SCRATCH BUILDING-- ROOFS

[Anonymous]

Can anybody help me with a layout problem? I am scratch building several buildings and I need help laying out the roofs. I want to layout a multi-pitched roof. Has anybody done an article on this topic--- if so can I get a copy of it.

[Anonymous]

Well, there are two basic ways to approach this:

1) Do the geometry, which is often quite challenging.

2) Try a mock-up made from cereal box or shirt card board. Cut and fit by trial and error. When everything is right you can either - give up and just use the mock-up, or use the mock-up as a template for the styrene or wood, or whatever you are making the "finished" model from.

Of the two, I'd say the second is probably easier in the long run, unless you are really good at math, and cutting & assembling.

Andrew

[CNJ831]

Masonjar's second approach is, I suspect, the method employed by most modelers (and even professional model makers). There are carpenter's tools that in the real world allow one to quickly determine the necessary angles and cuts but they are unavailable in a size suitable for model making. Certainly, the mock-up, cut-and-fit template procedue is how I've approached the problem over my years of scratchbuilding structures for the layout.

CNJ831

[Big_Boy_4005]

Here's an idea that popped into my head after reading Masonjar's answer.

Make a set of blocks with all the different pitches you want to use, two of each pitch.

Position the appropriate blocks at the angle that the side walls meet, this will work for any angle, not just 90 degrees.

Take one piece of roof stock and place it against one of the blocks, and mark the piece using the other block as a guide. You won't need to mark the entire edge, just enough to get the angle.

The piece that forms the other half of that hip or valley will be the same angle only opposite. A quick way to do this is to place the two pieces back to back and cut once.

If you use a protractor to measure the angles that you have created, you can make a table of values, and skip the blocks the second time around, and the math is done. The table will have 4 columns. One for each pitch, one for the wall angle, and one for the resulting cut angle.

If you need the pitch angles, a regular tri square or framing square can give you those.

[Anonymous]

Speaking of tools - here's one that might actually be small enough for you to use in HO scale. Might still be too bug for N, but would work in S, O, or G too...

http://www.leevalley.com/wood/page.asp?SID=&ccurrency=1&page=32581&category=1,43513,43552

The description doesn't give a size, but I got one for Christmas, and I can tell you that the "head' where all the angles are marked is only about the size of a business card. It has been quite handy, but I have not used it for roofing projects (yet).

Of course, the other part of all this is even if you can measure and calculate correctly, you still have to cut accurately. Test fitting is still required!


Andrew

[Big_Boy_4005]

Nifty gizmo, I just have a simple metal one about that size, but if you used a pair of those you wouldn't have to cut the blocks I was talking about.

WOW, I clicked on switch currency in the corner of that page and the price went to $3.50 USD, I'll take six!!!![:D]

Very true about the cutting and fitting, but that protractor would be a big help. Also remember to leave alittle extra material for the adjustment process.

[Anonymous]

Hey ppllawson,

Enter my scratchbuilt model contest I am putting together. I think you will have lots of fun. Check out the link below for the scoop. I am finalizing things still but most of the important details are there.

James.

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=12255