Arnold's take on the MEM Corliss

[arnoldb]

Thanks Vince  - you're most welcome to copy it  .  It was a bit spur-of-the-moment, and I'm not paying too much attention to fine-scale detail on this build, as I first want to get it running and see if there were any oversights during the design phase.  There shouldn't be - the team trashed things out quite a bit behind the scenes, but building on paper/virtual reality is different from actually doing it.

Alan, thank you 

Today's itsy bitsy bits...

First the pack nut.  I don't have any 16mm hex stock, and I really didn't feel like making the nut from A to Z, so I used some 12mm hex brass bar for it.  The hex nut section size is not critical.
I just turned the end down to 10mm to thread, and drilled a 6.2mm hole through it deep enough to part off to.  Then I threaded it M10x1.25 using the face of the tailstock drill chuck to start the thread squarely.  Here it's ready to get parted off:


A couple of licks with a file to neaten up the hex section a bit, and it's a nice fit in the cylinder head:


The cylinder block needs some "legs" to stand on.  I don't have suitable solid material to hog them from, so these will be a fabrication.  When the engine is running, there will be fairly large lateral forces applied to them, so using soft-solder is not an option here, and I'm also a bit wary about using threaded fasteners for this job.  My stick-welding is still too much chicken-$h1t, so I'll use proper silver solder to stick the bits together. 
I cut some over-size bits of stock from a bit of 3mm plate and 60x10mm flat bar to start off with:


The 3mm plate sections were milled to size to fit the top sections of the mounting feet, and then drilled to match the mounting holes on the cylinder block.  I added the two 2mm holes along the center line - these will be used to help keep things together when silver-soldering later on:


My shop-session was interrupted at this point by the arrival of my youngest sister.  She's a tour guide, so we don't see each other that often as she's mostly on the road or working at different lodges in the country, so we spent a bit of time nattering and drinking a couple of beers.  I have a personal rule that I don't go in the shop if I've had a drink, so that's it for today.

Kind regards, Arnold

[Don1966]

Arnold that's a nice bit of work.  enjoying it immensely.

Don

[ozzie46]

Excellent rule.

Great work by the way.   

  Ron

[arnoldb]

Thanks for checking in Don & Ron 

Today I started off on the two bits of bar that was shown along with the bits of plate in the second-to-last photo.  Those wire milled down to size:


An then had 2mm holes added to match those in the bits of plate:


The two blocks were still much too thick at 10mm, so I gave them a going-over with a 6mm ball nose cutter to slim them down to 6mm  while leaving the bases 10mm thick:


You might have noticed the pit-marks in the bits of plate from earlier - I don't have nice smooth 3mm plate; just a rusty old section.  I needed to clean up a bit more of it for the mounting plates - I use a rubber-backed sanding pad in the drill press for this:


Two more bits of 3mm plate ready to get machined down:


I just machined and drilled them as a pair - here the mounting holes are drilled, as well as the two obligatory 2mm locating holes:


On to rounding the corners on the bits of plate, and a bit of file-work.  I used a bit of 12mm rod, a permanent marker and the scribe to mark out the corner roundings, and set off to the vise.  I've found the easiest way to file corners like this is to first file a flat facet down to the line at about 45^o :


That is then followed by two smaller facets either side at about 22.5^o and 67.5^o.  These facets remove most of the material and forms a good approximation of a curve:

Then I use a finer file and follow the "curve" from the flat ends while stroking - this removes all the high edges left by the facets first, and with just a couple of strokes the corners are rounded.  I forgot to take a photo of this  - but you'll see the results in later photos.

I used a bit of bronze brazing rod to pin the parts together after adding flux in between all the bits and then clamped them together with a toolmaker's clamp.  Then I threw the Sievert torch at them with its 20mm nozzle - this makes a lot of heat very quickly - and heated the lot up to dull red.  When the flux flowed, I added some naughty cadmium-bearing silver solder from a stick and this flowed nicely into the joints.  The flame from the Sievert do tend to make things go horribly black from oxidization, so I made a "very quick" pickle - a table spoon of citric acid in 250ml of boiling water - and dunked the two bits in there to pickle off a bit:

Unlike other acids, the little citric acid spill is nothing to be worried about; one simply wipes it up with a bit of paper, but I do the pickling outside the workshop (here it was done on the steps outside the door), as the fumes will make any un-oiled metals rust like mad.

After 10 minutes in the pickle, and I could see the results - some slight spillage of silver solder, but not nearly as much as I've had in the past, and nice fillets all-round all the joints.  As I'd only applied the silver solder from one side, this confirmed good penetration:


As a final step, I milled the cut-outs for the exhaust chest cover:


The two mounting feet pretty much done:


Slowly coming together - a bit at a time:


Kind regards, Arnold

[vcutajar]

Arnold

You are really moving along at a fast pace.  In a short time you will have reached the flywheel stage and I would still be hacking at it.  As Tel said, the flywheel is a project on its own.

Vince

[swilliams]

Yes - nice progress Arnold. I'm also an old friend of the rust pitted stock 

Steve

[b.lindsey]

I look forward to your updates Arnold, its coming right along and should make a beautiful engine when complete.

Bill

[Captain Jerry]

Nicely done and rock solid.

The cylinder block needs some "legs" to stand on.  I don't have suitable solid material to hog them from, so these will be a fabrication.  When the engine is running, there will be fairly large lateral forces applied to them, so using soft-solder is not an option here, and I'm also a bit wary about using threaded fasteners for this job.  My stick-welding is still too much chicken-$h1t, so I'll use proper silver solder to stick the bits together. 

 Arnold

This statement made me wonder.  I thought they were just to support the weight and that the thrust would be taken up by the frame.  Many engines just cantilever the cylinder to the frame with no legs.  The web has many pictures of Corliss engines being moved for restoration and the entire engine is being lifted as a single unit.  So I got looking at the plans a little closer.  Either I am missing something or this design is very different.  I don't see that the outboard end of the trunk guide is fastened to the frame.  It just seems to be a close fit with no fasteners.  Is it meant to be held with adhesive or solder or is it intended to be left loose?  Locktite might be a little iffy but solder would seem to be enough to take the thrust.  If is is left loose, that would allow for adjusting the alignment but that would mean that the cylinder supports have to take the lateral force as you say.   What was the thinking for doing it this way?  Just curious. 

Jerry

[arnoldb]

Thanks Vince  - Yes, the flywheel will be quite a big project - it will push my skills and machines to the limit 

Steve, thanks  - There's some more of the pitted stock in today's post.  One's got to use what one has to use 

  Thank you Bill.  Its slowly starting to get to the point where I have to start thinking of the paint job and colour...

Thank you Jerry  .  During the design phase we didn't discuss the cross-head guide to crank-frame joint a lot.  From the plans, it is a slip fit as you say - and actually I prefer it that way, as it will make the engine a bit easier to assemble and disassemble when it comes time to getting it to run and painting it.
You're quite correct in that these bits would be solid on full-size engines.  I don't see the slip fit as much use for adjusting things, other than allowing a bit of leeway for mounting.  Adjustment would be done through the piston rod and connecting rod.  I did consider adding some grub screws (set screws) to the mix, but that would add unsightly holes.  Screws and/or soft solder might be fine to build up the cylinder mountings, but after having machined them, I don't think that's a safe option unless one machines very lightly indeed.  Machined from solid, there shouldn't be any problems.

Yesterday I spent  and  - it got to a point where I realized my desktop PC and laptop combined can't handle the number of virtual servers I need to carry on my studies, so I need to go spendybigbucks on a seriously powerful computer this coming week.  Dammit... Tool and stock money down the drain 

This morning I took the rotary saw my grandfather passed on to me two years ago outside the shop.  It's a nice and powerful machine, and came with a small mounting stand.  I proceeded to cut up some bits of teak:

Outside the shop's nice for this - no wood dust in the shop, and a light breeze will return the dust to mother nature  - or one of the backyard neighbours' houses much to the chagrin of the housewives.  I'll be sure to keep my house windows closed 

I haven't used my wood plane in a long time, and the last time I did, it was very blunt.  This teak is quite tough to work with, so I spent a good 20 minutes on the oilstone re-sharpening the plane's blade, and then put in some elbow grease to plane up the bits of wood on the cut edges with very fine cuts:

A longer plane would be better for this job, but this is my one-and-only, so it had to do.

Some wood glue, and a "cabinet maker's" bit of work with clamps - I've never ever tried this, so I'm holding thumbs:

This side of the planks was left in the weather, so it looks really dark and messy; the other side looks better.

On to metal again, and I hacked a couple of bits from some 12mm plate - as well as some more of the pitted 3mm plate.  12mm plate for the cross-head guide support is a bit thin; that should be 13.5mm according to the plans, but I didn't have anything suitable on-hand, so 12mm will have to do.  And yes, this will be another fabrication:


Off to the mill, machined to size, and the one end with the sticky-outy-bit (Zee terminology) for mounting the bearing on machined:


Some more machining with a 16mm end mill and I really hogged things out - this end mill isn't exactly the sharpest tool in the shed any more, but still gets the job done with a bit of heavy-handed machining.  I intentionally left the steps at the ends of the cuts:


With the workpiece re-mounted flat in the mill vise, I finished off the last bits.  The steps I left earlier roughly approximated the curves needed to finish off the cut-out with a 12mm end mill running at full depth:


I stopped there for today, but put together a couple of "family" photos:




Seeing as this is St Patric's day, a grumbly deep-pocketed old leprechaun decided to make fun of me, and made the prepaid electricity meter run out of pre-paid just when I was about to post - so this was a complete re-type of my post.  So here's one on the little green men  and a happy St Paddies to all involved 

Kind regards, Arnold

[steamer]

That's Sweet Arnold!

Dave

[Bearcar1]

AH yes, those irish laddies leprechauns, they can be a might capricious at time they can. Especially during the Celebration of Eire.    Things are shaping up very well indeed Arnold, and your work is once again to a high standard. Just a note about working Teak wood in case you, or anyone else for that matter that does not usually work with the stuff. Teak is an oily wood that lends itself to marine usage quite well due to this fact. It has and is used for the pass-through stuffer boxes for the propellor shafts on some vessels in fact. Anyway, the best procedure to follow when gluing the stuff up is to do so as quickly as possible after cutting and having a close fitting joint. Now here is the *trick* for a truly good joint, wipe the surfaces to be joined down with a clean rag that has been doused in denatured alcohol or acetone. This removes the surface oils and to some extent dries the wood out and allows for the glue to better penetrate. The wood will naturally replenish itself, but the glue will by that time have done its job. This is practice is probably not necessary for your application as the joint will be exposed to minimal if any stresses, but I just thought that I would toss about one of Mr. Hulvey's (HS woodshop instructor) teachings.


The Captain brought up a point I was wondering about as well on the frame not being a solid piece as in full scale practice but am laying back in the weeds and watching how this will unfold. Obviously the stresses exerted on that area will not be tremendous but I still wonder about it. Just me (is this emoticon politically correct?) well no but  .......... 




BC1
Jim

[tel]

  I'll be sure to keep my house windows closed 

So you can't hear the complaints? Good thinking! 

[vcutajar]

It's really coming along nicely.

Vince

[gbritnell]

You're making excellent progress Arnold.
gbritnell

[Don1966]

She's looking good to me Arnold. Great job as usual. Still following with great interest.

Don