Chris's Diesbar Engine Build

[crueby]

As ever, I'm simply amazed at the terrific progress that you are making with another very complex and unusual engine, it's looking marvellous.  The paint job on the upper frame looks great, ties the multi part assembly into a unit very nicely.  The crankshaft seen just above it is a glorious work of art in its own right!

Thanks!   

[crueby]

While the upper frame was off for painting, I made and installed the reversing control lever pivot blocks. The screw on the left locks it to the vertical post, the one on the right with the washer will be the pivot for the long lever that the engineer uses to move the valve manually when changing direction on the engine.

Then got the upper frame reassembled, hopefully this time permanently.

Next up arre the two slip eccentrics. Started out by milling some strips of flat bar to length, notching for the bolts, and drilling/tapping:

Here they are with the halves bolted together for boring out the centers:

The really fiddly parts are coming up, the eccentric strap arms and the lower fittings.

The lower rod going to the left goes to a leaf spring at the rear of the engine, which keeps the post from the valve link plate held in the hole near the bottom. The linkage in the middle and leading off to the right allows the enginer to release the post from that hole - it moves a plate you can see in the hole that pushes the post out into the gap on the lower right, allowing the valve link to move up and down via the long lever mentioned above. The strap on the lower right keeps the arm next to the post as it moves. When the engineer is done with the reversing action, the post goes back into the center hole. All those parts will be tiny, going to be interesting to make...   

[cnr6400]

  Looking great Chris! Did I hear right, that Lifting Larry the shop elf was putting new strings on a violin, for the fiddly bits to be made?    (can't hurt) 

[crueby]

Looking great Chris! Did I hear right, that Lifting Larry the shop elf was putting new strings on a violin, for the fiddly bits to be made?    (can't hurt) 

He was. I sent him off to find some elf sized cnc machines instead! He just took a nap...   

[Sanjay F]

Those fiddly bits look VERY fiddly, but they look great! 

[crueby]

Those fiddly bits look VERY fiddly, but they look great! 

Thanks!  And just for the record if I wasn't clear, the last picture, of the eccentric strap, and the rods/levers, is a picture of the parts on the real engine when they were taken off during maintenance!

[Michael S.]

Someone had complained about the old tape measure on Chris's workbench... 😉. So, the "workshop elves" quickly laid down some ship-decking-style flooring.
I can barely distinguish the parts from the original engine and model anymore.
Great work, Chris.

Michael

[crueby]

Someone had complained about the old tape measure on Chris's workbench... 😉. So, the "workshop elves" quickly laid down some ship-decking-style flooring.
I can barely distinguish the parts from the original engine and model anymore.
Great work, Chris.

Michael

They are surprisingly good at carpentry!   
 

[crueby]

The eccentric straps were center up in the four jaw chuck, drilled and bored to fit the eccentrics:

The outside was rounded off on the rotary table, leaving the bolt tabs and the flat for the arm attachment

Test fit with the eccentrics. They were given a light lapping with some Timesavers compound to get them spinning freely.

The flats were drilled/tapped for the screws to hold the arms



Then I have started making the arms, begininng with the flat bars to bolt them to the straps

The center hole in each one will be used to screw the arms in place for silver soldering. Next I'll get the ends of the arms drilled/tapped for those screws, and will thread the other ends to fit into the control blocks that attach to the posts on the valve link plates.

[Michael S.]

The eccentric rings look good. Very delicate.

Michael

[crueby]

Thanks Michael!

This afternoon I got a little more playtime in the shop, and drilled/tapped the rods for the eccentric strap arms. One end was screwed to the middle hole of the short bars I made earlier, which are the flanges to attach to the straps. Here one of the elves is holding one of them up prior to getting them silver soldered.

Then I had to make another whole set after the elves got all excited, yelling something about finally breaking into Captain Jack Sparrow's treasure chest with their new sledge hammers, and ran off with the first set.   

Then got them silver soldered, they are soaking in the pickle solution now to clean them up. Once clean, I can grind off the screw heads, and run in a length of 4-40 screw into the other end of the rods, where they will screw into the release fittings at the lower ends. I think I've figured out the steps to make the release fittings, as shown in the picture the other day. The main blocks will be milled out of a single piece, with a section milled out for the thin lever. A second thin piece will rivet back on over the recess to close it up again. Easier that way then trying to mill a really thin deep slot in the blocks. Or, so the current theory goes! Will find out over the next couple days.

[cnr6400]

  I'll bet you're glad you drilled the bars just behind the "heads" of the "hammers", if they were solid the shop elves would have taken off the hinges on the spirit locker doors in one hit! (did I just hear "let the games begin!" in a loud elf voice)

This occasional eccentric says your new Diesbar eccentrics look great Chris. 

[crueby]

I'll bet you're glad you drilled the bars just behind the "heads" of the "hammers", if they were solid the shop elves would have taken off the hinges on the spirit locker doors in one hit! (did I just hear "let the games begin!" in a loud elf voice)

This occasional eccentric says your new Diesbar eccentrics look great Chris. 

 


They did spend an hour trying to use those holes as bottle openers...       Hmm, what to use as an elf distracter tomorrow?   Oh, wait, make them build parts!   

[crueby]

The eccentric strap arms that I soldered up yesterday got cleaned up with pickle solution and a wire brush, then assembled onto the straps:

Now its on to the release mechanism at the bottom of the arms. I picked a piece of stainless flatt bar a little bigger than the final parts, and sketched out the outline on it for the two parts. Also cut/milled out a couple of small flat plates from some .060" thick flat stainless that will form the side plates over the internal recess that will hold the release plate. Holes were drilled in both sets of plates for some 1-72 screws:

The larger bar was tapped for the 1-72 screws, the smaller plates got clearance size holes. With them screwed together, the ends of the small plates were used to scribe lines onto the larger bar, to use as guides for milling recesses for the plates to fit into. I also drilled the holes for the valve link post to fit into.

Then milled out the recesses, depth to match the thickness of the plates, and length close to the scribed lines. The side away from the camera was left uncut, that will become the retention strap for the link post.

The ends were trimmed till they were a close fit on the plates, using the screws as alignment guides to test fit the plates.

Next, with the plates screwed in place, I can mill out the slots for the post to ride in. For reference of where I'm going with this, here is the picture of the real thing again:

The hole I drilled is in the center of the part, and the slot is the one formed by the outer strap, on the right hand side of the assembly in the picture. I am making the strap integral to the main part, where on the original it wraps around the bottom of the part and bolts on at either end. Bending a strap to that shape would be very difficult, and the bolts tiny, so I decided to make it all as one piece. Later on I will mill the recess for the pivoting plate at the center hole, and the slot for the control rod at the top. Long way to go on these parts!

[Kim]

Interesting method.  I'm having a hard time wrapping my head around it now, but I assume it will become more clear as you move forward.  I'm looking forward to it!   

Kim