The rec.models.rc.land Frequently Asked Questions archive
Bear with me here, folks. I've been railroaded elected as the person to generate and maintain the FAQ for the rec.models.rc.land Newsgroup. That's fine with me, but I'm going to need some source material from you guys- stuff to post here. I've helped a lot on the newsgroup, but right now I just don't have time to generate this entire document from scratch. So I need you guys to E-mail me with tips to be posted on this site. Anyone whose information is used here will be given due credit- so please, include your real name [if you like], non-SPAM-blocked email address, and any other pertinent information you feel I may need, with your submission. I am in particular need of any input you may have on the subject of turbochargers for nitromethane engines, at the moment.
...and for you wiseacres out there.. that email address is RC_FAQ, *not* RC_FAG.... ya bastards!
How do I keep my starter wheel on my handheld starter motor from flying off the hub while trying to start my nitro-powered cars?
This is a good question- the answer is to use Shoe Goo or Goop adhesives to attach it to the hub. Make sure to use enough to make a complete bead on BOTH sides of the donut, since only securing one side will concentrate the centrifugal force on the unsecured side, and may present a hazard if the donut flies apart.
What do I need to solder properly, and how do I do it?
If you're just starting out, I'd suggest getting a 60 watt iron at Radio Shack. While you're there, get a soldering iron holder [a wire loop that fits into a weighted base], a jar of tinning solution, Rosin core or Silver Solder [do NOT get acid-core solder! It eats electrical connections!], a tube of flux [again- not acid flux], a pair of hemostats, wirestrippers, heatsink compound [optional], and emery cloth.
For the iron, I'd suggest you buy it as 3 seperate pieces- heater unit, tips, and handpiece. This will enable you to expand your soldering tool collection in the future as you run across jobs that don't require 60 watts of heat- like replacing servo PCB leads and such. Plug your iron in, and dip the hot tip into the tinning mixture. Wet the sponge that came with the spring stand, and wipe off the excess on the sponge. You'll want to do this as often as necessary to keep the tip bright and shiny- it will tend to gather inclusions and trash from the process of being used.
So now it's time to solder- let's use the example of soldering motor leads and capacitors to a motor. First you want to strip your wires to the appropriate length. They should be stripped so that the exposed wire is approximately the length of the tabs you'll be soldering to. You'll need to "tin" the wires- this involves heating the bare wires with the soldering iron as you apply solder *to the work, not the iron*. Flow enough solder onto the wires to cover them completely, while still allowing you to see the striations of the wires underneath the solder. Now do the same to the tab on the motor, applying enough solder to form a shiny film over the tab.
Time to make the connection- hold the tinned wire onto the tinned tab and apply heat to the tab until the solder flows together. Now remove the iron and make sure to hold the wire still until the joint cools off. Don't move the wire before it cools because that will cause stress risers in the joint, and make for less conductivity. The joint should of course be shiny once it'd cold. A dull or clumped joint will fail and present additional resistance to the flow of electricity.
Now it's time to solder the capacitors to the motor. This is done for noise clamping and glitch prevention. You'll need 3 capacitors, or "caps". One goes from each pole [endbell plate] of the motor to the small eyelet between the plates- this accounts for 2 of the caps- one from negative to ground and one from positive to ground. The remaining cap should go between the positive and negative poles. While soldering these pieces on, first lace the leads through the appropriate connection points, then apply the hemostat to the caps as close as is possible to the cap body. These pieces are small enough that you won't need to tin them- just be careful to not overheat them or apply too much solder.
As a final note- when you're done you may find that you have some trash on the surface of your new joints- typically black flecks or pools of sticky rosin. These can be cleaned by using isopropyl alcohol and a stiff acid brush you can also obtain at Radio Shack.
How can I improve my Traxxas EasyStart system so that it starts easier?
I could write up a page on this- but that's already been done. Go here for the scoop!
How do I reverse the timing on my electric motor?
Check out this link for a good treatise on the subject of electric motor timing
I just got t-boned in the last nitro race at the track today. Now my brand new pipe is bent- is there any way I can take the bend out?
This one comes to us courtesy of Lee Muse: Here is what I do to get the bend out -> Seal off the exhaust stinger and
pressure tap. Fill the pipe with water all the way to the top and put it
into the freezer standing straight up. Allow it to stay over night. Check it
in the morning. This may have to be done 2 or 3 times to get the majority of
the bent in area out but it works for 90% of bent pipes.
Running your TRX Pro 15
by Matthew Kent
What you need:
1 TRX Pro 15 engine (usually in your T-Maxx, 4TEC, Rustler or Stampede)
Fuel (At least 16% castor oil content)
Battery for EZ start
Glow Plug spanner
Allen keys for the head
PLENTY patience.
Here goes:
If Traxxas fuel is available, use it. It's not had good reception for use in other engines, but for the TRX it is the best. Otherwise make sure your fuel has at minimum 16% oil. Fill up your tank, hold the exhaust closed and run the EZ start for 2 seconds till you see the fuel entering the carb. Leave the needles alone.
Follow the run-in instructions according to the manual. Don't touch the bottom end needle. Run the car with out a body, but be very careful. One flip on its head and the nice blue is gone. Don't try to straighten bent fins either. The head is brittle.
Once run-in is done, the motor should start running nicely. It will more likely start to annoy the heck out of you. What you are doing now in my opinion is still run-in. The motor only settles down after at least 2 litres (1/2 gallon).
Some things to watch out for:
1) Motor runs well for a while the cuts out and won't restart.
The motor is very likely overheating. Don't touch the bottom end needle. DON'T!! Make very sure you are using good fuel. If the motor cuts out and won't start easy, let it cool. Don't waste your time trying to restart it. It won't. Basically the carb has got so hot, it is pushing the fuel back up the pipe.
2) It won't run smoothly for very long.
This is probably tuning. You can expect to chase your tail with this for a while. I suggest when your engine is cool, tune it then. How I do this:
a) Make sure the wheels are well tightened and glued.
b) Set the car up on something it won't vibrate off. Get a friend to help.
c) Start the car.
d) Get your friend to open the throttle gently till full throttle.
e) Tune the top-end screw clockwise till the engine screams at maximum.Make sure you do this step carefully. Don't keep it open for more than 10 seconds at a time.
f) When you feel engine is at best, turn it anti-clockwise one click, so the engine is running at 95%
g) Run like this. If it still stalls, or overheats, let it cool. Run it again. Just try and run the engine through a couple tanks without tuning it.
3) It bogs when you accelerate.
Now you can start adjusting the bottom-end. Do tiny adjustments at a time. Do a good few laps at each setting, before you adjust again.
Let it idle for 5 seconds and floor it. If it bogs and struggles as you squeeze the trigger, bottom end is too rich. If it takes off nicely then starts dying, it's too lean.
I hope this helps you deal with this. I have mailed TRAXXAS and documented peoples response to this engine, and they welcomed the criticism. Hopefully they will either make better engines or start using something like an OS.
