another Snow engine

[fumopuc]

Hi Roger and Joe, thanks for watching.
Last weekend I have started to finalise the rocker arm brackets. Partly a good job for the CNC mill.
Two Aluminium bars from the scrap box have been prepared and in the CAD I have added 5 brackets side to side for the CAM program.
The holes for the bearing pins and the pockets could be made in one set up.
After flipping the bars around the pockets at the others side were made and also the dividing line from the brackets could be engraved in one set up for better later orientation during cutting the brackets of the bar.
The slot in the middle could be milled quit simple without CNC.
After cutting the brackets from the bar, a small fixture was necessary to fix them on the CNC mill for contour cutting.
Currently part number 4 is running at the CNC mill.

[vcutajar]

 

Vince

[Dave Otto]

Nice work on the brackets Achim; fun to see how you went about carving them out.

Dave

[tvoght]

An interesting sequence of machining steps, Achim.

Tim

[fumopuc]

Vince, Dave, Tim thanks for checking in.
Here a quick and dirty sample assembling at the engine.
The set screw bore and thread in  M 1.6 to secure the rocker arm pins are still missing and also the general finish of the parts.

[Don1966]

Achim just catching up on your progress and it's looking great. Your getting closer to that first pop and I am getting anxious to see it in it's glory. Always excellent work to follow.

  Don

[zeeprogrammer]

Nice shot! Always a pleasure to pop in here.

[b.lindsey]

Getting close now it seems Achim. Inspiring as always.

Bill

[Kim]

Wow, Achim, that's really neat looking.  I like how you made those brackets.  Your work never ceases to amaze me!
Kim

[kvom]

Yours is the first I've seen with the blackened aluminum.  I like the look.

[Roger B]

Almost there    M1.6 

[fumopuc]

Don, Carl, Bill, Kim, Kirk and Roger thanks for following my long term engine build. I appreceate it very much that there are people all over the world which are sharing my, not always successfully efforts to build this model. I the meantime there was some time to finish the rocker arm brackets.
First to do, was these tiny set screw threads (M 1,6 mm) in the brackets to secure the rocker arm pins.
These 1,6 x 3 mm set screws are really tiny, the coin and the tool looks huge and currently I have one in spare only, donīt tell it the shop gnome, please.
With the rocker arm brackets I have made some trials with the tumbler. After the usual process with the little stones I have tried a long time (20 hours polishing with walnut peelings. The result is fine if your are able to feel it, but not really visible at the pictures. A nice to have only.
Next to do was the making of the rocker arm pins. I have modified some of the shelf dowel pins.
A ground recess for the set screw and cutting to length by a Dremel cutting wheel.
Some scrap material used as a stop inside the collet block made it easy to make 9 parts.
A family shot of all parts and a mock up of it with the shafts and set screws.

[fumopuc]

... also starting with the manifolds already. The flanges are made and drilled by the CNC.
A quick and dirty mock up with the tube bendings, not cut to the right lenght.

A virtual milling of the rocker arms is under construction I am waiting for the ordered aluminium plate.
 

[crueby]

Looking great!   

For virtual milling, do you have the computer create virtual swarf?   

[Dave Otto]

Great progress Achim!

Looking forward to the rocker arm machining.

Dave