Octagon frame headache!


CGF II, Certified Grumble Framer Level 2
May 27, 2005
Whistler, BC
Chopped a dozen 8 sided frames this morning and it was a real pain!
I mean, chopping octas like these are usually a cinch but chopping a lot is a different story. Got a better idea of doing octas a little faster? Because of the oblique angles I do mine manually( wish they come up with a stop for angles other than 45s!)
Scallop ;I like to suggest that you try to find a copy of Barton's Multi angle Cutting Booklet. I don't know if it is stillaround but it is very through.

I also think that the reason that stops are all but impossible is the Acute angles require different amounts of allowance for waste depending on the degree of the angle being cut and the width of the moulding. This would almost mean a differnt style stop for almost every size angle if I understand correctly.
Why don't you build/improvise a simple but sharp device made of wood and ply? Just like you'd do if no special 45 degree stop was available to you.
For cutting octagons, I've had good success with a Barton multi-angle attachment on a 10-inch radial saw.

I don't know if they even make these any more, and you'd have to cut an awful lot of octagons to justify the expense and space, but this is the rig I use to cut nearly everything.

I use my chopper to cut fillets.

The book Buddy mentioned is great, but you probably already know what angles you need for the octagons. It will tell you what length each rail needs to be to get a particular finished size and how to cut a 20-sided frame, for example.

It won't tell you WHY you'd want to cut a 20-sided frame.
You chopped them? If you do a lot of multi angle frames, it is time to get a saw. A good one arm bandit from CTD would be great, even a cheap saw from Home Depot would be a lot easier than a chopper.

It does not matter what kind of saw you purchase, the quality of the cut depends on the quality of the blade you are using.

Another thing to keep in mind when using a single blade cut off saw, is that hand holding your work will give you open miters at the top. You must clamp your work.

I use a Makita 10-inch miter saw in making a cut approximately 1" longer than the actual measurement then trim the jagged edges to the actual size. This finished side is used to measure seven sides more which is also trimmed manually with the chopper. This usually works fine except for the occasionally uneven cuts in the final trim.

Im still waiting for the customer who'd walk in with an order for a 20-sided frame :D
Scallop your comment"except for the occasionally uneven cuts in the final trim. " sounds almost like it was taken directly from the Barton's manual. He suggest that the last cut will normally be used to compensate for the very slight disparities on the other angles which can't be cut to the very precise angle ,and this is made up on the final cut by trial and error.

But I am quoteing this from memory and a serious lack of experience .so maybe some one with a manual can quote and explain it better.

But suffice it to say if that is your only problem you aredoing just fine.
Buddy, Thanks for suggesting I get Barton's guide for multi angle framing( I ordered one this morning..)I liked the idea of being able to cut outrageous shapes like hearts,. footballs, etc. I made dozens of those designs on matboard because I dont know how to get on with it using mouldings. :cool: