Tender conversion to Vandy

paperkite Dec 14, 2012

  1. paperkite

    paperkite TrainBoard Member

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    I recently purchased an older Bman Northern 4-8-4 w/ the box tender ( AT&SF marks) and plan on patching it to UP and adding a vandy tender but not sure how to make the electrical connection from the vandy to the engine as the coupling post does not have a segragated pick up .. so does that make it not doable or is there a work around ? Thanks for any help
    Paul
     
  2. James Norris

    James Norris TrainBoard Supporter

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    Hi Paul,

    Is it one of the new Bachmann long vandy tenders that you will be using? If so the electrical connections are inside the tender. There is a circuit board inside that controls the light on the back of the tender and has the space to fit a DCC chip (this is blanked off as standard), there is also a fixing to fit a (can't remember if it's 4 or 5) pin plug onto. This then transfers power to the loco. I just soldered some wire onto mine. The new tenders pick up from both rails so I transferred both back to the motor for better around pickup. The wires that are either side of the drawbar (I believe) are not power connectors but a spring system to balance the lead truck with the drawbar. However they do rub on the power pick up system intermittently and can sum times be live. When connecting to the older locos the draw pin on the loco is the power connecter and this could cause a short, I cut mine off!

    Sorry if you already now this but if it is one of the older Bachmann short vandy tenders, these do not pick up power so without added and custom pickups you will not be able to run it with the loco.
    If you want I can dig out the 4-8-4 I have converted to the large vandy and post a pic?

    Hope that helps,

    James
     
  3. r_i_straw

    r_i_straw Mostly N Scale Staff Member

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    Many times I hard wire the tender pickups to the locomotive motor. Flexible wires with enough slack are the key. I have also upgraded the older Bachmann shorter Vanderbilt tenders for better electrical pickup by using parts from Kato passenger trucks. The bronze side frame inserts from the four wheel Kato trucks have the same spacing for the outside axles as the old Commonwealth six wheel trucks that came on the old tenders. I had to make modifications to fit them in but they work great.
     
  4. paperkite

    paperkite TrainBoard Member

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    James,
    Thanks for the reply ! It is a new vandy spectrum tender . I will open it up this weekend and have a look . I have to strip down the engine for a close inspection and cleaning ( front lite does not work ) . I am not sure about removing the drawbar post but will have a look at that as well .
    thanks again and may I contact you if I run in to concerns?
    Paul
     
  5. James Norris

    James Norris TrainBoard Supporter

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    Hi Paul,

    Yep no problem, allways happy to help.

    James
     
  6. oldrk

    oldrk TrainBoard Supporter

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    If you are using the new six axle vandy bachmann tender those stiff wires are indeed suppose to be live so you dont want those touching the metal post on the frame of the engine. If you flip the tender over you can see the wires actually rub on metal tabs that make contact with the axles. As stated earlier you could hard wire from the tender to the engine. It can be done from those wires on the drawbar. Now, sometimes the connections inside the tender dont make good contact with the wires on the drawbar. I have fiddled with those and got them working well.
     
  7. James Norris

    James Norris TrainBoard Supporter

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    It think it was because, as oldrk said 'Now, sometimes the connections inside the tender dont make good contact with the wires on the drawbar' lead me to believe that it wasn’t meant to be the primary power transfer. But then I have only used the new tenders with older Bachmann and Atlas locos that had the single power pin as the drawbar and didn’t want a short, hence why I cut them of.
     
  8. John Moore

    John Moore TrainBoard Supporter

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    First confirming that the new Bmann Vandy tenders as acquired separately do have the wires on the drawbar as current transfer. Look at the front truck of the Vandy and you will see that the stiff wires from the drawbar make contact with those tabs. Next depending on which incarnation of this locomotive you have the frame of the locomotive is plastic on a few of my older ones and the drawbar post on the loco is plastic. The T shaped pin that runs through the drawbar terminates inside the cab floor again flared out and imbedded in the plastic. There is no metal to metal on the locomotive drawbar post. BUT those two wires running underneath the tender drawbar will contact that metal T and short. So the metal T needs to go. Snip it off and push it through the plastic and replace with a piece of T shaped sprue say from a MT coupler sprue and glue it in the existing hole. You again have your T to prevent the drawer bar uncoupling. That said you should be able to attach very small flexible wires to the contacts in the tender and then run then to the locomotive motor leads. If you look at the rear of the locomotive and just ahead of the first wheel of the trailing truck there is a small screw on each side. The locomotive picks up it's current from the two brass plates that run down the side inside of the drivers when you look at it from underneath. The thin wires could be attached there or again run up into the shell to the motor. You can just loosen the screws enough the slip the bare end of the wire between the plate and the plastic frame.

    For the not faint of heart one can also fashion thier own split drawbar post from a split piece of brass tube laminated to a styrene rod. I isolate the brass halves from each other by having a piece of styrene on either side of the post front to rear and protruding just slightly to cause the tender pick-up wires to kick out and not contact across the gap in a tight turn. From each brass half of the new split drawbar that penetrates the cab floor I solder thin wire to run to the motor leads.

    Lots of options. Have fun.
     
  9. paperkite

    paperkite TrainBoard Member

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    photos of the 4-8-4 front truck tab , part of which appears to be broken , I looked at the parts sheet that came with the engine and it looks correct but does not provide juice ... the other is the vandy with the leads soldered to the posts that connect the rear truck to the whole thing. I will use my ohm meter to check for shorts .... DSCN0664.JPG DSCN0667.JPG DSCN0668.JPG
    thanks for taking a look.
    Paul
     
  10. oldrk

    oldrk TrainBoard Supporter

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    Did the wires come already soldered to the posts? They arent suppose to.I dont see anything wrong with the front pilot truck.
     
  11. skipgear

    skipgear TrainBoard Member

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    Step one - Find a newer northern. That appears to be one of the older versions or something that somebody has modified. If it is not at least the split frame version, I wouldn't put too much effort into this one. The older versions were notorious for the gears failing. The most recent versions are split frame and have blackened drivers.

    Step two - You will need to remove the wiper wires completely from the drawbar or make a new drawbar. The drawbar post on the Bachmann Santafe Northern is metal and the two wipers from the tender are electrically live and will short out the track when they contact the post. I think you probably want to make a new drawbar to get the right spacing between the tender and the loco as well as make sure the drawbar height is correct. Soldering two wires is the only way to do it right but don't solder to the truck pickups. It will cause the trucks to be stiff and more than likely result in derailments. Pull the shell off the tender and you can use the connections inside the tender to make your connections.

    [​IMG]
     
  12. paperkite

    paperkite TrainBoard Member

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    Thanks Tony, I realised that where I had soldered them would not work and got brave enuf to take the tender apart and will solder to the rivet for the spring tabs . I have some 26 gauge silicon wire comming to do the wiring as it flexs' very nicely . I can make the repairs for the axles if need be...
    Paul
     
    Last edited by a moderator: Dec 17, 2012
  13. John Moore

    John Moore TrainBoard Supporter

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    That was supposed to be 1129 or 1130 which are T shank and fit the Bman coupler box with the supplied adapter, the 1128 is also a T shank but it is probably too short.
     
  14. paperkite

    paperkite TrainBoard Member

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    Ah ha got it !
     
  15. skipgear

    skipgear TrainBoard Member

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    DO NOT SOLDER TO THE RIVETS.

    The 6 pin plug coming out of the top of the lightboard has everything you need. The two outer most plugs are left and right rail pickup. The next in from each side are motor outputs and the middle two are headlight output. They are marked on the circuit board. If you get real ambitious, you can hook up all those wires to the loco and make it decoder ready for a little extra work. I have been slowly doing this and soldering a connector (1.27mm pin spacing if I remember correctly) too make as many tenders as possible universally swapable.
     

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