BLI M1a/b performance issues

[Paradise275]

I had to send mine back. It ran well but when you increased the speed, the chuff sound went crazy.
It took about 4 months to get it back but now it runs perfectly.

Rick

[peteski]

I have seen several dozens of N scale steam engines (from many different manufacturers) and I have to say that this is an unusual design.  In a typical design the single-piece connecting rod is straight (flat), and the crank pins on the front and rear drivers are short, keeping the connecting rids close to the driver faces. In the BLI design the connecting rod is bowed out on the ends, and the crank pins are extra long.  Not sure why they had to do that.  If I was trying to fix this model I would straighten out the connecting rod piece, and shorten the crank pins.

[narrowminded]

I have seen several dozens of N scale steam engines (from many different manufacturers) and I have to say that this is an unusual design.  In a typical design the single-piece connecting rod is straight (flat), and the crank pins on the front and rear drivers are short, keeping the connecting rids close to the driver faces. In the BLI design the connecting rod is bowed out on the ends, and the crank pins are extra long.  Not sure why they had to do that.  If I was trying to fix this model I would straighten out the connecting rod piece, and shorten the crank pins.

The problem WAS when the rod went in close, the tight position, not allowing room for the connecting rod to clear the front pins, and I think adequately described but maybe not.  The extra end play on the pin allowed the rod to move out enough to clear but there was nothing to hold it there and when it floated inward it plain old crashed into the shoulder of the pin's head, full on bound, upper face of the rod fully and bluntly engaged with the radial face of the pin head, not just kissing it with a glancing blow.  Look at the picture again.  If anything, the guide rods on the cylinder should be a little wider but that's not a realistic modification.  That could be a design change though for a future run.   If it would help I can remove those spacers and take another picture of the rod crashing the front wheel pin but i thought this was enough to envision and understand the issue.

[peteski]

The problem WAS when the rod went in close, the tight position, not allowing room for the connecting rod to clear the front pins, and I think adequately described but maybe not.  The extra end play on the pin allowed the rod to move out enough to clear but there was nothing to hold it there and when it floated inward it plain old crashed into the shoulder of the pin's head, full on bound, upper face of the rod fully and bluntly engaged with the radial face of the pin head, not just kissing it with a glancing blow.  Look at the picture again.  If anything, the guide rods on the cylinder should be a little wider but that's not a realistic modification.  That could be a design change though for a future run.   If it would help I can remove those spacers and take another picture of the rod crashing the front wheel pin but i thought this was enough to envision and understand the issue.

No need for more photos for me - I get it. Still, this is a variation of a design I have not seen before. Yes, most steam locos have their cylinders located much further outboard than in the 1:1 loco to clear the rods. 

[narrowminded]

Yes, Pete.  And my problem with this issue and others with different manufacturers (or are they really one and the same?) isn't that something like that happened (although, how many years have they been at this? )  but how in the wide, wide, world of sports did they SHIP it like that?  It's truly perplexing to me how they do so much right and then completely blow the obvious.  Try as I might I can't understand it.   I believe it from seeing it time and again but I truly don't understand it.

[peteski]

Yes, Pete.  And my problem with this issue and others with different manufacturers (or are they really one and the same?) isn't that something like that happened (although, how many years have they been at this? )  but how in the wide, wide, world of sports did they SHIP it like that?  It's truly perplexing to me how they do so much right and then completely blow the obvious.  Try as I might I can't understand it.   I believe it from seeing it time and again but I truly don't understand it.

I imagine it is a lack of QC.  Maybe they even did a test run on a piece of straight track and it passed?  Or maybe they only test a random sample from the production run?  Dunno.   

[narrowminded]

I imagine it is a lack of QC.  Maybe they even did a test run on a piece of straight track and it passed?  Or maybe they only test a random sample from the production run?  Dunno.   

Yes, but this didn't move a mere few inches.  Had there been any speed at all it might have suffered some pretty severe damage as the one from that thread did.  The problem was immediate and because it was a very mechanical issue, the crankpin length hugely longer than would make sense, I can't imagine that it was just this one.  Maybe we'll hear reports and then, if it IS just this one, that's even MORE baffling.  How do you manage THAT with machined production parts?!  I don't really expect an answer because I'm not sure there is one that could resemble legitimate but I am expressing my disbelief in this issue, but also similar by style issues that I've seen with some frequency.  It's truly baffling to me. 

[peteski]

Too bad that we don't have and bottom-view photos in the other thread you found to see if its side rods were also bowed out on the ends, and to show how long the crank pins were.

Maybe as I said, maybe the QC is done on a random sampling of the models and yours was just an oddity?  We probably can't attribute the problem to shipping damage, right?

[narrowminded]

Too bad that we don't have and bottom-view photos in the other thread you found to see if its side rods were also bowed out on the ends, and to show how long the crank pins were.

Maybe as I said, maybe the QC is done on a random sampling of the models and yours was just an oddity?  We probably can't attribute the problem to shipping damage, right?

I mentioned it above, that I bowed those out slightly to assure they could not hit ever.  Even with the spacer in place if you took all play from axles, rod and crosshead linkages, everything else loaded in one direction you could make them touch.  With the slight bow and the spacer holding the rod out there is no longer any chance of anything hitting ever.  That was likely overkill but it's assured and causes no problem in the appearance.  That part is fixed to my satisfaction and any portion of it could be undone.  Why you would ever want to I don't know, but it could be.

[peteski]

I mentioned it above, that I bowed those out slightly to assure they could not hit ever.  Even with the spacer in place if you took all play from axles, rod and crosshead linkages, everything else loaded in one direction you could make them touch.  With the slight bow and the spacer holding the rod out there is no longer any chance of anything hitting ever.  That was likely overkill but it's assured and causes no problem in the appearance.  That part is fixed to my satisfaction and any portion of it could be undone.  Why you would ever want to I don't know, but it could be.

 I didn't understand your explanation until now - thanks.
So the extra long crank pins were needed to allow for the drivers to deflect sideways to allow them traverse sharp curves?  But with center drivers blind the drivers don't have to have a lot of sideways play.

[narrowminded]

I didn't understand your explanation until now - thanks.
So the extra long crank pins were needed to allow for the drivers to deflect sideways to allow them traverse sharp curves?  But with center drivers blind the drivers don't have to have a lot of sideways play.

You're talking logic here and then there's what was there.    Also the source of my expressed disbelief.   I understand those things but this didn't need any of those situations to hit, BLUNTLY, perfectly aligned to HIT directly, no glancing blows here, on both sides while running in a straight line.   The extreme amount of end play on the crankpin end of the connecting rod allowed those rods to ride inward, hitting every time that the rod drifted inward with nothing to stop it from doing that.  When it hit it would load up, kick the rod out a little and abruptly pop over the interfering pin.  It plain old didn't have any clearance when the rod rode inward and it didn't take any tools more than sub par vision to see it.   The spacer was the meat of the fix (.036" of it) and the slight bend at the cylinder end just assured that even when normal component play was all loaded one way, not likely but possible especially with time and natural wear in the little pivots, it STILL couldn't hit.  As I've expressed, this situation was about as beyond believable as it gets unless this is the only one, which is its own hard to believe situation.

[peteski]

I guess that without having a larger sample of these models to examine it is difficult to ascertain whether yours was an anomaly, or whether they are all built like yours.  We do have a fairly sizable contingent of SPFs here on TRW. I wonder how many of them own and run these models (and whether they experience the problem you have experienced).

[Cajonpassfan]

Thanks John. Good to hear. I have the P3 version, and while the sound is great, the mechanicals and pickup, not so much. I did some testing tonight, flipped it upside down, and discovered that the left side of the loco picks up current on all drivers and both tender trucks. Great. The only thing that picks up current on the right is is the front tender truck. The rest is dead as a doornail. It's difficult to test the mechanical components when electrical pickup sucks like this
Tbc I'm sure...
Otto K.

I finally had a little time to look at this issue again. When upside down in a cradle and connected with alligator clips on the front tender truck (the only part of loco/tender that picks up power on both sides), the engine runs flawlessly in both directions, with no snags or apparent surging. There is also no wobble, and even when pressing on the wheels with a finger, the is no reduction in rpm's; good torque. So it would seem my loco's issues are all related to inadequate electrical pickup on its left side. 

The next step will be removing the shells, but I don't want to damage anything in case I decide to send it back. Can any of you gentlemen who have done this advise me on how to do this (or perhaps point me to some other discussion on this if already covered)?
Any help here appreciated!
Otto K.

[Lemosteam]

@Cajonpassfan , @draskouasshat is the first and only person that I have heard of doing this.

[Cajonpassfan]

So of the hundreds (thousands?) of these SPF wonders out there, Drasko is the only guy who ever took the shell off?
Really? And he's not even a SPF
Come on, I know you're out there...
Otto K.