Project: Ultimate E-Maxx - Spyder
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Phase II: 7.2-Volt Fury
The time had come to release my creative restraints and dig into this project ferociously. I refused to allow joy & satisfaction cloud my vision of what the future could bear with the help of my trusty Dremel and many weeks of deep thought.
2/17/2001: In between heats at this Saturday's races, I was hard at work putting the finishing touches on some carved aluminum with my Dremel. These pieces had been under construction for roughly a week and were in the design phase for several weeks before this. They ended up being assembled into my original, prototype custom motor mount which allowed the installation of 540-sized motors just a fraction of an inch above the floor of the chassis tub, behind the transmission instead of on top of it. This lowered the vehicle's center of gravity and pitch momentum center (horizontal axis about which the truck would tend to rotate, leaning forward or backward, when changing speeds) while also moving its lengthwise weight distribution just to the rear of the midpoint between the front & rear axles. The stock setup had made the vehicle front-heavy and difficult to keep from nosing down off of jumps.
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I chose 14-turn double-wind (14x2) Speed Gem "Onyx" modified motors for power (being biased quite a bit by their color, which fit in well with the rest of the chassis) and a reliable, frequently-recommended Novak Super Rooster ESC to moderate the flow of current.
In an unrelated development, I also installed my second Powerline shock tower after stripping off its annodation and polishing it to match my first.
2/23/2001: On this day the latest innovation to hit the Spyder is my four-stage advanced ESC cooling system! The front of the body was trimmed away, letting the big space in my Powerline shock tower grab air as the vehicle moved at speed. Aiding this was a new 12V fan. The air was then channeled through a cowling around the ESC that was actually the cockpit section of the RC10 B3 buggy body I had used and wrecked on the Ultimate Stampede two weeks prior (how's that for recycling!). Finally, this cool, accelerated air was passed over ESC heat sinks that had been de-anodized for maximal heat dissipation and then stacked two high for truly "Ultimate" cooling.
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3/1/2001: This was a glorious day, for I revealed the Ultimate E-Maxx: Spyder in full to the Internet public and launched its home on the 'Web, UltimateTraxxas.com! Hooray!
3/9/2001: Out went my prototype, four-piece custom motor mount and in went the one-piece "production" version! It's always easier to do something the second time around, and this new mount took only about six hours to carve out of a 2"x2"x1/8" piece of aluminum angle bar using a hacksaw, Dremel, and large file.
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This new piece was significantly stronger and more precisely engineered than the original and was an absolutely perfect fit. The mounting screws were put in a different pattern to make maintenance easier and motor adjustments less restricted. I also trimmed away some excess plastic behind the screws that clamp the sides of the transmission together to make pinion gear changes as easy as pie. As an added bonus, the new motor mount had a wider base specifically designed to double as a hinge plate for my new custom 4-cell battery holders. (I was trying hard to make a 9.6V system work, as losing four batteries versus the stock 'Maxx saves 3/4 lb.)
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The new battery tray system was also significantly more secure than the stock version, holding the cells very firmly while giving them a slight bit of cushioning to smooth vibrations and eliminate chaffing. To remove one battery pack, one just had to pull out the body clip from the aluminum pin towards the front of the chassis tub, slide out the pin and let the front of the tray drop down, hinging on the base of the motor mount. Beautiful!
3/13/2001: At last I implemented with a permanent solution to the problem of snapping rear bulkheads! This new rear roll-plate solution bolts to my R/C Raven skidplate and to the chassis tub. As you see, I hadn't finished drilling all of the bolt holes when these pictures were taken, but the structure was there. The chassis mounting point would be reinforced with another aluminum plate for maximum strength.
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The point of this Mad Max-esque structure was to completely isolate the shock tower and its mount to the bulkhead from the damaging forces of roll-overs. I could have switched back to a plastic rear shock tower without fear, if I so chose. To the top of this roll-over plate would be attached a firm foam pad onto which, in turn, the new body (another MP6 1/8th scale buggy shell) would rest.
I also fashioned up some dual-stage springs using 2" Losi blue (3.9lbs/in) springs and cut sections of 2.5" Losi yellow (2.0lbs/in) springs separated by upper spring retainers butted top to top. Nice "cool" factor.
3/14/2001: Today I received a pair of Kyosho Atomic Force 17x2 "fat comm" motors and swapped them in. Much to my surprise, a test run showed apparently no loss in top speed versus the 14x2 Speed Gem's, plus a little better low-end acceleration and significantly increased run time. It looks like this is a winning combination. I 'll try it at the track this weekend.
3/18/2001: The Kyosho motors didn't let me down! The Maxx ran better than ever and ran strong to the end of every race!
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| The monster team savors its spoils: 3rd place in the Q1 offroad series |
5/25/2001: Well, a lot of my time has gone into the Valkyrie project of late, but the Spyder is still far from complete. In the latest round of modifications, I have changed the spring setup once again, still searching for that perfect setup. I may have hit the jackpot! I've also acquired some old MRC Thunder King (1/8th scale 2WD .21-powered truck) tires, retreaded them and fitted them to the Spyder with some custom-cut stiff foam inserts. At the Delta R/C off-road event today, I had more battery problems, but I've finally given up entirely on my Panasonic cells. I now just need to get a good charger (Novak Millenium) worthy of putting my new custom-matched & assembled 4-cell packs from Ballistic Batteries. Before today's monster truck main event, I hooked up with another racer who had a Millenium charger and he let me start a couple of packs cooking. I was only able to get 1/2 charge before the race began, but I ran it anyhow just for the fun of it. With these powerful batteries and this new spring setup and these new tires, the Spyder flew like never before. It was far & above the fastest thing on the track and very stable and controlled. I had no attitude problems in the air and I was able to take high-speed turns much sharper than before by entering a well-controlled powerslide. Smiles from ear to ear! These taller and narrower than stock tires also landed jumps extremely well.
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My only complaint is that the narrow grooves I treaded into these tires take a little more time to clean than I would like. I'll probably widen them at some point, but right now I'm just as happy as can be because of their great performance. As for the springs, the orange and blue ones up front are DuraTrax Maximum ST progressive-rate sets, the blues being quite soft and the oranges fairly sturdy. The short black springs up front are a rather stiff Losi set for touring cars. The entire setup gives a truly rebound rate, with the first few millimeters of wheel travel being fairly easy, and everything getting stiffer after that. In the rear, I kept a linear setup with one Losi blue 2.5" and one Traxxas spring on each side. Don't expect me to change this setup any time soon. Heh heh. Psych.