1:35 Bucket chain excavator Ertmer KB 1

[Bernhard]

... and the two side frames are soldered together.

[Bernhard]

The jig for soldering the cross profiles is made in three parts. Otherwise it could not be removed from the frame after soldering.

[Bernhard]

The outer cross profiles are soldered on.

[Bernhard]

Now the jig is unscrewed, removed from the frame and then screwed together again. Then the frame is placed upside down on the jig for soldering the internal cross sections.

[Bernhard]

Then the stiffeners are attached.

[Bernhard]

Now a few turned parts have to be made.
The chain deflection rollers are pre-turned and then, because four holes still have to be drilled in two of the rollers, they are finished on the rotary table on the milling machine.

[Bernhard]

The finished rollers.

[Bernhard]

Then a few support rollers have to be turned.

[Bernhard]

The flange bearings for the support rollers are a particular challenge.

[Bernhard]

Because they are so small, 3D printing is out of question, and I have no access to a CNC machine for milling.
My good friend Werner finally stepped in and milled the parts for me on his copy milling machine.
For this purpose I prepared two models made of aluminum. These are 5 times bigger than the workpieces.

[Bernhard]

The finished parts, milled from the solid with a 1 mm milling cutter!
Unfortunately it is difficult to photograph the parts adequately with the mobile phone camera.

[Bernhard]

And this is the new, provisionally attached part of the bucket ladder. Here, too, the rollers are not mounted until after painting.

Bernhard

[finescalerr]

Most satisfactory. How long did it take to complete the work you have just described? -- Russ

[Barney]

Engineering in miniature thats what its all about - an excellent project
Barney   

[5thwheel]

Extremely beautiful work.  But I would like to know where you found that giant match that you show with the parts.

Bill Hudson