Alternative for Bachmann smoke unit

[trammayo]

A few weeks ago, I was busy converting my Big Hauler tenders to electrical pick-up to augument the existing loco pick-ups which were affected by worn wheel plating. My last posting on the subject, brought a response from Neil Robinson when I mentioned the subject of a dead smoke unit.

Neil suggested a 6volt Graupner smoke unit and a LM2596 voltage dropper unit - the two being connected to the power source via W005 Bridge Rectifier (so that reversal of the loco would not affect the LM Unit after polarity changeover.

He also gave me instructions on how to do the work so here is my way of doing it. I'm a bit of a dunce when it come to electronic circuitry so Neil patiently, and very helpfully, answered my numerous questions.

First, the loco in question - a 2005 BH - that has earned its' keep so to speak.

I purchased the Smoke unit from Cornwall MODEl Boats (I bought a larger one from them previously). You get the Smoke unit complete with reasonably long wire tails, basic instructions, a small Hazard leaflet, a small bottle of (Seuth) smoke and a small 2ml syringe for filling up.

Next I ordered a pack of ten LM boards (working out at 79p each) off the Internet -

http://www.ebay.co.uk/itm/10PCS-LM2..._Measurement_Equipment_ET&hash=item53fcb1eba2 < Link To http://www.ebay.co.uk/itm...mp;hash=item53fcb1eba2
The boards are all in one sheet (two rows of 5) and just snap off.

The Bridge rectifier(s) - I bought five - were dead cheap. When all finally arrived (from different parts of the world) I pondered the project.

Below - the collective parts ....

First thing to do is carefully removed the end of the smokebox as pictured below ..

The wires were rather stiff, so I unscrewed the smoke unit's switch. The screws are tiny, so I stick a small magnet on the screwdriver blade which temporarily magentises the whole thing and I don't lose the screws!

Switch detached from smokebox end ...

More to follow .....

 

[trammayo]

Having had lunch ...

There are six wires to the switch - a pair providing the current with a lighter pair attached to feed the headlamp. The other pair, on the switched side, go direct to the smoke unit. The first thing to do was to remove this last pair. The old smoke unit stays put - there is plenty of room. On this particular production run, the smoke unit wires were rather stiff and easily broken (no harm there).

The Bridge Rectifier is clearly marked + & - (as is the board) and I prepped my wires (insulation stripped and wires tinned) ready to connect to the respective + -.

I used some heatshrink to go over the legs on the bridge (once the two wires had been soldered on) just in case of a possible short-circuit when pushing everything back in to the boiler. Another pair of wires were cut and tinned, then soldered to the bridge (no polarity to sort out as the rectifier does this for you).

Next you will need a small multimeter (digital is the best - cheap as chips on ebay) to test the output voltage on the opposite end of the LM board. The pair of tails from the bridge are then supplied with your Direct Current power at whatever the operating voltage is.

There is a blue coponent on the board, with a slotted head brass screw. Turning anti-clockwise reduces the output voltage of the board. It needs quite a lot of turns before you finally reach the required voltage (in my case, 6 volts). So once your meter has registered the required voltage, its time to go to the next stage.

I tinned the tails from the smoke unit, removed the loco chimney and slotted the unit inside.
Neil used some PTFE tape on the one he did but I just shoved the the tapering unit down inside the tapered bore of the chimney. Then feed the wires over the top of the old smoke unit and out to the front of the boiler before replacing the chimney.

Next, I soldered the pair of wires from the bridge unit to the switched side of the smokebox switch. Then I soldered the tails from the new smoke unit to the ouput side of the LM unit.
Then I refitted the switch and carefully slid in the board and wires followed by the smokebox end.

 

[trammayo]

After pushing the smokebox cover in place, I unpacked the syringe and drew out 0.8ml of fluid from the bottle and squirted it inside the new smoke unit. I put the loco and tender on the track and turned the controller knob. Within a few yards, the smoke started to appear - far and away an improvement on the old one!

Ten out of 10 for that Neil. Many thanks indeed.

And the last piccies are down to my usual standard. As is the case with analogue, turn the power off to get a static view of the loco and the smoke stops - so the pics were taken on the hoof!

Concluded.

I will certainly use this method again. At 300mA, it can easily be used on battery powered locos too. Quite impressive I thought.

 

[GJFREESTONE]

Hi Mick
thanks for that even I can follow your thread .
I have a question for you I have a lot of stainz which need smoke units will these units plug straight into the mother board? .Looking at their web page they seem just what I am looking for ? .
Graham Shrewsbury

 

[trammayo]

I have a question for you I have a lot of stainz which need smoke units will these units plug straight into the mother board? .Looking at their web page they seem just what I am looking for ? .
Graham Shrewsbury

Hi Graham. When you say plug straight into the mother board, I presume you are asking if they are suitable? All I can say is this, if the MB has a regulated 5-6v output, and it is suitable to solder the S.Unit's tails to - then yes!

 

[PhilP]

Hi Graham,

If you are replacing smoke units with white/black leads, then these are 5v units.. select the correct voltage and diameter from the Conrad website..
NOTE:
They do the Seuth (spelling?) units..
PhilP

 

[sparky230]

Graham standard stainz smoke unit, like the one in the number 2 on it's way to you is 18 volts, the older stainz you have to replace the whole stack but the later ones are a unit similar to a seuth

 

[GJFREESTONE]

thank you for that. I could of made a big mistake so when I phone them to order I will tell them what engine it is for .
Graham Shrewsbury

 

[ntpntpntp]

Those regulator boards look useful. I'll order a bunch of those for my bits and pieces box.

 

[trammayo]

Those regulator boards look useful. I'll order a bunch of those for my bits and pieces box.

Just a bump to bring it back to life!

 

[ntpntpntp]

Yes I did buy a bunch of those voltage regulator boards. Been useful for various projects, not just railway related!