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Blown head and tail lights on 2-8-2 Mikado HO

Started by OlddManWithHO, March 28, 2021, 10:02:04 AM

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OlddManWithHO

All,

    Got an Ho Mikado I was installing a Tsunami 2 decoder in and forgot to add the dropping resisters.   I assume both are blown as they dont come on.

    Don't see any reference on the LED parts in the breakdown parts catalog for the Mikado.  I think I might be able to do the headlight, but how involved is the tail light?

    Any part numbers?

Roger

jonathan

https://www.bachmanntrains.com/home-usa/board/index.php/topic,32325.0.html

Roger,

If this is about the latest USRA Mikado (sound value), the link above may help.  I tinkered with a couple--took photos as I disassembled.

The lights are LEDs. The original board holds the resistors.

If you are installing a tsunami, by replacing the old board, you will have to add your own resistors. I usually use 1K ohm, 1/4 watt resistors.  The original light cans use some sort of surface mount LED.  Though, the cans are big enough where you may be able to fit regular LEDs if necessary.

I don't know what sort of glue is used to hold the lenses on the cans.  That may be a bit of a challenge, but my experience tells me that the factory glue may be weak enough to pry out the lenses.  That's a bit of a stretch.  So, be careful.

Regards,

Jonathan

OlddManWithHO

Jonathan,

     Thanks for the link.   You have same loco as mine.  Now I've got something to go on.  Will open up tender and put in resisters.  I usually use 3.3K.  Even those keep the LEDs bright.

      I did the same thing to my 4-6-2 Lt Pacific a month ago.  Using those sound value boards in my old 0-6-0 switchers that have the sloping tender.

      Will have to add more lead weight to rear of tender where I had to remove that big weight that was in it.  Tender light in the tail.

      Upon first trial run of loco the tender kept derailing.  The screws holding the tender trucks on were too tight.  Lossened and all was good.

      What does the 'Q-3" under your cab loco number mean?

Roger

jonathan

The B&O's Mikados were the "Q" Class. Their USRA version of the Mikado was Q-3.

That's great idea about transferring the sound value boards.  I'll have to keep that in mind.  I have a number of the DCC, slope-tender 0-6-0s.

Regards,

Jonathan

OlddManWithHO

Jon,

    Did your loco come with rubber tires?   Mine did not have any and will not pull many cars.  Putting on frog snot now.

Roger

jonathan

Instead of bull frog snot (I have a bottle), I added weight.  Two 1/2 ounce slugs of lead went into the smoke box area, more weight in the steam dome and sand dome, plus a small strip of lead went under the cab roof.  The idea is to get the weight balanced between the center drivers.  This did the trick for pulling power.

I also double-head my trains as a rule.  With added weight, and two locos, I can pull a good sized train on level track--usually 20-30 cars in tow.

Regards,

Jonathan

OlddManWithHO

Jonathan,

     Need to ad weight to smok box area next.  Loco seems too light up front after I add the frog snot to back two drivers.  I've seen the front driver derail for some reason.  And traction still poor.

     You have photo of underside of tender?  I didn't see one.  My copper contact is sitting under the screw head on both trucks.  I have to tighten them down to get proper electrical connection else if loose poor to no connection.  Loco seems to depend on tender wheels for rail pick up.  I've got a keep alive on my decoder and I've seen loco stop several times from bad rail piclups.  If I tighten tender truck screws that stops tender trucks from pivoting properly.  i think next I'll have to solder a wire to those wheel pickoffs and hook into the track power leads going to the decoder.

    The reason I asked about your tender underside as my Lt Pacific tender looks different.  The copper pickoff is just sitting on top of screw and making good electictical contact.

Roger

jonathan

Roger,

The weight in the smoke box area will prevent the front drivers from climbing the rails.

The tender truck contacts, in Bachmann tenders, are held in place by the pressure of the axles.  They aren't held in place by the bolster screws. The pick up brushes sit on top of the axles.

Check the plugs between the tender and the locomotive.  They may not be seated properly.  You should be getting electrical pick up from the drivers.  I haven't had any pick up issues with the Mikado.

If you applied snot to just one driver (recommended), the electrical contact should be fine with all the other wheels gathering current.

Regards,

Jonathan


OlddManWithHO

Jonathan,

     Appears the the drivers are a little warped.  Need to find a replacement.  Dont see one under the Bachmann parts list for this loco.   :(

Roger

jonathan

Well, that's unfortunate.  Does it appear to have been dropped?  If you can't get replacement drivers, perhaps you can use a gear-pulling tool and a quartering tool to straighten things out a bit.  Not fun, but something is better than nothing (platitudes really help I know  ::).

You got me to thinking... so, I pulled one of my Mikados out of the roundhouse to do some cleaning and repair a couple of loose details.  I took a couple of photos, since you were having issues with the tender.

First, I get what you meant about the trucks.  There is some kind of washer or shoulder that holds the brushes:

DSC_0579 by Jon Vogel, on Flickr

The screws do allow you to slightly tighten or loosen, BUT there are nuts on the inside that complete the wiring assembly.  Too much tightening and loosening could dislodge those nuts:

DSC_0577_01 by Jon Vogel, on Flickr

DSC_0575 by Jon Vogel, on Flickr

Finally, I tried to get in close for a shot of the pick up brushes on the drivers.  Hard to get close, focus, and light on the subject, but:

DSC_0580_01 by Jon Vogel, on Flickr

You had mentioned current pick up was an issue.  Hopefully these shots might help you sort it out a bit.

Wish I could help more.

Regards,

Jonathan

OlddManWithHO

Jonathan,

     Yep, that looks like my trucks too.  Going to remove the warsher and copper contact and sand down with fine grit to get a better contact surface.

      Seems this loco is a returned loco as I found the screws loose on that bottom plastic piece that presses up on the driver wheels.  After tightening them up loco did run a little better.  Got the loco off of Ebay from a resaller.  Listed as new.

     Next thing to do is try to pry off smoke box lid so I an add lead weights.  Without the frog snot loco can only pull two passenger cars up my helix.

Roger