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Discussion Starter · #1 ·
I'm planning a car mod which involves running an SCX RX81 or RX91 series motor. Has anyone hard-wired one of these, rather than using the copper strips? How easy/successful was it? I'm not a good solderer, but I'm determined not to be defeatist(sp?) about it. Using a different motor isn't an option, because the car is going to be 4WD and I don't want to resort to using bands.

TIA
Stuart.
 

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i'm really bad at soldering (i think I need a more powerful soldering iron!! Well, thats my excuse) If they have the usual copper strips to touch the corresponding strips in the chassis it isn't that bad. I just bent the strips up away from the chassis and soldered wires on and it runs great. It can be done no problems even for a complete amateur like me

Hope it goes well

Matthew
 

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*** Leo A Capaldi ***
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Soldering the copper strips is very much a standard thing to do to a car that gets a lot of use. Using the strips also has the effect of fixing the motor more rigidly so worth doing.
For the "chicken legs " that feed up to the lights, replace those with wire if you want the lights to work, alternatively fold them up out of contact (or cut them off).

Kind regards, Leo
 

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Rich Dumas
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You do not need a powerful iron to work on slot cars. I use an Ungar 40 watt iron and I can solder thick brass and spring steel chassis with that. The secret to good soldering is clean surfaces and good heat transfer. An iron that has the heating unit built right into the tip always works better than one that has a separate tip. In many cases you need to be able to turn the heat down. I plug my iron into a light dimmer, you can buy a soldering station with that feature built in. Everything that you want to solder needs to be clean and free of oxidation, a little steel wool or a rotary too with a wire brush is good for removing oxidation. Always use flux, rosin flux is used for electrical connections and acid flux is good for mechanical connections. You can get solder with flux of either type inside. To start with the tip of your iron needs to be clean and should have a little melted solder on it. The power should only be turned up enough to melt the solder and you can wipe the tip on a damp sponge to clean it. Before you join two parts it is best to tin them seperatly. You can then position the parts together and when you touch the iron to them the solder will flow nicely. At that point you can add a little more solder if necessary. If you have used acid flux that must be rinsed off when you are done soldering.
 

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Everything RichD said!!

Clean the parts to be soldered with a scouring pad. Just like mum uses to clean those pots and pans. The parts must be VERY clean. Solder will not stick to metal oxide.

1. Clean parts well
2. Let soldering iron heat up and clean tip using a damp sponge. Just wipe tip in the sponge.
3. Tin (apply a small amount of solder) the tip with solder
4. Apply tip to part. And apply solder at the point where the tip meets the part so that a solder melts quickly and forms a molten metal bridge between the tip and the part. The solder should flow like hot butter within 1-2 seconds. If it balls up then the parts are NOT clean.
5. Tin each part seperately.
6. Now join the parts together and solder them

Practice on some scrap parts until you are good at it. It you make a mess of it, no problems, no damage done. Keep practicing.

For soldering larger metal areas or metals containing large chromium content (stainless steel) I use phorphoric acid (the stuff they put in Coke, but dont use Coke as the sugar content will play havoc with the soldering). Coat parts with a few drops of phosphoric acid prior to soldering.

Have fun and keep practicing until you get it right.

cheers
rick1776
 

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Discussion Starter · #6 ·
Thank you all for the input.
At the speed I work, if the project is complete by this time next year it will be a miracle!
 
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