[MOC] Oehler DDK 240 BL

[eric trax]

Hello everyone. Just a modest post today. The model has been sitting finished on the shelf for a year, so it’s time to share it.

I have a soft spot for the color turquoise. After building classic Oehler trailers, I liked the color scheme so much that I decided to build another one—this time for transporting straw/hay bales. The model is relatively simple, featuring essentially just one mechanism responsible for lifting the side walls. The entire unit is controlled from the tractor and powered by a single L-motor. Each wall is controlled independently thanks to a small gearbox located in the chassis.

I tested various solutions to enable the side walls to lift while remaining level. The load bed is over 60 cm long, so this was a challenge. I ruled out pneumatics almost immediately because two linked cylinders tend to operate sequentially rather than simultaneously. Ultimately, I settled on a system of axles and pulleys with string that, combined with the side wall arms, act like a small crane. The mechanism has few versions and now operates satisfactorily and, most importantly - smoothly.

 

 

Does the model have any flaws? The side walls, built with connectors and pins, span 76 studs in length, making them quite flexible. Initially, I considered inserting steel wires to stiffen the structure, but I gave up on that. The side walls are also quite heavy, so I had to add extra rollers at the top. Previously, the strings ran through the connector holes, but the friction was significant, sometimes causing issues when lifting the sides. Unfortunately, this detracts from the model's appearance, but functionality is the priority.

Photo gallery:

https://bricksafe.com/pages/erictrax/oehler-ddk-240-bl

Short video:

 

Edited yesterday at 07:03 PM by eric trax

[yqc]

Very cool model! Do you have instructuons for it somewhere?

[1gor]

Very nice to use turquoise color and it fits Fastrac very well. Good to see that you put tractor tires on Scorpion; baloons looked to cartoonish. Hope that MF will be finished soon.

Kind regards

[TLCB]

Featured at

The Lego Car Blog

[ord]

Great work. The demonstration with the telehandler was very satisfying to watch.