Trying to solve a mystery truck problem

[jward]

to answer your questions.

you can pop the sideframes off and solder the wire to the metal plate than the wheel bushings ride in. it is a steel alloy, the same as the top brackets on the truck. be careful not to use too much heat or you will melt the gearbox. use of a heatsink is recommended. do NOT solder to the bolster tab as this will interfere with the tracking of the truck.

as for the motor brush. it will not seat itself, you have to do this yourself. some brushes have a slot where you can use a screwdriver to align them, some do not. if your brush has a slot, note how the slot is aligned or better yet mark its position before you work on the motor. it is very easy to accidentally move the brush while working on the motor.

[Jim Banner]

It looks like Jeffery beat me to it while I was taking the photos.  But I will post it anyway.

Here, in two thousand words and more, and before you get a PD headache, is the way I solder to Athearn trucks.  In this case. it is an F-7.  The secret is to tin a small spot on the metal side cover of the truck frame.  It helps to put a bit of plumbers paste flux on the metal frame, then melt some solder onto your iron, and finally press the iron firmly on the metal frame.  After two or three seconds, the solder should flow out.  Let it cool, then use a Q-tip and water to wash away the slightly acidic flux.  Next tin the wire.  Finally, sweat solder the wire to the metal frame by heating both the wire and the frame with the soldering iron.  This method allows you to solder on the wire without over heating the plastic.  It helps if you have the joint positioned so that the wire will be hidden in one of the recesses of the plastic side frame.  Otherwise, you will have to carve a bit of the plastic away to make room.  The carving isn't hard but holding on to the side frame without breaking off brake cylinders and swing hangers can be a problem.  Note that the wire was then tacked to the metal frame with ACC so that it bends in the central part of the wire, not right at the joint.



While I was taking a photo of the wire, I thought I would also take one showing how it is possible to mount a decoder in this locomotive and still leave room for the optional weight.  The Digitrax DH123 decoder is sitting on a styrene box that just clears the truck tower as you swivel it through its full range of motion.




And there you are - two pictures = 2000 words plus another three hundred thirty-five more to boot.

Jim   

[jonathan]

You guys are steely-eyed missle men!  I wanted to solder to the side like Jim's photo, but was concerned about melting the gearbox as Jward mentioned.  So, if I'm careful, and work with efficiency, I shouldn't melt the plastic on the other side.  That's good.

Jim, I always use flux (well, after my first failed attempts at soldering a few years ago).

I am beginning to believe my unusual sounds and running eccentricities are being caused by my brushes not being seated properly.  I just noticed last night that they are concave!  I was just throwing them back in willy nilly after hard wiring the motor.  No wonder I saw blue sparks from the commutator tonite!  First opportunity at the bench I will have to disassemble yet again and turn those brushes back to where they belong.   Was going to have to do it anyway to finish isolating the motor.

Then I gotta get a magnifying glass, a really big one...

All this can't be leading to the dark side, can it (DCC)?

Thanks for leading me down the path, yet again.

Regards,

Jonathan

PS.  gotta chance to do a little "brinelling" tonite.  Amazing how great something works once you're shown the way. 

[jward]

no problem.
my experience coems from about 30 years of tearing athearns down and rebuilding and regearing them. the electircal pickup system, especially the steel bar that conducts power to the top of the motor, has always been the weak point in an otherwise well thought out drive. hard wiring these locomotives drastically increases theis reliability. and once you've hard wired both sides of the motor eliminating those areas where power was conducted through the metal bar and chassis, it is a simple matter of inserting a decoder in the leads from trucks to motor to convert to dcc.

one other fix can be made to eliminate problems if you are using metal couplers. if these couplers are used in the coupler boxes athearn supplies, they will conduct electricity at whatever polarity the chassis is. two units coupled back to back will short out through the couplers. so what i always did was to drill and tap the hole in the coupler mounting pad on the chassis, to accept a 2-56 screw. i then used kadee's draft gear boxes to insulate the coupler from the frame. note, this doesn't work on the older switchers, the s12. sw7 and calf. those require the use of plastic shank couplers.

[Jim Banner]

I don't know if a big magnifier, even a lighted one, will keep you away from "the dark side."  I have used a big one (8"?) with a fluorescent tube wrapped around it for many, many years, and still went down the path to darkness.  First I used one at work, for working on tiny circuits.  Then the fellows gave me one when I retired (and threatened to take it away if I ever came back.)  Not only is it great for small work, but it is a real help when taking digital photos.  My camera seems to work better in normal mode and with the magnifying glass, I don't need to use macro mode.  It also gives even lighting from all sides, although sometimes I use a kicker for creating more depth.  When I remember, I colour correct in the camera, otherwise I do it in Picture Publisher (similar to Photo Shop) or not at all.  The photos a few posts up were not corrected and show the purplish green cast typical of fluorescents.

If I have lead you down the path, then I am pleased that you saw fit to follow.

Jim 

[jsmvmd]

Dear Jonathan, et al,

I cannot add a fig to this thread, but being a fan of the space program, I just had to respond to that great line !

http://zhurnaly.com/cgi-bin/wiki/Steely_Eyed_Missile_Man

Best Wishes,

Jack