Chris' Built-up MEM-Corliss Build

[crueby]

Oh, and the chips from making the steps on the outside of the ends were the long finger grabbers. I've gotten in the habit of pausing the cranking every turn or so to break the long strings until the final passes, so the final finish is smooth. One thing I like about working brass is smaller cooler chips! Some steels make for really hot chips that always seem to land on tender spots on back of hands.

[Captain Jerry]

Chris,

I know that your design sketch above is a working sketch and not a final design drawing.  You will soon be facing the need to make passages between the valve bore and the cylinder bore.  That is commonly done by drilling and having a drill bit start or end on a cylindrical face has been an occasion in the past, for broken and stuck drill bits.  On one of my Corliss engines, I avoided this by using a slitting saw on the cylinder and a shop made slotter on the valve.  My design was not exactly like this one but it did use a cylinder bore liner so the process was very similar.  I don't know if I got any pictures of the method but I may have some drawings.  I'll see what I can dig something out if you are interested.

Jerry

[crueby]

Chris,

I know that your design sketch above is a working sketch and not a final design drawing.  You will soon be facing the need to make passages between the valve bore and the cylinder bore.  That is commonly done by drilling and having a drill bit start or end on a cylindrical face has been an occasion in the past, for broken and stuck drill bits.  On one of my Corliss engines, I avoided this by using a slitting saw on the cylinder and a shop made slotter on the valve.  My design was not exactly like this one but it did use a cylinder bore liner so the process was very similar.  I don't know if I got any pictures of the method but I may have some drawings.  I'll see what I can dig something out if you are interested.

Jerry

I would definitely be interested in how you did it. I was figuring on starting the holes with a center drill tip, and/or making a small flat with an end mill like I have done for passages on other engines, but had not gotten to exactly how yet - the holes at the ends of the slot would be the toughest with the largest angle of the cylinder bore.

[vcutajar]

Will be following you Chris.  Interested in how you are going to make the cylinder.

Will this be a fast build like the Monitor?

Vince

[crueby]

Will be following you Chris.  Interested in how you are going to make the cylinder.

Will this be a fast build like the Monitor?

Vince

This one will be a slower build, other stuff going on this time of year plus I want to do more details on this one. So, get the bigger tub of popcorn so it lasts...!

[crueby]

Okay, stock prepping days.... I had gotten the plate material rough sawn down from the larger bar, leaving one straight edge from the original bars to use as a reference for milling the other sides down to dimension (photo 1). Also got the mill vise turned sideways on the table and carefully squared up, added the headstock riser to get enough reach out over the table, and ready to mill the end plates down to size. (photo 2). Jerry - remembered to leave some chips in the photo for you this time! 


Wait, whats that - you there, in the back of the room - Zee, isn't it? Yes, question? 


Oh, why are there two thickness plates? Good question! For this design, the end plates need to be thick enough for both the valve bores, plus the mounting bolts that hold the valve bonnets on. I went with a two layer setup for this for several reasons:
- I did not have stock that thick and wide handy, but I did have two pieces that stacked up to what I needed
- The thicknesses happened to work out such that the bolt holes on one side of the valve would center nicely on the thin plate, while the valve bore would still be well within the edge of the thick plate
- The end plate has all the mount holes for the cylinder covers, on the design as a series of shallow blind holes (so they dont interfere with the valves). With the thin plate on the outside, I can drill/tap all those boltholes as through holes, which is both easier/safer, and I don't have bottoming taps in a lot of the sizes (yet).

So, with the end plates made up in two layers, everything still works, and some things get easier. Lucky. The two layers will be bolted together for machining, and when all machining is done they will be given a coat of loctite to seal them and final bolted together from the inside with the end of the bolt filed off flush on the outside.

Also, some of you on another thread were asking about the latest RC submarine last week, last photo shows a picture of that all set up and ready to head over to the pool later today for its sea trials - hopefully will have video of it to show tomorrow. Or, it will be in pieces again for a change if something does not work...

[zeeprogrammer]

Wait, whats that - you there, in the back of the room - Zee, isn't it?

Yep. Just waiting for something interesting. 

Looking forward to the video. 

[Don1966]

Another project already, dust doesn't settle on your shoes. I'll be following along......

 
Don

[crueby]

Another project already, dust doesn't settle on your shoes. I'll be following along......

 
Don

Not much dust, unless it is sawdust!

Today is more stock prep, finishing up milling the edges of the end plates.

I did get out to the pool last night with the local RC submarine jockeys, below are some pics of my new Great White shark sub and a short video of it chasing a Skipjack model. It ran pretty well for first time in open water, couple tweaks needed to the ballast and rudder linkage, but it swam nicely.

<a href="https://www.youtube.com/watch?v=N8aqn1QA-Ms" target="_blank">http://www.youtube.com/watch?v=N8aqn1QA-Ms</a>

[Flyboy Jim]

Chris, Your shark looks great and runs great! 

However there is one downside for me. I've been swimming laps 2 or 3 days a week at the local pool. I'm thinking it just won't the same anymore knowing that "Jaws" could be lurking. 

Jim

[crueby]

Chris, Your shark looks great and runs great! 

However there is one downside for me. I've been swimming laps 2 or 3 days a week at the local pool. I'm thinking it just won't the same anymore knowing that "Jaws" could be lurking. 

Jim

The people that run the pool here asked if they could borrow it to clear the kids out at the end of the sessions...! Just listen for the Jaws theme while you are swimming....

[crueby]

Today I got the rest of the edge milling done on the end plates (photo 1), and got a start on drilling/tapping the holes for bolting the plates together (photos 2 and 3). With the edge of the plate lined up with the corner of the fixed jaw on the mill vise with a straightedge, worked out how many turns in the top/bottom mounting holes needed to be, and started going through all the plates drilling/tapping the holes (clearance holes in thin plates, tapped in thick ones). Once the top/bottom holes are all done, will do likewise with the holes in the side edges.

While laying out those holes, looking for places that they will not interfere with any other parts, finally decided how the steam passage and side plates will be attached. The top/bottom plates will be 1/2" thick, and will be shaped like a capitol letter I, with the flanges at either end used to bolt them into the end plates from the inside. The side plates will be bolted through from the outer ends, and be made from 3/16" stock. The same holes being used for now to hold the plates together will be used for the top/bottom/side plates later on.

Last photo shows the first pair, with the top/bottom holes done and the bolts test fitted. For now, will be using socket head bolts, later on those will be replaced with hex head. Will continue on with the rest of these holes, then move on to boring out the cylinder hole...

[tvoght]

Following along Chris. Argument could be made for making the cylinder this way even with a larger capacity machine.

--Tim

[crueby]

Following along Chris. Argument could be made for making the cylinder this way even with a larger capacity machine.

-Tim

Sure - lots of ways to make any part. This way uses smaller stock, allows for the occasional goof up without it being a huge disaster. So far its working out well for building a larger engine that normally would be too big for a small lathe/mill - hopefully that continues! I'll be looking through a lot of the other threads here later on for tips on making a built up flywheel. Fortunately the headstock on the sherline lathe can turn to the side, so I can hold the flywheel to the side of the lathe bed for final trueing.

- - - - - - - - - - - - - - - -
Now that was interesting - to make the reply above, I had to take one of the dashes out from in front of Tim's name or it kept giving me server errors. Learned on previous posts that multiple dashes make the MEM website barf on my keyboard. Wish that could get fixed someday...   

[zeeprogrammer]

Still waiting. 

The shark is pretty cool. Got a name for it? Ever think about sticking a camera inside/on it?