Lgb mallet 20851

[Adam1989]

Hi guys I am new to the hole mts set up 2 of my locos have direct decoder sockets but, my mallet looks like it’s to old for that, so what chip should I use, how many should I use. Also is it an easy conversion to do has anyone got any pictures or diagrams thanks guys.

 

[PhilP]

Not too difficult..
Do you have sound in your Mallet? - If not, do you want sound?
Answer to above will decide how we advise you further.
PhilP

 

[Adam1989]

No factory fitted sound I would like to have the option to fit it at a later date though.

 

[stockers]

It can certainly be done but it is a bit fiddly.
You probably have the older design three pin gearboxes in there. These need a bit of conversion. Then it is usually easiest to rip out most of what wiring is there and replace with a shiny new decoder big enough to power both motors - Personally I would use a Massoth XLS (includes sound).
Have a look in the digital section on here and the subsection of decoder fitting - that'll show you the three pin conversion and the decoder install.
Not the easiest job for a newbie but doable - keep asking here.

 

[Adam1989]

So from what I can gather if it has the older 3 pin gearboxes it’s harder, but if it’s the later ones with 4 pins it’s a lot easier.

 

[stockers]

Correct. but dont panic. I changed mine in my early days with DCC.

 

[PhilP]

So from what I can gather if it has the older 3 pin gearboxes it’s harder, but if it’s the later ones with 4 pins it’s a lot easier.

as Alan says..
Just adds a bit more 'faff' to the job..

Read through the threads indicated, then take the top off-of your loco, to see what you are up against. - If you can post a picture at that point we can point you in the right direction..

PhilP

 

[Adam1989]

No problem when I get chance ill take the body off and get a picture.

 

[Zerogee]

I'd second all the comments above, including those on choices of decoders. If you decide you want sound from the start, then putting an XLS in is probably the easiest way to go; if not, then use an XL (effectively an XLS without the "sound" part) now and then you can fit an S module later if you choose. Don't be afraid of the old three-pin gearboxes (or even the much older "clamshell" type units); first thing is to look at the bottom plates of the gearboxes - if they have a little embossed capital "D" in the plastic, then they will be 4-pin, if not then they will be 3-pin. If they are 3-pin then all you need is a little bit of modelling experience, the ability to do some simple soldering (just wires onto terminals, nothing fiddly like soldering tiny electronic parts), and most importantly the nerve to open up your loco in the first place!

Once you're over that first hurdle, show us all a pic of the insides and between us we can tell you where to go from there.....

DO NOTE: the LGB Mallet tends to have a nasty little "hidden" screw at the front, under the smokebox area, which (from memory of opening mine up) I think you can only get at by wrestling the front power bogie well out of the way to one side.... until you get to that last screw, the bodyshell won't come off......

Jon.

 

[penylanpip]

I seem to remember that the small air tanks underneath the water tanks will unclip with a little persuasion... the front bogie will then swing easily, giving access to the offending screw under the centre of the smokebox.

 

[Zerogee]

I seem to remember that the small air tanks underneath the water tanks will unclip with a little persuasion... the front bogie will then swing easily, giving access to the offending screw under the centre of the smokebox.

Good catch, Phil - yes, that was the bit I'd forgotten about - it's a few years since I took my Mallet apart! With the air tanks in place, the bogie won't turn far enough sideways to get at the "hidden" screw - but when they are removed, it will.
Seem to remember it took me a while to figure that out......

Jon.

 

[PhilP]

Yep, but you only need to remove one tank.. Bogie will swing enough then.

The tank clips clip to the outside, at either end, so a good squeeze inwards on the ends with a firm pull, should free it..
If all else fails a thin flat-blade screwdriver can be used as a lever. - Be subtle!

 

[Adam1989]

So I managed to get chance to get it out of the box this morning quickly and got a picture of the bottom of the gearbox

 

[Zerogee]

OK Adam, that looks like good news.... the little embossed "D" just to left of the black-and-white sticker should mean that you have got four-pin gearboxes, so you won't need to do any fiddling around inside them - fitting the decoder should be a relatively straightforward rewiring job inside the loco body.

Although LGB didn't start marketing DCC systems or locos until the very end of the 1990s, they had started to prepare for the introduction of it several years earlier - so most locos made from the early to mid '90s were fitted with 4-pin gearboxes ready for the later introduction of decoders and the MTS control system. Just in case you don't know (and apologies for restating it if you do), with a four-pin "DCC ready" gearbox there are two terminals that come from the track power pickups (wheels and skates) and then two terminals that feed the power back to the motor, and these pins are all electrically isolated from each inside the gearbox. In an older 3-pin "non-D" gearbox, one side has two pins (one from track power and one back to the motor) but the other side has only a single pin which is connected inside the gearbox to that side of the track feed, AND that side motor terminal. It is that connection that has to be isolated to convert an old 3-pin box for DCC operation, by isolating the single pin from the motor terminal and soldering a new wire onto the motor terminal, so that you then have the necessary two connections from track power and two back to the motor and can thus wire in a decoder.

Next stage is to gird your loins, take a deep breath and start removing screws to get the body off......
While you've got her upside down (oo-er...), you should be able to see the aforementioned clip-in air tanks that restrict the sideways swing of the front bogie - one of those will have to come off so that you can get at the secret screw!

Jon.

 

[stockers]

Once you are in the connections are pretty easy.
http://wiki.massoth.de/tiki-index.php?page=82x0xxx+XLS+Sounddecoder
Down load the installation PDF and ONLY look at page 7 to start with - this will quickly become obvious what is going on. You may need to remove old electrical bits from inside your loco.
Then on to page ten and work out the lights -front, rear internal and common return (labelled Dec+).
Take it slowly - one wire at a time and its is not at all difficult.

 

[dunnyrail]

The one little bit of advice that I can give is to make sure you get in your head which of the 4 wires out of the Chassis are from the Track and which are from the Motor. I always but always double check this with a Meter by touching the probe to the varying pins and looking for a connection to the wheels, both sides.

On the LGB Locomotives that I am currently faffing with the 2 Inside Pins are to the Wheels and the Outer ones to the Motor. This is I believe the norm, however I still always double check as to get it wrong is to trash a Decoder. Please do not ask how I know this!

Oh did any one mention Dip Pins? These are pretty important as well if your existing Circuit Board has them, this Chassis may be too old not sure? If present I believe that they all need to be turned off on a Chip Adding excersize.

 

[Zerogee]

You're correct on the pin layout, JonD, the outer pins are to the motor and the inner ones from the track pickups. The LGB plug that will be connected to all four pins will probably have an all-black 4-way ribbon cable attached, but embossed into the top of the gearbox casing itself, right next to the pins, will most likely be the abbreviations for the old "standard" LGB colour code, in German of course: the four pins will be marked "gn" (Grun = green), "br" (Braun = brown), "ws" (Weiss = white) and "ge" (Gelb = yellow). If you use a Massoth decoder (XL or XLS), it will come with two sets (one for each power bogie) of the four coloured leads (green, brown, white, yellow) with individual push-on connectors to go on the pins - the green and yellow pins and wires are the motor connections, and the brown and white the track power.

Jon.

 

[dunnyrail]

Other thing I forgot to mention is to use the LBG Chip Colour Code, thanks for the reminder Jon. I am a little anal about it, but it pays dividends in the Long Term.

 

[John Russo]

I did a couple of 3 pin installs two years ago. The 4 pin will be easier. No hacking.

This guy's two videos were helpful.

 

[Alexander0654]

My Mallet is next on the list to be DCC'ed. Just turned her over and looked at her bottom ( not an easy thing to do ) and discovered 2085D . For sure 3 pin gearboxes.
Ha-Ho just a bit more work.

To help myself and the OP can anyone provide the correct Massoth part number for an XLS board for these loco's.

Thanks

Alex