Kato mechanism for BLI PA?

[squirrelhunter]

So I have a BLI PA that I bought used and (I think) has a paragon 2 decoder that seriously melted the front truck (the front axle where the meting occurred is very locked up).

Has anyone tried to put a Kato PA mechanism under a BLI shell? I was underwhelmed with how the BLI decoder worked in the first place, so I don't really want to buy a new BLI chassis or pay for them to repair it.

[greenwizard88]

If the PA is anything like the ES44AC, the truck should just pop out. They're something like $10 or $15 for a replacement, and you can just pop it back in. The BLI motors aren't bad, it might be more cost effective to repair it and replace the decoder instead - unless the chassis or shell is also somehow melted.

[robert3985]

I had something verrrry similar happen to one of my Kato F-3's I was running on a friendly club's layout a few years ago.  It wasn't the decoder that melted its front truck, but a bad, non-DCC friendly turnout on their return-loop module..."non-DCC friendly" meaning the two point rails were the same polarity when thrown, rather than each point rail being the same polarity as the adjacent stock rail.  It was a very sharp "Y" turnout...and I don't remember what the brand was.  Soooo....you might want to consider that as the cause rather than your engine's decoder.

Cheerio!
Bob Gilmore

[jdcolombo]

Bob is correct - this almost certainly wasn't the decoder.  What probably happened is that the wheels shorted across the track, but not enough to produce a "dead short" that would have caused the DCC booster to shut down.  Instead, the wheels acted as a resistor, which built up enough heat to melt the plastic around the wheels and truck.  This happened to me with a steam loco tender.  One of my cats got into my train room, decided that everything would look better if it was knocked over, and one of my 2-8-2 tender trucks literally melted down to the nubs.  The decoder in the tender was fine. I replaced the truck, and all was well.  And I installed a door on the train room

Having said that, the Paragon decoder in the BLI PA's is . . . not the best.  I posted a thread on how to replace both the decoder with an ESU LokSound and the speaker with a 11x15mm cell-phone type that sounds 10 orders of magnitude better than the stock BLI speaker.

Here's the link:

https://www.therailwire.net/forum/index.php?topic=38621.0

After this heart transplant, my BLI PA's run and sound terrific.

John C.

[randgust]

Yeah, that makes sense.   Remember that the PA truck has a longer fixed wheelbase than about any other diesel truck out there, which makes it both derailment-prone to kinks and vertical curves and subject to shorting out on diverging switches, etc.  It may find things nothing else will.

[squirrelhunter]

This is all helpful- let me give a little more detail about what happened and why I was thinking about a chassis swap.

Here is the truck:


So this was a used PA I picked up off eBay. Mostly run at trainshows, it worked fine at first. It was part of a hard (same address) consist with another PA.

But then the decoder started to randomly "forget" its address and reverted back to address 03. I'd reprogram it, and it would work for a while before forgetting again.

I was getting ready for a show this fall and I decided to use the BLI consisting info from their manual to consist the PA's with an E8. I use a siding on my layout that can hold 4 six axle engines for programming (I take all other power off my small layout) This is where things went haywire.

So I did all the steps to program the units, and this unit kept forgetting its address and would either be totally non responsive to the throttle or would try to take off at max speed. I tired a reset of the decoder and even took of the shell to push the reset button. None of it worked and after the last try it tried to do the max speed thing again but it stopped and that was when I saw the truck was melted.

I mamged to salvage things for the show by taking the chassis from another BLI PA I have, but I'd like to put a chassis back under that shell.

I'm looking for a relatively low effort way to solve the issue, hence the idea of using a Kato PA chassis if one will fit relatively easily. I was underwhelmed with the stock decoder before it went nuts, so I don't want to replace it in kind. I just have a lot of unfinished projects right now and I'm trying to stick to not starting any major new ones 😅 until I get some others finished.

[robert3985]

Wellll...I'm betting that modding a Kato chassis to fit properly under the BLI shell is going to be a lot more work than ordering a new truck, swapping it in for the melted one, and installing an ESU Loksound decoder.  Should be pretty easy. And, John C.'s ( @jdcolombo ) instructions will get you through it without any mysteries I am sure.

Just sayin'.  Since I've never swapped a Kato chassis into a BLI shell...it might be really easy.  However, if you're going to want to put sound in the Kato chassis, I'll say that my experience with installing sound DCC into Kato E-Unit shells was not easy...mounting the speaker and the keep-alive capacitor was what took the time, a big drill press and my mill.

Anyway...good luck!

Cheerio!
Bob Gilmore

[robert3985]

...
Having said that, the Paragon decoder in the BLI PA's is . . . not the best.  I posted a thread on how to replace both the decoder with an ESU LokSound and the speaker with a 11x15mm cell-phone type that sounds 10 orders of magnitude better than the stock BLI speaker.

Here's the link:

https://www.therailwire.net/forum/index.php?topic=38621.0

After this heart transplant, my BLI PA's run and sound terrific.

John C.

John, just because I wanted to see your instructions on how to do this, I used your link and went to the page the instructions are on.  The photos are all gone.  For me, they're blank, and when I click on 'em, they give me a big circle with a minus sign inside.

I don't think it's my computer.  You might want to check it out.

Cheerio!
Bob Gilmore

[peteski]

John, just because I wanted to see your instructions on how to do this, I used your link and went to the page the instructions are on.  The photos are all gone.  For me, they're blank, and when I click on 'em, they give me a big circle with a minus sign inside.

I don't think it's my computer.  You might want to check it out.

Cheerio!
Bob Gilmore

Same here.  Funny thing is that I used to see this on some of your photos Bob. It looks like a Google Photos thing.

As for removing metal from Kato E-unit chassis, I just started using a band-saw with a fine tooth metal cutting blade.  Much faster than milling (if you have a band-saw).

[bbussey]

John, just because I wanted to see your instructions on how to do this, I used your link and went to the page the instructions are on.  The photos are all gone.  For me, they're blank, and when I click on 'em, they give me a big circle with a minus sign inside.

I don't think it's my computer.  You might want to check it out.

Cheerio!
Bob Gilmore

I went to the thread as well, as I have a pair of BLI PAs that never have run well. It appears the pics were on a Google site and no longer are present.

[jdcolombo]

OK folks.

I modified the message and uploaded the original photos from my computer.  Try the link again.  It should work now.

John C.

[bbussey]

I just saved it to PDF.  Thanks John.

[robert3985]

Same here.  Funny thing is that I used to see this on some of your photos Bob. It looks like a Google Photos thing.

As for removing metal from Kato E-unit chassis, I just started using a band-saw with a fine tooth metal cutting blade.  Much faster than milling (if you have a band-saw).

Yup.  It's a Google thing...rotten bastards.  Can't keep from over-modifying things all the time making things more difficult for millions of people who have trusted them.

@peteski  Peter, I do have a band-saw, but for the speakers I'm using, they are circular and form a near perfect pressure fit when I precision drill the right sized hole from the bottom of the frame now, up into the big chunk of mystery metal Kato uses on its E-Unit Chassis (which is difficult to cut).  Older versions I modified had the hole going completely through this metal chunk, and I had to machine a friction-fitting brass cap/plug to make it air tight as per your suggestion...not a big deal using my 6" lathe...but with the new protocol, that isn't something I have to do, and I also don't have to drill out as much chassis metal, making the frame stay heavier.

Needless to say that cutting a near perfect circular hole only halfway into a chunk of metal isn't something that a band-saw does very well!   

Here's a photo of my first attempts, drilling the speaker hole all the way through and using crappy, but readily available and cheap, Digitrax drop-in sound decoders.  I still drill the hole in the same place, but start from the bottom up and don't go even close to completely through the metal block, drilling a small hole into the top of it for the speaker wires, and then sealing the hole after all has been checked out and run a bit.

Photo (1) - Initial Digitrax Sound Decoder installation on my COLA Kato E-9's and older E-8's showing frame modifications for speaker and keep-alive capacitor:


I'm sure the band-saw works fine on some decoder installs, but I don't find it particularly difficult to clamp a chassis on to my milling table or into my drill-press vice.  My point was that without special tools like you and I have, it is going to be more difficult for the OP to modify a Kato chassis than to solder in a new ESU Loksound decoder and snap in a new truck on the OP's melted model since very little chassis modification will need to be done on his existing BLI chassis.

AND, with John's now-functional instructions, all the guesswork is gone.

Cheerio!
Bob Gilmore

[peteski]

Yes Bob, in your instance (round speaker), band-saw would not give the desired result.  I use "sugar-cube" rectangular speakers so I have no need for round opening.

[squirrelhunter]

Thanks for the input everyone, especially jdcolombo for re posting his pics.

My main hope in asking the original question was that the Kato chassis was a good swap or one that might need a little filing, and I'd pickup an ESU equipped Kato and swap shells.