Trains.com

American Flayer SIT 312 reverse unit problems

2526 views
11 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Monday, March 5, 2012 5:25 AM

diremaker

Thanks Larry, motor runs fine in both directions. Guess now I need to focus on the reverse unit.  The wires look great so I'll re-solderer the fingers and go from there, unless you have any more helpful advice?!? Since the reverse unit cycles so nicely, is there anywhere else I should look for a crossed wire.  Again, from a visual inspection, it looks good. Light works too.  Should I just rewire everything?

diremaker, did you ever get this loco running properly?

Rich

Alton Junction

  • Member since
    October 2011
  • 969 posts
Posted by TrainLarry on Tuesday, February 21, 2012 6:31 PM

Glad to hear that your motor is fine. You need to check the reverse unit to insure the contacts are installed properly, and then rewire the engine. A wiring diagram is here. You need to hook up the wires exactly as shown, or the motor will not run, or reverse properly.

Larry

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, February 21, 2012 4:39 AM

diremaker

Thanks Larry, motor runs fine in both directions. Guess now I need to focus on the reverse unit.  The wires look great so I'll re-solderer the fingers and go from there, unless you have any more helpful advice?!? Since the reverse unit cycles so nicely, is there anywhere else I should look for a crossed wire.  Again, from a visual inspection, it looks good. Light works too.  Should I just rewire everything?

The only other thing that I can think of is the driver wheels.  Are they binding in forward?  Seems like if the driver wheels work well in reverse, they should work well in forward.  But, in the past, I have had some similar problems as yours, and the cause has been the driver wheels.  You might try removing the linkage, or connecting rods, and see if the driver wheels are turning freely in both directions when power is applied.

Rich

Alton Junction

  • Member since
    December 2010
  • 14 posts
Posted by diremaker on Monday, February 20, 2012 11:57 PM

Thanks Larry, motor runs fine in both directions. Guess now I need to focus on the reverse unit.  The wires look great so I'll re-solderer the fingers and go from there, unless you have any more helpful advice?!? Since the reverse unit cycles so nicely, is there anywhere else I should look for a crossed wire.  Again, from a visual inspection, it looks good. Light works too.  Should I just rewire everything?

  • Member since
    October 2011
  • 969 posts
Posted by TrainLarry on Monday, February 20, 2012 11:19 PM

If the motor runs good in reverse, the armature can not be bad. If you get smoke from the field winding, then you may have a wiring issue, with some wires possibly crossed. Also pull the armature out and check to make sure the wheels are turning freely in both directions and not binding. This could stall an armature. If you can totally disconnect the reverse unit from the motor, you can isolate the motor and check it alone. Hook one transformer wire to one brush, the other brush connect to one field winding, and the other field winding gets connected back to the transformer. The motor should run in one direction. Disconnect the wires to both brushes and reverse them, and the motor will run in the opposite direction.

It must pass this test before you go any further. If it runs in both directions, you probably have a wiring or reverse unit issue. If it does not run in both directions equally well, you have a motor issue. Make sure all motor bearings and wheel bearings are properly lubricated first.

Larry

  • Member since
    December 2010
  • 14 posts
Posted by diremaker on Monday, February 20, 2012 9:35 PM

Rich and Larry,


Thanks for the advice.  I again checked the drum and fingers and everything is making contact...I removed the fingers, re-aligned and still, the unit is cycling great.  But, still in reverse.  There is a slight movement from the armature that it wants to spin forward, but it doesn't and then there is some smoke from the field.    Problem is that I don't have a matching armature without pulling another engine apart!

 

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Monday, February 20, 2012 6:25 PM

TrainLarry

 It sounds like you may have installed the contacts incorrectly. Make sure you put the contacts in their correct positions. The drum will work in either orientation; there is no wrong installation for it.

Larry

I am with Larry on this one.

I have the exact same steamer.

It sounds to me like the copper finger contact boards are switched or reversed.

Rich

Alton Junction

  • Member since
    April 2003
  • 305,205 posts
Posted by Anonymous on Monday, February 20, 2012 6:14 PM

Lou,

          I've had this problem before with Gilbert steamers.  I've seen two causes:

1.  Dirt on the drum.  Even after I think that the drum is totally clean, it can still have residual dirt that can cause one direction to be inoperative.  Cleaning a second time helps.

2.  One finger not making contact with the drum after twisting the tabs to secure the fiber strip to the unit.  I've seen this issue more than once after reinstalling the fingers.  With the reversing unit sequenced to what would be the forward position, press on the fiber strips.   If that doesn't help, lightly press on each finger.

I don't see the armature being the problem since the motor runs in reverse.

  • Member since
    December 2010
  • 14 posts
Posted by diremaker on Monday, February 20, 2012 3:28 PM

No, i'm now familiar with these trains...the drum is in correctly.  I am actually waiting for someone to tell me its the armature...which I think is the issue.  Anyone else suggest I buy a new armature first? 

Engine runs strong in reverse when I get it going...nothing forward.  I just can't see it being the reverse unit.

  • Member since
    October 2011
  • 969 posts
Posted by TrainLarry on Monday, February 20, 2012 3:26 PM

 It sounds like you may have installed the contacts incorrectly. Make sure you put the contacts in their correct positions. The drum will work in either orientation; there is no wrong installation for it.

Larry

  • Member since
    January 2005
  • From: Lake Worth FL
  • 4,014 posts
Posted by phillyreading on Monday, February 20, 2012 3:17 PM
Have you tried removing & flipping the little roller wheel and putting it in again, it might be 180 degrees out of sync. Either that or try the wires again, either wired wrong or a broken wire, and make sure it is working correctly.
Interested in southest Pennsylvania railroads; Reading & Northern, Reading Company, Reading Lines, Philadelphia & Reading.
  • Member since
    December 2010
  • 14 posts
American Flayer SIT 312 reverse unit problems
Posted by diremaker on Monday, February 20, 2012 2:38 PM

Hello all,

I've recently been working on a AF 312 SIT and have already rebuilt the SIT unit and have been messing around with the boiler now.  I've removed and cleaned the drum, new fingers, all the wiring looks great.  New brushes and its been lubed up.  Only problem is that the reversing unit cycles great, but it seems to line-up incorrectly or something, because the only way I can get the loco to move is by hand manipulating the drum...then I can only get it in reverse.  The fingers are making good contacts, besides rewiring the whole loco, any one have any ideas why I need to manipulate the drum to get the loco in reverse...then it won't go forward.  It a 4 cycle reverse unit.  All the mechanics in the reverse unit are moving freely, and like I said, it never sticks and cycles fine.   Thanks in advance!

 

Lou

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

FREE EMAIL NEWSLETTER

Get the Classic Toy Trains newsletter delivered to your inbox twice a month