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Chuff sensor?!?!!

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  • Member since
    March 2015
  • From: Oregon
  • 188 posts
Chuff sensor?!?!!
Posted by 5150WS6 on Monday, December 30, 2019 10:55 AM

Hi guys,

Finally getting my Westside Brass SP Daylight 4449 loco set up for DCC.

I'd like to the chuffs and things times right with the sound and the Loksound manual mentions a magnet and sensor combo. I know they were called chuff sensors at one point. 

Loksound mentions a Hall IC setup.....but I can't find any of the sensors at all.....anywhere.  Am I maybe just looking up the wrong term or something?  Or do they just not offer the sensors anymore?

Thanks for the info guys!

Mike

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 1:02 PM

I haven’t had much luck using Hall Effect (1881) detection with small magnets.  They work good with large magnets, just too touchy with tiny magnets.
 
EDIT:
 
You might try a tiny reed switch, I found this one on eBay this morning.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,229 posts
Posted by gmpullman on Monday, December 30, 2019 1:32 PM

In one of my early Tsunami steam decoder installs I used a bronze wire that contacted a square cam lobe on one of the driving axles.

Does your Westside engine have one?

Out of dozens of later installs I have not used an external sensor. Most of the recent decoders have a pretty decent chuff-timing adjustment that can be fine-tuned to give you good results.

BLI uses a reed switch reading a magnet on the flywheel. They are prone to failure as the mechanical contacts wear out after time. I have heard of some fellows gluing tiny magnets on the inside of drivers but this seems like too much hassle for me.

 BLI_Chuff_detail by Edmund, on Flickr

Bachmann makes these handy roller stands that make setting the chuff rate easy without chasing the locomotive all over the layout:

 IMG_6625 by Edmund, on Flickr

Good Luck, Ed

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,321 posts
Posted by selector on Monday, December 30, 2019 2:06 PM

I would strongly advise you to simplify your train modification the way Ed does it. I do it the same way he does.  I use the CV for chuff rate.  I have a number of BLI engines produced since maybe 2010, and they have the chuff sensor mechanism.  I read posts in forums about them breaking all the time, and not just BLI's versions.  So, I use the chuff rate CV setting built into all modern steam decoders.  If you set your speed to about 15 or 20 mph, and then adjust the CV value to get the correct rate for the speed, you'll find that it will be quite accurate over a range of speeds.  Very reliable, just as realistic, and not prone to quitting suddenly and requiring you to open things up and do repairs.

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,229 posts
Posted by gmpullman on Monday, December 30, 2019 3:01 PM

Another advantage of using the CV adjustments, in addition to what Selector points out, is that when your locomotive is running at higher speeds the exhaust "chuff" can take on an annoying pulsating sound. 

By using the CV settings you can slightly reduce the "high end" so there is more of a distinctive exhaust rather than a buzzing drone sound. Your ears and eyes can't count the wheel revolutions too easily at that speed anyway.

I sorely wish Broadway had a way to override the reed switch. It is time they did away with that anachronism.

Good luck, Ed

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