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Discussion Boards => HO => Topic started by: ferroequinologist on March 12, 2025, 09:02:26 PM

Title: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: ferroequinologist on March 12, 2025, 09:02:26 PM
Hello,
I'm currently working on my HO Kato layout, and while my locomotives seem to run fine on it, I noticed that my largest engine, a Bachmann Spectrum K4, seems to buck or jump whenever its driving wheels hit the insulated frogs on the turnouts. This quite often results in the leading trucks derailing, causing a short-circuit. I'm wondering, then, what modifications I could make to either the locomotive or the turnouts to prevent this issue.
Title: Re: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: jward on March 13, 2025, 04:26:08 PM
Have you checked the flangeway width at the guardrails. A hacksaw blade makes a good guage for this. If the flangeways are wwider than the top end of the blade, you need to put shims in them to narrow them, because they aren't guiding the wheels away from the frog points. What number switches are you having trouble with?
Title: Re: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: Len on March 13, 2025, 04:49:56 PM
I've had some issue with Kato's HO turnouts where the flangeway of the frog itself wasn't deep enough and the flanges of some locos would ride up on the frog. A bit of fine sandpaper wrapped around the edge of a bit of styrene sheet added enough depth to cure the problem.

Len
Title: Re: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: ferroequinologist on March 14, 2025, 05:59:54 PM
Hello,
So, if my understanding is correct, I should use sandpaper to file down the flangeway until it's just about the same level as the locomotive wheels. I don't have sandpaper currently, but I do have some metal files and am wondering if they would work just as well.
Title: Re: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: ferroequinologist on March 14, 2025, 06:04:04 PM
Quote from: jward on March 13, 2025, 04:26:08 PMHave you checked the flangeway width at the guardrails. A hacksaw blade makes a good guage for this. If the flangeways are wwider than the top end of the blade, you need to put shims in them to narrow them, because they aren't guiding the wheels away from the frog points. What number switches are you having trouble with?

Hello,

That sounds like a good idea, and I have some shim metal I could use for that. I use #4 turnouts on my layout, and while I was informed that the K4s handle better on #6 turnouts, the #4 switches are the only type that enable me to configure a passing siding into my track plan.
Title: Re: Question Regarding Spectrum K4 Bouncing on Kato Turnout Insulfrog
Post by: trainman203 on March 15, 2025, 11:32:20 AM
On my secondary layout, I am forced to use no.4 switches.  I too am using Kato Unitrak and while I am generally very well pleased with it, my Bachmann consolidations pick at the frog point with the lead driver, resulting in a little hop that is pretty annoying. 

I don't think there's much I can do with that.  I had the same problem with atlas switches in the past, but with the plastic frog, I was able to bend the point very slightly out of the curve. I'm afraid to try that with the metal Unitrack.

Manufacturers will always tell you the bare minimum switch and curve that their engine can get through, but you should always go as wide as you possibly can with those.  Unfortunately, on my little layout down here on the Gulf Coast, spatial constraints have forced me back into virtual toy train territory with those aspects, unable to run my 2-8-2's.