Your thoughts are required

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Artie

Well-Known Member
Joined
Sep 9, 2009
Messages
597
Reaction score
7
Ive just machined up one cylinder and partially machine the other...... as per the pic

25012010717.jpg


My point is I quite like the cast appearance of the cylinder with minimal machining and flashing removal..... what do you guys think? Im happy to cast another cylinder to maintain the 'patina'. If I use a fully machined appearance I might as well as used a piece of bar stock. I think it partly about appearance.

Your thoughts are appreciated, remembering there is no right nor wrong... YOUR opinion is vailid.....

With thanks

"confused from aus" = Artie

I know tel uses segmental build and I liike that concept as its far simpler than my cast project....... I think my next one will be tel influenced.

In case you are wondering the 2 sides shown are the steam chest mount face and the cylinder mount face.


 
with all the time spent working on the casting it would be a shame to cover that up. . looks good with a rough surface.

Thats my 2 bits.

kel
 
Hi Artie and Kel, in answer to your question, of all the engines I have built or am currently building, they were all built from castings...so far none of the finished builds were painted and I am leaving all castings in a slightly ''fettled'' state only machining where needed...the Corliss will most certainly have a less ''Fettled'' finish to it as the castings , to me, look much better, more earthy if you like...as far as metal finish and paint work is concerned, to each his own I say.
All the best for now,
John.
 
John,
I'm nearly finished with my first casting engine, a PM Research horizontal engine. All of my previous engines were made from barstock. For me, the casting kit was a real challenge. But I must say I prefer the "as is" look of the casting and I'll probably leave it mostly unpainted.

My latest project is a barstock engine which Stuart offers as a kit, the James Coombes Mine engine. If I had the confidence to make it from castings I would have gone that route but for now it's barstock.

Your cylinder pictured here looks similar to the Coombes Mine engine.

Cheers,
Phil
 
Artie,
My general approach to model finishing is to do with the model what would have been done on its prototype, or at least replicate typical practice, so far as can be reasonably accomplished. If it would have been an exposed cast surface on the prototype, or in typical practice, then that's what I shoot for on my model. If it would have been fettled to smooth, or covered in cleading or sheathing on the prototype then I do that on the model, and so on. I agree that regrettably some nice machine or hand work might get covered up by this from time to time but such is life. To me a raw casting, machined but unfettled, unpainted, etc, looks unfinished.
One place where I am tempted to stray from this practice is on large flywheels. Some large flywheels, especially those of beam engines, weren't turned (or polished) on their rims, they tended to be installed as-cast and on a model I'm always tempted (and usually cave in) to give them a far spiffier finish than they had in life.
Philjoe5 said:
My latest project is a barstock engine which Stuart offers as a kit, the James Coombes Mine engine. If I had the confidence to make it from castings I would have gone that route but for now it's barstock.
Phil,
The Stuart Coombs engine furnished in bar stock? This is something I've not heard of, . . . or do I mistunderstand and you are building a Coombs engine (like the Stuart model, not furnished by Stuart) from bar stock? I have contemplated building the Sanderson Bean engine from bar stock.

Harry


 
I would also be inclined to fettle the casting as the mould lines and sand texture are way out of scale, though a bit of uneveness stops it looking machined.

Harry if you fancy the sanderson from bar stock have a look at this and the next 3 pages, very similar style engine.

Jason
 
Harry,
I'm building a barstock version of the Coombes engine from plans supplied by Thomas Kokchinak. Sorry if I implied Stuart was involved in my build.

Cheers,
Phil
 
As Jason stated, sometimes the casting process does leave an overscale appearance. In that case, as I have done myself with castings, is to flat it down some if possible. I did find it very difficult to do and still retain an authentic finish, I always tended to clean off a little too much.

I did have some barstock bits grit blasted by a friend, which gives a very good appearance, but not to a 'casting' sort of finish. I have now gathered together some very course grit and large glass beads myself, to try to give a good 'cast' effect on machined parts. I will try it out as and when I get some engines out of storage to finish them off.


Blogs
 
Thanks guys, I think Ill go the route Blog mentions, tool finish and the grit blast the areas that could be left cast.

"with all the time spent working on the casting it would be a shame to cover that up", Kel, I agree and thats what prompted the question. Its also what stopped me when on the mill yesterday from cutting too far inbto the second casting.

Thanks all for your thoughts.

Artie
 
From the same guy that built the beam engine a fabricated cylinder with blasted finish

Another way to get the cast look is to run a slow rotating carbide burr over the surface.

Jason
 
As Jason's link shows, normal grit blasting does usually leave a fine finish.

Mine were the same, and with a coat of paint, the effect is totally lost. Here are mine that were done by a mate.

finger2bits2.jpg


I think that is way too fine for a scale effect, and was not what I was really after. Hence, I will be trying some heavier grit or glass bead to attempt to impart a slightly heavier surface finish effect. I think the glass bead might have a better outcome, as that should be a very small planishing effect rather than a cutting one that you get with grit.

It might work, but on the other hand it might not. But there is no harm in trying.


Blogs

 
I gave this a lot of thought and played with various finishes but in the end decided to make a 'feature' of the brass cylinders. Thank you guys for your input, it was muchly appreciated... some pics of what I ended up with....

The original finish, from the sand...
06012010600-1.jpg

25012010717.jpg


What Ive ended up with.....
31012010758.jpg

31012010802.jpg

31012010781.jpg


I like it... ;D
 
Good result Artie - I like it too.
 

Latest posts

Back
Top