The Sabino Compound Engine

[crueby]

Sorry for the delay, just finished the "Saturday jobs". Sketch attached with highlight notes (I hope all needed) for the delta jig. Let me know if anything's unclear still. Cheers CNR6400 

Aha, gotcha!  Yes, that would work great. Picture/1000-words, still true.




You are hired. Your shop elf uniform is in the tool chest on the left...   




 
Chris

[Kim]

OK, I get it   That's pretty clever.  It's a lot easier to measure the gap than an overlap, that's for sure!

Kim

[cnr6400]

My pleasure gents! hope the idea helps. 

Hired, eh? shop elf uniform, eh? Might be able to get the jacket around my forearm.....

I think I am more use these days fixing 60 year old dump trucks with horrific mechanical issues to deliver popcorn! 

[crueby]

My pleasure gents! hope the idea helps. 

Hired, eh? shop elf uniform, eh? Might be able to get the jacket around my forearm.....

I think I am more use these days fixing 60 year old dump trucks with horrific mechanical issues to deliver popcorn! 

That works too!  Gonna need a bigger microwave....   

[Don1966]

Still with you Dog! Man you just amaze me your cranking out parts like your life depended on it. Awesome results Chris….



 
Don

[crueby]

Still with you Dog! Man you just amaze me your cranking out parts like your life depended on it. Awesome results Chris….



 
Don

Thanks Don, am having a great time with this one!

[crueby]

Lots of threading today. Started with drilling/tapping the bottom stem on the yokes where the eccentric arms will attach


and the holes in the top that will hold the bearing blocks


Ran in a batch of 1-72 screws, the heads will be trimmed off to let the bearing blocks go on, another nut on top to hold them. I didn't really need to thread the holes in the yoke tops, but that makes it easier to assemble and tighten things up with the bearings. Scaling the picture down for the forum made the threads almost disappear!


Now on to the arms. The lower end is threaded 5-40 to go into the eccentric straps. Later, using CNR's neat old trick, the top ends will be trimmed to length and drilled/threaded for the 1-72 screws on the base of the yokes. I'm using a single-point threading on the lathe to put in the 5-40 threads nice and straight. Using the Sherline threading attachment set up on a used lathe bed/headstock I picked up last year - have used this on the Holly model too. Learned pretty quick to use plenty of oil on the cutter, and back the cutter out before rewinding to the start of the cut or it likes to break off the very tip of the insert - not sure if that a common issue, or just since the threading inserts I got were cheapos.


First one test fit with a nut made from hex rod (these are extras made in a batch from the Holly build) and screwed into the eccentric strap. After theese parts are done I need to remember to make the oilers that sit in the hole next to the arms.

Enough shop time for the day, time to head outside!

[cnr6400]

 

[steamer]

For a second I couldn't tell what engine that was.....Yours or Sabino's!


 

[crueby]

Thanks guys, very much appreciated!   

[Dan Rowe]

I agree with Dave that looks like the real deal. It always makes me smile to see the set screws. Just a tiny part on this super detailed build.

Cheers Dan 

[crueby]

I agree with Dave that looks like the real deal. It always makes me smile to see the set screws. Just a tiny part on this super detailed build.

Cheers Dan 

Me too, those little details really make a difference!

[crueby]

Catching up on progress on the eccentric arms/yokes - started with running in the arms and checking measurements for the offsets on the HP ones. The LP arms go straight up to the reverse links, but the HP ones need to bend over to that side a little since the engine bed crossbar position forces the eccentrics aft somewhat.

The HP arms were then bent to shape, S-curve above the eccentric strap, and then used CNR's method to lay out and cut all the arms to length. I didn't build a full fixture, but used the post-on-a-plate method to measure the parts and determine how much to trim off each of the arms. The top ends of the arms were drilled/tapped 1-72 to match the screws in the bottom ends of the yokes. Here are all the parts test fit and ready to silver solder the yokes to the arms. Note that the ones in the foreground have straight arms, those are for the LP valves. The ones behind have the arms bent over to the side, those are for the HP cylinder. Each pair has one yoke facing each direction, so the openings come out centered on the links.

All the arms/yokes are stamped with a number for thier position so I can keep them in the proper place after soldering.

[crueby]

After silver soldering the yokes onto the arms, the shop elves got them in to soak in some vinegar, thinking I was making cherry lollipops for them.... 

[RReid]

Replace the vinegar with bubble soap and let'em have some fun.
Great looking assemblies by the way. If I didn't know better I would assume castings were involved.