Large Scale Central

Modeling a Cow Catcher

Modeling
#1

OK so I am working with a local high school trade school. This is a cooperative school from various districts from around the county that teach the trades. I was presenting a project to him for a milling project that didn’t pan out. But as we were talking the subject of 3D printing came up. He teaches 3d printing as part of his course. He wanted to take on a cow catcher project for my #4 build. He likes the idea of one of his students taking pictures and drawings and working up a 3d model of it and then printing it. Well that leads me to this. I really don’t know how wooden cow catchers are built. I now that it is 61" wide, 33.5" high and 42" long, and has 16 beams. The picture above is the exact pilot I want built. The main question I have are the shape of the wooden beams. They are parallel to one another when viewed from the front and taper as they go out and back.

Is each beam the same width and depth at the top and the same width and depth at the bottom? and then are they shaved (for the lack of a better word) to give the angle from center to the outer edge. I cant envision it nor really explain what I am asking. each beam would have a differnet taper the lnger ones being the center and the shorter taper at the edges. And then there is the matter of slicing off one edge to get the miter?

Am i amking any sense?

More than likely I will purchase a pilot off Ebay to take with me so they can look at tit and then use my dimension to make up the design but I would like to understand the real deal as well.

#2

Hi Devon,

If you go over to MLS and check the Mason Bogie class I think you will find most of your answers. The pilot was made of wood and Dave Fletcher had plans drawn up for it. The staves where all glued in place then it was sanded to get the bevel on them. Its all explained in the section on making the pilot.

Chuck

#3

Devon,

Here’s a little more Cow Catcher info. After the first two pages skip down to page 7 for engineering a Cow catcher.

http://dls-website.com/documents/WoodworkingNotes/CowCatcher.pdf

#4

Devon–

I have built a pilot for one of my 7/8" scale engines. this is a more modern pilot than the one your show in your photo. I took some liberties but perhaps it will help illustrate how the vertical inclined “spokes” work.

What this photo shows is the base…the part that lies just above the rails. I have slotted it to accept the “spokes” my spokes are solid triangular pieces which were notched to fit a plank that screws to the buffer beam and have an extension to fit into the slots of the base. note that the spokes are just sawn out of a piece of 1/8" walnut. they run up and down and forward and aft and have (as yet) no beveling.

here it is assembled. you can see that the front surfaces of the spokes have been beveled. the bevel is carefully worked out. at the base, the inner edge of the spoke matches the base. the outer edge would have stuck out until it was beveled. to do this I first sanded the bottom front of the spokes (where the tab fits into the slot) to match the base. Then I sanded the bevel to cut the outer front corner off the spoke. the angle of the bevel matches the angle at the base and doesnt change as it moves up the spoke, however it is less deep. at the very top there is no bevel at the bottom the bevel goes all the way across the front of the spoke. the goal is to have a straight line between the top and bottom.

you can see a shadow line on some of the spokes in this photo. I stick some sand paper of a flat surface and use that to make the bevel. Move the spoke against fixed sandpaper. you can get very good control this way.

here is what I was going for

this is a more “old fashioned” type pilot. I built the spokes up square then beveled them all at once. the effect is different. I am not sure it is better though, and was hard to do. the surface is not flat but is a rolling curve. I think I used a half round mill file and followed up with sand paper.

#5

Great stuff guys. Between Eric’s example and the Mason bogie class I can fab one up. Sorry the hyperbolic parabaloid drafting lesson went over my head. But the beauty of that is teacher will understand it and he can teach it and have the 3d printer spit it out.

So thanks to all

#6

Its, ah, um, called a Pilot.

#7

Gee, I thought the pilot was the guy who flies the train! the engineer is the guy down in the engine room who says “I can nae do it, Cahpin”

#8

No the Pilot is the guy who goes out in a small motor launch to guide a big ship to dock.

For me the guy in the engine room said; We tried shoving a hot dog in the warp drive, bu’ she did na a work!"

John

#9

David Maynard said:
Its, ah, um, called a Pilot.

Not all the time, everywhere!

Here is what Wikipedia has to say…

“In railroading, the pilot (also known as a cowcatcher or cattle catcher) is the device mounted at the front of a locomotive to deflect obstacles on the track that might otherwise derail the train.”

I’ve even heard it called a cow splitter!

#10

I have always called it a pilot. But most laymen call it a cow catcher. More information can be found with google on cow catchers than can be found on pilots. So what it is really called and what people call it are sometimes very different things. After all my proper name is Devon but I get called all sorts of things (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif). BTW MR. Maynard you knew what I was talking about so mission accomplished(http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-innocent.gif)

#11

Devon, I knew what you was saying, I was just being a snot. I tend to do that from time to time. In model railroading, and rail-fanning, many terms are used incorrectly or the wrong terms used. So while I know what is meant, it makes me twitch just a little, when the wrong term is used.

#12

are you sure, that the cow catcher and the pilot are the same thing?

i thought the pilot to be the platform, from which the cow catcher is hanging.

#13

David Maynard said:

I was just being a snot.

And I in return!!! I knew what you were up too. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#14

Korm, that would be the running board, or footplate if you are in the UK.

#15

Korm Kormsen said:

are you sure, that the cow catcher and the pilot are the same thing?

i thought the pilot to be the platform, from which the cow catcher is hanging.

Now I always thought that part was the pilot deck? See as far as I know (which ain’t much) everything forward of the steam chest area is called the pilot “something.” The beam which the cow catcher is attached too is the Pilot beam, I thought the flat part was the pilot deck, of course you have the pilot truck, but I have always been told that the cow catcher itself was simply the pilot. Although I like cow splitter as well, sharpened steel beams would be good as well and you could call it a cow slicer, or a sharpened grid pattern say 2" squares and you could call it a cow dicer. Use vegetable oil in your oil can and weld a flat plate of steel on top of the fire box and you would have a griddle. find a way to catch the slices or cubed pieces and you could make sir fry.

See always thinking. call the meat that comes out the pilot cut and serve it to passengers for $5.00 a plate.

I should have been a RR manager.

#16

David Maynard said:

Korm, that would be the running board, or footplate if you are in the UK.

Now aren’t the running boards the boards along side the boiler?

#17

Devon, that is what I found on the internet, and the internet is never wrong. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)I like your answer of “Pilot deck” better.

#18

Devon Sinsley said:

Korm Kormsen said:

are you sure, that the cow catcher and the pilot are the same thing?

i thought the pilot to be the platform, from which the cow catcher is hanging.

Now I always thought that part was the pilot deck? See as far as I know (which ain’t much) everything forward of the steam chest area is called the pilot “something.” The beam which the cow catcher is attached too is the Pilot beam, I thought the flat part was the pilot deck, of course you have the pilot truck, but I have always been told that the cow catcher itself was simply the pilot. Although I like cow splitter as well, sharpened steel beams would be good as well and you could call it a cow slicer, or a sharpened grid pattern say 2" squares and you could call it a cow dicer. Use vegetable oil in your oil can and weld a flat plate of steel on top of the fire box and you would have a griddle. find a way to catch the slices or cubed pieces and you could make sir fry.

See always thinking. call the meat that comes out the pilot cut and serve it to passengers for $5.00 a plate.

I should have been a RR manager.

A real Ron Popeil

Mr. Ronco!

#19

John Caughey said:

A real Ron Popeil

Mr. Ronco!

It slices, it dices. . .Oh wait isn’t that gihnsu

#20

Devon Sinsley said:

John Caughey said:

A real Ron Popeil

Mr. Ronco!

It slices, it dices. . .Oh wait isn’t that gihnsu

Very Good!(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)