Model Engine Maker

Help! => Specific Engine Help => Topic started by: zeeprogrammer on July 04, 2015, 02:59:54 PM

Title: What is 'b.m.s'?
Post by: zeeprogrammer on July 04, 2015, 02:59:54 PM
Hi all,

I've been drawing up E.T. Westbury's Paddle Engine from some plans and there's some notations for material I haven't been able to figure out.

Most (all) of the material choices are straight forward but I'm still interested in knowing what the following mean:

b.m.s.    ('something' mild steel?)
g.m.       (eh?)
m.s.p.    (mild steel plate?)

As an aside, I've attached my progress thus far. I'm using Cubify Design. Some of it is experimentation such as color choice. You'll also notice some parts fully colored (faces AND edges) while others color just the faces. Most of the parts are using default settings.
 
The plan (such as it is) is to modify some of the parts so it looks a bit more 'real'. An example is the frames. They are currently just plates (per plan) but I'd like to make them look more cast and thick. I'd also want to add lagging to the cylinders, oil cups...that kind of thing.

I enjoy drawing. It's been useful to find errors in the plans, to visualize the project, and even make some material choices when material type isn't critical and more color choice for contrast etc. becomes available.

No immediate plans to start building. The number of life interruptions has been too high to provide sufficiently large enough chunks of time.
Not that I haven't been busy. I've been working on things that allow me to frequently get yanked out of my hole yet pick up easily where I left off.

Thanks.
Title: Re: What is 'b.m.s'?
Post by: sshire on July 04, 2015, 03:04:47 PM
The drawing looks fascinating. What are the overall dimensions?
If you can convince T it will power a rototiller, you may be able to work in some extra shop time.
Title: Re: What is 'b.m.s'?
Post by: kev on July 04, 2015, 03:05:04 PM
Bright Mild Steel?
Title: Re: What is 'b.m.s'?
Post by: Stuart on July 04, 2015, 03:10:46 PM
G.M.

Gun metal   Aka bronze


Stuart
Title: Re: What is 'b.m.s'?
Post by: zeeprogrammer on July 04, 2015, 03:41:55 PM
Thanks!

I'd wondered about 'bright'.
Gun metal...of course!  :slap:

The drawing looks fascinating. What are the overall dimensions?
If you can convince T it will power a rototiller, you may be able to work in some extra shop time.

No. Then I'd be roto-tilling.  ;D

Cylinders are 3/4" bore. 1" inch stroke if I recall correctly.
Frames are about 8" long. Overall height about 4"

I'll have to remember to throw a drawing of a scale in.

Attached is a drawing of the paddle wheels. 5 3/4" diameter. About two inches side-to-side.
I've come across several references that indicate this model is appropriate for a 6' boat.
There was also a reference to scale the engine down (maybe 2/3rds of this) for a 4' boat. They recommended not going smaller.

You could knock this project out in a couple of days right Stan?

It probably won't be until retirement that I can work on this.
Title: Re: What is 'b.m.s'?
Post by: Stuart on July 04, 2015, 04:20:35 PM
Zee

The definition for BMS is correct as said but I would call it in your terms cold rolled full of stress.

But my normal term for it is GCQ Good ( debatable) Comersial Quality , ie you don't know what you are getting it may turn ok but mostly not.

I buy my stock from a UK firm called M-Machine they call all their stock for what it is ( sorry for the old UK terms ) but you order EN1A that's what you get . Yes it a bit more but you know what you've got and therefor get less waste from trying to be unmachineium and therefore make scrapium.

Stuart

Ps when you retire you will have no time best get it done now . I gave up work 17 years ago at 51 and still wonder how I found time for work
Title: Re: What is 'b.m.s'?
Post by: philjoe5 on July 04, 2015, 04:56:11 PM
Zee,
Finish drawing up the plans, sell them (I'm in), retire early.  It's really that simple :Lol:

Cheers,
Phil
Title: Re: What is 'b.m.s'?
Post by: sshire on July 04, 2015, 05:13:56 PM
Zee
What happened to your copy of "Arcane, Obscure and Osolete Metal Terminology?" I'm thinking you left it at the diner on our last trip. The waitresses keep mumbling "silver steel" and "Durabar"

Yes. I'll get started as soon as:
1. I complete titivating the 1/4 horse
2. I try to remember what I knew about cabinetmaking for the 1903 sewing machine base. Used to be able to hand cut a tight dovetail joint in 15 minutes. Now, I'm staring at Japanese saws, chisels and water stones as if they're mystery tools.
3. I finish the drip oilers.

Title: Re: What is 'b.m.s'?
Post by: Tennessee Whiskey on July 04, 2015, 05:54:21 PM
I know by now y'all all know I'm crazy, but, I wonder sometimes at our level of stress and run time,  is the grade of metal all that important.  Now,  I understand when it comes to long crankshafts, cams, and such, I can see. However,  a single thro crank turning 100 rpms, moving a 1/2" bore piston with a couple of thou or better clearance , will it really matter a hill of beans  (one of grandma's expressions  8)) . Just thinking out loud.

Cletus
Title: Re: What is 'b.m.s'?
Post by: Stuart on July 04, 2015, 06:35:55 PM
Cletus

My view on material is I would sooner have something I can machine to size and get a good finish , the only way I can do that is to start with a known material that I know will give me what I want rather than waste time trying to get it on size with a good finish with junk material.

I do agree that we do not need a chrome moly ( I think that is 4140 ) for our small engines when EN1A will do fine and machine like butter

That my two cents/pence on the subject but we all do what we do ,after all in the end it's up to us what we use ,as we are not constrained with liability claims

Stuart
Title: Re: What is 'b.m.s'?
Post by: Jasonb on July 04, 2015, 06:44:32 PM
Its not just the qualities of how the metal will perform on the model its also how it will react to what we do with it, take that single throw crank, if you cut it out of cold rolled its quite likely to move as the stresses are released and only be any good for a bananna boat engine but make it out of hot rolled or stressproof and it should stay where it is.

I also think the same way as Stuart, I'd rather spend a little more on a known material than something cheap with a coating of rust, with a known metal I can be sure I will get the finish I want rather than spend extra time and effort trying to get a decent finish on some unknown grade that is a pain to machine.

J
Title: Re: What is 'b.m.s'?
Post by: sshire on July 04, 2015, 07:15:19 PM
100% in agreement. One example for me was threading drill rod. The threads were dangerously rough and sharp. Aloris threading tool, many different cutting oils. I've switched to 12L14 drill rod and the threads are beautifully smooth. Perhaps it was my technique with the O-1 drill rod but, the results are much nicer.
Another was Durabar vs mystery cast iron. Not worth the price difference vs the results.
Title: Re: What is 'b.m.s'?
Post by: kvom on July 04, 2015, 07:19:24 PM
As you may recall I made a start on building this engine many moons ago.  I had made about 75% of the parts aside from the paddlewheels, and was/am dissatisfied with a number of them.  I have the intention to resume it at some point, with hopefully having learned some things in the interim.

Originally I machined the frames and hornblocks in one piece from aluminum.  That worked, but I dislike the appearance.  For a reword I'd make the frames from steel with the hornblock stock welded on before machining.  The outer frames can be made thicker without too much of a problem, but the inner frames would require detailed analysis to get everything to fit and be lined up properly.

Originally I figured to make the paddles non-articulating, but I'd consider printing them in metallic plastic now.  I also planned to skip building the water pump as I had no intention of putting it in a boat or running on steam.
Title: Re: What is 'b.m.s'?
Post by: zeeprogrammer on July 04, 2015, 07:33:03 PM
the grade of metal all that important

All good points. So many things go into choosing the material.
Wear, stress, time and effort needed, aesthetics, cost, availability, safety, tarnishing, paint-ability and on and on.

Going back to the g.m. (a.k.a. bronze)...

I notice in the drawings that some parts were specified as g.m. while others where specified as bronze.
Yes g.m. is a type of bronze but why would the drawings specify both and not just either?

Brass, gunmetal, and bronze are all based on copper with varying degrees of tin, zinc, and other goodies.
Some references seem to consider these all sort of the same. I imagine that depends on context though.

What considerations (if any) do you all make when choosing between them?

Ah kvom...I did want to mention that I had pored over your thread. It was very helpful to me. For one thing I'd noticed the cylinder cover and how the holes matched to the cylinder. I moved mine.

It was a bummer though that you hadn't done the water pump. That's the one part I've been struggling with to draw. For whatever reason I haven't been able to get the shape in my head. I wish an isometric drawing was available but haven't found it. I haven't found a good shot of it on the internet either. Not many people made it. I haven't even figured out how it works. I don't see a valve of any kind...but I don't know much about this kind of stuff.
Title: Re: What is 'b.m.s'?
Post by: Jasonb on July 04, 2015, 08:41:49 PM
On the smaller stationary engines it is quite common for the parts to be cast in a yellow metal and this is typically what you see described as Gun Metal so things like the cylinders, valve chest etc would be GM. Other small turned bronze items like bushes, glands would be made from bar so these would be called out as bronze, parts that may come into contact with steam that you dont want rusting but don't need the properties of bronze or run against bronze may well be given as brass
Title: Re: What is 'b.m.s'?
Post by: Jo on July 04, 2015, 09:00:52 PM
Gunmetal is a type of bronze which was originally used to make guns before it was superseded by steel. It is the type of bronze that foundry's make our castings  :embarassed: out of. There are two types of Gunmetal: Admiralty and Leaded GM, the Admiralty stuff having a better tensile strength and is more expensive. The Leaded GM replaces 2% of the zinc with lead making it easier to cast  ;)

We also talk about Phosphor Bronze but when we do we refer to three different materials: Drawn Rod, Hard Drawn Wire and Cast P.B which is used for bearings. Often evil stuff to machine  :ShakeHead:

Jo
Title: Re: What is 'b.m.s'?
Post by: zeeprogrammer on July 05, 2015, 01:35:29 AM
Thanks.

But all I can say is that all this makes my head hurt.
But not so different than going to school and realizing there's just so much more to learn and understand.
Cool. If things were simple...we'd all be the same.
Which is not a good thing. It's the differences that drive.

Anyway...this just points out how much more there is to learn and how much I depend on those who already know more than I.

This is a teaching forum. You can't get more of an accolade than that.

I have my own area of 'expertise'. There's no more satisfaction than people learning from me.

So thank you.
Title: Re: What is 'b.m.s'?
Post by: Stuart on July 05, 2015, 08:27:44 AM
All part of the community service , this is what makes this forum great the members have a vast pool of knowledge and are willing to share it .

We all have some knowledge however small that can help others , the question only has to be asked


Stuart
Title: Re: What is 'b.m.s'?
Post by: ironman123 on July 12, 2015, 09:10:16 PM
banana milk shake. >:D :LittleDevil: :lolb: :lolb:
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