Stuart Twin Victoria from scratch

[Jack3M]

Been not feeling so well, so not much done, plus the lost PLA mold needs to cure completely before I fire it.

So, made parts and sprues with thin wall, no fill. Glued them all together in a grouping that would fit in the mold and allow air to escape when the pour occurs.



The gaps have been filled with some CA. Really unsure how this will do in the burnout.



Weighed the whole thing and brought up into the living area and placed it near the wood stove. Next step will be oven at 350 (upside down) when no more weight change. Then fire it in the forge upside down.

After the burn out, some compressed air to blow out the ashes. The PLA does turn to a white ash at high temps.

Once these are done the casting part will be completed.

 

[Cogsy]

I'm keen to see how that lost PLA turns out for you as well. I'd like to do it but lack a burn-out oven to use. If it works really well I might have to start working on a plan to get/make one somehow.

 

[Jasonb]

Just be careful how you go when you pour that one as the investment is usually left in the (metal) flask. For safety put in in something like a bucket and lightly pack sand around it just in case it should crack and open up.

 

[Jack3M]

Cogsy,
I don't have a burn out over per se, I will just use the forge. I have less than $100 into the one in the photo above.

 

[Jack3M]

Well using plaster of Paris was an almost total flop. Almost because the process does clean out the PLA very well. Unfortunately, the POP doesn't handle the firing process at all well. I went to take it out of the furnace and it disintegrated into jillions of pieces. There were spots tho, that I could see that the PLA was completely gone with no trace of ash.

I need to cast a chunk of bronze for a Southworth Duplex Pump I just screwed up on. Therefore will give the sand another try. Need to check a couple stores in Portland to see if they have investment, and wax for between pieces sprues.

This duplex pump is so cool.
http://www.southworthengines.co.uk/steam-feed-pumps/duplex-steam-pumps/
If you order, tell Bob I sent ya. He was nice enough to GIVE me a set of plans for a Corliss that I can try to work up into Solidworks. Very old, whispy, unclear PDF files. Haven't even begun that project yet.

 

[Jack3M]

In researching for investment powder I have learned that wax and in particular rapid prototype plastics expand enough in the burnout process that they can cause the mold to break into little pieces. Sounds like what I saw with the plaster of paris. Any knowledge shared about that would be appreciated.

 

[Cogsy]

Can't comment on wax but I have some experience with PLA from 3D printing. I know PLA expands as it is heated but realistically, if the mold is made with thin enough walls not only will expansion be minimal (with a minimal volume of material to expand) but the walls themselves will be reasonably easy to deform as they are heated and should buckle rather than split the plaster. The stuff gets quite 'plastic' at reasonably low temps too (say 70 C) so it shouldn't be able to expand much before losing its rigidity. Unless the mold is made for high strength with lots of infill I just can't see it happening with PLA.

 

[Jack3M]

Ya I did it with no infill

 

[Jack3M]

Well, at the cost and shipping, investment isn't worth it for this much. I still need to make the steam chests and covers. Covers are as simple as sheet, the chests just waste a bunch of metal. (I have learned once run thru mill or lathe, the chips really will not melt, mostly just make a slag.) So at that, will progress slowly for now, as I have another steam project going, and spring is coming. I need to get the bottom of our boat painted before putting back in the slip, no later than the first of next month.

Be assured, I will update as I go along. I am almost finished with the other steam project. Weather will play a big part in how much I get done, the worse the weather, the more that gets done.:fan:

 

[Jack3M]

Made a couple pieces yesterday for this, as I was going to have to switch to the 3-jaw. With the 4-jaw on for a different project, just made these up quickly from the casting.

 

[Jack3M]

Had some more spare time between, waiting on some parts. Took out the flywheels and began a more thorough cleanup. I found them both not to meet MY requirements, so I cut them up and cast them again late yesterday. Be later today before I pull them.

 

[Jack3M]

New flywheels came out much better. Keep forgetting photos. But the first one is cleaning up nicely, will try to remember photo soon

 

[Jack3M]

No matter what, they are still going to be rough. I guess it will just be the trait of this one. I have to remember how much I have learned so far regarding this whole casting process. If I had to do this all over I would give myself more metal to machine off. I was not generous enough. Since both flywheels need to be exactly the same, on the same axle, there is still much to do, this being just the first of the two.

Fishing season is open, just waiting on the salmon to get upriver this far.

 

[Jack3M]

Got them both done and painted sitting on crank drying paint....cold in garage not drying well.

 

[Jack3M]

The week from hell. About all that pertains to this is the fluke accident that occurred. Something dropped onto a piece of metal, flipping it up into the mill while it was operating and it busted 2 gears. That was Monday and it has gone downhill since. Many other things not pertaining to this stuff so I will not bore you.

I have managed to make a few pieces, lathe work only. Need to buy some steel stock for several other small pieces. I am considering buying a pair of cylinders from Stewart, don't have the skill to cast them well

 

[Jack3M]

Well a pair of cylinders will run about $50 for me plus shipping. Just ordered $100 of steel and cast iron. This project is beginning to look like it will cost more than a kit would have. Time will tell. (Of course I will have left over 'stock' by doing things this way for the next project.)

Still thinkin on the cyls. Need to go fishin and think on it. At least the boat didn't have serious issue, one that can be worked around and not get stranded.

This has been a :fan: week. Finally looking like things are turning the corner.

 

[Jack3M]

Update, no photos. Fishing season has commenced, so not doing much. Have managed to make the steam chests and covers, some load bearing beam things, and milled the bases true. The bases still need a bunch of filing to clean up before photos.

Of course, still had to fix the mill, which gave me opportunity to lube everything while it was apart. Made a tramming tool for the head as it had to be moved to do the work. (That one of Utube that uses a pair of harbor freight dial indicators.) It does make life much easier.

So maybe some photos next time, not much to see really.

 

[Jack3M]

Picture time of several of the parts, both during and after. Also decided to print up a plug for the Eccentric arm end so I can cast that, along with 2 parts I didn't realize I needed 4 of instead of 2, so more casting to do too.



The completed basic steam chest and cover. As you can see in the next pic, I need to alter the plans as I figured it would be easier to make the 'spigots' by actually using a bush on one end and an O-ring and gland. (Learned that method on a previous project and I like it very much, plus it looks really cool.) The upper bush will be reamed along with the other opening so it will be true.



Of course the bases. Forest Green rattle can, 2 heavy coats. Light sanding to bring the mounts back out clean.



And the Cylinder heads, the bottoms are mostly made too, I also modified the plans to cut the glands out of bar stock while making the balance of it. That has not been done yet. I get a kick out of veering off the plans to make a job look better or make it a lot easier to make it or service it. (Several years in mechanical industry, just not machining.)



Thanks for looking.... I do note the number of visits even for minor posts, so thanks for following. Makes it worthwhile to take the time to post this stuff, I get so impatient, LOL

 

[Jack3M]

Cylinder base before and after completion of the gland and recess for O-ring. Also, the cylinders arrived today. I am glad that I bought them. The ports are cast in. Far above my ability for sure.

 

[Jack3M]

Ok fishing over for now. Been doing a bit here and there, just not posting the photos I took until process was all visible.

First shot is the gland for the cylinder base. There will be an o-ring and it slides into the base part from the previous post. Holes for bolts and such I do at the very end once all my parts are built.


Then started working on some of the guts for the steam chest, the slide and it's carrier shaft. Back side has .093 depth for steam/exhaust passage. Just solid piece of bronze cast for these. Took the photo before both were done so only need to post once for this.