Brushless LST2 conversion - This is how to do it!!!

[lincpimp]

Ok, here it is. This is the big daddy of monster trucks. Nothing I have fooled with has all of the strength and design this truck has. Plus it has really big shocks!

Electronics specs: Hacker c50 11xl (1500kv), MMM V3, FP 4500 30c 6s lipo, stock twin 590mg steering servos, spektrum 3001 rec. Gearing is currently 63/24, but I plan to get a 26t pinion and run a 59t spur. Current top speed is just shy of 40mph. I have a 10xl c50 to try out, and a 1521 1y (big power!)

So I actually started with an Aftershock. Good part about this model is that it is relatively cheap at $400 new (compared to a 650 dollar lst2), plastic body shocks (still plenty strong, and lighter than the lst2 al body shocks), and the forward only tranny. Also has great diffs with al cases stock. I sold the xr2i radio and nitro motor so I got some money back (about $150 IIRC...)

Bad part is that it comes with the weaker original lst suspension arms, driveshafts and hubs. This is not too bad, but the rear tie rods (like a tmaxx, the truck has matching front and rear hubs, so it has to have rear tie rods, and this truck likes to bend them and rip out the rod ends). I upgraded to the lst arms, hubs, and big 8mm outdrive driveshafts with giant 15x21mm inner bearings. I run 20mm hubs and losi 420 rims with 40 series rubber.

So the mods started with me putting the TiN coated ring and pinion gears and some nova rc 7075 diff cups in the diff cases. Only took one shim to get the gears perfect, and that shim happened to be in the diff stock. This kind of thing indicates good quality machining that is held to tight tolerances. I only upgraded the diffs cause I got a smoking deal on the gears, and figured why not. Plus I plan to thrash this truck and had issues with savage diffs holding up under big power.

After that I swapped the gears in the tranny to get a slighly higher ratio. Simple mod, requires slight clearancing on the inside of the trans case. Completely reversible too. Basically threre are 2 gears in the tranny, a 22t and a 23t, I swaped them to help out my slower turning motor (1500kv on 6s) get to 40mph with my available gearing choices. Picked up a tdr (the dude racing) single speed hub, and a losi 63t TiN coated spur gear. I also got the motor mount from tdr, nice stuff, and the only game in town for lst electric conversions.

Now since the FOC that the aftershock comes with eleminates the reverse and high/low selector (mechanically actuated, kinda cool), and the tdr single speed hub eliminates the OWB, I can use motor brakes! That also means the brake servo is removed, thus making room for a forward mounted battery tray. This is critical to handling, as the fd rear mounted tray is a crap idea (imagine that...).

Made the tray out of kydex (thanks rchippie!) as usual, and mounted it to a pair of custom riser blocks to clear the servo wiring. I did have to cut the hinge portion off the rec box. Hated to do that, but I needed the clearance. The flightpower 4500 30c 6s lipo is almost square in cross section, and I did not want to push it up against the tranny as it would cause issues with the spur gear. I added 2 small posts inside the rec box and use 2 body clips to hold it on, along with the stock front pin. Also made the MMM mount out of kydex, and used the stock upper rear brace screws to hold it down.

I would like to add that was the only mod done to this truck. No holes were drilled in the chassis, nothing clearanced, ground or otherwise messed with. Only aftermarket parts are the diff cups. This is a very well designed truck. The only mod I will be investigating is a single steering servo conversion. Nothing wrong with the stock twin 590mg setup, it actually works very well, but I want a single servo. This will be tried out on my upcoming lst based 6x6 project (you will all want to see this...) and plan to use a 1/4 scale servo too (so cheap and sturdy).

I have thoroughly researched this truck (the lst forums are great) and it is by far the best I have tried. It is a bit heavier than an erevo, but it is bigger and definately stronger. Plus the design is very simple and effective. It takes about 1-2 mins to get the diffs out, maybe 8 screws total. But the drivetrain is very strong, so after the diffs are shimmed (the stock aftershock diffs very prefectly shimmed out of the box, btw) no real need to get at them, unless you want to experiment with various weight fluid. Suspension comes off easy too, tranny has 4 bolts, not much to remove to get the servos out. The most burried part is the steering bellcranks and they are not difficult to get to either. Less than 10 screws removes either bulkhead assy (no need to do it to get to the diffs). Bumpers are big and flexible, and my only complaint is the lack of a wheely bar! I can put a muggy wing mount on, and use the wing to keep the truck on the wheels! The tranny is very strong, all metal gears and the bevel output allows the motor to be mounted transversly behind the tranny, eleminating most of the torque twist and adding force to keep the front wheels on the ground (touring car tech here).

Ok, now for the pics, thanks for the patience and feel free to ask me anything about this truck!