1:35 Bucket chain excavator Ertmer KB 1

[Ray Dunakin]

Amazing stuff!

[Bernhard]

Russ:
I didn't write down the hours. In any case, this is a long-term project.
I started in April 2017 with a visit to the Feldbahnmuseum Wiesloch and measuring the excavator. Then about a year passed until the 3D model and all details were drawn. Since then I am working on the realization. Next week I should get the last missing parts, the laser-cut chain links. Then I just have to assemble the chain, paint everything and finish it - and then I have to look for a new project.
Although I'm retired, of course I didn't work on the bucket chain excavator all the time. I also built other models in between, and I also have other interests.

Bill:
The match is a special design for people who can't see too well.

[finescalerr]

That's about the amount of time and effort I expected, Bernhard. Nobody can build a model of such superb quality by taking shortcuts. -- Russ

[Bernhard]

The levelling piece on the bucket ladder is still missing. Fortunately, this is a little easier to build.

[Bernhard]

The side parts are also soldered together in a jig.

[Bernhard]

For soldering the cross profiles I use again the jig for the middle part of the bucket ladder.

[Bernhard]

And also on this part some stiffeners have to be added.

[Bernhard]

The two chain deflection rollers are pre-turned first.

[Bernhard]

Then the inner contour is milled out on the rotary table on the milling machine.

[Bernhard]

This is where it gets exciting. Now the spaces between the spokes must be milled free with a 1 mm milling cutter.

[Bernhard]

After I broke off six cutters, my friend Werner sharpened a single cutter for me, which is a bit more stable. With this I could finish milling both rollers without breaking any more tools.

[Bernhard]

Then the rollers must be carefully cut off from the tensioning attachments.

[Bernhard]

Finally, the ribs are attached to the spokes, then the pulleys are ready.
But they are not mounted until the chain is finished. The chain gets the right tension due to the final position of these rollers.

[Bernhard]

Further I need two hangers with pulleys, from which the bucket ladder and the levelling piece are suspended.
Both brackets have the same function, but look different. Obviously at that time they used what was at hand.
The hangers are brought into shape with the help of two bending gauges.

[Bernhard]

The finished hangers.