Okay Forum friends, I've got an engineering challenge for the group. I'm trying to modify some HO Atlas piers from the incline set. For anyone that may not have seen them, all four sides lean in. I want to put a 45 degree angle on the downstream side of them in order represent something close to a prototype for the area that I model. I have three of them supporting bridges (Two of them are straight from each other sp that set only needs one with the angle.) I want the 45 to be as close to vertical as possible. Where I'm running into the issue is that compound angles are needed and I have no idea how to compute them. (My 3 dimensional Geometry is not great.) I have as many of the dimensions for the two different pier sizes. I hope they are enough to compute the panel size.
First unit: Vertical Height - 1", Top Width - .617", Bottom Width - .914", Slope Length - 1.028, Slope Angle - 73.37
Second Unit: Vertical Height - 1.25", Top Width - .617", Bottom width - .859, Slope Length - 1.282", Slope Angle - 77.17 degrees
If any other figures are needed, please let me know.
Thank you as usual for any assistance that can be provided.
I'm having a hard time visualizing this. Perhaps a drawing would help. Are you planning to cut the piers at the corners, reshape them and re-assemble them?
It takes an iron man to play with a toy iron horse.
FRRYKidI want the 45 to be as close to vertical as possible.
I thought you wanted the top edge to cant in until I reread that line. Now I am clueless
Henry
COB Potomac & Northern
Shenandoah Valley
Here in the Northeast, most bridge piers have some sort of pointed edge on the upstream side to serve as an ice cutter and to allow for the free flow of water around the pier. The sharp edge is often seen on the downstream side as well. Is that what you're talking about? If so, I guess I'd build up the area with styrene, or perhaps modeling putty.
Tom
Here is a picture of the two piers if it helps to see what I am working with.
The base part are just set in place. They aren't glued yet.
BigDaddy FRRYKid I want the 45 to be as close to vertical as possible. I thought you wanted the top edge to cant in until I reread that line. Now I am clueless
FRRYKid
I want the 45 to be as close to vertical as possible.
If the 45 has to canter to get the engineering right, it has to canter. I'd like it straight, but if it's not possible, it's not possible.
So you want the face of the piers to mimic the base with the 45 degree angle?
The sharper side faces upstream to cut the current. What are the piers made out of? As I think about it, the bases in your pic are to cut the current. If your prototype looks like the above Harpers Ferry pier, there is no base. If the Altas pier is plastic, there is not much you can do as it is probably hollow. You could build a styrene mold and cast plaster piers and carve the stone work.
That is the idea (break the current) as well as deflect anything that could damage the pier (logs, ice jams, etc.) It is inspired by peiers seen of the MRL (ex-NP) line. The base is just to match the Atlas pier. I'm changing the Atlas piers to look like poured concrete. The green on the sides is putty to cover the stone work.
Maybe one of these would work.
FRRYKid That is the idea (break the current) as well as deflect anything that could damage the pier (logs, ice jams, etc.)
That is the idea (break the current) as well as deflect anything that could damage the pier (logs, ice jams, etc.)
The main reason bridge piers are built pointed like that in the 1:1 world is to prevent scour (erosion and washing away of the river bottom that would undermine the base and cause the bridge to collapse).
Robert
LINK to SNSR Blog
You could carve your own out of pink or blue foam, I've used blue as it colors over easier for stone walls. The Connecticut Valley Model RR Club has a number of piers made from it on their Crawford Notch N scale layout. After carving the foam to shape they used a black ball point pen to draw in the lines between the stone (or blocks). Then paint it to your local rock color. You can also leave smooth for a concrete look. You can cut it to any angle you need, glue on or carve off to fit your needs.
Just checked, go to their 2015 show on You Tube, it is shown on a segment of that video. Used to be some nice still photos of them, but I couldn't find them with a quick check just now.
Good luck,
Richard
I am not an engeneer, just a "go ahead and do it" guy.If you draw a center line down the face of the edge and use that as a guide to cut/remove corner, would give a pointed face. But would lose top surface.
If you going after a pour concrete look, as others stated, IMO be better off stsrting from scratch, wood,foam plastic, get exacty what you need
cowman You could carve your own out of pink or blue foam
You could carve your own out of pink or blue foam
That's an interesting thought. That's makes me think that I might be able to carve something that might be able to be attached to the piers. I have some styrene on order but if that doesn't work, I will go to the foam option.
I mock up structures and things with paper, cardboard or box board (like the box cereal comes in). Folding up some paper, cut it at different angles until you are happy with the shape then cut the paper into pieces and use those pieces to cut styrene (or cardboard if you want the mock up to be a little stiffer).
Do a quick Google search for 'paper model shapes'...it'll show some examples of how to make a flat piece of paper into different shapes (some simple, some impossibly complex). Many people have made incredible things out of paper (one guy made an Airbus airliner from manilla file folders...it's a huge model and even has moving parts!).
By printing out and assembling the shapes, you will see how different shaped faces make different 3D models. The skills should transfer to model railroading nicely.
http://delray1967.shutterfly.com/pictures/5
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