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View Full Version : Radius question......ANOTHER



coach
02-13-2009, 09:09 PM
I have a new customer that uses large radius pieces of plywood. The latest was 167" with a 6" wide plate,,making the inside radius 161"
My concern now is......how can I figure how to make the end cuts so the parts can be placed end to end to make a circle without field cutting the angle on the ends?
I was placing two radius' 6" apart and using a poly line slicing through the ends from a height of the radius at the center point on the plywood.
The angle was incorrect.

Second time I made the outer radius then offset inward 6" then I snapped a polyline to connect the parts. Not sure if this is right.
I could sure use some help on this....thanks for any help.

David

Gary Campbell
02-13-2009, 11:04 PM
David....
I just tried this to make sure...
Make a 167" rad circle centered at x=48 y=-119
offset 6" to inside
open polyline tool with first point at 48,-119
you can either drag the other end to maximum available on the sheet or select a degree amount if you are looking for an even number of pieces to get a full circle. this pic shows 2 lines 26.5 degrees either side of vertical. (max length from sheet (+/-)
If you need exact pieces to make a circle you will need to select angles that have multiples that equal 360 (i.e. 6 pcs @ 60 degrees = full circle)
Node edit and remove all unwanted vectors.

In any event as long as the start point of the line is at the center of the circle... all will fit together.


5145

Gary

scottbot
02-14-2009, 02:05 AM
David,
I use AutoCAD for this kind of thing because I'm a lot quicker at it. I drew a circle with a 167" radius and offset it inwards 6".
I then drew a line from the centre of the circles straight up. After that I did some trial and error polar arrays to see how many array segments it took to get an arc that would fit on a sheet of plywood.
It took 12 segments which results in a 30 degree angle on the ends.
I trimmed one segment out of the circle and copied it on the outline of a 4'x8' sheet of plywood. I got 6 segments on 1 sheet.

I've attached a .dxf of that layout that you can use if you like. You'll need 2 sheets to complete the circle.

How are the segments joined in the field? If you put Rob Bell's puzzle joint on each end they would go together nicely.

Let me know if you want some help with that.

Scott
167" radius segments

5146 (24.9 k)

sailfl
02-14-2009, 05:00 AM
I would like to access Scotts file but I can't save it. I have AutoCAD. What am I doing wrong.

Thanks

myxpykalix
02-14-2009, 06:26 AM
right click once on it
click "save target as"
it comes up as:
167_radius_segments-38780.unk

change the filetype designation from .unk to .dxf and save it where you want.