Hard wiring decoders and brush caps

[MrCrab]

Hi all, this my first post to these boards, I hope some one can help me with soldering mobile decoaders to the brush caps of the non-DCC can motors that come with the Bachmann DC F units. I'm pretty decent with my Weller soldering iron. I use low heat, a fine tip, good thin solder, and tin all my leads. Still I'm burning/melting these motors at an unsustainable rate. I this point I feel it's got to be a technique thing that I am missing.  Please help keep my railroad solvent by sharing any techniques I seem to be lacking. If this keeps up I'll be able to run the first dummy unit train MRR history! Thanks

[Mike C]

 Have you tried removing the caps from the motor first ? Careful , there is a spring in there !  Or get some phospher bronze and make a tab to wedge under the brush cap and solder to it . The motors I have done all had a small tab attached to the cap , I always solder to that .

[MrCrab]

No I didn't know the caps were removable. They seemed like one could bend the cap up but that really didn't isolate it from the plastic yoke that holds the motor. How do you remove the brush caps? That sounds like the solution to my issue. The spring you mentioned, is it the one that makes connection on one side of the frame or are you referring to the two springs that keep tension on the brushes?

[Joe Satnik]

Caution - Terminology: 

Cap = capacitor?  or

Cap = physical motor brush holder ?

[Mike C]

 I think they should screw out . BUT I have not taken apart any motors in a long while . The spring would be inside the cap and hold the brush against the shaft . Is there already a small tab on the brush cap that you could solder to ? If it unscrews I would just loosen it and wedge a small tab under it and solder to that . Maybe someone that has done a DCC conversion on this loco could be of more help .

[poliss]

You need a hot soldering iron. The hotter the better. You want to melt the solder as quickly as possible and then take the iron away from the job.
Using low temperature means it takes longer to heat the solder and induction heats up the other parts, causing them to melt.