BlueBrixx BR 89 MOD: 3 axle tender steam locomotive

[Toastie]

Dear all,

as discussed in the TrainTech forum,

Spoiler

 

I am posting here in the Community forum some modding on a 10-wide BR 89 fully LEGO compatible display model from BlueBrixx, I got as birthday present this year. Why in the Community forum? Because this is - well - a BlueBrixx (BB) set MOD - mostly using LEGO stuff though.

This is how she currently looks like (see below for changes to the original BB model) featuring a PoweredUp (PUp) City hub, PUp L motor, PUp color sensor, and custom rods:

 

The TrainTech forum post referenced above shows in addition a turn table I made explicitly for the BR 89 – as I don’t have any more space in my attic to 1) accommodate a full circle of track and 2) no more floor space at all. Which means she has to run on slightly curvy track mounted to the sloped walls in my room, and since I don’t want her get too bored when just steaming back and forth, I thought she might enjoy being turned around at one end of the track section from time to time …

Why the BR 89? Because I got her 50 years ago as H0 model from Märklin (in German) as Christmas present from my parents – but then really never got into model railroading – LEGO just was so much more attractive to me back then. Nevertheless, this engine is still available today from Märklin, and the 10-wide BB model looked really nice to me on their website.

Some remarks

BB BR 89 original set

€70 – which a very good deal, bricks and plates with good quality having mostly superior clutch power as compared to LEGO pieces. Colors: I am a bit color-blind, but an expert on shades of gray, and there is room for improvement (some black pieces). However, I like the less perfect, less glossy appearance of a steam engine – have never seen a real one, even when perfectly restored, in super-glossy colors.

Changes/additions

• Rebuilt the lower frame/driving gear/running gear. Main changes: Front axle driven by a PUp L motor (original: center axle/BB PF M motor). This also allows removing the clearly visible “Technic gear 20 Tooth” as seen in this step of the original BB instruction:
  
  
  Furthermore, narrowed the frame at the center axle/wheels from 4- to 3-wide, allowing the flanged center wheels to move inward when negotiating corresponding curves. As the BR 89 is running in eye height in my room, I simply do not like the blind wheels. These are perfect and unavoidable in other builds, however in this case I reverted to the split axle design originally shown by @Ben Beneke on his BR 23 and used all six wheels with flanges. I have motorized Ben’s BR 23 over 10 years ago using the same approach as shown here:With regard to the 89 it is even tougher for her to manage R40 curves, see MLCad picture below, as the front and rear axles are 13 studs apart and the big train wheels don’t help at all. On the split axle there is a piece of medium soft foam inserted between the “Technic axles 2” pressing the wheels very gently onto the connecting rods. When going through a curve, the inner wheel is moving correspondingly and moved back on straight track:
  
   
• Lowered the position of the motor within the frame and moved it forward. This is required when the cabin space shall remain (almost) as “spacious” as in the original, as the PUp L motor is two studs longer than a PF M motor. Added/moved some plates here and there to make the frame a little sturdier, as it became rather “brittle” with the PUp L motor installed.
   
• Rebuilt the lower section (frame) of the smoke box to attach a PUp color sensor facing down as well as for the wires (motor and sensor) and accommodate a PUp City hub, which is 3 plates higher than a BB RF battery box. The upper body of the engine seen from below in the picture below does not fit this way onto the frame - this was work in progress. I disassembled the upper body layer by layer and rearranged the layout on the fly when building up the engine on the new frame:
  
   
• Rebuilt, raised (1/2 stud), and moved (1 stud) the cylinders so that the valve gear still runs free, the piston rods are almost on the same height as the wheel axles, and the main rod does not become too long:
  
   
• Moved the connection point of the main rod to the rear wheel (as in the real engine) using custom connection and coupling rod(s) and added some "valve gear":
  
   
• And placed the PUp City hub partly on top of the motor with a one-plate-spacing for the wires:
  
   
• An ESP32 Dev kit (nothing else required, about 10€) programmed within the current Arduino IDE (C++) using the current Legoino library from Cornelius Munz is controlling the setup (turn table and engine operation).
  
  
  Manual control can be done with the PUp remote (left dial keys: turn table motor fwd, rev, stop; right dial keys: BR 89 motor fwd, rev, stop; center key: emergency, all hubs turned off immediately), however this is intended for debugging only, as the setup runs autonomously. The turn table features a PUp L motor as well, so on both table and engine, repeatedly pressing the fwd key increases speed (not power) by 5% using a smooth acceleration profile; same for rev. Stop is a brutal stop though!

Some remarks on the original BB BR 89 set: As said, the original BB version is a display model. It features 6 flanged driver wheels; in addition, they give you two blind drivers as well – which tells you that this model is already sturdy enough to go through curves. The original idea is to put the engine onto a (very nicely done!) stand, which elevates it slightly above track level, and then use a BB PF compatible M-motor along with the BB RF battery box and RF controller to "just" turn the wheels. A PF M motor is not powerful enough to run her on track. YouTube's user Bricked4You has published some very nice videos on retrofitting the original display model into a nicely performing LEGO track compatible engine (in German), which is also nicely coping with R40 curves, using a BB PF-L compatible motor.

Instead of using BB’s PF compatible stuff (L-motor, RF battery box, RF controller) I wanted to operate my 89 with TLG’s PoweredUp gear – why? Because using a tacho motor (e.g. PUp L motor - BL price for a new motor is about 1/3 of what LEGO asks for on their shop website) along with the “SetSpeed” command (rather than “SetPower”), she moves slowly but steadily, curved track or not, i.e., is far less affected by changing friction forces. The regulated rpm setting is ensured by the motor’s built-in rotation sensor and the PoweredUp hub hard/firmware, which reads and translates the rotation sensor data into appropriate power settings to maintain the "desired" speed. I really like to watch the valve gear when a steamer moves slowly …

And I wanted the entire setup (BR 89, turn table) to run autonomously without any user interference (other than moving the BR 89 into startup position). One issue in this scenario is “safety”. When the 89 dives from the approximately 1.5 m height and crashes into the 9/12 V train layout below, serious damage is to be expected – and I don’t want that to happen (I also don’t like crash-videos ...).

The TrainTech link given at the top of this post shows the (elevated) track the BR 89 has to negotiate along the wall.

(Note that the following two files are deep linked on BrickShelf - thus you are taken directly to the file content. When moderated, I will change this to point to the files) 
LDraw model including the PUp stuff is available here (note that there are two versions of the drive mechanism – the “new” one is described here); current Arduino sketch as well – rename .txt file to .ino to load it into the Arduino IDE.

Video will hopefully follow in a couple of days, I sure hope – I am terrible at doing videos .

Best regards,
Thorsten

P.S.: YES, there is also real cheating going on here :

1. I filed off the "flange"(?) at the long side of the "Technic Pin 3/4" (LDraw #32002), which is driving the center wheel and thus needs to slide in and out in curves as well, as the wheel is moving but not the side rod. On the short pin side, it is legally attached to the center hole of the custom side rod.
2. The would-be Walschaerts valve gear is missing (among many other things) the union link - and the combination link is made from a broken "Technic flex system cable". The intact cable terminal is legally fixed to the upper "Technic flex system pin hole connector" (LDraw #2900), the broken cable terminal is (illegally) just sliding in and out of the lower connector.
3. I like illegal stuff 

 

Edited May 28, 2022 by Toastie

[JopieK]

Nice review of a very nice locomotive @Toastie. 10-wide makes it much easier to put in all those intricate drive gear parts etc.

(b.t.w. I would say if most of the parts are LEGO it would be totally fine to put it in TT)

[dtomsen]

Very nice work and yeah, we want this back in TT where it truly belongs 

[dr_spock]

Nice MODs to the Bluebrixx set. It would be too funny if the BB set was cloned with all LEGO pieces. 

I made a simple jig to cut down flanges without a lathe.  Manually turn the train wheel by hand and be mindful where your fingers are in relation to milling bit. It is quick and dirty.

[Toastie]

On 5/28/2022 at 9:19 AM, JopieK said:

I would say if most of the parts are LEGO it would be totally fine to put it in TT

Well - that is the problem: Upon modding her, I used > 50% of LEGO pieces. However, that caused a heavy left over of BB pieces. I then fired up MLCad - "recorded" everything - and then reverted as much as I could to the BB parts I had. After all - it is their very set. 

I'd say I am now on a 80/20 BB/TLG ratio, and that renders moving this post to TT - far less favorable.

7 hours ago, dtomsen said:

in TT where it truly belongs

Thank you very much!

I do think so as well, as you can do every single change brick/plate wise in LEGO world - and actually there is more you can do with LEGO stuff as you can do (currently) in BB world.

But it is, what it is - and it is no problem at all.

2 hours ago, dr_spock said:

It would be too funny if the BB set was cloned with all LEGO pieces.

Oh yes - oh yes. But then, you'll need to fan out at least three - four times what BB asks for - the "stand" alone is accounting for about 1/3 of the piece count not even explicitly shown here .

2 hours ago, dr_spock said:

I made a simple jig to cut down flanges without a lathe. 

This is just so nice to watch: You know, when I drilled my first hole into a LEGO plate, I thought: This will be the end of the universe. Well, it was not. For my Croc I literally drilled through a couple of plates - and now I can fire-up the City hub inside by pressing a tile on the roof .

Skillfully (!) cutting down a flange like that, when you don't have the blinds - just perfect!!! All that surplus ABS flying around - my world.

 

Thank you all for the very nice replies - here in the Community Forum.

BTW - as this is also the forum hosting the "What are you listening to " thread: I am listening to:

"Wer wartet mit Besonnenheit
Der wird belohnt zur rechten Zeit
Nun, das Warten hat ein Ende
Leiht euer Ohr einer Legende."

Well, and then all hell breaks loose ...

Thanks again for finding me here.

All the best,
Thorsten

[dtomsen]

If you feel up to the challenge, Thorsten, may I recommend this classic German schlager then: 

 

Edited May 29, 2022 by dtomsen

[Toastie]

On 5/28/2022 at 9:19 AM, JopieK said:

10-wide makes it much easier to put in all those intricate drive gear parts etc.

Absolutely, really.

What I find challenging though is to live up to what the original designer did. When you throw in a PUp L motor and the City hub, the going gets tough, 10 wide or not. When you design bottom up - with these feature in mind up front - it >may< be easier.

To be honest, I had a terrible time modding @Ben Beneke's BR23, but only before he told me it was more than OK. He encouraged me to do so.

With the BR89, I have trouble reaching out to "Alex", the BB designer, to ask for permission on messing with his design. I sure hope, this is OK with him.

All the best,
Thorsten

[Toastie]

8 minutes ago, dtomsen said:

may I recommend this classic German schlager then

Hee hee - you know, I was born in "very" Northern Germany - never felt the difference between Slesvig and Schleswig - 45 years of enjoying vacation on the most beautiful island in the world - Fanø - yes, I feel up to the challenge.

Thanks a lot!

All the best,
Thorsten

[Toastie]

Update (I did this now on three different posts - hopefully I don't get mod-flak ... for that)

Video is available here: