Sierra Sound-TraXX

[tac]

glitch?

Every now and then, the Soundtraxx system in my AccuCraft K27 misses a beat, usually while I have an audience to impress, rather like your prize Weimeraner poo-ing on the steps of the grand maison at a show.

Everything is clean and lines up, and the [new] battery is fully charged up.

Any ideas from you electronic whizkids out there?

Best

tac
Ottawa Valley GRS

[Kevin Strong]

How are you triggering the chuffs? Mechanical wiper? Magnetic reed switch?

Later,

K

[tac]

Afternoom, Kevin - it's triggered by a 180 degree-positioned pair of magnets on the leading axle of the lead tender truck.

Best

tac
Ottawa Valley GRS

[Loco Bill Canelos]

Hi Tac,
It's hard to diagnose from afar, but I don't think it is electronic.  I have four sierras and any problems I had were due to the chuff sensor and triggers rather than the electronics.  Does it seem to happen at a track joint or on switches??  Might be an occasional bump causes the problem.  Maybe try the sensor on a trailing axle.  Also you might check axle sideplay, it could be the wheel with the magnets occasionally gets to far away from the switch. 


All this just guesses of course!! but hopefully helpful!!

Regards, Bill   

[Kevin Strong]

My thoughts are along the same line as Bill's. Magnetic reed switches are very good, but very sensitive to the slightest change. Sometimes the magnet moving by as little as 1/16" can cause the switch to not close. I've got one on my B'mann 2-8-0 right now where it's nice and even going forward, but in reverse, it's uneven. The magnetic field of one magnet is different enough to where it causes things to go awry. That's where I'd look first. Make sure there's as little play as possible between the switch and the location of the magnets on the wheel. Use small washers on the ends of the axle to keep the lateral play to a minimum. If practical, move the magnet a touch closer to the magnets, too.

Later,

K

[Chuck N]

TAC:

I have occasionally had the problem when the engine goes into or out of a curve.  The axles slip in and out a little bit in the journals.  You might try putting  some washers on axle between the wheel and journal to minimize the lateral slip.

Another thing that causes my chuff to miss a beat is a track magnet, the kind that are used to trigger the bell or whistle on LGB and some other sound systems.

Chuck

[Tony Walsham]

It has been my experience that reed switches and magnets work best if the reed switch is mounted at 90 degrees to the magnets.  They are certainly less susceptible to missing a beat because of sideways slop by the axles.  Reduce the slop anyway by using spacer washers, leaving just a very small amount of slop to prevent axle binding.

[tac]

Tony, Kevin, Bill and all - many thanks for the sage advice, and yes, there is a lot of side-play, to the extent that the magnets can actually touch the sensor or be as much as 4mm away from it.  I'll pack out the axles between the wheels and the frame to stop it happening.

And yes, it most often happens on the transition from bridge to terra firma.

Thanks again, All.

tac
Ottawa Valley GRS