The Trinity Monster motor blowup page.
Trinity Monster Stock. Good motor. Some would even say great.
They are very fast, rev very freely and are very easy to gear.
...But they are gathering a reputation for being... how shall we say, fragile.
Mine was about 2 - 3 months old, and had maybe 40 or 50 races under it's belt.
Some would say that it had given of it's best, but I want more for my £27.50.
Mine is not the first to blow up... it won't be the last.
What I want to do here is have a bit of a play. See what the damage is,
find out how a stock motor is wound, and maybe attempt a repair.
First, some stuff which I have heard and which I have read "out on the 'net".
- Stock motor armatures can't be rewound because they are welded together.
- If you solder the wire ends to the armature, the solder will melt when the motor is used.
- You'll never get it to balance properly after you've rewound it.
Anyway, Just how bad can it be ?
Still looks kinda good from the outside. If you hadn't seen the plume of smoke
trailing out the back of the car, you wouldn't guess from this picture.
Inside though...
Now it is clear. One lobe of the armature is blackened and burned.
Close inspection shows that the wire is burned clean through in one place.
How did I finish the race with it in this state ?
The commutator looks OK. There is enough meat left on it to justify having a go at rewiring the armature...
... although maybe not as a 27 turn single :)
This is a shot of the endbell and the brushes. The brushes are standard Trinity 4499s
There doesn't seem to be anything here which could have caused the damage.
I wonder why only one of the three windings perished in the conflagration ?
The windings on these stock RC motors are welded onto the top of the rotor, just below the comm.
This can be dealt with by using the mini angle grinding attachment of a dremmel or similar.
Here's one I prepared earlier.
Grind through all three attachments to free the wire for removal.
The wire is wound around each armature lobe in turn. As this is a stock motor,
it is wound around 27 times before moving on to the next lobe,
via being welded, (and making the electrical connection), to the comm.
also in this photo, above. You can see a small drilling in the armature stack.
This is done after the wire is wound on to balance the armature and stop vibration.
I'll need to re-balance the armature after I re-wind it.
Two lobes unwound, one to go.
What a lot of wire. There is in fact 1.64 meters around each lobe, making 4.92 meters altogether in the motor.
The wire is 0.7mm diameter measured with the enamelling on. the wire with the enamel burned off measures 0.645mm in diameter.
All that wire weighs circa 15 grams. 37.5% of the total weight of the armature, which was 40 grams when it was intact.
Here is the denuded armature ready for rewind.
Later --->
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