Author Topic: Choice of Material for Kozo's A3 Switcher  (Read 4461 times)

Online Kim

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Choice of Material for Kozo's A3 Switcher
« on: July 22, 2017, 09:09:05 PM »
While it's a bit early for me to be scouting out a new project, since I still have at least a year before I complete my Steam Tractor build I've been working on, I can't help myself.  I'm starting to think about new projects.  Don't worry, I'll finish. I'm just doing some early thinking...

Anyway, I'm considering making Kozo's A3 Switcher.  I'm reading through his book now and it's just fascinating. Very detailed instructions on many interesting operations.  While I might not need that level of detail on many of the operations, I still find it interesting and am learning a lot by just reading his book.  And it seems like it would be a super fun build to do!  Plus, I've always wanted to build a steam locomotive!

But, on to my question:

In his book, Kozo specifies almost EVERYTHING be made out of brass, and a bit of stainless here and there.  I love working with brass as much as the next guy.  But WOW, would it get expensive FAST!

So, I'm wondering if it seems reasonable to build it out of mainly CRS, with some brass, stainless steel, or copper where it's important.  For example; anything that touches the water should be stainless or brass.  Anything that has to be rounded or formed, or is part of the boiler, should be copper, and so on.

But is there a reason he uses brass for everything?  He does a lot of fabrication by silver soldering brass parts, using little brass screws to hold the pieces together. But it seems you could do all of that fabrication the same way, just substituting CRS and standard stainless fasteners?  Much cheaper than brass. And since I'll be paining it, there's not much value to the pretty brass.  And it'll be like 1/2 to 1/4 the price if I swap out a lot of the brass.

Any thoughts on why he specified brass for everything?  Was it mainly for easy of machining?  Or are there other reasons?

Thanks,
Kim

Offline crueby

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #1 on: July 22, 2017, 11:15:48 PM »
It may partly be what he had available, but most likely he wanted the extra wieght to help pull passengers, would give the loco more traction. I built his New Shay, and with all the brass it came out to about 55 pounds. Lots of that was the copper boiler, it was 20-ish pounds as I recall.

 He did specify 303 stainless for certain parts, and I liked the way it worked I am using it for most of my Lombard build, also on my Corliss build last year. It cuts pretty nice, no rust, takes silver solder well, and is lots cheaper than the large sizes of brass. Brass is available in more of the smaller sizes, but you can get 303 in round, square, hex, flat in a lot of sizes. For the thin sheet for tank sides, etc, brass is still better, but thin sheet brass is still fairly cheap.

Offline 10KPete

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #2 on: July 22, 2017, 11:38:55 PM »
When I went through Kozos book I came away with the that same thought: I'd have to use cheaper materials!!!

I about a week I had all the substitutions worked out in my head.  If the fertilizer hadn't hit the fan I'd be building it in 7 1/2"......

Great book-- gonna sell mine....

Pete
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Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline kvom

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #3 on: July 23, 2017, 12:00:34 AM »
Brass is only slightly heavier than steel.  Certainly many of the parts could be steel, esp. if you're going to paint them.

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #4 on: July 23, 2017, 12:18:25 AM »
It may partly be what he had available, but most likely he wanted the extra wieght to help pull passengers, would give the loco more traction. I built his New Shay, and with all the brass it came out to about 55 pounds. Lots of that was the copper boiler, it was 20-ish pounds as I recall.

 He did specify 303 stainless for certain parts, and I liked the way it worked I am using it for most of my Lombard build, also on my Corliss build last year. It cuts pretty nice, no rust, takes silver solder well, and is lots cheaper than the large sizes of brass. Brass is available in more of the smaller sizes, but you can get 303 in round, square, hex, flat in a lot of sizes. For the thin sheet for tank sides, etc, brass is still better, but thin sheet brass is still fairly cheap.

Thanks Chris,
Since I don't expect to actually be running this on a track anywhere, I'm not worried about losing a few pounds of weight on the engine :)

Yes, I think the Stainless stuff I'd leave as is, and some of the brass, but for a lot of the framing and structural work, I'm hoping that steel would work just fine. Mainly for the cost savings. 

Even the thin and smaller sized brass seems to be about 2x the price of steel for anything I checked.  The stainless is cheaper than brass, but  more than steel.

But since you've built the New Shay, you have a much better idea of how his construction techniques might or might not work with steel vs brass.  So I really do appreciate your thoughts on this!
Kim

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #5 on: July 23, 2017, 12:19:30 AM »
When I went through Kozos book I came away with the that same thought: I'd have to use cheaper materials!!!

I about a week I had all the substitutions worked out in my head.  If the fertilizer hadn't hit the fan I'd be building it in 7 1/2"......

Great book-- gonna sell mine....

Pete

So you won't be building one, Pete?  That's sad :(
Maybe you want to consider changing your mind and next year (or so) we could do a parallel build? :)
Kim

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #6 on: July 23, 2017, 12:21:20 AM »
Brass is only slightly heavier than steel.  Certainly many of the parts could be steel, esp. if you're going to paint them.


This was my thinking exactly, kvom!
Kim

Offline crueby

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #7 on: July 23, 2017, 12:28:38 AM »
It may partly be what he had available, but most likely he wanted the extra wieght to help pull passengers, would give the loco more traction. I built his New Shay, and with all the brass it came out to about 55 pounds. Lots of that was the copper boiler, it was 20-ish pounds as I recall.

 He did specify 303 stainless for certain parts, and I liked the way it worked I am using it for most of my Lombard build, also on my Corliss build last year. It cuts pretty nice, no rust, takes silver solder well, and is lots cheaper than the large sizes of brass. Brass is available in more of the smaller sizes, but you can get 303 in round, square, hex, flat in a lot of sizes. For the thin sheet for tank sides, etc, brass is still better, but thin sheet brass is still fairly cheap.

Thanks Chris,
Since I don't expect to actually be running this on a track anywhere, I'm not worried about losing a few pounds of weight on the engine :)

Yes, I think the Stainless stuff I'd leave as is, and some of the brass, but for a lot of the framing and structural work, I'm hoping that steel would work just fine. Mainly for the cost savings. 

Even the thin and smaller sized brass seems to be about 2x the price of steel for anything I checked.  The stainless is cheaper than brass, but  more than steel.

But since you've built the New Shay, you have a much better idea of how his construction techniques might or might not work with steel vs brass.  So I really do appreciate your thoughts on this!
Kim
I think the 303 option is worth the extra cost - it cuts very nicely, not all that much tougher to machine than brass, and no rust to worry about - it is designed to be a 'free machining' alloy. In general, steel would work just as well as brass for his techniques. He uses a lot of silver soldering, some soft solder, lots of nuts/bolts/screws, so those all work with either metal. Aluminum would be problematic for a lot of it. I wound up buying the larger sizes of brass and steel through places like Yarde Metals, who have a 'drop zone' with offcuts of lots of metals, usually in the larger sizes only but some small stuff sometimes. They are usually about 3' long chunks, at a big discount, and the shipping is very reasonable. Lots of local suppliers have offcuts available for a great price, just the selection varies day to day so it can be tough to find a specific size.

One thing about brass, is that you can stress relieve it at home (500 degrees in the oven for an hour, let cool), which allows you to start with larger thickness/width stock and mill off one side without it warping, which is not as easy with a lot of steel alloys. Kozo calls out lots of metric sizes for stock, usually you can find a inch size close to it, but not always.

I had tried 12L14 steel for the wheels on my Shay, cut nice but they rusted REALLY fast, wound up having to polish then clear coat them right away to keep them looking nice. Using non-stainless steel can be a big headache for rust, the 303 solves all of that.

Offline Steamer5

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #8 on: July 23, 2017, 03:07:29 AM »
Hi Kim,
 A friend built the Heisler in 5" gauge, built it in steel no problem. The only thing he did different was he figured that silver solder was too expensive to use, so the wheels are brazed instead. There's a Switcher on that " other" site pretty sure that's in steel

Cheers Kerrin
Get excited and make something!

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #9 on: July 23, 2017, 05:20:41 AM »
Thanks for the detailed answer, Chris. Yes, sounds like the 303 stainless would be good to look into.  I've found the same rust issue with the 12L14, but I was assuming it'd be painted or at least given a clear coat for the 'non painted' surfaces.  I understand that might not work as well if it were going to have a hard life running around a track. But sitting on a display shelf, clear coat would probably be fine. :)

Thanks for the pointer, Kerrin.  I'll have to go check out that other site.

Kim

Online Jo

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #10 on: July 23, 2017, 07:35:14 AM »
Plus, I've always wanted to build a steam locomotive!

:facepalm: The slippery slope......

If you must then may I suggest you use some castings http://www.friendsmodels.com/productsforsale/kozowheelsdrivers.html  :naughty:

There is no real reason to use Brass in smaller sizes over normal materials like bronze or steel. Electric mice and steaming rats are normally build in brass as the constructors do not have a full machine shop to hand and can use soft solder for construction. Once you get to G1 and above brass is normally reserved for coachwork as it does not rust.

Jo

P.S. The term "Brass" covers many different types.
Enjoyment is more important than achievement.

Offline kvom

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #11 on: July 23, 2017, 01:39:58 PM »
I used the Friends castings for the wheels and cylinders on my build.  Very good quality.

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #12 on: July 23, 2017, 03:33:14 PM »
Plus, I've always wanted to build a steam locomotive!

:facepalm: The slippery slope......

If you must then may I suggest you use some castings http://www.friendsmodels.com/productsforsale/kozowheelsdrivers.html  :naughty:
Hmm.... the castings might seem like their own slippery slope.  "Its just drivers, come on, give it a try! You can quit anytime you like!"   :LittleDevil:
I don't know Jo, I think you might be the cautionary tale here...  :lolb:

Yes, Brass is pretty broad.  But generally, I'm thinking of 360 leaded brass. Or maybe 260 cartridge brass for sheet/plate stuff.

Thanks for the link, Jo, and all the input.  I do appreciate it!
Kim


Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #13 on: July 23, 2017, 03:34:50 PM »
I used the Friends castings for the wheels and cylinders on my build.  Very good quality.

Thanks kvom,
Despite my ribbing Jo about the castings, I may decide that's the way I want to go for the drivers.  I do want to look into making them myself - Carving them out or fabing them up.  We'll see.

Thanks,
Kim

Offline crueby

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #14 on: July 23, 2017, 04:12:29 PM »
Plus, I've always wanted to build a steam locomotive!

 :facepalm: The slippery slope......

If you must then may I suggest you use some castings http://www.friendsmodels.com/productsforsale/kozowheelsdrivers.html  :naughty:
Hmm.... the castings might seem like their own slippery slope.  "Its just drivers, come on, give it a try! You can quit anytime you like!"   :LittleDevil:
I don't know Jo, I think you might be the cautionary tale here...  :lolb:

Yes, Brass is pretty broad.  But generally, I'm thinking of 360 leaded brass. Or maybe 260 cartridge brass for sheet/plate stuff.

Thanks for the link, Jo, and all the input.  I do appreciate it!
Kim
The 360 brass is definitely better for all the rod/bar stock, cuts much easier and cleaner. For the thin sheet stock, usually no choice but to use 260.

The spoked wheels on the New Shay were pretty interesting to make, quite finicky on the fit of the spokes. Kozo showed how to make jigs for holding and soldering, which worked well, but it was an awful lot of little parts to fit. Still, fabbing them up from scratch is much more satisfying in the end.

Offline Bobsmodels

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #15 on: July 23, 2017, 05:59:07 PM »
Hi

there was some discussion of materials substitution in this build of the A3

http://www.homemodelenginemachinist.com/showthread.php?t=20460

Bob

Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #16 on: July 23, 2017, 09:52:25 PM »
Thanks for the link Bob.

So, I read some of that, and they seem to be singing the praise of Hot Rolled Steel, rather than Cold Rolled.  They seem to think it has less stress rolled into it when being formed, so it will go banana shaped on you less as you mill it into shape.  But I remember Hot Rolled steel being very hard to work with (though, granted, I don't have a lot of experience with it).

I know you have to do some stress relief in CRS.  But if I'm going to bother to do that, will it be better just to anneal hot-rolled stuff and save even a little more money, hoping that annealing makes it easier to work with?  Or should I stick with the CRS and just do my best at stress relief?

So many questions! :)
Thanks,
Kim

Offline Bobsmodels

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #17 on: July 24, 2017, 01:11:17 AM »
Kim

I am partial to things that do not move when machining them.  So I would use either hot rolled or 4140​ or 1144(stress relieved stuff) where things need to stay put ie fluting a side rod or making linkages.  Hot rolled has the disadvantage of not being dimensionally accurate (rounded edges)so you need to buy larger size and mill down ie if you need a 1 x 1/2 a 1 1/8 x 1/2 would need to be purchased.  Use as little 12Lxx as possible as it rusts.  The use of steel in places where Kozo calls for brass might be better from a strength point of view but this is a small model so I doubt it would actually make a difference.  If silver brazing is necessary then stick with the brass.  Stainless is good for looks sometime, like the side rods nice and polished, but if you do not intend to polish them bright then just steel.  Making fasteners from stainless has advantage of nice looking and removal later with no rust.

Remember when making the copper boiler NO BRASS for anything ie bushings, manifold etc, use only bronze. If you opt for a steel boiler, same thing no brass.

In a model this size you are not using that much material so cost is usually not an issue, use the material that will make your life easy.


Hope this helps


Bob

Online Dave Otto

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #18 on: July 24, 2017, 01:24:38 AM »
Hi Kim

I guess it really depends on the part and how much machine work is involved in it. HRS tends to have rounder corners (unless you are cutting from plate) and of course the the mill scale that needs to be removed. I haven't found HRS any more difficult to work with than CRS (we're not talking bead frames here). Keep in mind that SS bar stock will also go banana on you just like CRS.

If you are going to paint I don't see any reason to go with SS, I personally prefer the look of steel and cast iron on a model; yes SS will not rust but is just doesn't look the same.

I do agree with your thinking, there is no reason to make a model entirely from brass or SS unless that is your desire.

Just my thoughts,
Dave


Online Kim

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #19 on: July 24, 2017, 04:06:28 AM »
Thank you Bob and Dave for your thoughts.

I do appreciate everyone taking the time to reply!
Kim

Offline Stuart

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Re: Choice of Material for Kozo's A3 Switcher
« Reply #20 on: July 24, 2017, 10:42:02 AM »
Kim

If you have charcoal barbecue cut up your CRS into suitable lengths,get the BB going put in the steel cover it with charcoal and just leave it until it’s gone out and cold , that should do the trick

Note do not quench from red as you will have a very thin case harden

Stuart
My aim is for a accurate part with a good finish

 

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