multi angle frames - help !

[Adam]

Maybe I can blame it on being a Monday or the fact that I have never actually cut one, but I have 2 multi sided frames to build and I cannnot figure out the angles. The 1st is an octagon ( 8 equal sides at 8 1/2" each). The second is 13 3/4 x 63 3/4" with angles in the four corners. The top and bottom pieces will be 6 7/8" with 45degrees in the corners. Re: the octagon I thought it would be simple enough. My first mistake. I cut the angles at 22.5 degrees( what a co worker had suggested). I can't seem to figure this out...Anyone with some multi sides experience have any tips for me. Guess I should have stayed awake in Geometry class!

Thanks.

[TADPORTER]

You forgot to add 45 to the 22.5 (=67.5 for the oct.)

Cant help with the other

---Mike

[JRB]

Woodworkers Supply sells jigs for cutting multi angle frames on your table saw. They are not expensive and even if you don't use a table saw the jigs will give you the angle information you need. They come in a set of three jigs. they are called Miter-Mite, order # 826-935, $19.95 set. Also be sure to get their catalog, it is loaded with swell stuff you can use.

Their phone number is 800-645-9292

John

[Frame Harbor]

Adam,
Mike is right with the octagon. The angle of 67.5 degrees stays the same regardless of the length of a side. One side's length gives you the "diameter", or the opening size only. In your case, that opening would be of 22.36 inches from one corner to its opposite corner (presuming 8 1/2" length was referring to inside dimension).
Wish I could say some about your second project but you did not make it clear to me. I simply don't understand what that frames looks like. As of geometry, you are right. Of all math thought in school, geometry is by far the most useful to remember and master, especially when we dream of becoming multi angle frame makers http://www.thegrumble.com/framer/ubbs/smile.gif Come back with more details or send me an Email, maybe I can be of help.
Cornel

And, without any connection to the topic, just for the fun of it I'd like to paraphrase Sue May http://www.thegrumble.com/framer/ubbs/smile.gif
"Everyone is born right-handed, only the greatest can over come it!" I'll try
"Everyone is born straight frame maker..."
Framer, isn't a multiangled frame easier icon for a wedgie?

[Adam]

The second one is like the octagon except 2 long legs on the sides. I am assuming it should work out the same except for subbing longer legs on the sides instead of equal ones. I'll find out in the morning when I give it another whack.


"The first man to compare the cheeks of a woman to a rose was obviously a poet , the second quite possibly an idiot."

Dali said it not me.

[Frame Harbor]

Adam,
Please don't! You will only waste your time and molding. The second frame cannot be approached like the first multi-angled one. The second one has different angles to be calculated because, unlike the first one that approximates a round frame, a circle, the last one is an "oval". Still cannot help you unless you spell right its shape, size, number of pieces to be used in construction or, better off, make a fast drawing and fax it to me at (509) 356-3672.

[Adam]

http://www.connectexpress.com/~lalonde/multi.jpg

Here is a diagram of the second one.
Total size is 13 3/4" wide by 63 3/4" length.
B & G = 6 7/8"
A,C,F,H = 45 degree angles

The customer wants these exact image sizes but I can flex within an inch on the 6 7/8" if it makes anything easier. I am going to pick up the book that was mentioned but I need to get this one done sometime soon before my customer beheads me for designing beyond my means. Thanks.

[John Ranes II, CPF, GCF]

Adam,

Two references that will help you out, when these framing problems occur in the future:<UL TYPE=SQUARE>
<LI>"the framer's ANSWER BOOK" by Paul Frederick
<LI>"BARTON'S Multi-angle Framing Guide"
[/list]

The miters are really quite easy in that you take 180 divided by Number of sides (8) = 22.5. 90 degrees minus 22.5 = 67.5 degrees. (This would be constant in both of your projects.)

From Paul Fredericks book, he gives the formulas (ratios) for determining sides (rails) and overall dimensions......

The side of a regular octagon equals 0.414 of the distance across, from side to side. The distance across from side to side equals the length of the side multiplied by 2.414. The distance between two opposite corners equals the length of the side multiplied by 2.613.

For example: Your first project with rails of 8.5 inches in length would produce a frame 8.5 x 2.414 = 20.519 from side to side. Or 8.5 x 2.613 = 22.211 from corner to corner. Frame Harbor calculated a slightly higher figure as he was taking rabbet space into consideration. Be careful here, as you allow additional rabbet space in multi-angled frames, it multiplies, and you can end up with much more than required!

Your second project is a bit more complicated..........but you should think of it in terms of extending the sides of regular octagons. (I'm assuming that you want an octagon cut as you mention all FOUR corners, but then mention a 45 degree corner at the bottom)

By stepping backwards I came up with corner rails of 4.86 inches.(A,C,F,G) These would produce a reg octagon of 11.732 inches. By "extending" the top and bottom rails an additional 2.015 inches in length you produce your top and bottom required dimensions of 6.875 inches(B & G) Finally by "extending" your two side rails an additinal 52.02 inches, you obtain side rails of 56.88 inches (D & E)

These calculations would produce a frame with an exact opening of 13.75 x 63.75

By the way, both of those publications I mentioned above should be available at the PPFA bookstore at most Decor and PFM shows.

Regards,

John

------------------

The Frame Workshop of Appleton, Inc.
www.theframeworkshop.com (http://www.theframeworkshop.com)
Appleton, Wisconsin
jerserwi@aol.com
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[This message has been edited by John Ranes II, CPF, GCF (edited March 14, 2001).]

[John Ranes II, CPF, GCF]

Adam,

Just saw your image and I believe that my calculations will work........Remember that this does Not create any rabbet allowance......you must increase the dimensions a bit more if needed.

John

[Whynot]

Adam,
Sorry to be so late with my answer to you. I posted my answer once but it didn't stick to the board.
John Ranes was right in his approach to the problem and remember his good angle. However, I believe his numbers to be inexact. My computations led me to the following result:
Side A, B, C, F, G and H are equal to each other and measure 5.7" in front. Sides D and E are also equal to each other and measure 55.7" in front. All angles are equal to 67.5 degrees. I was confused until I saw your pictures. As my numbers are slightly larger than John's, start with my solution for, if anything wrong, you still can trim it down to John's.
Good luck, Adam
Cornel Rosca

[Adam]

Thanks for all the advice. I was able to cut the frame and it looks nice. I am borrowing a friends vise in the morning that allows angle adjustment so I can get this built. Frame on!

[Susan May]

Things like this is why I come to the Grumble!

------------------
Sue May :)
"You want it when?!?!?"

[Whynot]

Susan May, are you paying me a mini compliment? LOL
Cornel (Frame Harbor)

[Adam]

woohoo...she's built and beutiful! I am borrowing this nifty old (looks 50 ish) adjustible corner vise for a few days but need to get one for myself. Anyone know a distributor for these things? I've yet to see one before this but then again I haven't been looking. Thanks.

[Susan May]

The compliment was for any and all who answered the question! The reason most of us come to the Grumble, is to learn from other framers.

I just felt glad to see nice clear answers.

------------------
Sue May :)
"You want it when?!?!?"

[Whynot]

Susan, There were not all that many contributors though: JBR, John Ranes II, Frame Harbor and me. But I tryed hard to sound as if I was any good http://www.thegrumble.com/framer/ubbs/wink.gif
Cornel

[jframe]

Adam,

The vise you used may be a Barton Multi Angle Vise, made by the same company that publishes book I told you about in my email, "The Barton's Multi Angle Framing Guide". I know they are located in Mississippi, but you'll have to look in your Decor Sources Issue for the address.

I had one of the vises, but I still found it faster to assemble with Corner Weld glue. Just apply Corner Weld glue and hold the pieces together for a minute, let them dry for a while, then under pin them. I suppose the vise would be a good thing if you are going to nail them.