Cutting piezos and not your fingers.

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miked
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Re: Cutting piezos and not your fingers.

#46 Post by miked »

A couple of questions. Please keep in mind I haven't started yet; I like to get all the info for everything before I start making sawdust...or plastic dust in this case.

For cutting the piezos on a tablesaw, should I use a fine (80-tooth laminate) blade? Or is my 50-tooth combo blade OK? Also, about the housing screws. Do they have to be ground down BEFORE you trim the body housings or do you need to cut them down before gluing them together b/c they get in the way? Thanks much.

Bruce Weldy
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Re: Cutting piezos and not your fingers.

#47 Post by Bruce Weldy »

miked wrote:A couple of questions. Please keep in mind I haven't started yet; I like to get all the info for everything before I start making sawdust...or plastic dust in this case.

For cutting the piezos on a tablesaw, should I use a fine (80-tooth laminate) blade? Or is my 50-tooth combo blade OK? Also, about the housing screws. Do they have to be ground down BEFORE you trim the body housings or do you need to cut them down before gluing them together b/c they get in the way? Thanks much.
I just used my regular carbide combination blade. No need to worry about the screws....just go slow and steady. And wear eye protection.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

miked
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Location: San Antonio, TX

Re: Cutting piezos and not your fingers.

#48 Post by miked »

Thanks, Bruce. So you just chopped right through the screws? That's bad for the blade and creates metal projectiles though. :chainsaw: It took me forever to save up enough to buy my tablesaw...I barely want to cut wood with it for fear of damaging it. OK, bit of exaggeration...sorta. :noob:

Bruce Weldy
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Re: Cutting piezos and not your fingers.

#49 Post by Bruce Weldy »

miked wrote:Thanks, Bruce. So you just chopped right through the screws? That's bad for the blade and creates metal projectiles though. :chainsaw: It took me forever to save up enough to buy my tablesaw...I barely want to cut wood with it for fear of damaging it. OK, bit of exaggeration...sorta. :noob:

You really just kinda' file the screws. I only did it after someone here on the forum said it wasn't a problem - and it wasn't. The carbide blade is much harder than those little crappy screws.

Or you can take 'em apart. Mine came from the batch that were glued - so I really didn't have a choice.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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AntonZ
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Re: Cutting piezos and not your fingers.

#50 Post by AntonZ »

Mount the pizzers alternatingly and set the blade lower. No need to cut them off if you mount them like so. Much safer pizzer cutting. Better safe than sorry applies whenever near a table saw in my book.

Image

First look at the screw positions in that array. That's what we are talking about here.

Then note the way the elements are put back on the pizzer horns. That makes correct wiring easier.

miked
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Re: Cutting piezos and not your fingers.

#51 Post by miked »

AntonZ wrote:Mount the pizzers alternatingly and set the blade lower. No need to cut them off if you mount them like so. Much safer pizzer cutting. Better safe than sorry applies whenever near a table saw in my book.

Image

First look at the screw positions in that array. That's what we are talking about here.

Then note the way the elements are put back on the pizzer horns. That makes correct wiring easier.
:clap: Genius. Thanks very much, AntonZ! I haven't had a chance to take a good look at the piezos (or test them yet); so the actual "tweeter" part, the element unscrews? Just so I have it straight: You remove the element, cut the horn housing, then screw the element back on, just 180 degrees/however many degrees from where it was?

Also, it seems many folks trim/glue up one side of the array and then cut the 45. I've read "it eases assembly." Is that true, or just personal preference? The arrays are the part of the build that's got me the most nervous. Mostly b/c if I screw it up, I've got to order more and that's time+money. Thanks again!

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AntonZ
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Re: Cutting piezos and not your fingers.

#52 Post by AntonZ »

Yes, you can take the elements off. Also a good thing if you want to paint the arrays after gluing. I have cut them first (side and 45 degree) then glued on the jig. Others prefer trim/glue then cut 45. Up to you I think. Don't forget wax paper on the jig, saves a lot of bad words.

Don't fear the arrays. I actually find it easier than the wood. You may want to purchase a few cheap "bad" piezo's if you can find them (the $0.50 versions) and use those for practice.

Dissolve some piezo off cuts into acetone (in a closed jar - it evaporates like crazy), stir a few times a day for a few days. That makes a good black cement to close any openings. Make sure you have good ventilation, it also dissolves your brain cells :fruit:

miked
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Re: Cutting piezos and not your fingers.

#53 Post by miked »

Thanks much for the tips, AntonZ. I haven't decided yet if I'm going with a "blacked-out grill" with foam behind it or a see-thru grill and that would determine if I paint the arrays to hid the seams or not. Years ago I bought about 10 feet of grill cloth and never used it. Don't see how I could use that with a perforated/expanded metal grill though. Will probably go with the black AC foam/filter material if I decide to go blacked-out.

Grant Bunter
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Re: Cutting piezos and not your fingers.

#54 Post by Grant Bunter »

Mike, if you decide not to alternate the piezo's as per Anton's (great) suggestion,
just take you time feeding the piezo's through. I only had issues with the screws if I pushed to hard to fast...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Tom Smit
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Re: Cutting piezos and not your fingers.

#55 Post by Tom Smit »

I've made a jig for myself for use on a mitre saw. I took out the toothed blade and installed an abrasive blade. The jig is placed against the back fence, and then moved over to the right to meet the blade when it's dropped. I ended up with a near-perfect 2" wide tweeter! A spacer is installed when cutting the second side (can be seen in the second vs the third photo) Oh, and all made from scrap. :)
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LelandCrooks
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Re: Cutting piezos and not your fingers.

#56 Post by LelandCrooks »

Nice Tom.
If it's too loud, you're even older than me! Like me.
http://www.speakerhardware.com

BassheadUK
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Location: Southwest UK

Re: Cutting piezos and not your fingers.

#57 Post by BassheadUK »

Has anyone made such jig for a festool track? Would that even be possible....?

hmmm :confused:
I plan to build a couple of DR250's & Autotuba.
WARNING - LAB12 T39's are EXCELLENT

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Chris_Allen
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Re: Cutting piezos and not your fingers.

#58 Post by Chris_Allen »

BassheadUK wrote:Has anyone made such jig for a festool track? Would that even be possible....?

hmmm :confused:
I think it would be possible, you would have to put your piezos upside down though and cut over the top.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

sine143
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Re: Cutting piezos and not your fingers.

#59 Post by sine143 »

has anyone made abs molds for melded arrays? sems like it would be the way to go lol.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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jswingchun
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Re: Cutting piezos and not your fingers.

#60 Post by jswingchun »

Chris_Allen wrote:
BassheadUK wrote:Has anyone made such jig for a festool track? Would that even be possible....?

hmmm :confused:
I think it would be possible, you would have to put your piezos upside down though and cut over the top.
I made one for my EZ track saw. You do have to flip the piezos upside down. I haven't made one for cutting the angle, just for trimming the edges. I will probably have to cut the angle on the miter saw.
Omni 10
Omni 10.5
OmniTop 12 x 4
Wedgehorn 8 x 3
XF212
T39 @ 18" x 2
T39 @ 20" x 2
T39 @ 28" x 2
Jack 110 x 5
Jack Lite 12
XF210
XF210 (Slant only, no crossfire)

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