BLI PA-1 Noise?

[jdcolombo]

Hi folks.

I have just managed to test run four BLI PA-1's that I received last week.  These models are overall excellent.  They are the first to model the NKP PA-1 with the correct numberboards, correct paint, correct Mars light/headlight arrangement, etc.   The sound is excellent - very ALCo-y.  Overall, I'm very pleased, with one modest exception.

All four of them run very smoothly, including exceptional slow-speed creep.  But one of them is quite noisy at anything above about 15 smph (they all make a little noise, but this one is REALLY noisy).  It's sort of a high-pitched rattling noise, that seems to be coming from the gears in the trucks; I've heard a similar kind of noise from one of my old ConCor PA-1s, but never tried to track it down in that unit.  With the good sound from these, however, the noise is a distraction, sometimes overshadowing the sound of the prime mover (which I've reduced the volume on quite a bit; these things are LOUD sound-wise out of the box).

Has anyone else run into this, either with the PA's or BLI's E units?  Any fix short of sending it back and asking for a replacement?  The unit in question otherwise runs fine - no stuttering, lurching, etc. 

John C.

[jdcolombo]

Well, not exactly sure why, but the front truck wheels of my noisy PA were very much narrow in gauge; I re-gauged them, and now the unit is much quieter.  Putting the wheels in gauge causes less side-to-side play in the wheel sets, so maybe that was the problem.

In any event, very happy with these models overall.  Look great pulling an NKP passenger consist.

John C.

[peteski]

John,
this is a 2nd loco where regauging wheels seems to fix a noise problem. See https://www.therailwire.net/forum/index.php?topic=32420
Something must be causing the noise (besides the wheels being out of gauge).  It would be interesting and beneficial to figure out what it is.

[jdcolombo]

John,
this is a 2nd loco where regauging wheels seems to fix a noise problem. See https://www.therailwire.net/forum/index.php?topic=32420
Something must be causing the noise (besides the wheels being out of gauge).  It would be interesting and beneficial to figure out what it is.

I was tempted to take the truck apart, but the trucks are hard-wired; I'd have to desolder the wires to get the truck out.  My theory is that originally the wheels had excessive side play, which was causing the gears not to mesh well.   They were REALLY narrow - so much so that they were "hopping" over the frog on my #7 Atlas turnouts.   In fact, that's why I checked the gauge to begin with (should have done this when I took it out of the box; lesson learned).  My recent Atlas units have been just a hair narrow; but these were maybe 1/2mm narrow.  That resulted in a lot of side play in the wheels.  When I re-gauged them, it took out a lot of this side play, which may have caused the gears to line up better.

I CAN reliably recreate the problem.  Push the wheelsets back in so that the gauge is narrow, and the noise returns.  Gauge them out, and the noise disappears.  However, it is only this one truck that acts this way.  My other 3 PA's also had narrow wheel gauge (though perhaps not QUITE as narrow) and were pretty quiet.  This one, however, made a racket going down the main line.  So I suspect that perhaps the central tower gear is a tiny bit "off" where it is supposed to be, and if the wheel axles move too much, it causes the main gear not to mesh well with the wheel driving gears.

Right now, it's relatively quiet and working well, so I'm inclined to leave it alone.

John

[peteski]

Thanks for the additional info - sounds like a logical explanation.

[High Hood]

Hey JD you think you'll make a video of them?

[Cajonpassfan]

Bump! And help!

I recently purchased a BLI ABA UP set, with a dummy B. I already owned a similar, earlier ABA set, in ATSF Warbonnet. They look great and sound pretty good (although not as good as my custom made dummy B "deep rumble" units. I think the decoder is capable of reproducing a fine range of sounds, but the 14 mm 50 ohm speakers are not.

While happy with the earlier units, the new set is EXTREMELY finicky when it comes to electrical pickup, even though it has the new "improved" axle end pickups, a la Kato I'm told (not!). It stalls constantly in places where other engines have no problems, my finicky brass steam included. I've checked the units to ensure there is no broken wires or intermittent connections and concluded that I need to add weight and hardwire at least two units together. To be fair, they weigh in at only 102 grams, less than the original run, and much less than the Kato PA's, which weigh in at 142 grams each.

So I have two questions:
One, am I the only one wih these pickup problems, and if not, how do you address it, and
Two, are there any 50 ohm speakers available to fit the dummy B? A 14x26 50 ohm speaker would be ideal, a 16x30 could be made to fit. The 50 ohm impedance is what makes this install unusual...
Regards, Otto K. [ Guests cannot view attachments ] [ Guests cannot view attachments ]

[wmcbride]

I have BLI PA'a from the earlier run and one from the more recent runs.

All of them run smoothly and quietly (when the sound is turned off so I can tell).

I would suggest returning the noisy unit to Broadway Limited. I did this on one engine in the past and they confirmed a problem and replaced it.

It sounds as if you guys just got lemons.

[BruceStikkers]

I have the earlier E8a and b units and they run fine. The sound is also very good.

Bruce Stikkers

[Cajonpassfan]

Well, the E units (I have a number if them) are heavier and consequently have more reliable pickup. The new PA's weigh less than 3.6 oz., 102 grams. I managed to squeeze another ounce of weight in each, using tungsten disks and filling inbetween with tungsten putty, see pics below. The difference is night and day, I'm much happier with their performance now. They also pull much better, to the point I'm concerned about stressing the motors too much... I may replace the traction tire wheelsets with ones without tires. [ Guests cannot view attachments ] [ Guests cannot view attachments ]
Regards, Otto K.

[Cajonpassfan]

Looks like I'm having trouble posting images today... Here's trying again, but can't post more than one image at a time... odd

[Cajonpassfan]

Now I can...