Under The Hood: Polar Express 1225 Berkshire

Great work Mitch. Must have been really soft brass to wear like that, or no grease.

Plenty of grease, so the brass was soft.  And thanks!   

it looks like this 1225 is not too much trick to open I strongly think I have a lazy smoke piston or broken either way it’s smokes but weak and often no puff to it any other tricks I should know to fix this? it’s a super nice engine that was rarely run by the past owner

rebuilder posted:

it looks like this 1225 is not too much trick to open I strongly think I have a lazy smoke piston or broken either way it’s smokes but weak and often no puff to it any other tricks I should know to fix this? it’s a super nice engine that was rarely run by the past owner

Examine the piston.  Should look like this:  

If the bracket is off or one or both of the balls are out,  the piston won't work right.   Good luck!  Keep us posted on your progress.

Mitch 

thanks Mitch i’ll keep my fingers crossed solving this problem if it were a post war steamer it’s a piece of cake at least on most this will be my first adventure on this design i’ll post the results

Nice Mitch!  Any chance you happened to count out the gear ratio while you were in there?

Another possible factor in the wear... most of the newer locos are geared much lower with a single-thread worm (as opposed to a triple-thread worm on a 736.)  Don't get me wrong, the lower gear ratio and slower speeds are much preferred.  Lionel could have gained back some longevity by using a steel worm, and a bronze (or brass) worm wheel.

Ten years is still a long time.  Not a problem, as long as spare parts are available.

The worm on the new replacement looks to be a larger diameter, is this just an illusion of the photograph? If both the worm and the worm gear are brass, that would explain why they failed so early. For better wear characteristics, the worm should be steel with a brass worm gear. Just another example of cheapening the product through poor engineering practice at the expense of product longevity. Might want to get a spare set of parts while they are still available...

Bill in FtL

Ted S posted:

Nice Mitch!  Any chance you happened to count out the gear ratio while you were in there?

Sorry,  no. 

Ten years is still a long time.  Not a problem, as long as spare parts are available.

As opposed to, say, my 1666 which is still going strong 73 years later?

Bill Nielsen posted:

The worm on the new replacement looks to be a larger diameter, is this just an illusion of the photograph?

Just an illusion of the shadows in the photo.   

Might want to get a spare set of parts while they are still available...

Another contrast with postwar:  With postwar, you can get the worm and gear by themselves.  With the modern [rhymes with snap], the best you can do is get an entire axle and an entire motor assembly... 

Mitch 

any advise or steps to follow to open a polar express 1225 for smoke piston repair or replace?

It's pretty straightforward.  Remove the four screws holding the shell to the chassis,  then undo the screw holding the smoke unit in place to access the piston.   Good luck!   

M. Mitchell Marmel posted:

Another contrast with postwar:  With postwar, you can get the worm and gear by themselves.  With the modern [rhymes with snap], the best you can do is get an entire axle and an entire motor assembly.

True for the 773, and F-units with horizontal motors.  For everything else, the worm was cut into the armature shaft (and not all armatures were alike.)  Not arguing, I agree with you!  This is one of the pet peeves I have with a lot of modern-era designs.  Even the new Legacy brass hybrid has the worm pressed onto the motor shaft.  Transferring that gear to another motor will be difficult or impossible.  So the "spare part" I was thinking of is a motor complete with worm and flywheel.

They made enough of these baby Berks that cannibalism will be a viable strategy 20 years from now.  Some of the rarer, more expensive items made this way will end up as shelf displays 

Ted S posted:

They made enough of these baby Berks that cannibalism will be a viable strategy 20 years from now.  

Heck,  cannibalism is a viable strategy now.  Where do you think Lionel gets its spares?   

Mitch 

I just wonder if there are any tricks I should know of to replace the smoke resistor in the non lionchief 1225 polar express loco

M. Mitchell Marmel posted:

Ted S posted:

They made enough of these baby Berks that cannibalism will be a viable strategy 20 years from now.  

Heck,  cannibalism is a viable strategy now.  Where do you think Lionel gets its spares?   

Mitch 

That's true. It's very difficult to get the Chinese factories to supply spare parts. It just is not in their mind set. Use it once and throw it away, is how they think.

Great write up Mitchell.

The hours operated is a much better indication of actual usage than years of age of the engine.  The evaluation of wear of moving parts is a better indication of use.  Most engines spend most of their life in the box, on the shelve or setting on the layout.

The wear of the gear(s) on Mitchell's engine may indicate a heavy use engine.

Charlie

rebuilder posted:

I just wonder if there are any tricks I should know of to replace the smoke resistor in the non lionchief 1225 polar express loco

Not that I recall.  Once you have the smoke unit unshipped, disassembly and reassembly are fairly routine operations. 

Mitch

thanks for the input Mitch. this loco I got at a good price never run much just a weak smoker like they all are on this model but it will be worth the improvement

hello, il french, sorry for the english.

its possible to change the two gears and use module 0.5 .

the Lionel Gears are in module 0.6, not very ofen used  and the quality is poor.

you Can use  motor Gear / axle Gear in brass module 0.5, the distance is the same. ( only 0.1mm différence).

the axle Gear must have 25 feets in 0.5

the speedy réduction Will be better, because the Lionel axle Gear have only 21 feets.

for the motor Gear, take the same, diameter 6mm in brass.

a little difficulty is to remove the wheel from the axle to change the Gear.

for the rest, its quite easy.