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View Full Version : Half8 on the "Big Dog" Track



rstnboy
05-21-2005, 09:04 PM
I just got back from the local 1/8 track where I finally got to put the Half8 to the test and I must say it came out smelling like a rose :D . It handles nearly identical to my MP777 even down to the on and off power steering. It jumps and responds to throttle/brake in the air just like it as well. At the beginning of the run, with a fresh battery, it was clearing the doubles that occasionally give the 1/8 buggies a bit of trouble and it took the woops sections almost as well. Some softer springs would have helped here but picking the right line solved the majority of the upsets. Surprisingly, the stock tires provided quite a bit of grip on our dry, dusty track.

Now for the setup:

1. AON 4900 with 12 tooth pinion
2. Kyosho oil shocks with 30 front and 25 rear
3. Mamba 25 brushless controller
4. 2S2P 1800 mah lipo pack
5. Futaba 2PL w/R142JE receiver
6. Hobbico CS-35MG steering servo
7. O-ring slipper mod

Motor temps reached 175, with an outside air temp of 97, after 15 minutes of solid running and the controller only hit 124. I can probably attribute this to running full out over a large percentage of the track and the fact that it is almost 100 degrees outside. I suspect gearing up a couple of teeth will actually bring the temps down a bit due to being able to run the motor at a bit lower rpm through the technical sections. The battery pack barely got warm so I know I have some room there.

I ran a total of around 20 minutes and nothing broke :eek: even after plowing nose first into the face of the second mound of the double (more than once), tumbling end over end for about 8 feet (again, more than once), and buggering the 4 foot high table top.

halfEIGHT
05-22-2005, 05:53 PM
Was that with or without a heatsink? And, how did lap times compare to big brother's?

rstnboy
05-22-2005, 06:34 PM
That was without heatsink. The AON motor is 4mm larger in diameter than the Mamba motor so the heatsink I have won't fit. The lap times were around half to two thirds as fast as the big buggy, depending on the lines through the more technical sections. The chassis/drivetrain wasn't the limiting factor, it was the top speed of the motor. The Half8 could have gone faster with taller gearing and still handled the track fine.

halfEIGHT
05-22-2005, 08:25 PM
What is the shaft size on the AON, same as Mamba or same as stock?

rstnboy
05-22-2005, 11:05 PM
It is 2.0 mm...same as the Mamba. I believe stock is 2.3 mm.

BitHed
05-22-2005, 11:31 PM
...correct...mamba is 2.0, AON 4900 is 2.0 and stock is 2.3...HPI RS4 Micro pinions are a sweet fit and have enough teeth to solve any meshing problems...

...Crunch mentioned that one of his Hong KOng brutha's was using a 9t but my motor mount is maxxed out at 12 so I dont know whats going on there...I would motion that 12t is the smallest you can go...

rstnboy
05-22-2005, 11:43 PM
I got an 11 tooth RC18T pinion to work but I wouldn't attempt to go any further without augering out the motor mount holes in the chassis.

BitHed
05-23-2005, 01:00 AM
...an 11? Thats pretty good...I might try and go back one or two and fit a 13 or 14...but i have my 4900 SO dialed now its just beautiful :D

vindictor67
05-23-2005, 03:14 PM
I'm using the associated 11 t also. The mesh is Sweet :D

TNB
05-25-2005, 05:42 AM
I just got back from the local 1/8 track where I finally got to put the Half8 to the test.
Below are photos of one of the local tracks where I "test" my Kyosho Mini-Inferno(s). By the way, my motor temps were hotter when running back-to-back 3-cell LiPos.

http://www2.mini-zracer.com/albums/album667/Finishline1_051505.jpg

http://www2.mini-zracer.com/albums/album667/Finishline2_051505.jpg

http://www2.mini-zracer.com/albums/album667/Finishline3_051505.jpg

mOOsE
05-25-2005, 05:50 AM
thats a very nice track. I wish we had support like that in Colorado. RC just isn't popular here...

TNB
05-25-2005, 04:26 PM
Local area R/C tracks:

One quarter scale track (Super Nationals),
Two on-road tracks (HPI Challenge, Paris Memorial Race, 1/5 scale Motorcycle Championships, etc.),
Four off-road tracks (Silver State Nitro Challenge, point series races, etc.).

One of the LHS also had a 4L RCP Track, but sold it. I have an even larger track but the on-road portion is boxed up now. There is also a boat pond and a couple of flying fields. In addition, there were also a couple of other tracks and LHS but they closed.

Then there are the go-carts and the full-size tracks. :)