Less Pulmore for More Smoke Question

Mechanically, you could probably find a different set of gears giving you a different ratio to provide less movement for a given motor rotation. Heck, maybe you can invert the existing gears (put the small gear on the worm drive shaft and the large gear on the output shaft - EDIT: Never mind - inversion would increase the speed!).

Electrically, you could add resistors inline with the motor, but that would be wasteful as the power they prevent from going to the motor gets converted to heat. You could also add a circuit board that could act as a speed controller, but I think most of the off the shelf options in this arena are coupled with command control of sorts.

 Rather than resistors which can be load sensitive wire one or more diode back to back pairs in one of the motor leads. This will drop the voltage to the motor relative to the smoke unit and should give what you want. Several threads on this on OGR including the current one on slowing a train downhill  https://ogrforum.com/...43#77734316091314643 

Thanks for the replies.

Been doing some searches.  I read the downhill thread but my issue is somewhat different.

Diodes seem to be the way to go.  I have some IN4007 ones I found in my parts drawer but I think these might not be heavy enough?  They are one amp.  It appears that they should as well be in series?  And how many?

Connected to either motor lead?

Am I in the ballpark?

Thanks

Dave

Dave 

Those diodes are for very high voltage. For a pullmore you'd want ones rated at several amps but 50V would be plenty. Using bridges saves space/wiring just hook them up like in that thread. Should be available from DigiKey, All Electronics,, Jamco and etc. I'd suggest 6 amp and anything over 100V.

They can go in either motor lead. Each diode pair gives a .6V drop allowing a fairly fine tuning of the relative power to the motor and smoke unit.

The voltage rating of the diodes is pretty insignificant for this use.  If you want the bridges cheap, look on eBay.  If you want them now, I turn to Digikey or Mouser, reliable and fast.   For a Pulmor motor, I'd be using a 6A bridge or two.

Thanks Guys for the replies.

UPDATE

Please over look the rough work.....will be neat and tidy when the troubleshooting is done

I tried different combinations and one 5 amp 50v did the trick wonderfully!

BUT....always a but eh....

This engine has the Railsounds 1 - whistle - bell - and chuff sounds.

With the diode installed the horn remains on when moving.

In the pictures you can see the small connector with one wire detached.

There are no sounds with that wire detached.

That wire goes to the motor side with the diode.  The diode truly did it's job when directly attached to the motor winding wire and then to the terminal.

The diode is interfering with whatever that wire does.....or so it would appear....

Appreciate any help

Dave

The location of the diode is creating a DC offset detected by the sound board activating the horn/whistle. I don't have the wiring setup of this particular locomotive memorized to better advise. Let me see if I have reference materials to look things up.... EDIT: Lionel Supplement 14 has a nice parts list, and Supplement 15 only has a rought exploded diagram which dosen't contain the electrical detail I was seeking. My physical reference of prewar switchers use a different motor setup.

Installing a single diode or a string of diodes will cause a DC offset that is used to active the horn/bell. What you need to do is connect two diodes back to back (one pointing each direction) this allows the full AC through but dropped by about .7V. If you need a greater speed reduction add additional PAIRS of diodes then there will be no DC shift.

Installed a second diode one pointing in each direction.....is solved the first issue Scotie....but now no motor....eunit functions and sounds are good....but no movement.....no power to the motor.

The two diodes pointing in different directions need to be in parallel with each other and those need to be in series with any motor lead. You might have your diodes in series with each other. That will not work.

You may find out that .7 volts is not enough to make a difference.

As I understand it, the diodes need to be in parallel - did you pit them in series?

Series:

Field-----[DIODE]-------[DIODE]-------Terminal

Parallel:

                  [DIODE]
Field-----<               >-------Terminal
                  [DIODE]

One diode needs the silver band pointing to the field, the other diode needs the silver band towards the terminal.

Thanks Guys....you were all correct......I now have the two diodes in parallel and movement and sounds are active and function normally.

However, it now is not enough reduction of voltage.  I have a 6 amp bridge rectifier at the ready.

How would I incorporate this into the mix to achieve the reduction?

Appreciate the help

Thanks

Dave

I would just clean it up and add a couple more pairs of diodes....

Add the diodes in series ; "inline", in addition if needed.

Thanks Adriatic....completed this and added another 6 amp bridge...

This is the ticket.

Along with the smoke unit mods and this effort.....very nice smoke at slow speeds without having to pull and anchor!

Now to tidy and bundle this up....

Thanks Guys for all the responses....always nice to add to the grey matter data base ! 

How will you fit all that in the shell?

Ah.....Rob...........that will be in my next set of pics......

Most of the those legs can be cut down and I believe there is enough room between the motor and E unit.

We shall see.................

All buttoned up.  Everything fit  in nicely and made a wonderful difference in the output of smoke for this conventional engine.

Nice tight work too 

Somehow I completely missed electronics class. 

I'm always amazed at the knowledge and the work!! 

Put in a Dallee #400 electronic reverse unit and done.

Marty,

That's a good board but wouldn't help his problem which was the motor operating at a lower voltage than the smoke unit. The diode drop method fixes this and in the process has learned some useful things and done a great job packaging and soldering the bridge rectifiers so it all fits very neatly.

I do not know much about fixing trains.  Good luck with your problem.

Scotie posted:

Marty,

That's a good board but wouldn't help his problem which was the motor operating at a lower voltage than the smoke unit. The diode drop method fixes this and in the process has learned some useful things and done a great job packaging and soldering the bridge rectifiers so it all fits very neatly.

     I haven't looked because it was done, but Marty's suggested board may have a similar drop across it on the motor controls, and a direct passing of full voltage to the element. 

   It would have a bridge rectifier or equivalent diodes, plus diode equivalents within the transistors used to switch applied power; so I could see it performing the same drop and replacing the e unit.  

     If so, bottom line, the "hands on puzzle" & slightly higher price (and it is pre-fabbed) would be the only reasons not to consider it.

The Dallee 400 puts DC current into your AC motor making it run excellent.    I am not a fan of any Pullmor motors.  They are what they are.  

Soo Line posted:

All buttoned up.  Everything fit  in nicely and made a wonderful difference in the output of smoke for this conventional engine.

The diodes did exactly what @Soo Line was looking to do for much cheaper than the Dallee 400 which hasn't even been established to do. No need to knock this elegant cost effective solution @Soo Line has chosen or present an irrelevant distaste towards traditional technologies/engineering.

I see this all to common in classic vehicle threads: "Where do I find a wheel cylinder for my [classic vehicle here]" which gets flooded with "Use this $2000 kit to upgrade to disc brakes" burying the real winner of a response "Looks like you don't need a full wheel cylinder. A $10 wheel cylinder rebuild kit (PN 12345) from this parts supplier will do. If you choose to replace the whole cylinder, it appears they have those as well.". Same can be said for the needless 6V to 12V conversions I see - "6V systems suck - I upgraded mine replacing the wiring harness, battery cables, ignition battery and such and now I don't have starting problems". What is totally lost on them is that a 70 year old 6V system was engineered very well and if refreshed in the same way, would start just as reliably. In all likeliness, they probably had some combination of bad connections, worn out battery cables, or a weak battery. But instead of taking away that well maintained systems work as engineered, they take away that 6V systems are terrible.

Anyways, @Soo Line, nice clean result there! Kudos! Same to all those who helped with arriving at this diode setup!

Like I said earlier, I do not know much about fixing trains.

I bought my 18000 new back around 1990 and the first thing I discovered was that the e-unit took more voltage to cycle than the motor took to start running, so once the e-unit completed it's cycle there was enough voltage going to the track that the little 0-6-0 would take off much faster than it should have. Impossible to start at a creep.  I stacked 4 pairs of diodes back to back and that cured that problem and as mentioned smoke output was much better.  Though I am not able to tolerate much smoke. Wish I could.  I have a big box of brass gears from slot car days so I fiddled around till I found two that would fit and mesh properly on the motor and drive shaft that bumped the ratio from 2.11:1 to 3.? :1  I don't remember what the tooth count on the new set is. The old set was 9 on the motor shaft and a 19 tooth nylon gear on the drive shaft they are 36 pitch gears.  The new set is 48 pitch (smaller teeth) which was common on slot cars, both are brass. Though I was happy with the low speed performance the new gears whined rather loud. I decided that a cover over them would help so I fashioned one out of 1/16" brass sheet and it helped but not enough. The next experiment was to find a gear lube that would do the job.   After going through every gear lube I could find I made a goop out of STP, Graphite and very fine sawdust and it worked very well.  When running without a load and no other trains running I can just hear the gears. If any other trains are running or if the B6 is pulling a load the wheel noise drowns out any gear noise. Now if I could get enough lead inside the boiler so I could use all the extra torque at the wheels.   Another benefit of raising the final gear ratio is the loco is much less prone to slow down and speed up on hills. I am about to convert that loco to TMCC and will check the final drive ratio while I have it on the bench. J