A3 vs Connor Beam vs Raritan

[Harlock]

The A3 book has very detailed descriptions on how to complete each machining operation, good for a beginning machinist. It also has a chapter with notes on scaling up to 7.5" gauge / 1 1/2" scale. I have not seen the Raritan book but I believe that was Kozo's inspiration for the A3 series. People have scaled up its design before.

The Connor Beam engine requires less precision work than the other two and is a fine runner and fun to look at in motion. No castings, commercial industrial cylinder sleeves on built up cylinders, no rods in the running gear, just a crank and chains. The smaller 2+2 (0-4-0) is small and easy to deal with. Along those same lines, you might also add the CliShay to your mix of considerations. Another very simple geared engine.

I would second the advice of building the engine you think you want, not just because it's the easiest one to build. You will find that you enjoy the process of creating something you like. These are all very different engines.

-M

[Weibel]

Do you think that if I am asking between these three locomotives that I am really sitting here cutting hairs about scale anymore?

Well quite frankly considering 2 of the 3 listed locomotives in the title of this post are, AS DESIGNED, 3/4 scale locomotives are we supposed to guess?

Ken-

Touche.
Touche, I apologize if I seemed short (no pun intended on being short physically as well- which I am).

[JaTro]

I still hope somebody will show on chaski build of this:
http://www.friendsmodels.com/productsfo ... ge420.html
Apologize for thread hijack, but i consider this nice begginer engine.
I will, once... so I am biased. Sorry for OT.

[Pontiacguy1]

Looks like a really interesting model to build. Only problem is that it wouldn't have very much pulling power. I can imagine that it would pull one light car with the driver on it on a fairly level track, and that would be about it. It really didn't give any specifications such as weight, length, height, boiler diameter, etc... But I imagine it would not be much more than 120 pounds, if that, and only about 60 or 70 on the drive axle.

Same thing with the old 4-2-4 C.P. Huntington locomotive that used to be in the Little Engines catalog. It was a really good looking locomotive, in my opinion, and totally unique. However, it really couldn't pull much at all. The locomotive was about the same total weight as the Little Engines American, but only had about half of the weight on the drive wheels. Saw Leo Myers' 4-2-4 run a lot down at Mid-South in the 80's. It ran well, but he could only pull himself and a very light train around our lower loop. Still, it was really neat to see it.

[Benjamin Maggi]

Same thing with the old 4-2-4 C.P. Huntington locomotive that used to be in the Little Engines catalog. It was a really good looking locomotive, in my opinion, and totally unique. However, it really couldn't pull much at all.

I remember seeing this engine in the LE advertisements from the 1970s and it showed the engine with several people in a gondola or flat car behind him. I can only imagine it was taken on a downhill part of the track.

[gwrdriver]

Of course that photo could have been staged . . .

[JaTro]

Do you think that Connor Beam steam engine got more pulling power?

[Harlock]

Do you think that Connor Beam steam engine got more pulling power?

That's a tough call, but I'd say the beam engine would win out over the A3 and the Raritan would be last.

According to my A3 book, the A3 cylinder bore at 1 1/2" scale is nearly 1.75" which is quite a bit of available power so long as the boiler can keep up and there's enough weight. At 6 1/2" and fairly short, the boiler isn't huge for the cylinder bore on the A3, as a rough observation. One of the 1 1/2" A3 builders here might be able to comment.

The beam engine, if the 4+4 has the same specs as the 0-4-0, has a 2" bore X 2.75" stroke and 20% overdrive on the gear reduction, and a 12" dia vertical gas fired boiler. I'm pretty sure the 0-4-0 version is smaller in all respects. I posted a question on another group to see if I can get the answer.

The beam engine is essentially a climax by other means. There is some mechanical loss in the beams, jackshaft and chains, but the gear reduction can be a great advantage. Most 0-4-0 beam engines I have seen and one I have operated will pull an engineer's car (with you, propane and water) and a small bench car with a couple of adults and a kid or two and a display caboose up decent grades with no problem, and did not have any slipping issues when I ran it, well balanced for power to weight ratio. A certain member of this group likes to brag about the pulling power of his larger 4+4 beam engine. He has said in the past, "I have hauled 11 preschool children, 11 adults and myself around the SVLS track with no problems. With beams working up and down while I run it is quite an attention getter." Of course the SVLS track is basically flat. It'd be nowhere near that much on a steep track.

The Raritans I have seen scaled up I remember being pretty small, I would put it at the back of the pack. According to a page I found, the Raritan's cylinder bore is 3/4" at 3/4" scale so it'd be 1.5" at 1.5" scale if you did not adjust the bore. Here is a scaled up raritan project that was previously sold on DLS: http://discoverlivesteam.com/discoverfo ... tm#Raritan

-M

[JaTro]

Sorry.
I didnt finished my question. Obviously:-), as english is not my first language.
Do you think that Connor Beam steam engine got more pulling power then Friendsmodels 4-2-0?
Where will be 4-2-0 in above list regarding pulling power. Sorry again for OT.

[kenrinc]

Sorry.
Do you think that Connor Beam steam engine got more pulling power then Friendsmodels 4-2-0?

I've not seen any B&O 4-2-0s and from what I gather, besides the castings for wheels, everything else is "in development" which means, it may be available, but most likely not. Regardless, it's my understanding that the only parts that will be made available would be the wheels and cylinder/steam chests. I'd do a search on Chaski for CP Huntington as the performance, as a guess would be probably be close. It's really designed for an engineer and possibly one passenger. The Connor beam would most likely win out in pulling power.

I'm still in the process of learning what the 1.5" A3 can pull. My consist with no passengers weighs roughly 300lbs; a boxcar and gondola. I've pulled myself and 2 adults which combined weigh roughly 520lbs. The A3 has no issues doing this when running at the GGLS Tilden track on the inside loop (grade up and over the tunnel). The engine weighs roughly 250lbs. Haven't been able to weigh it yet.

Ken-

[Dick_Morris]

Note that it's the weight on the drivers and their material is a primary determinant of the traction (factor of adhesion). There have been posts here saying that steel drivers have considerably more traction than cast iron. My recollection is that it's on the order of 20%, but I'd willingly accept corrections. Given the difference, it appears that it is well worth adding steel tires to a locomotive that would have marginal traction.

There are other factors that affect the maximum pulling power available (including steam pressure at piston, stroke, bore, and wheel size), but it will always be limited by the available traction.

One way to improve traction on a C.P. Huntington would be to add weight in the foot plate area so that some of the weight on the front truck is transferred to the drive wheels. I'm not sure how the rear truck is sprung and equalized, but carrying the minimum amount possible weight on that truck that would allow it remain on the track would give the best traction.

[rexcsmith]

I have just gone through the 1st locomotive question myself. I was going to build a 3/4" A3, but when I started cutting the wheels, I thought... "hmm, that's little small". Then I decided to do a 1 1/2" A3. Before I got started on it, I talked to another train guy here in Portland who had built the Mogul and then I ended up getting the plans for a 10 Wheeler from Allen. I've already started cutting parts for it. However, now I find that I need a more robust milling machine to get it done sometime in my lifetime. dang