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Old 09-09-2010, 08:33 PM   #1
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Default Losi Ten-SCT done right

In this thread, I'm going to highlight the build of my Losi Ten-SCT conversion, and shed some light on the reasons behind doing it how I did.

First up is the chassis. I fabricated it of 6061 T-6. It's 1" over stock, which puts the wheelbase at 12.8" when the rear hubs are in a neutral position. They are adjustable +/- 1/8" or thereabouts. I didn't want to go the easy route of flipping the arms as this induces drive shaft angle issues. There's no sense in messing with the best 4x4 geometry on the planet (Losi 8ight 2.0) so I wanted to keep all those angles stock.

The Losi conversion, no matter how you design the hexes, is at the maximum legal width, so that narrows your list of bodies considerably. I made the body mounts to fit the widest bodies out there that I kinow of, the ones designed for a Blitz. The Stock blitz body mounts and fits just fine. Speaking of the hexes, I shaved and cut the stock ten-t hexes to 12mm and 5mm in thickness.


Left, right, and views from above. I decided against black anodizing at the last moment and went with blue to match the shocks. You can also see how much the driveline has been straightened. Center diff has also been moved rearward 10mm.




Blue anodizing turned out great...on the small parts. I need more amps for the chassis sized parts evidently. 10 amps was not enough, and 50 amps made more of a hard coat anodizing that doesn't take the color quite the same. Oh well, It's a racer, not a shelf queen.

Good enough for govy work I guess. During this build, one of my foremost concerns was making the truck look as factory as possible. I ended up being ably to retain the factory mudguards, and managed to fabricate the chassis with zero extraneous holes.


In my original mock up, I used a slash 4x4 rear bumper. It was fine, except it stuck out too far for my liking. Since this is my no compromise racer, I decided to bob the bumper. Turned out good except for one misdrilled hole. Note to self, don't try to watch TV and drill at the same time. This also removed 15 grams of weight, and moved 25 grams 1" lower on the truck. Front bumper is a stock slash bumper with a fabricated delrin piece for the top mount. Body mounts are stock slash 4x4 mounts, on delrin angles.



Coming from the slash 4x4, what I wanted most was a Low center of gravity, and better weight distribution. I think everything substantial is below the bottom line of the chassis on a slash if the images were superimposed. It's LOW and WIDE. The shiny part on the battery try is vinyl I used to hide the esc wires under the raised lip of the battery tray.
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Old 09-09-2010, 08:34 PM   #2
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Another weakness of the other trucks out there is their poor front end geometry. I can go on forever about suspension theory and design, but I won't, unless prompted. I will just point out how deep the suspension is set inside the 0 offset wheels, like it should be, to align the pivot points with the wheel centerline. Every other 4x4 sct to date fail miserably in this regard when in ROAR legal format.



Driveline significantly straightened. Uses a ten-t rear center DS for the front center, and 8ight-T rear center DS for the rear...slightly lathed down on the ball end.
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Old 09-09-2010, 08:34 PM   #3
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Not being satisfied with the stock blitz body, I ordered a Desert Rat 2.0 Blitz body. The Rat is slightly wider up front to clear the width a little better. More importantly, It pushes the legal limit on body height. The roof line is over 3/4" lower than the stock blitz body. If you don't think that matters, raise your current bodies just half that and see what happens to your traction rolling frequency The body also follows the lines of my designed parts very closely, fits like a glove. It's also shorter though, and made my rear bumper stick out even further. Being as I race with some questionable fellows from time to time, I decided to bob the bullseye to make it easier for them to resist Pitting me :wave:






Ok, on to WHY I moved the center diff backwards and towards centerline ~10mm. Three reasons really. First, weight distribution. The 550 motor and center diff are significantly heavier than the battery/esc/and battery tray. By moving the center diff more central by 8mm, the left to right weight bias is exactly the same(with a 330 gram battery)....so I actually improved on weight distribution. Secondly, if you have ever driven losi 8ight scales, you know the angle of the front drive shaft cause it to produce heat and wear prematurely. heat=drag, and anything to reduce drag is a great thing for electric vehicles. The center rear driveshaft is slightly angled angled now, as you can see in the pic. Third, by moving the center diff over, and back, by using the 10-t rear center driveshaft on the front, now allows the use of a Losi 8ight-T rear center driveshaft in the rear as it becomes the perfect length. Using a longer front center driveshaft further straightens the center driveline as well. This also moves the front to rear weight bias to a "stock" location by shifting the diff rearward 10mm. Along with careful placement of the battery tray, the for/aft weight bias is exactly the same as a Losi 8ight E buggy(which should make sense cause it has the same footprint). Will this slight angle of the rear driveshaft negate the benefit of reducing the front drive shaft angle? I don't know...but the primary focus here was a perfect weight bias. It certainly would have been easier to leave everything in the stock location....but I strive for optimal and not what's easiest.

I hope everyone enjoys the post and the pics :thumbsup:
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Old 09-09-2010, 09:11 PM   #4
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looks great. If losi makes one I will probably sell my Jammin. I also really like the desert rat body. Just got one today and painted it up for my blitz. Looks much racier then my silverado body.
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Old 09-09-2010, 10:07 PM   #5
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You have way to much time on your hands Josh Looks like with the cheater truck you should have no problem putting a full lap on everybody now ...... it sure does look perty though
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Old 09-09-2010, 10:38 PM   #6
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Originally Posted by pink_sleeve View Post
You have way to much time on your hands Josh Looks like with the cheater truck you should have no problem putting a full lap on everybody now ...... it sure does look perty though
I guess we'll see. Maybe with all your spare time you could make one too
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Old 09-09-2010, 11:51 PM   #7
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I guess we'll see. Maybe with all your spare time you could make one too
I would have made an SC44 instead
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Old 09-10-2010, 02:43 AM   #8
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Looks really good Josh. When will the chassis's be ready?
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Old 09-10-2010, 02:57 AM   #9
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Knowing Josh, chassis' will be ready by next summer!!
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Old 09-10-2010, 06:40 AM   #10
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Looks really good Josh. When will the chassis's be ready?
I'm not sure. We'll see how well this chassis works first, and go from there
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Old 09-10-2010, 06:42 AM   #11
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I'm not sure. We'll see how well this chassis works first, and go from there
When you get the chance, we'd love to see a vid of it in action...
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Old 09-10-2010, 08:58 AM   #12
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Do you know what your front to rear weight ratio is? I am working on doing a factory looking conversion too, but I was planning on mounting the motor and battery a little farther back than what your are. Some video would be great if you could!
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Old 09-10-2010, 09:20 AM   #13
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Do you know what your front to rear weight ratio is? I am working on doing a factory looking conversion too, but I was planning on mounting the motor and battery a little farther back than what your are. Some video would be great if you could!
1470 grams front/1430 grams rear so it's just 40 grams from being 50/50. I think if you went any further back with the weight it would have some handling quirks. The Eight E 2.0 was right at 49/51 weight bias.

Last edited by Ridley; 09-10-2010 at 09:31 AM.
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Old 09-10-2010, 11:01 AM   #14
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Videos? Maybe after next weekend eh Josh?
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Old 09-10-2010, 02:01 PM   #15
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Videos? Maybe after next weekend eh Josh?
Hopefully I'm fast enough with it to be in your OEOSS race video
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