Fox Valley wheels - with resistors

[GaryHinshaw]

...and all sizes out of stock again.  Hopefully Matt decides these are worthwhile!

[eric220]

Just snagged a package from BLW. Most versions are still in stock there.

[Cajonpassfan]

Bump...
Well, a discouraging bit of news....
Tonight, I started adding one resistor wheelset to cars getting the Fox Valley treatment, i.e. three FVM axles w/o a resistor and one with per car. I started with some Bluford hoppers which weigh in at 23 grams, or .8 oz. No joy, the Ohmmeter reads zero resistance, until I push down fairly hard on the car with my hand. My BD-20 occupancy detectors have no clue the block is occupied....Does anyone else have experience with this phenomenon? That kind of blows a big hole in my signaling plans
Otto K.

[Santa Fe Guy]

Hi Otto. I run M/T 33 inch wheels with only one FVM metal wheel set with a resistor on every car about 160 in total. I had one of the younger guys in our group do the (dirty work) installation. Sometimes we do not get a detection on my panel with just one car and I'm using using BDL168's. The FVM wheels sometimes have a machine coating on them and needs to be run in, sometimes the car needs to be manually moved however most times it works ok. That's one of the reasons we went for a metal wheel with resistor on all cars to help the system.
Have fun
Rod.

[Cajonpassfan]

Thanks Rod, appreciate your thoughts, as always.
Still, it is a bit disconcerting. What I hear you say is that if I leave a couple of cars on the main and take the rest of the train on the adjacent track to do some switching, the system may or may not detect the presence of those cars?
I guess I'll have to clean the wheels (although they look clean) and do some experimenting. I'm sure heavier cars will "read" better, but it's not easy to add weight to empty hoppers (and I'm not about to run loaded coal trains back to Newcastle, so to speak).
Anyone else with experience care to chime in?
Thanks, Otto K.

[eric220]

I haven't had any problems detecting them with just one axel on a Bowser caboose. Then again, I'm using the RR CirKits detectors, which I find to be more sensitive than the BDL168s.

[Cajonpassfan]

Well, at this point I didnt fully test it with the detectors wired,  just an ohm meter, and I get zero resistance, fully open circuit as if there is nothing across the rails. Nada. If I push down on the car, I get a reading... so it's not about the type of detector, at least not yet.

[peteski]

...just an ohm meter, and I get zero resistance, fully open circuit as if there is nothing across the rails.

Zero resistance is a short. I think you mean infinite (or higher than the meter's range) resistance reading (which is open circuit).

[Cajonpassfan]

Yep, I mean open circuit, nada, zero reaction from the ohmmeter... like there is nothing connecting the north and south rail (until I push down on the car). If zero resistance if the wrong term, I stand corrected.
Otto

[peteski]

Yep, I mean open circuit, nada, zero reaction from the ohmmeter... like there is nothing connecting the north and south rail (until I push down on the car). If zero resistance if the wrong term, I stand corrected.
Otto

When a digital ohmmeter reads an open circuit, it doesn't show zero on display (resistance or ohms). Most meters show a "1" (indicating infinite resistance).  I guess I'm a stickler when it comes to electrical terms.   

[mmagliaro]

Have you actually put an ohmmeter across one of those resistor wheelsets on the bench?
Maybe omething isn't up to snuff with those
wheelsets.  Maybe the little resistor isn't really making good contact to those wheel backs and pressing
down just flexes the wheelset a little so the resistor touches.

If an ohmmeter on the two wheels of a wheelset still reads open circuit, that would be important to know.

[Cajonpassfan]

Good point Max,
I did do just that, and get about 8-9K Ohms on my cheapie meter, so all's right with the wheelsets themselves.
And Peteski, the same cheapie meter defaults to the "lazy8" infinity reading when nada happens...yes you're a stickler and a pain,  but you're also correct
Otto

[peteski]

...yes you're a stickler and a pain,  but you're also correct
Otto

 

Another possibility is that there is some sort of thin insulating film on the wheel treads.  Thin enough to be broken by the sharp test probe of the ohmmeter or by putting extra pressure on the car while it is on the track).  Try cleaning the wheel treads and the track, then put the wheel on the track and measure the resistance (after the cleaned wheel is back in the weighted car).

[Santa Fe Guy]

Another possibility is that there is some sort of thin insulating film on the wheel treads.  Thin enough to be broken by the sharp test probe of the ohmmeter or by putting extra pressure on the car while it is on the track).  Try cleaning the wheel treads and the track, then put the wheel on the track and measure the resistance (after the cleaned wheel is back in the weighted car).

That''s why I mentioned the same issue with FVM wheels a few threads back. It does seam to make a difference.
Rod.

[fire5506]

I would also try putting the wheels in a different position in the car. It could be the way the car sits on the track that wheel isn't getting enough pressure to make good contact.

 When I have read different articles on putting resister wheels sets in a cra it is usually recommended to put 2 wheels in them, one in each truck.

Richard