Building the Invincible Summit

[RMNixon]

I brought my first Summit in January of 2010 and the past five years with it have been a blast! I drove it stock for about 6 months, then put a Mamba Monster/2200kv brushless system in it. I drove it that way for another 6 months or so until the diffs blew up. I rebuild the diffs, put the brushless system in a proper 1/8th scale monster truck and went back to brushed. I had just gotten into FPV around this time and wanted to go back to brushed to make a smooth FPV rig out of it. In addition to replacing the brushless system, I ripped out the stock radio system and put in a 9 channel Turnigy system running DragonLink and a 1.2ghz video transmitter and pan/tilt control on the camera. It's a ton of fun, especially in the winter when it's too cold to stand outside and control an RC.

While I've been having a lot of fun with my FPV Summit I really began to miss having a stock Summit for when I just wanted to go bash around and not worry about ruining a ton of electronic equipment. I already have a few "go super-fast" 1/8th scalers, a comp-level AX-10 crawler and a couple SCX10's for scaling duties, so I don't need something to be a fast basher or a super-slow crawler. What I'm really after is a super, ultra reliable trail truck that can do a bit of everything and NEVER break down. The Summit in its stock form is almost perfect for this!

I debated for months whether I should buy another Summit for non-FPV duties and finally decided to go ahead and do it. It was a lot of money to spend and I was worried about buyer's remorse since I already have one Summit. I can tell you, I have absolutely no regrets about increasing the size of my Summit stable!

As I said, this Summit is going to stay mostly stock - most all of the upgrades that I make will be to enhance its durability and reliability rather than increase its performance. The goal is to be BULLETPROOF!

I've only made a few performance-related upgrades. The first was the addition of a Holmes Hobbies BRXL WP ESC. Compared to the EVX-2 (or ANY other brushed ESC) it's absolute butter! Being able to set throttle curves and ramp up/down power through Castle Link really changes the behavior of the truck and the low speed control is SICK! Oh, and drag brake on a Summit is great! The second performance-related upgrade was to ditch the stock rear springs for Traxxas double-orange springs. I run the truck with these springs front & rear with no pre-load. The truck sits with the driveshafts just above level and it performs SO much better than stock. The last performance-related upgrades I made were to gear down with an 11t pinion for better low-speed control and the addition of the Traxxas roof light bar for better night-time playing.

Now on the durability upgrades!

From my experiences with my first Summit I learned that the drivetrain is the weakest link on a Summit. I began by loosing the slipper clutch 1/4 turn out from stock (about 1 & 1/4 to 1 & 1/2 turns out from full spring compression). I am hoping to find a setting soft enough to keep the driveshafts from warping and breaking, but not so loose that I burn up the clutch. So far, this seems to be the optimal setting. After 1 month of hard, almost daily runs of 1 to 1.5 hours my driveshafts look brand new with no warping or distortion around the CVDs. FWIW, I had MIP axles on my other Summit and couldn't get them off fast enough. They are NOT a durability upgrade! In the future I am hoping to run a set of LEM aluminium axles once they're available.

Next up were the diffs. I purchased a set of LEM aluminium diff cups with hardened gears. I assembled these and shimmed them up so there's no play or binding in the diffs or diff cases. I removed the stock diff oil and repacked the diff and all diff bearings with Bel-Ray waterproof grease. Finally, I filled the bulkheads with hot glue after putting the diffs back in to keep dirt out and keep free-play/slop to a minimum.

Next up in the driveline was the transmission. I hate all the slop it has and I think, given enough time, this slop will cause wear on the tranny. Now to be honest, I've NEVER heard or read about anyone having issues with a Summit transmission, but why take chances? I installed a LEM aluminium dog carrier in the tranny and the difference is night and day!!! The transmission drops into low/high gear immediately and there's almost no slop! Very worthwhile upgrade!

The final driveline upgrade to was take out all the stock wheel bearings, open them up, pack them in waterproof grease and re-install.

To ensure no ESC problems I also installed a 10amp Castle BEC unit set to 6.0 volts. The truck itself runs off of 2 4s 4500mah batteries wired in parallel. This gives me 9000mah of 4s power, enough to give me 1.5 - 2 hours of runtime on a charge. The Holmes ESC runs on anything from 2s to 6s, so I also keep a small 1500mah 3s battery in my pocket when I'm on the trail. This gives me about 15-20 min to get back home without having to carry my truck back.

Topping off the durability upgrades are a set of T-Bone racing bumpers and skids, Outwears motor and chassis covers and stock Canyon tires that have been sealed with RTV silicon to make them waterproof.

And that's it! Like I said before, this truck will stay on 4s, running the Titan 775. When LEM releases their aluminum axles I'll pop on a set and call it good. My goal is to never have to stop this truck for a repair, only for planned maintainence and cleaning. The only failure points I see left are servos, arms and maybe a worn driveshaft or two after some time. I've got spares of all these on my bench ready to go.

Thoughts and feedback welcomed, especially any weak points I may have missed in this build.


Here's a quick summary and links to everything in case you want to check it out yourself!

Vehicle:
- Traxxas Summit 1/10


Performance Upgrades:
- BR-XL WP ESC
- Double Orange springs in rear
- 11/68 gearing
- Traxxas roof light bar


Durability Upgrades:
- LEM Aluminum Diff Cups and hardened gears
- LEM Dog Carrier in transmission
- All wheel and diff bearings packed with Bel-Ray Waterproof Grease
- Castle BEC
- 2x 4S 4500mah in parallel
- T-Bone Racing skids and bumpers
- Outwears motor cover
- Outwears chassis cover
- RTV silicon sealed Trxxas Canyon AT tires


And now pictures!
Here it is with the stock shell painted olive drab:



And with its new shell in Tamiya PS-19 Camel Yellow:

[rcgeek65]

Sorry if its not a big summit, but do you guys know if these hot racing diff gears for traxxas 1/16 trucks are any good? Hot Racing Traxxas 1/16 Summit VXL RC Car upgrades and Hop-ups

[fyrstormer]

rcgeek, those diffs work well, but you have to modify them a little. They don't have seals to hold silicone diff oil inside, so you have to use grease instead. Before assembling the diffs, you need to carefully sand-down the edges of the spider-gear holder and the two sides of the diff case, so they are as flat as possible. (400-grit emery paper from the paint section of an auto parts store works well.) That will allow those parts to have the tightest possible fit, to minimize grease leaking out from centrifugal force. Unfortunately, Hot Racing doesn't do this for you.

Unless you're running a Mini Summit with tons of power (in which case, you should just convert it to a MERV instead), you shouldn't need to upgrade the diffs at all, just shim the diffs to ensure a good mesh and use a good waterproof grease on the ring and pinion gears.

[fyrstormer]

RMNixon, in addition to the double-orange springs in the rear, consider putting purple springs in the front. They work very nicely with the double-orange springs in the rear, since the front rocker arms have more leverage, thus making the front suspension softer.

Also, have you tried TVR's Ball-X Rzeppa-style CVD axles? They're true automotive-style CVD axles, and they come with boots to keep grit out of the balls-and-channels assembly.

[T I N Y]

Good luck...keep us up to dated on how it's going..

[twissted]

I really like the LEM stuff.

[thehighroad]

Nice truck. I might add an e-revo wheelie bar. They do a nice job protecting the rear bumper for when the throttle finger gets a little grabby on asphalt. I like to keep my stuff pretty new looking and one wheelie is enough to scrape the hell out of the soft plastic bumper and led's. The other thing is also cosmetic and it is adding clear coat or clear tape to the front chrome bumper. They are always scratched and look nasty. Putting the clear coat or tape on them keeps them looking new.

The dewalt swap to me is a good durability upgrade too. They are easy to work on and are actually rebuildable. I haven't had a 775 fail on me though so I guess that could be something to do if that happens.

The stock body is pretty heavy and generally the lighter it is, the less stress on the drive line and chassis there is. Along those same lines if you run it in water, be sure to have some pin holes in the tires so that it can drain. Otherwise the tires get water logged and will hold it for months. Water logged tires just murder the drive line. The stock wheels and tires are really light weight when dry though so that is good. Mud slingers, big joes and the like are way too heavy imo for the axles and diffs.

I can see the dual servos swapped out for a single being worth while. They are always fighting each other and lack torque anyways.

[twissted]

The strongest Summit on the Planet!
Well kinda! It a Losi LST2 with a Traxxas Summit Tranny!
<iframe width="560" height="315" src="https://www.youtube.com/embed/4zBBPhoDylE" frameborder="0" allowfullscreen></iframe>

[cmbscx10]

Nice build and great write up.

Question on the LEM Upgrades. I am looking for the dog carrier but the website states it is out of stock. The "Contact Us" is blank. LEM on Fleabay is basically blank. They have a summit dif cup and 2 other items. Are they out of business?

I am deciding on a Summit or Wraith trans for a build and if there are no upgrades available for the Summit trans it is off the list.

Thanks for any info.

[twissted]

You have to email them through Ebay. He only seems to respond there. Ask him when the dog carries are going to go back into production. I have 3 paid for and waiting. If more people will ask the better! I need another for a build I'm working on now also.

[cmbscx10]

Originally Posted by twissted

You have to email them through Ebay. He only seems to respond there. Ask him when the dog carries are going to go back into production. I have 3 paid for and waiting. If more people will ask the better! I need another for a build I'm working on now also.

Thanks twissted. Sent them an ebay message.

[alexchen86]

RMNixon, I had a used trashed Summit off Craigslist for cheap. tranny was barely operational...rebuilt everything back to stock with no intention of keeping it. Basically fix it up throw on anew body rebuild what needs work and sell it off. At that point I already had a brushless Emaxx edition fully loaded, a completely bulletproof old school eSavage, a brushless edition Erevo completely stock, a platinum edition Revo 3.3, and an original Slash 4x4 Platinum.

I was not looking for another monster truck let alone Traxxas product. I saw way too many things that could go wrong which the previous owner probably never even read on how to properly engage the lockers or whether he kept them open I don't know....at least the servos were all or working fine surprisingly. Then I see people dropping in huge Tekin RX8 1/8 brushless high speed high torus setups on 6s and I'm like wow the 775 Titan can already destroy a Summit in the wrong hands....how is this possible running such a ridiculous sensored brushless system?!

We all know the tranny is the weakest link so a good slipper or a well adjusted stock slipper is a must at the expense of torque loss but saving the transmission internals. It wasn't until I built my own 11 pound 1/10 KOH scaler on 4s while a few months later the Wraith came out....

That's when I learned lightweight rigs are the best crawlers and trail rigs. Perfect for a Summit....put her on a diet! You can't ask for more suspension crawling flex with Indy front and rear and the ability to individually control the lockers.

The days of heavy steel and bling on any off road vehicle is over. The more weight, the more stress on the weakest component next to break, and of course heavier rigs are going to experience inefficiency from heat build up in the electronics especially having a large truck with huge tires wheels!

[cmbscx10]

Originally Posted by cmbscx10

Thanks twissted. Sent them an ebay message.

Just an FYI. I have not received a response from LEM. A little disappointed to be honest.

I went with a Wraith Trans instead. If i blow it up for some reason i might look at the summit trans again.

[twissted]

I hear that installing metal gears will help with the Wraith tranny. Good luck with your build. I just got a refund from paypal for the 3 that I ordered. I don't think he is into the R/C's as he once was!

[fyrstormer]

Steel gears are a must on the Wraith. And if you're not going to run a sensored brushless motor in your Wraith, you need the RX4WD AX2 gearbox (which already has steel gears) so you can lighten the load on the brushed motor when crawling.

[fyrstormer]

Originally Posted by alexchen86

The days of heavy steel and bling on any off road vehicle is over. The more weight, the more stress on the weakest component next to break, and of course heavier rigs are going to experience inefficiency from heat build up in the electronics especially having a large truck with huge tires wheels!

That is ridiculous. Steel and titanium have vastly higher strength/weight ratios than plastic does, and even cheap aluminum has a comparable strength/weight ratio to plastic -- good aluminum is better than titanium in that regard. (carbon fiber is nice if you can get it, but instead of bending it just snaps when it fails, and cutting it generates tiny airborne carbon fibers that can cause lung cancer.) Yes, metal weighs more than plastic, and yes, metal parts can exert more force on the remaining plastic parts, but eventually you get to a point where you've replaced all the parts that can't handle the increased load with a combination of steel, titanium, and aluminum, and you have a rig that won't break anymore. I reached that point with my Wraith about 7 months after I bought it; the only thing I've replaced on it since then is the axle housings, and only because the crappy little screw-holes that the lockouts and steering knuckles attach to stripped-out. Now I have beef tubes in the axles, and the lockout and steering knuckle screws thread into the beef tubes instead. They're never going to come loose again.

[twissted]

Carbon Fiber rules!

I use a lot of carbon fiber that has seen a lot of rock duty!
Watch the video.

[fyrstormer]

Carbon fiber is indeed nice, but its applications are limited. It can't be used on any parts that might scrape against rocks, because it will splinter and lose strength extremely quickly.