Difficult soldering job--elec. motor

Discussion in 'The Projects Forum' started by hillshaveeyes57, Oct 15, 2012.

  1. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
    here's the motor i'm trying to solder connections to:


    i fried two already. they worked fine for a little while, then i put a duct-taped partition around each wire (bulky as hell). it worked fine for awhile still, but then overnight it was like the motor burned out. i tested each one (minus the leads coming off of their terminals) and the motors are fried now! i think i may have fried the motor while heating its terminals to get some solder on there. or is that REALLY it?

    each motor is extremely small...could easily fit within the diameter of a penny. i didn't expect them to be so small. my question/problem i'm working on is how to i get some lenthy leads off of the terminals without threatening the motor's integrity? aligator clips? that's the only thing i could think of. i'm going to order some more, but really don't want them to fry again. any help is appreciated!!!:D
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    Its just your "skills" man... ;)
    Gotta solder it fast.
    Those terminals look like they are just supposed to rest against an exposed PCB pad though (or something like that) and aren't for soldering.. But it should work just fine..

    Might want to apply some liquid flux to them first to clean the contacts really well, then wrap the wire around a few times and solder quickly. Then heat shrink tube over for a "professional" look.
    spark8217 likes this.
  3. stanman11


    Nov 23, 2010
    take a sharp knife and scrap the insolation of the wire. its invisible on the copper wire but it is there. Do not use a lighter
    and yes the connections on the motor arent for soldering but you can if needed
  4. ifixit

    AAC Fanatic!

    Nov 20, 2008
    Hi hillshaveeyes57,

    How long are you running the motors for? Since there intended use is an intermittant duty application, they may not last long if run continiously. Do they get hot?

    Just a thought,
  5. MrChips


    Oct 2, 2009
    I have a ton of these for my robotic bug project. You can take the weight off the shaft if you need to.

    Those contacts are not so tiny. You should be able to solder to those contacts. Just watch your technique and as mcgyvr says, you gotta solder fast.

    An alternative is to make a pair of miniature slip-on quick connects that you can salvage from some connectors, e.g. relay sockets.

    Alligator clips are way too big.
  6. KJ6EAD

    Senior Member

    Apr 30, 2011
    Clip a heat sink or hemostat to the tab near the motor body and solder your wire on the end of the tab away from the body.
  7. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
    i practiced on the burnt out motors awhile. soldering that is. i think my soldering is fine. i hit the tip of my (hot) copper wire with a good blob on the end and get it to drop on a slightly heated motor terminal. that part was fine all along now that i look at it.

    someone posted the question if the motor is heating up and it is...a lot. they get hot really fast and that was running off a direct current coming from a 9v battery. so...i'm thinking maybe i just burnt them out.

    i was planning on running them through a 555 hysteric oscillator circuit i have built separately and am hoping now that since the circuit incoporated capacitors and resistors that the motors will be able to last longer. esp. since they will be used intermittedly, or b/c they'll be oscillating.

    good idea with the hemostats and the flux also! thanks for the help people!!!
  8. MrChips


    Oct 2, 2009
    9v would certainly kill the motor if they were designed to run at 3v.
  9. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    Soldering with a blob of solder on the tip is not the best method to make good connections. Use the hemostat, then wrap once or twice your (bare and clean) wire around the (clean) copper tab, place your soldering iron tip touching both the tab and wire along the joint between the two (away from the motor body), let it heat up briefly (1-2 seconds) and touch the solder to the wire, while removing the tip. The solder should flow through the joint. If not, let it cool and try again, holding the tip for a longer time.

    Also, from the link you provided - these motors are only supposed to run from 4.5 Volts maximum. 9 volts is way too much, and will burn them out :eek:. They will run from as little as 1.5 Volts (one AA battery) for a while.
  10. Sparky49

    Well-Known Member

    Jul 16, 2011
    Will we see a write up of your project? :)
  11. chrissyp

    Active Member

    Aug 25, 2008
    How about using a conductive adhesive instead of solder?
  12. MrChips


    Oct 2, 2009
    OP says his soldering is fine. He is destroying the motors by applying 9V.