars fast, of course.

CVT tuning, Weight, Driver skill.

I understand what your saying.

 

Again it is all speculation, but assumingTTU and USF used the same swingarm setup,   had the same weight, same tires, etc., with a higher cg TTU would probably oversteer more IMO than USF in terms of actual inches of lateral slide in a turn, but because of TTU's longer wheelbase, the measured "degrees of oversteer" would be about the same. Further proof (speculation) that you can reach the same end result in a variety of ways.

The big thing with composite rims it they are able to deflect elastically, and then return to their original shape, and thus not bend and cause the bead to break and loose air. They also typically come with bead locks to keep the wheel on the rim at low tire pressures and when 'flat'
We are looking into them right now, but are still trying to determine if it is worth it. Any other teams have experience with either composite rims, or even just a bead lock aluminum rim? 

Agreed. Someone can start a new thread about carbon composite rims if they want to continure discussing it.

Originally posted by dillon_b12 What's the obsession with carbon composite rims?  From what I've heard from sport ATV guys, they leak, aren't as light as Douglas(depending on label), and cost about 3x more than Douglas.

The main cons of the rims are Cost and Weight, but the big pro is the durability.

Last year, across all 3 races we changed ONE tire. A sharp rock pierced the tire sidewall within the last hour at Wisconsin.  That includes hitting the railroad ties in Auburn at full boar EVERY LAP.

More pics dammit!

looks like you don't have the 12" required that extends from the lowest point of the seat to the upper LC on the RHO.

Hi guys!

I dont have more pics of the car :( sorry, because we are still finalizing stuff like the suspension and steering.  However, when its done I'll upload the SW model for you to check out.

Answers to the questions from before.

Wheelbase is -> arg! I forgot, will check tomorrow
Seat is the Jegs Highback Pro II with the seat cover
http://www.jegs.com/p/JEGS/JEGS-Pro-High-Back-II-Race-Seats-and-Seat-Covers/1118147/10002/-1
Really cheap seat that is quite comfy!  Really low for the cost report.

tire size: fronts 22x7 Holeshot XC , rears 22x8 Mudlite AT

Charles ->  Good catch!!  I see what your saying!  Thanks for the note.  I will make sure to change that :)



Ok!!

We started construction back on Jan 3, and have just finished day 5.  Hopkins has a nice Intersession period.  Class for us starts back up again on Jan 21, which gives us a lot of time to work on the car

Putting in some long days but its paying off, we are moving ahead quite rapidly with car construction.

Below are some pics along with some captions of how our construction works.





Here's our setup for jigs.

We use a smooth pressed cardboard with high quality wooden blocks.  Pretty simple.  This is our RRH being constructed and assembled before being welded.





Here was our main step today.  One of our guys had the idea to use ratchet straps to hold the notched frame pieces together for tack-ing.  He saw it on the USF website, thanks guys! 

I guess I should mention that we do our tacking with a small portable MIG welder in our labspace, but do the actual welding in our Welding room with a really nice TIG.  I think its a great combo, the trigger style of the MIG makes it really easy to get a lot of tacks down vs trying to balance a foot pedal for tacking with a TIG.




Here's where we are at so far.  Lots to go for sure, but hey, its progress.

Cool, ok well I need to get some rest....

Catch you guys later,
Adam

Looks great so far!  We use the method to jig the frame of the car.  Same tube bender too!

We started fab work this Monday and here is our progress thus far:

Edited by Redhawk_Racing - 2010-Jan-10 at 3:14pm

We use a plane of bend bracket for 3D bends, very simple (I made our team's) to make and use.  http://www.offroadfabnet.com/forums/showthread.php?t=924

Helps for 3D bends, and we also use it to make sure we have notches on either end of a long tube in the exact same plane.  Or if notches need to be in specifically different planes, whatever.  Way better to just turn the tube a known amount than to tilt the head of the mill.

Hi guys,

Edited by jhu42 - 2010-Jan-25 at 3:53pm