mechanical smoke unit re-timing?

I'd be interested to see this too.  I picked up one of these locos at a train show earlier this year at a very good price, so I wasn't too worried if it had some problems.  After an initial run indicated some maintenance required, I went ahead and did that.

One of the things I found during the inspection was a broken cam lobe that ran the smoke piston.  The cam, located on the front driver axle, was a plastic one-lobe cam that had split apart where the axle passed through.  I fished out the two pieces and saved them, then de-soldered the smoke unit in order to disable the smoke for the time being.  I plan on scratch-building a new brass 4-lobe cam sometime then replacing it on the axle.  Possibly this coming winter when more time is available for such things.

In a nutshell, after removing the boiler, looks like one will have to remove the valve gear from both sides of the drivers, then pull one drive wheel off of the front axle.  Thereby allowing the axle to be pulled partially out of the frame far enough to to place the new cam into position.  Then push the axle back through the lobe and frame.  Press the removed drive wheel back on, reattach the valve gear on both sides, and anything else that was disassembled.  Might not be a bad idea to install an on-off switch for the smoke unit at this point, also (if at all possible).

Hopefully somebody has already done this and has some pics/videos/tutorials available that they could post.  If not, it unfortunately will be awhile before I get around to doing it.

Mixed Freight posted:

I'd be interested to see this too.  I picked up one of these locos at a train show earlier this year at a very good price, so I wasn't too worried if it had some problems.  After an initial run indicated some maintenance required, I went ahead and did that.

One of the things I found during the inspection was a broken cam lobe that ran the smoke piston.  The cam, located on the front driver axle, was a plastic one-lobe cam that had split apart where the axle passed through.  I fished out the two pieces and saved them, then de-soldered the smoke unit in order to disable the smoke for the time being.  I plan on scratch-building a new brass 4-lobe cam sometime then replacing it on the axle.  Possibly this coming winter when more time is available for such things.

In a nutshell, after removing the boiler, looks like one will have to remove the valve gear from both sides of the drivers, then pull one drive wheel off of the front axle.  Thereby allowing the axle to be pulled partially out of the frame far enough to to place the new cam into position.  Then push the axle back through the lobe and frame.  Press the removed drive wheel back on, reattach the valve gear on both sides, and anything else that was disassembled.  Might not be a bad idea to install an on-off switch for the smoke unit at this point, also (if at all possible).

Hopefully somebody has already done this and has some pics/videos/tutorials available that they could post.  If not, it unfortunately will be awhile before I get around to doing it.

I have that engine myself. It never ran right. I hope to repair it some day. I did buy it new. Just an idea is there anyway that smoke cam could be made in 2 pieces and clamped around the Axle? Sure would save a lot of work if it could.

4 lobe cams can be made, a better smoke unit upgrade would be to ditch the mechanical puffer and use a MTH PS1 smoke unit like I did on this postwar Berkshire. The smoke unit PCB is wired to track power, and the fan motor is turned on/off via a cherry switch operated by the original smoke lever.....even if y’all managed to get a 4 cam installed, with piston puffer smoke unit your performance will be lackluster at best.......Pat

I'd add fan driven smoke, trying to get a puffer to put out decent smoke that fast is probably a pipe dream.

update: I've disassembled the locomotive into most of it's individual components, but now I have another problem: the one part I cannot get open is the part where the gears are. From what I can tell it's two pieces of metal with the gears sandwiched in between, but there doesn't seem to be an easy way to open it up. Anyone know something I'm missing?

Pictures?

gunrunnerjohn posted:

Pictures?

here you go, but bare in mind I'm not the best photographer:

The above is what I've managed to strip the locomotive down to. Not very organized I know.

If you look closely, you'll see a tiny crack just above where the axles are, this is what makes me think that there are two pieces of metal with the gears in between, and not just one that has been welded shut, but I still don't know how to separate them.

That little hole there is currently my only real view into the gearbox, not nearly enough.

I don't have a clue what you're trying to accomplish, but that's basically a one-piece frame casting. There are no gears in there.

TRW

You ARE in the gearbox.....; to remove that gear, you first have to remove the third axle from the front of the loco to allow removal of the last set of drivers which has the worm gear mounted on the axle. Then you have to worry about quartering the wheels on the two removed axles in the correct manner. Lots of critical work; you'd be better to install a fan driven unit as others have said already.

There is no point in pounding out axles and removing gears, that's a recipe for disaster!  You're just asking for problems with quartering if you don't know what you're doing.

If you want four chuffs/rev, consider the old magnets on a driver and a reed switch.  As far as synchronizing the smoke, again, fan driven smoke. 

I've adapted my Super-Chuffer II to run in a conventional locomotive, it would manage the smoke unit and give you chuffing smoke and smoke at idle. Here's a sample with an MTH fan driven smoke unit and the Super-Chuffer.

Alright, fine, I'll install a fan driven smoke unit. But for that I need advice as well, I want it to puff, not spray, and given that my locomotive has a steam chest effect, I need advice on how to handle that too.

Robert Strait posted:

gunrunnerjohn posted:

Pictures?

here you go, but bare in mind I'm not the best photographer:

The above is what I've managed to strip the locomotive down to. Not very organized I know.

If you look closely, you'll see a tiny crack just above where the axles are, this is what makes me think that there are two pieces of metal with the gears in between, and not just one that has been welded shut, but I still don't know how to separate them.

That little hole there is currently my only real view into the gearbox, not nearly enough.

That gear in your last photo has nothing to do with the timing of the smoke puffs. That is the rear axle where the motor meshes with the gear. The smoke unit is driven by a cam on the front axle.  Someone handy may make a four lobe cam in two pieces and glue or solder it on the axle. However getting the right shape to allow full movement of the piston on the smoke unit will take some critical tolerances and a lot of trial and error.  Making a two lobe cam will be a lot easier.  I'm with GRJ if you want lots of smoke and four puffs per rev put in a fan driven smoke unit.          j

Robert Strait posted:

Alright, fine, I'll install a fan driven smoke unit. But for that I need advice as well, I want it to puff, not spray, and given that my locomotive has a steam chest effect, I need advice on how to handle that too.

To achieve chuffing smoke, you have to first have a chuff switch that opens and closes the proper number of times for each driver rev.  Next, you have to control the smoke fan from the chuff switch. 

harmonyards posted:

4 lobe cams can be made, a better smoke unit upgrade would be to ditch the mechanical puffer and use a MTH PS1 smoke unit like I did on this postwar Berkshire. The smoke unit PCB is wired to track power, and the fan motor is turned on/off via a cherry switch operated by the original smoke lever.....even if y’all managed to get a 4 cam installed, with piston puffer smoke unit your performance will be lackluster at best.......Pat

The funny thing is, I just so happen to have an MTH PS1 fan driven smoke unit laying around, but I'd need a very detailed step-by-step tutorial on how to install it. I would also need an idea on how to attach the two rubber tubes for the steam chest effect to it in such a way that it would still work.