Well, Siegfried Linkwitz is not around to answer you about speakers and brains. Have a look at these pages. Maybe, you'd find what is perception there or somewhere. 🙂
I did a trial cut of foam core board on my RAS (radial arm saw) and it gave a clean and precise cut. I wouldn't try ripping as the blade would try to pick up the foam core. I stopped the saw and removed the foam core before pushing the saw back behind the fence. I suspect a chop/miter saw might work as well.
If I do any foam core builds I will do rough cuts to get the stock within the limits of the RAS, get a clean square edge and do the rest of the cuts on the RAS. A table saw might work if one had wood or cardboard on top of the foam core to hold it down.
If I do any foam core builds I will do rough cuts to get the stock within the limits of the RAS, get a clean square edge and do the rest of the cuts on the RAS. A table saw might work if one had wood or cardboard on top of the foam core to hold it down.
good god foam core is so easily cut with a sharp knife why in would one use power tools???
it like trying to cut paneling that's unsupported with a jigsaw....
it like trying to cut paneling that's unsupported with a jigsaw....
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For me it would be accuracy and clean cuts. I have tried it both ways and occasionally my sharp knife would tear the paper or crunch the foam. YMMV
For me it would be accuracy and clean cuts. I have tried it both ways and occasionally my sharp knife would tear the paper or crunch the foam. YMMV
It's why I built jigs for the knife. Saws were not my friend. Even a plywood blade in backward made a mess.
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Jigs are good. I tried using my little matt/photo trimmer but the blade wasn't sharp enough, it may have worked with a new blade.
I was quite surprised that the RAS worked as well as it did on the foam core. I thought that I might have to cover it with stiff cardboard over the cut line but a RAS cuts down rather than up as does a hand held circular saw. Also the saw kerf in the RAS table serves as a zero clearance insert does on a table saw.
Jigs are good. I tried using my little matt/photo trimmer but the blade wasn't sharp enough, it may have worked with a new blade.
I was quite surprised that the RAS worked as well as it did on the foam core. I thought that I might have to cover it with stiff cardboard over the cut line but a RAS cuts down rather than up as does a hand held circular saw. Also the saw kerf in the RAS table serves as a zero clearance insert does on a table saw.
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I use my jigsaw with special blades that look like kinda knife available at the hardware store. Cuts perpendiculaly without that pollution of foam messing around when cutting with a saw.
Metal straight edge and utility knife with breakaway segments for when you need a new sharp edge. Cut steady strokes a little at a time. 8-10 total strokes they will cut cleanly.
I am more frugal than that. I strop the edge after about 20 cuts rather than snap off a tip. 🙂. The time you use making the jig is made up for in cutting time and accuracy.
14 pack for $10 - no need to strop (you use a barber’s cowhide strop?) the blade. I used to do that on my single X-Acto blade. Made 50 speakers with that one blade and bottom edge of a china ceramic bowl rim as sharpener.
14Pack Utility Knife Retractable Box Cutter (18mm Wide Blade Cutter) Retractable, Compact, Extended Use for Heavy Duty Office, Home, Arts Crafts, Hobby https://www.amazon.com/dp/B07RDDB76W/ref=cm_sw_r_cp_api_glc_fabc_4cK0Fb3MGB83T?_encoding=UTF8&psc=1
I failed to mention the speed factor of the RAS. Of course I already had it on hand so why not make use of it. I could cut pieces 2 up for even more speed.
Hey X,
The blades I use are actual Olfa blades. A variety store was closing and a 10 pack of blades was $1 CAD or about 75 cents USD. There was no limit so I bought them all. I ended up with about 50 packs. That was back around 1995 and I still have maybe 10 of those packs.
The strop I use is wheel #3 on an electric sharpener.
The blades I use are actual Olfa blades. A variety store was closing and a 10 pack of blades was $1 CAD or about 75 cents USD. There was no limit so I bought them all. I ended up with about 50 packs. That was back around 1995 and I still have maybe 10 of those packs.
The strop I use is wheel #3 on an electric sharpener.
The first jig was for the 36" and the second for the 48"
First: The top. The metal straight edge guide unfortunately hides the slot from that angle. The fence you see is for the table saw, not related to the jig.
Second: Underside where you can see the slot, a bit of the guide and the wood ruler used as a fence that you butt the foam board to. The foam goes under the jig.
Last: Partway through a cut. The paint can is just to stop the jig from sliding around as I was cutting on the table saw. You can see the foam board slid under the jig.
The disadvantage is that you have to lift the jig to get your cut piece out.
First: The top. The metal straight edge guide unfortunately hides the slot from that angle. The fence you see is for the table saw, not related to the jig.
Second: Underside where you can see the slot, a bit of the guide and the wood ruler used as a fence that you butt the foam board to. The foam goes under the jig.
Last: Partway through a cut. The paint can is just to stop the jig from sliding around as I was cutting on the table saw. You can see the foam board slid under the jig.
The disadvantage is that you have to lift the jig to get your cut piece out.
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The second jig was a little better as a 48"er includes a lot of cutting and I wanted it to go a little faster. Not much in the way of pics but I think you can get an idea of the workings. The metal straight edge plays no part here. The fence is on the right and the brown guide is elevated on the ends to allow the black foam board to slide under. This way I didn't have to lift the jig up each time. The guide was again just clamped in place.
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Thanks Eddie, I know I didn't invent anything, I just made use of things on hand to get the job done well and in a timely fashion.
Thanks BP.
I think the funnest one so far was the Penthorn. Not the end all with the sound but most fun to design and build. Yes I made them but without X's inspiration and encouragement to begin with, like all the foam cores, they would still be a dream.
I think the funnest one so far was the Penthorn. Not the end all with the sound but most fun to design and build. Yes I made them but without X's inspiration and encouragement to begin with, like all the foam cores, they would still be a dream.
