I got some solder stuck in the teeth of a metal pinion gear. I've tried using the tip of the iron, a solder sucker, a screwdriver, my pocket knife, and the edge and tip of an Xacto knife to get it out. Teeth with a little solder in them were cleared with the Xacto knife, but the rest aren't clearing. I'm using a 60/40 Tin/Lead solder. Hope you guys can help.

Removing solder from pinion teeth?
#1
Posted 18 July 2020 - 08:33 PM
#2
Posted 18 July 2020 - 08:37 PM
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Steve Meadows
#3
Posted 18 July 2020 - 08:39 PM
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Dominic Luongo
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#4
Posted 18 July 2020 - 08:50 PM
Attach the motor to the power supply. Heat up the pinion on the motor and then hit the power. Depending on the motor a few volts will do the trick.
Why wouldn’t the pinion fly off if it’s hot enough for the solder to fling off?
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Steve Meadows
#5
Posted 18 July 2020 - 09:16 PM
I do this all the time as suggested by Dom...just hold the tip of the iron against the end of the pinion until the pinion spins freely on the motor shaft when pushed with a small screwdriver, then hit the power. The iron holds the pinion in place, the solder flies off the gear teeth onto your shirt (so you may want to move out of the way) and the solder between the shaft and gear sets up as you move the iron away from the shaft. All the motion is rotational so the pinion pretty much stays where it started.
Note: this works best with the motor mounted in a chassis so it doesn't torque when the power is applied. I set my power supply at 5 volts and just hit the power switch.
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#6
Posted 18 July 2020 - 09:16 PM
Hold the motor level and only heat the teeth. The solder will fly out everywhere.
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Larry D. Kelley, MA
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#7
Posted 19 July 2020 - 12:13 AM
Slinging solder out of pinion teeth, with a power supply, is a common slot racing technique that has been around forever.Why wouldnt the pinion fly off if its hot enough for the solder to fling off?
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IIRC, Slick 7 even described how to do it in the literature for their power supply.
You have to hold the motor with the shaft pointing away from you, and not cross over into the path of the flying solder, when you are hitting the switch.
Also be aware of any pets in the room.
I've heard of at least one story where a sleeping cat or dog, wasn't too thrilled, to be woken up by hot solder.
When I would do it with G7's, I would always then remove the pinion, re-tin the shaft, and reinstall the pinion, so I would wind up with a small fillet of solder on the base of the hole.
With Retro, and other lower power motors, I sling it, and run it.
Of the 100's of times I've done it, the pinion has moved, a handful of times, mostly towards the bearing.
I don't recall the pinion ever coming off.
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Mike Swiss
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#8
Posted 19 July 2020 - 02:11 PM
Here's what I do so that doesn't happen. Before soldering the pinion on the motor I put a small drop of oil on the teeth and rolling it in your fingers. Make sure the I.D. of the is fluxed. Proceed to solder. The pinion will smoke as it is being soldered to the motor shaft that is just the oil burning off.
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#9
Posted 19 July 2020 - 03:58 PM
Attach the motor to the power supply. Heat up the pinion on the motor and then hit the power. Depending on the motor a few volts will do the trick.
Works perfectly. I don't have a power supply, so I just touched the motor tabs to a 9 volt battery.
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#10
Posted 19 July 2020 - 05:01 PM
I've been throwing them away all this time.......
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#11
Posted 19 July 2020 - 05:46 PM
It works, and works well! Just make sure you don't spin it at you or anything you don't want hot solder struck to. And use protection!!! You don't want molten solder in the eye!
Rotor
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