I have modified the coupling using a 5mm x 5mm (internal) brass box sleeve.
It is made by K&S metals in Chicago, and should be available at most hobby shops. #154 7/32 square brass hollow.

Firstly I removed the complete coupler shank from the Brawa model. I had to dismantle the car, by prising off the under-floor.
I cut out the bottom of the Brawa box, and repositioned the cut-out piece at the top of the box. I also had to shave the outside of the box sides by about 1/10mm.

This diagram shows how I cut the box to size, then fitted it over the existing Brawa coupler box.


The picture shows the end result. The Brawa coach is to the left, a standard Marklin coach to the right. The coupler no longer fouls the Brawa buffers. I am not particularly happy about this modification,
firstly, it took me over 2 hours,
secondly, I have to get a new set of coupler shanks to restore to original if necessary. I have ordered a set from Brawa.

And in that regard, reading back over some of the replies, Alberto mentions the original Brawa coupler. Yes this is still in the box, and I had not thought of using it. I will try that when I restore an original Brawa coupler shank.


regards
Kimball

I've a number of BRAWA models too.

They're very nice, very fragile and a bit expensive despite Made in China!

My cars (usually Württemberger and early SBB era) are an almost perfect fit to my other Märklin cars. My special favorites are the KWStB Kgl. Post car and the baggage car with milk cans, shown on the next pics.





Due to the rather long coupling distance with the original BRAWA couplings I've changed all of them to the Märklin short coupling - no problems so far!

Following is a picture with (most of) the couplings discussed here. From left to right:

- ROCO short coupling (not compatible with any other coupling. A quite "popular" issue can be seen here too - the plastic extension bends easily outward which means the coupling will not work anymore.
- ROCO universal coupling, height adjustable. Good to use with the new Märklin Schienenbus (if you want to pull some goods waggons).
- ROCO universal coupling. Compatible with standard NEM362 couplings and Märklin short coupling. Due to the open coupling bow it will have problems when driving with a (typical Märklin shunting) loco with just a hook; it will simply uncouple in curves. As mentioned, they are currently not available due to patent issues. However, according to some rumors ROCO will come up soon or has already delivered a new "universal coupling Made by Modellbahn GmbH".
- Standard coupling (ROCO shape)
- Standard coupling (Märklin shape)
- Standard coupling (BRAWA shape)
- Märklin short coupling. Compatible with standard NEM362 couplings and ROCO universal coupling (amongst others).
- Märklin/RTS electric conductive coupling. Compatible with standard NEM362 couplings and somewhat compatible/useable with Märklin short coupling. Not compatible with ROCO universal coupling.



In order to have the Märklin/RTS electric conductive coupling work seamless with the Märklin short coupling just cut out a small part from the coupling section as shown by the blue arrow in the next (just enlarged) pic. This will eliminate the barrier for the brass contact extension.



I've numerous ROCO, etc. cars. Their issue is the buffer height as mentioned by Pietro. Usually I overcome this in different ways: try to use the ROCO universal coupling at those cars, mount a Märklin short coupling w/o the metal coupling bow, remove the buffers (looks really ugly!) or shape them a bit.

Hope this info helped some more about couplings; although it doesn't really address the coupling height issue as reported in the entry posting.