Intermittent Sparks Going Through Fastrack Switch

 What is the minimum radius for whatever engine it is?

O-31 according to the manual

Huh...

Well I guess you have to carefully watch what the truck does as the engine crawls over that spot. I can only guess that a wheel climbs up the rail if the truck looks up in the air.

I think that is what is happening. It's more frequent on the turn that is slightly pitched. I put a shim under the track and that helped out. The plywood sitting atop the pool table is a bit warped but I'm not ready to take the layout apart just yet for a more permanent fix.

As to my other question, when this happens is there a risk of damaging anything in the engine? I'm reminded of the saying where there's a spark there's a fire and in the short run I don't want to risk wrecking anything. I could just put the engine on the shelf until we build a more stable layout. Apologies if the question seems to fundamental, but new to all of this.

There is a chance of a spike of voltage causing electronics in the engine to fail. Not to mention the metal welding happening to the track, wheel(s) or roller.

The end of this thread has some info on how to protect the engine electronics with a Transient Voltage Suppressor that you can install in the engine.

https://ogrforum.com/t...rials-andamp-manuals

I have the same problem with my K-Line Big Boy's tender, and it only happens when reversing to the turnoff.  Does yours happen only in one direction, or in any direction?  My problem is the last axle on the tender has blind wheels to allow it to make tighter turns, and I bet your diesel has blind wheels on the inside axle of each truck like my RailKing EP-5 does.  On the BB, the wheels are metal, on my EP-5 they are plastic.  When going on teh turnout backwards the force pushes the rear of the tender towards the through and the blind wheeled axle connects the center and outside rails causing the spark.  If I'm going faster, it just keeps going, but if I'm going slow, like to pick up cars from the siding, it'll trip the breaker on my Lionel Powerhouse 180.  Being the EP-5 has plastic wheels, I've thought about ordering an axle from MTH and replacing the BB's so that it's no longer an issue.  If your blind wheel are metal, this may also be your problem.  I think it's an issue on FT switches because they are powered differently due to the builtin auto anti derail.  Yes, the manual switch doesn't have the circuit to move the points, but the rails are all still wired the same.

Sinclair, mine only sparks one way - coming into the switch from a turn. I'm not as familiar with the specifics of the engine as you are, but I will take a close look to see if it caused by what you suggest. I know that wherever I have the track laying flat and have other FT switches, I don't get the sparks, so I think it is do in some part to the pitch between the curve leading up to the switch and the switch. So far, the engine rides through the switch and I just get the sparks without it tripping the breaker on the MTH Z-1000. Thank you for your comments - learning from it all!

It looks like there is one or more issues here:

1.  Is the FT switch in specs in the frog?

2.  Is the MTH wheelset in specs?

Combo there of?

Have you tested the current with a voltmeter as the engine goes through the frog?

I had one WbB diesel with blind drivers that caused sparks on a FasTrack switch.  A little piece of black electrical tape cured it for me.  The tape has stayed put for many years now.

Basically, the switch is too sharp for the big loco, even though the loco can negotiate sharp curves. These are six-wheel trucks with no flanges on the third and fourth axles of the loco, yes? So they hang out on a sharper curve and find places to short on some switches. You may want to reconsider your track plan and try to arrange routing so that loco doesn't have to take sharp turnouts.

Keith has an expedient fix with tape, as long as that doesn't cause problems for other locos losing contact with the center rail.

There is also a rubber past which can be used as an insulation.

I'm going to give the black electrical tape tip a try.

Loco seems to navigate the O36 curve/switch combo perfectly on the end of the layout that is level. Going from a straight and turning into a switch works fine on both ends of the layout, but it's that one area where the layout is warped  and the curve is going slightly up into a straight that I get the big spark. The loco does have 6 wheel trucks (2 plastic wheels per truck) and does hang out on the curve as described by Ace, but so long as the track is flat the tight curve itself doesn't seem to be the problem.

In the fall we'll be moving the layout to a bigger room and make it more permanent being careful to level everything. Definitely will consider using wider turns on one of the loops to lessen the likelihood of this being a problem going forward.

Being one who just puts the train on the track and hits "go" I'm not sure what in spec means for the FT switch or MTH wheelset? Haven't tested the current either although I will admit to buying a voltmeter at Home Depot after reading something about dead spots on FT 10" straights from time to time. Would I be looking for a drop in voltage by doing this test? Or what should I be looking for is the better question?

Thanks for all the help!

I have the Williams EF-4, the U33C, and the K-Line EP-5.  The box saids they are rated for O-31, but they are more comfortable on wider curves and switches.

Have you tried your engine on MTH tracks?

Haven't tried the engine on MTH track, Dominic. I have all FT and have been buying added pieces here and there in anticipation of bigger layout. Even bought 2 more O36 switches at York last month, so for now I am committed to FT. I have one MTH engine now, a pre-order on another ES44AC with different paint scheme (same length and 6 wheel trucks though!), a Lionel Legacy GP7 and 4 other Lionel conventional engines all rated for O31 curves.  Need to stay within budget for the year which includes a few more pieces of rolling stock and possibly the bto Legacy Polar RR 0-6-0 switcher - no funds for changing gears on track.

One engine on one switch.  Not worth changing to a new track system.  However, have you placed a new FT switch at the problem location?  Reuse the switch with issues, say in a yard?

That black electrical tape solution looks good!  I have a BRAND NEW MTH FEF Imperial that was doing that on the tender due to the blind wheels making contact with the Fastrack's rails.  I just took off the middle set of wheels to fix the problem.  But after reading this I'm going to go back and maybe try the electrical tape solution!

A possible cause could also be a curved track on either side of the switch. To check this out, simply set up a test track section with a few straight sections of track on all 3 sides of the switch, then run the engine in question through all the turnout and direction combinations and see if there is still the problem. I have resolved more than one fastrack switch problem by adding a straight section of track leading into the turnout, thus moving the curve further away from the switch. even a 5" section addition helped me with numerous issues, particularly with steam engines.

You could also use this test setup to try a different switch of the same size to see if the problem is with the individual switch.

Also check for a loose piece of metal (metal shavings) as this can cause contact arcing.

I have had a switch that was sparking similar to your description. It was on my "to fix" list. I then dismantled my track to make some wiring changes, and after putting things back the same way as before, the sparking problem is no longer there. I have no idea what caused the problem, nor why it went away. 

I have also had issues when the switch is not level. I use a plastic straight edge and lay it across the switch rails in all directions, and from inside to outside rails to be sure the switch is sitting flat on the table. Also check the tracks going into and out of the switch to be sure they are level as well. 

If the wheels are on the verge of touching or not touching the rails, you can get issues. My problem was that at very slow speeds, the engine would stall on the switch. This may not cause sparking at the wheels, however it may be worth checking out anyway.

Good luck. Remember, troubleshooting is fun!