Chris's Slew-Crowd Engines

[crueby]

She's a runner! and a nice runner at that. Great news Chris. Doesn't take much extra clearance to mess up small control linkages sometimes. Glad you found it.    I could see it was trying to slew itself around on the bench when it was running! Must be instinctive...

Thanks Jeff!  And after slewing around it tried to crowd me off my chair! 

[Kim]

 

Wonderful!  That was some great sleuthing work, Chris!  Nicely done. 

And thanks for the great video.  One down, only three to go! 

Kim

[crueby]

On to the next couple engines!  After some MORE time playing with the Marion engine,  , Its still running quite well, finally turned off the compressor and got a start on cutting the blocks for the Bucyrus and Erie valves. The Thew valves will be a bit different so will do those separately. So far have the four bronze valve blocks trimmed to overall size, ready to start shaping details in.

[cnr6400]

  When you take those blocks back from Bucket Bob be ready for some grief counseling - he mentioned to one of my shop gnomes on the Elferizon network that he planned to buy 11,204 cases of Elfensteiner stubbies with some "gold bars" he found....

[crueby]

After wrestling the bronze blocks away from the shop elves, I got started shaping them down. All of these steps were production-lined, using the work stop in the vise to position the blocks the same spot repetitively. Started by milling the slot down the length for the valve rod, and a cross slot for the adjusting nut. On these two engines the rod is too close to the valve face to have room for even small-pattern nuts like I did on the Marion valves, so I'm going back to the more tradition model engine style with a wide bar with threaded hole near one edge for adjusting the valve position.

Then drilled three side-by-side holes in each one to connect the two end chambers. Since the whole valve is shallower, also had to switch from two 4-40 holes to three 2-56 holes. Like on the Marion valves, these holes extend from one end through to where the far chamber will be.

Then set up to mill the chambers in. To speed things up since I am making four identical valves, I got set up for one cut at a time on the first valve, then repeated the cut for each of the others. That saved a LOT of time stopping to measure and sneak up on each position. The center chamber is .050" deep, the end ones are .150" deep to connect with the drilled passages.

The four valves so far...

Then tapped the ends of the holes for plugs,

and loctited in the ends of 2-56 brass screws. They were then cut and trimmed off flush.

Still left to do on these: make a batch of the adjusting nuts, and lap the bottom faces of the valves. Then I can start installing the first pair on the Bucyrus engine and getting it timed and running. After that, I need to drill/tap the cylinder drain holes in the Erie cylinders, and get that one assembled and running. Then can do the drains on the the Thew engine, and make/install its valves. Going to be a busy few days!
 

[Kim]

The valve production line is up and running, turning out good looking valves! 

Kim

[cnr6400]

 

[crueby]

Thanks guys!  This morning I made up a batch of adjusting nuts for the rest of the valves, and got the valves/nuts installed on the Bucyrus engine:

Then spent some time fixing an air leak, and getting the valves timed with the drain plugs removed. Once it seemed good, I put the plugs in, applied pressure, and it runs!!   

<a href="https://www.youtube.com/watch?v=MKvR-_Nq6E8" target="_blank">http://www.youtube.com/watch?v=MKvR-_Nq6E8</a>
And then there were two left to go...

It still needs a little timing tweaking for the one direction, with the throttle lever moved away from the camera/towards the crankshaft, but it does run in both directions! Having the drain plugs on the ends of the cylinder is making it SO much easier to time the valves. Need to remember to add them to all my future builds. On some engines, rather than drain valves I would loosen the end cap bolts to let a little pressure escape there, but this is much better.

Also, got the okay from the guys at the engine club with the steam crane to stop out any time and get more measurements/pictures, so the next warmish and dry day I'll be driving out there and spend a little more time with the camera and tape measure. I need to get more info on the underside of the track frame to map out how the drive clutches/brakes are configured, and I want to trace a few more control linkages up in the cab.

[cnr6400]

  Runner #2! Great news Chris.  Also great news that you're able to go for another research visit to the Erie crane. Not sure why you want to do it in nice sunny weather though - you'll miss the "ambience" of thunder showers and cold wind, or better yet a full snowstorm and below zero....

[crueby]

Runner #2! Great news Chris.  Also great news that you're able to go for another research visit to the Erie crane. Not sure why you want to do it in nice sunny weather though - you'll miss the "ambience" of thunder showers and cold wind, or better yet a full snowstorm and below zero....

   

[crueby]

After getting outside to mow the lawn, trim some trees, and take a read/nap on the front porch, I went and took another look at the Bucyrus engine. And had a Homer Simpson Moment. Doh!  Forgot to lap the bottom faces of the valves before assembling them onto this engine! It was running, but blowing a bit of air past the valves into the exhaust constantly. So, marked where the valve rods where adjusted do, took the valves back out, lapped them on a coarse then fine diamond sharpening plate, and reassembled things again. This time also put a drop of loctite on a couple of the pivot screws to ensure they would not back out in use. Then gave pressure again, and off it went, better than before!
<a href="https://www.youtube.com/watch?v=G4bL7zx_lDI" target="_blank">http://www.youtube.com/watch?v=G4bL7zx_lDI</a>
        
Next up will be the Erie engine. Just unscrewed the bolts holding the cylinders onto the frame, so I can drill/tap for its drain valves. At some point soon I need to make some actual drain valves, for now just am using some hex head screws to plug the holes for running.   Very happy how quick this engine got running, and hope the last two are the same. The Thew engine will be a finicky one to assemble, a lot less finger room around its moving parts. The barring lever/wrench that I printed the other day has been well worth the effort too, makes it easy to do precise rotations of the crankshaft during adjustments.

[crueby]

And one more into the running column. Earlier I had pulled the cylinders off to drill/tap for the drain valves, later this afternoon that was done and things put bnack together. After a quick visual centering of the valve travel, and one adjustment on each eccentric angle, it took off running. Grabbed the camera:
<a href="https://www.youtube.com/watch?v=4tj5gBtC3p0" target="_blank">http://www.youtube.com/watch?v=4tj5gBtC3p0</a>

A little more tweaking needed on the timing to smooth it out, but its running pretty well on first try.     Will look at the timing more tomorrow morning. Might head out to the crane for some more measurements, will see how the weather looks, might go the next day instead. Fun in all directions!   

Just one more engine to go - the Thew. Need to make the valves for it, drill/tap for the drain valves, and get it running. Then I'll get the drain valves themselves made, and plumb up the whole set of engines for a run! Need to make a simple display base to bolt them down to, keep them from walking across the bench when running. Home stretch!

[crueby]

Did a test, and changed my mind  about making a single base for all the engines. Tried a piece of that rubber grid made for keeping small rugs from sliding on the floor. Worked perfect under the boom section the engines are mounted to, absorbs the vibrations and stopped the engine from walking on the bench top. I'll  cut a section of it to go under each one. That will give more flexibility  in where I  display them, could be all together or in smaller groups.   

[Admiral_dk]

Great progress and to see three out of four run now 

I'm guessing that you are adding a few more bits them before you consider them finished - but I'm not sure how much, as they aren't ending up installed as part of something bigger 

Per     

[crueby]

Great progress and to see three out of four run now 

I'm guessing that you are adding a few more bits them before you consider them finished - but I'm not sure how much, as they aren't ending up installed as part of something bigger 

Per     

Thanks  Per,  only things to be added are the drain valves. They will just be on the short sections of boom, I'm not going to  build the entire steam shovel for each, that would be massive. Next model will be the oscillating  engine from the steamship Diesbar that Michael helped me develop  plans for.