Hi there.
As some of you may have seen elsewhere, I have got my hands on a 83434 lok. I assume it is electrically the same as a normal 3434 lok. I would like to convert it to proper digital with 5-pole motor, but then I noticed something on this page:
http://home.istar.ca/~axelh/explodes/parts34.html

It has a note that the 3434 can only be converted to digital by having it done by Märklin. Does anyone know why this is, and what the problems by home-converting it will be?

I am not sure about this particular model, but is there enough space for the thicker magnet? Sometimes milling is required, and in some modles there is not enough space, even with milling.

Charlie

John's reply I think is the closest to the truth. I don't see any mechanical problem in converting a loco like that. Swiss Headlight Changeover is a quite complicated thing to convert, although not impossible. However, John's option is the cheapest anyway... Good one John!

Regarding Swiss lighting scheme, you can also do what I did with my starterset Delta Ae3/6: I used a 60901 and the lighting PCBs of the 39560 croc.

There's a thread on this somewhere. You may find the references I used there too.

Luis

I opened my lok last night, and came to the same conclusion: It is the decoder, that seems to the problem. It has a switch to toggle between the pickup shoe and the pantos. And it also has a special contact area to line up with a spring tab from the pantos, so the current can find its way down to the decoder.
It looks like there is enough room for the magnet, so that won't be an issue. The light isn't a problem either. The pcb's for the leds just take the standard lighting wires (yellow, gray and orange) in both ends.

I'll see if I can find a replacement decoder board, perhaps as a spare part. And if that is too expensive, I may try to hunt down a cheap model to make the suggested swap.
If everything fails, I may be tempted to cut up the existing decoder board, leaving only the switch and contact area, and then install a small decoder. Perhaps the 60921 kit or a LokPilot 2.

Anyway, thanks a lot everyone. I now have some serious thinking to do, before I proceed.

If you replace the current pcb with another "anyname" decoder, you will loose the swiss light switching and the LED resistors that are also contained on the original pcb. 60921 sounds fine; the LoPi-2 comes with a NEM plug which is of little value here unless you add the female plug to the pcb. By looking at the layout I doubt that it might work by just cutting some hole for the new decoder.

The c91 based pcb #602569 has PG19 which usually results in a dealer spare part price of about 100€. In any case you'll need the 3 HLA motor parts which add another 18€.

Regards,
Lutz

That's was it. I'm all done with the conversion. I ended up using a LokPilot 2.0, which was easily placed beneath the original Delta decoder. Darn, that LoPi sure is small. The old decoder board is now used only for selecting between track and catenary power.
Using the two extra function outputs (and programming the registers correctly), I now have the choice of classic or swiss light on F1.

I would like to thank you all once more. Without your ideas, I may have ended up with a inferior or more expensive solution.