Help creating a low budget Hyper 7 brushless

[simplechamp]

I bet it didn't pop out, more than likely disintegrated into a fine mist of metal shavings and shrapnel!

[DrKnow65]

SC, that actually crossed my mind, though I think it's more likley that it either twisted and got shorter or it broke in half and went flying.

Still having fun trying to get video to YouTube. I've found that my harddrive is too full to backup my iPhone, which means I can't update, which makes it hard to get the video onto my laptop aarrgghh. It's a hopped up quad core Dell m4400 with a 80gb solid state drive, and 8gb of ram. Super fast but I have to keep alot of stuff on a secondary drive.

I'll get it sorted soon...

P.s. I have spare dogbones from a parts car.

[DrKnow65]

Well here it is, in all it's epic failure glory


http://www.youtube.com/watch?v=rixf1DXCo28 <- Direct link (allways buffers better for me...)

or the imbedded video

[DrKnow65]

Ok, I've hacked on a whole new rear end after finding out that all my spare dog bones are for an Ultra GT I lost the wing in the swap, but I'm bound and determined to play with this new setup for at least a few packs this weekend.
I'll have to keep it to the pavement for the time being as the new rear end isn't sealed fully by the chassis. I've got a set of belted ofna tires that work great for parking lot bashing anyway...

The data logging is very cool and according to Brian's calculator with a 16t pinion, 46t spur on the CD, 3.07:1 diffs, and 4.25" tires I am already geared for 75mph top speed
(max RPM for the motor from the log was 55,400 and if you adjust down the pack voltage in the calculator to the voltage it was doing at that rpm, it's nearly exactly what the calculator comes up with).

With my 18t pinion I should have no problem hitting an actual 70mph, accounting for a bunch more drag as I was on a low traction surface during the first run.
I saw an average of 8 amps and a peak of 101 amps, a lowest voltage of 28.6v, and a high of 2880 watts.

One of the guys who I see at church Sunday likes to drive his cop car 24/7 and should be cool about radar'ing it for me. Or I could test my squaretrade insurance and strap my iphone to it for a GPS reading just have no idea where to put it

[DrKnow65]

Man this thing flies! Max motor temp was 135'f so it looks like I can step up the tooth count a little.
I may even toss in the 1717 as by the numbers under load it should top out a ~49k rpm only 4k above the "max" of 45k that's printed on the motor

I ran it out in one of the school parking lost that's about the size of a football field and you barely get it topped out before you're slamming on the brakes
it still lacks traction and goes straight into a dognut most of the time you hit the throttle. It makes enough power to do wheelies, but there's just not enough bite.

I also balled up another foam inside one of the belted ofna tires (second time), looks like I need to get some molded foam inserts.
If you didn't know the ofna's come with a foam strip insert that isn't a full circle. I may just pick up a set of foam on-road tires as well to see if I can find the best traction.

[lincpimp]

The molded foam inserts really are the way to go. I have used quite a few of them and found them to work excellently, plus they last longer.

[simplechamp]

I've been doing a lot of research on tires myself for my on-road Jammin. GRP Rally are a good choice, also Sweep radials and Ipanema radials.

I know the GRP Rally tires I have feel way different than my Ofna belted radials. They are tacky, but the overall feel of the tire is very firm and low-profile. I got them as premounts, not sure what type of foams they have (if any? it's hard to tell). They just seem more realistic to a real 1:1 racing tire.

EDIT: P.S. it was funny in the video to hear the Castle beep off 8 cells, not used to hearing that!

[DrKnow65]

SC, can you post up a link to the GRP's you have? I am only seaming to find them on the manufacturers website and I imagine they're going to be lent expensive and weeks away if I order them from overseas... I need an ULTRA sticky tire for this beast

[simplechamp]

I lucked out and found a brand new set on RC Tech forums, they are GRP Rally, B Soft compound. Losi used to carry them under their own label, but discontinued that. Might be able to find them on Ebay, otherwise you might be stuck ordering direct.

Otherwise I've been told Ipanema and Sweep radials are very good too and very similar to the GRP Rally. And they are much more readily available, you can order directly from Sweep and they are in the US.

[DrKnow65]

Found em' on eBay... Got to clear it with the wife (short check after the holiday season), but I should be able to pick up a set and some rear CVDs too.

[simplechamp]

I haven't used mine yet, but have only heard good things about them, especially with guys doing high-speed runs. I guess they really don't balloon at all, and I'm not surprised really, they feel very solid.

Very nice build, I don't think I could handle all that power though Just a question though, what body are you running in the video? I'm chasing something to replace my old nitro one that is more hole than body, and not real sure on what fits.

Kieren