I've always liked the BR 81 as a lower end engine with a all metal body. To the best of my knowledge, Märklin has never produced the BR 81 in an era II version. Since I model mostly era II, I decided to upgrade my BR 81 and give it the full works.
Upgrade to digital w/sound
Motor converted to ball bearings
Telex couplers at both ends
Full LED lighting including cab lighting
Adding smoke
Redecorating to era II
Adding engineer (driver) and fireman figures
I started with a 3032 I had had for some time. I had originally converted it to digital with and older Uhlenbrock decoder that utilized the original AC motor. Also this decoder had 1 function available and I had also added telex couplers. I disassembled everything down to the basic frame. I then drilled out the rivets holding each screw base lamp to the chassis so they could be removed. I also drilled out for the bearing (2 x 5 x 2.5) in the frame to 5mm to be able to install the motor ball bearing as well as a 4 mm hole in the new motor shield for the other ball bearing (1.5 x 4 x 2). Remember that for the older engines the 5 pole replacement armature shaft is 2 mm on the frame side and 1.5 mm on the motor shield side. I then drilled down through the chimney with a 3.5 mm to accommodate a Seuthe 21 unit. After fitting the new bearings and installing the new magnet and armature and rotated it to insure that everything was aligned and there was no rubbing. I installed the motor brushes and tested the motor with DC and it ran well in both directions.
Now, I was onto the lighting. I wanted to have the LED's protrude like the original plastic lenses so I carefully ground off the lip on each edge of the LED's so that they would fit snugly into each lamp hole in the body casting. I them wired the 3 front and 3 rear LED's in series with a 47K resistor making sure the anode (+) and cathode (-) were wired correctly so all three LED's would light and the higher K value resistor ensured that the LED's wouldn't be so blinding bright. These were tested before and after installation for correct operation and finally secured in place with a clear gloss. (Future Floor Finish)
I installed the 21 pin wiring board and its holder to the same location as where the original mechanical reverse unit was installed. I wired a 3 pin JST plug to accommodate the connections for the front LED's and the smoke unit and a 2 pin JST plug for the rear lights. I wanted to be able to remove the body if needed later without the need to unsolder the wires. After making all the wiring connections, I placed black friction tape over the motor to not only help in holding the wiring in place but to hide the motor when viewed through the cab windows especially when the cab light is on.
The speaker was mounted to the opposite side of the 21 pin board with double sided tape. I used the square style speaker Märklin supplies with some of their sound decoders. It's the one with the metal speaker protector installed. It was too tall to fit in this space without interfering with the installation of the body so I removed about 1 mm equally from each end being careful no to damage the frame of the speaker inside. I resealed the speaker enclosure by gluing a strip of plastic stock at each end. I use double sided tape designed for outside use to secure the speaker enclosure in place. I find that this hold much better and therefore requires less to get the same holding power that normal double sided tape.
I now turned my attention to the redecorating the cab shell. I didn't want to get into completely repainting the engine. My solution was to mask off the area below the cab windows where the "DB" logo was and lightly airbrush out the logo with some flat (matte) black. I applied several thin coats until the logo was almost invisible and then stopped as I didn't want to apply any more paint than was necessary. I wasn't able to find DRG lettering and settled for white German eagles in the style used during the war by Peddinghaus. I also applied white ring decals also made by them to the buffers at each end. After
doing some minor touch up painting on the rivets of the saddle tanks, I sprayed each side with a satin clear coat to blend the decals and add protection. The figures I added the the cab came from a set from Faller which I believe are repackaged Preisler figures. I had to modify both for a better fit and remove the inside half of their bodies to allow clearance for the motor. After the mods, I repainted both adding extra details. They were finally glued into place inside the cab.
I installed the decoder and did the final assembly securing the body to the chassis. I did have some minor setbacks but was able to finally get it all the wiring carefully stuffed inside the body and secured it onto the frame. Initially, I couldn't get a set of the lights to work and had to remove the body only to discover that a wire had broken next to the solder connection on the decoded board. After this everything tested OK.
I must admit that this conversion had some "trying" times to say the least
, but I rather please how it can out in the end.
Chuck
P.S. Pics to follow.
