Yet another DuneRunner :)

[Phill]

No matter what you use for the brake not having the end points correctly adjusted will overload the servo

Fuel line works great with the correct adjustment

That coupling disintergrates no matter what

After about 90 minutes of running, I am completely impressed with how the dunerunner is evolving. The drivetrain had a lot of friction in the beginning, now it's much-much better, the car is coasting for long distances, the brakes also improved dramatically (altough I think I'm still gonna replace the spring with a stiffer one) and the engine is really starting to come alive! I'm still not giving it WOT, I want to get through ~2L of fuel before considering it fully broken in, but still, using the road tyres on pavement, it's drifting, it's doing donuts as soon as it catches the slightest trace of dirt, I love it Regarding the brakes, I think what some people do (replacing the spring with a piece of fuel line) could be partially responsible for the failure of the throttle/brake servo. From my understanding of the system, the servo needs to be able to make its full travel when braking and fully compress the spring. The power of the spring will be the one doing the actual pushing on the brake lever. Replacing it with something that doesn't allow the servo to go all the way (like a piece of fuel line) I think would put a lot of stress on the servo, increasing the chances of it failing. I'm gonna wait for 1-2 more hours and if by then I'm not completely satistified with the brakes, I'll just replace the spring with a slightly stiffer one.

On the downside, you can see below the cost of stupidity. I use a piece of napkin in the exhaust to keep the smell of gas as low as possible when storing the car and today I obviously forgot to take it out before starting it. It only idled for 2-3 seconds before I realised my monumental mistake and removed the napkin, but apparently it was enough to blow the coupling As a bonus, I didn't notice the problem (everything sounded normal) and ran it like that for 25-30 minutes which obviously got oil everywhere on the rear of the car... Any idea if the baja couplings will fit? I have an upcoming order from DDM and they don't have the original redcat coupling.

 

[Ice_2k]

No matter what you use for the brake not having the end points correctly adjusted will overload the servoFuel line works great with the correct adjustment

Won't the fuel line "refuse" to compress all the way and thus stop the servo from getting to the endpoint?

 

[Phill]

Won't the fuel line "refuse" to compress all the way and thus stop the servo from getting to the endpoint?

You adjust your endpoint to suit the length of fuel line

If you have your servo end point at full turn you will end up burning it out

See your radio manual for end point adjustment

 

[designed2survive]

My take on throttle servos.

Wether you use fuel tubing or spring, load still has to be there therefore servo will suffer. High torque servos will suffer less than others. Too much load though will shorten the life of that servo faster. Specially when used in prolonged period of time at once.

The key is to:

1- find that middle groung for enough load without sacrifying braking power.

2- set your endpoints properly. Braking endpoint need to be set to no more than when you reach full braking. After that you are not adding more to the braking, you are adding more stress on the servo. Throttle endpoint should be set to not pass the point where the carb throttle shaft can no longer rotate.

The servo is eventually gonna die one day, but with good endpoints and proper load you will be maximizing it's life.

 

[Ice_2k]

Thanks guys, I'll give the tube line a go then.

 

[Ice_2k]

Yet another DuneRunner

Just realised... isn't the dual rate adjustment on the stock Tx for the steering? How do I set endpoints for the throttle servo?

Please don't tell me I need a better radio )

 

[Phill]

Check your radio manual

Just realised... isn't the dual rate adjustment on the stock Tx for the steering? How do I set endpoints for the throttle servo?Please don't tell me I need a better radio )

 

[RampageHopUps]

Just realised... isn't the dual rate adjustment on the stock Tx for the steering? How do I set endpoints for the throttle servo?Please don't tell me I need a better radio )

I won't tell you then.

 

[Ice_2k]

Check your radio manual

The knob on the Tx is clearly marked "ST. D/R", so it's definetely only for steering. They probably used the same radio they use on the electric models...

@Rob Tell me what?

 

[Dongskie]

Our stock radio doesn't have an endpoint adjustment, only a trim.

We need a better radio.

 

[RampageHopUps]

@Rob Tell me what?

You asked not to be told you need a better radio. Alot of people don't need a better radio, but you are looking for more features than a beginner radio could offer.

 

[Ice_2k]

Yeah, I figured that out a while ago, I was just kidding

 

[Ice_2k]

Added HPI air filter, outerwears for air filter, flywheel, pull start and snappy rc fuel venit kit. Work in progress. At the moment, I'm having some issues with the snappy kit, fuel starts leaking everywhere around the grommet when priming the carb.... I just got a reply from the snappy rc guys telling me that I shouldn't fill the fuel tank all the way because it will leak. I have to say I'm a little dissapointed about this... I spent ~37$ (I also got the FFRC brass fittings) and I was considering this an upgrade... altough my stock venting was working just fine, I didn't have any issues with it... seems a little weird that after spending some money I now have a solution which no longer allows me to fill up my gas tank...

 

[Ice_2k]

 

[phreerider]

good stuff man!

 

[Ice_2k]

Thanks bro! Any advice on the snappy kit issue? I'm seriously considering reverting back to the stock tubing....

 

[phreerider]

the vent thing , snappy has a lot of parts ...more opportunity to leak. most will leak some. the stock is my choice with remote vent on cap. if the vent is working the grommet/hose union on the tank should seal and remain dry...a basic fuel filter on the cap is fine. the one way valve thing may not be working so well if the bulb is pushing out fuel.

the less you mess with the grommet the better, they can tear if you get too rough with them. lube with 2 cycle oil a bit and makes everything easier.

 

[Ice_2k]

Now I wish I would have left it alone Stock was going great, no leaks, no nothing.... I'll try adding some tubing before the vent valve, maybe that will make it leak less....

 

[phreerider]

the stock tubing will crack over time BUT ITS THE EXACT SIZE and works . the more you handle it the more it(the grommet) will leak. vent thru the cap keep it easy. expect a little(tiny) leak at cap nipple tap , but its nothing compared to a wet tank.

 

[Ice_2k]

Do you happen to have a link to the remote cap vent you're talking about?