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[rockislandmike]

Worked like a dog since I got home from work 3.5 hours ago, and finally completed the inner ROck Island mainline loop, allowing me to run two trains simultaneously on the separate loops.

Looks very kewl when they're passing each other in Amarillo, with only 2" track centers.

However, I noticed something curious about my Athearn SW1500 switcher. On the inner loop, there are four power feeders to the track. At two of them, the switcher slows down to a crawl and sparks a bit, then after it passes them it speeds back up. At the other two feeders it's fine. Note, the two feeders that are causing problems, are both surrounded by insulfrog turnouts (switched for the mainline of course). My GP38-2, however, flies through all the inner loop feeders just fine.

Any thoughts on this one ???? I have another switcher coming for my b-day, so I'll be curious to see if it has the same problems.

 

[cidchase]

Hi Mike,
Are the (unpowered?) frogs a tad high, lifting the wheels and lightening the contact with the track?? I'm unfamiliar with the pickups and wheel configurations on those two locos but it might be a possibility

 

[TinGoat]

Switcher problems...

Originally posted by rockislandmike
However, I noticed something curious about my Athearn SW1500 switcher. On the inner loop, there are four power feeders to the track. At two of them, the switcher slows down to a crawl and sparks a bit, then after it passes them it speeds back up. At the other two feeders it's fine. Note, the two feeders that are causing problems, are both surrounded by insulfrog turnouts (switched for the mainline of course). My GP38-2, however, flies through all the inner loop feeders just fine.

Any thoughts on this one ???? I have another switcher coming for my b-day, so I'll be curious to see if it has the same problems.

The way the loco picks up power from the tracks can make a difference while going through turnouts with non-powered frogs.

How does the Switcher (Athearn SW1500) pick up power from the rails? One truck only? Right side of one truck and Left side of the other? Or all 8 wheels?

If you can modify the trucks to pick up power with all 8 wheels, it should correct the problem.

Another factor is the wheelbase. Longer locos can usually reach across problem spots like un-powered frogs. Shorter locos like switchers will get hung up on these spots.

A brand new switcher will likely have fewer problems because it will probably pick up power with all 8 wheels. Your old switcher probably only pick up power from 1 truck.

One other quick fix might be to add some more weight to the old switcher. If the flangeway is too tight, like cidchase suggests, the extra weight might be enough to help the loco keep contact with the rails. This can also add to the pulling power of the switcher. An ounce or less of weight might be all that you need. A way to check this is to run the Switcher through the trouble spot very slowly while applying a little weight to the loco with your finger. If it still stalls, then the flangeways are probably not the problem and you need to look at power pickup. If the problem is cured, then go ahead and add a little weight at a time untill you get satisfactory running.

 

[rockislandmike]

Thanks guys, that should help.

PS Ron - it is a brand new switcher, just bought it a few weeks ago.

 

[TinGoat]

Brand new?

Hi Mike,

Is the Switcher an Athern, or an Athern Genisis.

It may be brand new out of the box, but it may be an older model.

Most newly released feature 8-wheel electrical pick-up. But if it is an older model, you may only have 4-wheel electrical pick-up.

One other thing that I thought of is this...

Does the switcher have rubber traction tires on some of the wheels? Some of the wheel treads might be covered by a rubber band to give extra traction.

The wheels that have traction tires, may be able to pick-up electricity from the rails, but only through the wheel flanges.

It is still a common practice to use traction tires on smaller locos. In that case, you may want to remove the traction tires to improve electrical pick-up. You will however lose pulling power. You will want to add the extra weight to the loco to bring the pulling power back up to what it was before removing the traction tires.

 

[Vic]

Mike, If its an older model pop off the shell and make sure that the contact strip is correctly in place. Sounds like its shorting out when the truck(s) swivel.

 

[rockislandmike]

Didn't have time to do too much testing last night, but picked up the offending switcher, and it does have all-wheel pickup, no traction tires. I'll have to check the turnouts or try adding weight.

 

[Gary Pfeil]

I'm not aware of any Athearn diesel that doesn't have all wheel pickup. Perhaps if you go back to the sixties. If the turnouts are back to back perhaps both trucks are on frogs at the same time?

Gary

 

[kettlestack]

Michael,
It could be that the switcher draws less current than the geep. the lower the current needed by the loco the more important it is to have good connections at each rail joiner.

Power fed from the approach end of an insulfrog is fed beyond the switch by a tiny tag on the closing blades engaging with the stock rail on insulfrogs, check for spark burn marks on these tabs.

Just something else to consider. Good luck.

Errol