Like I said - “high” speed may not be the answer. 
My truck is grounded for now until I get the new servo saver so I guess I’ll work on code, maybe work on the model railroad, work on the enclosure or, hell, just spend some time with my wife!
Yeah, well…
For right now, I got almost the entire Xmission taken apart. The only reason I am stopped is because my electric screw driver ran out of juice, so I have to wait for it to recharge. Whatever I fried, it’s deep within the case.
Man up, manual screwdriver!
Hahaha… @ Chris. Yea dude put your wrist into it.
I would, but using a manual screwdriver would be a great way to strip these guys. You have to be able to apply pressure as you are unscrewing, otherwise the screws will slip. Slip == Strip.
This is not fun work :
Hehe, i remember having all these problems before i got a LST2. Broken parts every day. I figured it was cheaper to get the more expensive truck and break one part a month if i reallllly smashed it.
For ABS systems, why not just build one yourself? Use a reflection sensor on your wheel and paint the wheel alternately black/white for reflection. If breaks go on and the RPM drops too fast, ease off on the break power (or drop brakes completely then re apply slower.)
As far as wheelie bars go, we’ve never needed them. Nitro trucks take a second or so to spool up and have clutches that slip a bit, so while you CAN back flip it taking off with the modded engines we run, you have a bit of control. We can hold a wheelie for 10-15m.
Just remember, your controls are proportional, you don’t have to go on/off 
Here’s an old video of us bashing one day: [url]http://www.vimeo.com/1250906[/url] - I’m “Mark” in that video. Glenn stripped 2 spur gears (engine was out of alignment) and I broke a fuel tank (rear shock tower crashed into it). The wing at the back had to get 2 new clips but was fine other than that. The “why savages suck” is my old Savage that i bent 9 shock shafts on and broke a bunch of other stuff in one day (including bent chassis rails, bent aluminium A-Arms). That was when i switched to Losi.
[url]http://www.vimeo.com/1250910[/url] is lots of big air on concrete. Remember these weigh 8kg+ with a full load of fuel.
If you want to stop getting back flips, why not add a distance sensor (maxbotix sonar?) to the bottom of the truck. One at the front, one at the back, if the front goes up to much, ease back on the throttle. If there isn’t a waypoint too close then just hold the wheelie for “mad props”.
Stiffer springs and heavier shock oil weights will save you a lot of these tumbles i think though. You roll because the suspension is softening up too fast, so the G force can compress it too much. If you don’t have oil shocks, upgrade to oil + spring.
The most awesome r/c car hobby shop folded a little while ago so unfortunately i cant point you there. Try [url]http://www.amainhobbies.com/index.php/cPath/1/n/RC-Cars-Trucks[/url] - they are where people seem to be going now for good prices & good range. They should stock the full range of spares for your trucks.
Well, I don’t know what’s wrong. I took apart the entire thing and everything looked normal. No stripped gears or anything.
I guess the only choice I have is to put it back together and hope it works. If it doesn’t I guess I’ll take it to the hobby shop.
Mark, do you know what might be wrong? I took it off a small jump and when it landed it just made a grinding noise when I gave it throttle. When I opened the transmission cover, the motor was disengaged from the slipper clutch. I re engaged it, but I still got the grinding noise.
no teeth missing or not meshing properly? If the mesh is too tight it can grind a bit. You should be able to put a bit of paper into the gears and have it run through (about 0.5mm gap between the teeth ends and the wheel on the other gear.
Are any shafts bent?
You don’t have a bit of munched gear in there somewhere, or some sand?
Your motor isn’t making the grinding noise? If you get sand into the motor it will grind like buggery before the sand takes the varnish off the wires and everything shorts out in a big plasma-y explosion Bent motor shaft will do similar.
Can you isolate the grinding noise with partial rebuilding?
Can you upload high res photos of your gears all layed out and the transmission and your motor->spur mesh?
Hi Mark,
I examined all of the gears very closely, they are all pristine! No nicks, scratches or missing teeth :think:
No shafts bent…
Motor is spinning smoothly…
Can’t isolate the sound with a partial rebuild. It’s coming from the diff though.
I almost have it back together. If it works, great! If not, I’ll see about posting some high res stuff.
Is it diff (which is at each end of the car and drives the wheels) or is it the transmission (in the middle of the car)?
Mark - one of the reasons the Stampede seems to be popular is price , clearance (4") and the fact that the body mounts are nearly level front-to-back. It makes putting up an electronics tray a lot easier.
On the Maxbotix thing - I’ve done a lot of testing with these (I love 'em) and under 20cm, at least on the XL models all range as 20cm - with sonar you just can’t get that close and get a stable/accurate reading unfortunately. You could use something like IR though, like a short range Sharp sensor if you wanted to but I don’t think it’ll be worth it.
Since this is a robot (well, going to be) rather than a racer/basher/etc some of the requirements/needs are different. The Stampede seems to be a decent truck for this function once we work out some of the quirks (like me re-aligning the wheels for example).
Any suggestions you have though I’d love to hear. You’ve got a lot more experience with these buggers than I do.
Mark,
If you are familiar with the layout of the XL-5’s Xmission case, it’s something in the motor side, IE NOT the clutch or the pinion.
at any rate, I put everything back together, and it seems to work! There are a few weird sounds, but those will probably resolve themselves when I grease everything.
You have a stampede right?
Does it grind when you have the transmission out by itself, or only when it’s connected to the universals on the drivetrain? Are the uni joints clean?
Put a layer of Molybdenum grease on every gear, if they are metal you can put a quite a bit on there, if it’s traxxas’s usual plastic-fantastic job then just get a very light layer and make sure everything has 0.1mm or so of grease on it with no gaps.
If the planetary system is plastic, is anything cracked? try pulling the gears apart (ie: grab a gear on either side with your fingers then try to pull the gear apart).
Are your ball bearings all spinning freely? Ball bearings can be unseated inside with large impacts if they are not well made. Make sure they can all spin for a second or so if you grab the middle and spin the outside with a finger. If not, get some CRC/WD40/Silicone spray in there. Really flood them while spinning it to wash them out.
If you have metal parts and they have dirty (ie: dust and grit) grease on them, oven cleaner or citrus degreaser (the aerosol sort that foams up) is great to clean them.
Hi Mark,
Thanks for your help, I think I’m just going to hand this one over to the hobby shop. I did my best on it, but I don’t think I did a good enough job. Everything works, but it sounds funny and the clutch is wobbling.
EDIT: The is a brand new car, and I have only been running it on concrete so it is very clean. Nothing is cracked.
Sounds like a bent shaft to me then. Only a tiny bend is required to get some real wobbles happening. If you run your motor without the pinion on it, does the shaft spin straight? When you look at it, you should see a solid line the width of the shaft (5mm) not a \ / shape.
Check the shaft on your spur too. Put it on a flat surface (like a desk) and roll it along. If at any point there is a section rising up even the tiniest amount you’ve bent something.
Don’t bother trying to straight a bent shaft, just replace it. You’ll never manage to fix it - i’ve tried many times before to fix them but never quite managed to.
At this point, I have the car back together again and I have no intention of ever opening the tranny up ever again. I’ll let the hobby shop deal with it. They need the business anyway.
My might be right about the bent shaft, but how would that happen? It hit a tree root when everything happened. Also, wouldn’t the tranny be totally isolated from shock?
Things have weight… shock force makes things move, if something can move independently of something else then you get bent stuff.
You’d be surprised at what damage internals of a car take. This is one of the reasons why i dislike Traxxas’s engineering, everything is plastic - and usually fairly brittle plastic too unfortunately. Tamiya are worse.
Well i hope your LHS can fix it cheaply for you Make sure you tell them to call you before doing any work/replacing parts. Sometimes they go a little silly and can cost you a bunch 
What do you think the going rate is? Like $20 an hour? How long do you think it would take an experienced tech to rebuild the tranny?
I have no idea what it would be because i dont know where you are.
But hobby shops here don’t so much charge per hour but are more of a :
You can have it fast or you can have it cheap. Choose one.
They will fix it fast if it’s a priority and charge you a lot for it (usually hourly) at about AU$40 or more, or they will fix it when they have nothing to do and do more of a flat rate for it.
I’m in Missouri, USA. My nearest is Hobby Town USA.