jroz

Okay guys so project panther has run into yet more drama. New metal hull is in, new gearbox is in all working great then I had to go and put some upgraded motors in the thing. The motors work fine, the pinions are in place, everything good EXCEPT left stick on the controller now makes it go right and vice versa. Some details. The panther G is using the Taigen MFU, but the motors were advertised for Heng Long, no idea if that could effect it. The stock motors that came with the new gearbox steered in the right direction. And before anyone asks, yes I've tried swapping the plug in ports on the MFU. I either get forward backward fine, left right mixed up, or forward backward mixed up with left right fine.

Anyone have any idea what's causing this?

I'm starting to learn that every time you improve something in these tanks it messes up something else lol!!

YHR

Try swapping the plugs into the MFU. If you added grears that have an extra shaft you may have to change the polarity around as well. The extra shaft makes the output gear spin in the opposite direction of the stock gears/

Cheers.

jroz

Yeh I had a feeling it might be that. The motors I got were set up for use with the stock HL gearbox. I managed to adjust the pinions to fit into the new 4 shaft gearbox totally oblivious to the fact that the extra gear would mean the motors would have to spin in the opposite direction. Is changing the polarity of these motors a massive task? If so I might just give up and shove them in a new tank.

jroz

can just switching the wires around reverse the direction of the motor?

YHR

Yes. As long as you have a soldering iron this can be done in a couple of minutes

Max-U52

Another way to reverse polarity is to tease the plugs out of the JST casing and switch them there. Kevin has a good video on the RCTA site for getting the little metal sockets out of the plastic JST plug casing, and then just swap them. That reverses polarity, just as though you soldered the wires to opposite sides of the motor.

jroz

I think I'll go with the soldering option I ordered an iron a couple days ago to fix some other bits, so may as well use it for this too . Thanks for the help again guys. Don't think I would of got very far with this project without you hehe!

YHR

Yes a soldering iron is just about essential in this hobby

jroz

Yeh I learned that the other day when my battery, still attached to the tank, fell off the desk it was sitting on and yanked one of the leads out of the power switch.

Max-U52

Make sure you get a good stand, too, with a sponge. Nothing is more important than keeping the tip clean if you want to get good performance out of your iron. I have a very worn out sanding stick I use on mine to keep it in order and it works great.

jroz

I'm also thinking a dremel or something similar wouldn't go amiss.

TheBennyB

Your on the right path. A dremel is a must in my opinion. Depending on the model you get, the right angle attachment is highly recommended as well as the chuck. Ditch the stock collet. If you don't have small dia drill bits, the dremel pack isn't a bad idea either.

http://www.amazon.com/Dremel-575-Rig...gle+attachment

http://www.amazon.com/Dremel-4486-Mu...s=dremel+chuck

http://www.amazon.com/Dremel-628-01-...mel+drill+bits

jroz

Well here's a corker. So I switched the wires around on the motors, plugged them into the tank and ran them. They both worked fine at first, both turning in the direction I had hoped for....then my MFU melted. This is really weird. The motors ran fine on that board as they were originally configured, but when reversed, they friend the board. Anyone have any idea why this would happen, because I'm at a total loss. The motors both function...they just fry the mfu..

Green Amphibian

Sounds like there is a short in the wiring somewhere. Check the soldered joints so nothing is touching anything but the solder tabs of the motors.

Herman

jroz

I just noticed, the solder on one of the engines was touching the metal of the opposite gearbox, because of the length of the motors. Any chance that solder joint touching the metal of that gearbox could of caused a short??

jroz

Well here's something odd. I re soldered a joint I didn't quite like the look of, but it wasn't much more than removing a tiny bit of solder that was touching the green bit of a bit of chip board at the end of the motor, that the solder tabs are touching anyway. I fired up both the motors in an old heng long 17ghz board I had lying around and now they seem to work. No fried board. The only drastic difference is that the motors are no longer in the tank and so that one solder joint is no longer touching any metal from the gearbox. So could it be that the board fried because that solder joint was touching the other gearbox??

YHR

Yes that can happen. A direct short on the motors will draw a huge current. If it is any consolation I must have fried a dozen Rx18s, because of issue that I created. I did the exact same thing on a gear box I had tightly fitted into a Sherman. The Poles on the motor shorted through the opposing metal frame that I did not notice touching. The thing really flamed out.

Sorry to hear. You always need to be careful with wiring to insure there are no shorts.

And always remember to disconnect the power to what it is you are solding on. A dropped tool or screw can cause a damaging short as well as an errant soldering iron.

TheBennyB

All good tips. Also a sleeve of shrink tube over the motor wire and pole your soldering too may help future contacts with the opposite gearbox if it'll fit. Just remember to put the shrink
tube on the motor wire before you solder....think we've all been down that road of soldering up a couple leads and the cut to length tube is staring at you from your workbench. Pic is from a Tammy Pz IV with more room to work with but you get the idea.

jroz

Oh boy, do I feel stupid. That was an expensive mistake. I've already soldered it so I guess the best thing to do now would be to put some electrical tape over the soldered ends of those motors to prevent a similar accident. Ran the motors for a while out of the tank, they seem fine. Was worried I'd somehow broken them, so that's a relief. Thanks for the feedback guys.

Shark27

jroz, You never want any electrical motor terminal touch anything metal except the wire that feeds it electricity. Heat shrink tubing is your friend, do yourself a favor and go down to the local home depot or harbor freight or your favorite electrical supply store and pick up some heat shrink tubing of various sizes, it is cheap insurance.

De-solder the wires you recently soldered, minding the polarity of course, slide heat shrink tubing of the appropriate diameter onto the wire to be soldered, keep it away from the solder end or it will shrink prematurely. Use a piece long enough to cover the entire terminal and the end of the wire that is exposed. Re-solder the wire into position, be sure not to get the wire too hot.

Let it cool down a bit, then slide the shrink tubing over the terminal with the wire soldered on and then use a match, candle or cigarette lighter and pass the flame under the shrink tubing quickly, you may have to rotate things to get the other side of the tubing to shrink and it will shrink down onto the terminal and insulate it from shorting out on anything.

You may have to bend the motor terminals a little to get them away from the other motor, as the shrink tubing will make the wire stiffer.

If you don't think you have enough room or don't want to de-solder the wiring, you can always use liquid electrical tape, it is even easier than shrink tubing, you don't have to de-solder anything you just paint in on with a brush, over the terminal and wire end, let it dry and you have insulated your terminals. 3M makes some called "Scotchkote" as well as a company called Gardner Bender called "Liquid electrical tape".

Photo below is my Tiger 1 motors with the heat shrink tubing on the motor terminals.

Happy Tanking
Steve

Imex-Erik

Heat shrink is the best option but I've found hot glue/silicone works too if you are in a tight situation (literally). Sometimes wires can rub against the gearbox if you have an upgraded and larger motor. A bit of glue where the wire will rub will help to protect against a short as well. I really like hot glue a lot as you can remove it fairly easily and it is a cheap material to work with.