Smoke unit repair

If its an older unit running from track power its likely a 27 ohm.

8 ohm is only used with the newer "smart" smoke units using an 8 VAC variable regulator to vary smoke intensity.

Is it conventional or TMCC?

Rod

It's obviously the 27 ohm resistor, very easy to obtain.  FWIW, I'm having good luck using a 22 ohm resistor in those, that and the Lionel suggested mods to older TMCC smoke units makes it smoke like an MTH locomotive.

Tanks for the help.Should I still put some wadding in the chamber with the resistor?Tnx

Yes on the wadding, but no sleeve on the resistor. Put enough wadding in so that the resistor pushes down into the wadding.

I see Chuck beat me to it.

Thanks so much guys.Cant wait for the parts to get here.Nick

Follow up.Got the parts.It was a nightmare putting this boiler back together,but it works good.Thanks guys Nick

I buy the ceramic coated 3 watt ones at Digikey and hit them with the Dremel wire wheel.  In less than a minute, I have an uncoated resistor.  They're less than a dollar, and you can have any value you desire.

gunrunnerjohn,  Do you have a part number or link for the 22 0hm resistor on Digikey? Their are so many products on that website that I don't want to get the wrong item.

22AECT  It is a wire wound resistor.  G

Here's a direct link to the 22 Ohm 3W WireWound Resistor.

If you use a Dremel wire brush, it'll take the ceramic coating off without damaging the windings, it's quick and gives you the bare resistor.  You can also use it with the ceramic coating, I use them that way in something like the Dockside switcher, there's too much metal around to risk the bare resistor.

EDIT: Fixed incorrect resistor link!

And we all hope that ceramic coating is not carcinogenic, because it does disintegrate into a very fine particulate.  G

OOPS!  Wrong link, that's a .22 ohm resistor!

I'm fixing the link in the previous message!

Really makes a difference, doesn't it. 

C'mon Eric, we need pics! Or at least I do!!

Especially since I have a 681 as well!

are these fan driven smoke units your guys are talking about?

Dropping the resistor value in the puffers works as well.  I did that for one of the RTR Dockside switchers recently for a customer that brought it back "because smoke was not working".  Actually, it was working, it's just pretty anemic on the RTR sets as they run at a very low voltage and the smoke unit doesn't heat up.  18 or 20 ohms and they produce decent smoke at the lower track voltages.

John - My only experience with modern puffers is the PE and all the smoke billowing out the bottom! I'm assuming the smoke unit in the Dockside switcher is a different type of puffer?

The Dockside switcher has a "unique" smoke unit, has a really odd piston arrangement.  It's totally different than something like the PE.

Thanks John!