Cutting piezos and not your fingers.

Helpful hints on how to build 'em, and where to get the stuff you need.
Message
Author
User avatar
Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Cutting piezos and not your fingers.

#16 Post by Tom Smit »

Harley, that is one sweet lookin' jig!

TomS
TomS

User avatar
Dave Non-Zero
Posts: 1939
Joined: Thu Jul 13, 2006 4:59 am
Location: Dundee, Scotland
Contact:

Re: Cutting piezos and not your fingers.

#17 Post by Dave Non-Zero »

that jig needs this jig - :fruit: :hyper:
-1 for thought terminating cliches.

Built and/or own:
8 x T48 24" 3015LF
6 x DR280
2 x DR250 old style beta10
2 x T36s 20" delta15L
1 x TAT
1 x dual Lab12 30" T60

In Progress:
2 x DR280

User avatar
Harley
Posts: 5763
Joined: Mon May 08, 2006 2:45 pm
Location: Christchurch, New Zealand - Authorised BFM Cab Builder

Re: Cutting piezos and not your fingers.

#18 Post by Harley »

LelandCrooks wrote:Would you move to the frickin states so I can come over and steal stuff out of your shop? :clap:
I'd have to get Obama to pass a law to convert to 240V so all my tools would work. :mrgreen:
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

User avatar
Dave Non-Zero
Posts: 1939
Joined: Thu Jul 13, 2006 4:59 am
Location: Dundee, Scotland
Contact:

Re: Cutting piezos and not your fingers.

#19 Post by Dave Non-Zero »

He should! then everyone could run their BFD PA systems +LED par cans from one 13amp socket like i do all the time! 120v sucks! :owned:
-1 for thought terminating cliches.

Built and/or own:
8 x T48 24" 3015LF
6 x DR280
2 x DR250 old style beta10
2 x T36s 20" delta15L
1 x TAT
1 x dual Lab12 30" T60

In Progress:
2 x DR280

User avatar
djohnson573
Posts: 324
Joined: Tue Oct 28, 2008 7:41 am
Location: Florida

Re: Cutting piezos and not your fingers.

#20 Post by djohnson573 »

Hope you don't mind me tacking on to this thread. I went to the shop with the intention of building that elegant jig that Harley introduced only to discover an issue with my set-up. My old table saw is an 8" vice a 10", so I'm using a 7-1/4 blade. In measuring the tolerances I discovered that the height of the blade is insufficient to reach the top of the housing barrell and screw head. If I used 1/4" for the sled base it might squeak through, but I would like something more substantial than that (3/4 preferred). So, what alternatives do I have for making this work?

It looks like there will not be an issue with the 45 degree cut. Input from the experts would be appreciated. :)
Dennis

Built/Own:
- 4 x Titan 39 (14"W) BP102 loaded
- 2 x TLAH
- 4 x OT12 Deltalite 2512 loaded
On Deck:
- 3 Auto Tubas

User avatar
DJPhatman
Posts: 5412
Joined: Mon Aug 14, 2006 5:08 am
Location: Warren, MI
Contact:

Re: Cutting piezos and not your fingers.

#21 Post by DJPhatman »

Build the jig as a circular saw sled, where the saw comes up from the bottom. You will absolutely need a brace for the piezos while you cut them, as you don't want your fingers anywhere near the blade.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

User avatar
djohnson573
Posts: 324
Joined: Tue Oct 28, 2008 7:41 am
Location: Florida

Re: Cutting piezos and not your fingers.

#22 Post by djohnson573 »

DJPhatman wrote:Build the jig as a circular saw sled, where the saw comes up from the bottom.
Do you have any pictures of such a setup? Would it work even though the circular saw blade is the same blade I have on my tablesaw?
Dennis

Built/Own:
- 4 x Titan 39 (14"W) BP102 loaded
- 2 x TLAH
- 4 x OT12 Deltalite 2512 loaded
On Deck:
- 3 Auto Tubas

User avatar
DJPhatman
Posts: 5412
Joined: Mon Aug 14, 2006 5:08 am
Location: Warren, MI
Contact:

Re: Cutting piezos and not your fingers.

#23 Post by DJPhatman »

djohnson573 wrote:
DJPhatman wrote:Build the jig as a circular saw sled, where the saw comes up from the bottom.
Do you have any pictures of such a setup? Would it work even though the circular saw blade is the same blade I have on my tablesaw?
No, sorry Dennis. I cut mine (128) on a Ryobi mitre saw. My 1st build, I cut them all on a cheap Craftsman table saw, using a plywood/laminate blade.

A hand-held 7 1/4" circular saw should cut to a total depth of 2 1/4", minus 1/2" saw sled = 1 3/4".

Do you have access to any other types of saw? Band, scroll, mitre, larger table saw?
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

User avatar
djohnson573
Posts: 324
Joined: Tue Oct 28, 2008 7:41 am
Location: Florida

Re: Cutting piezos and not your fingers.

#24 Post by djohnson573 »

I do have a miter saw (chop style), but my eyeball calibration made it look like the depth of cut was about 1/4 inch shy. I recall someone on here grinding off the lugs, but I can't find the post.
Dennis

Built/Own:
- 4 x Titan 39 (14"W) BP102 loaded
- 2 x TLAH
- 4 x OT12 Deltalite 2512 loaded
On Deck:
- 3 Auto Tubas

User avatar
Harley
Posts: 5763
Joined: Mon May 08, 2006 2:45 pm
Location: Christchurch, New Zealand - Authorised BFM Cab Builder

Re: Cutting piezos and not your fingers.

#25 Post by Harley »

djohnson573 wrote:I recall someone on here grinding off the lugs, but I can't find the post.
That's what Leland does and also what I do.

The perpendicular cut i s made just high enough to cut through the body, no more. You have to be careful grinding off the screw. Too much pressure too quickly and the screw becomes airborne at a mighty rate of knots.

However, once you've done a few, you get the hang of it.

This method sure beats using your expensive blade to cut through the screw heads. Even the toughest tungsten tipped blades go dull after cutting through not too many.
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

User avatar
djohnson573
Posts: 324
Joined: Tue Oct 28, 2008 7:41 am
Location: Florida

Re: Cutting piezos and not your fingers.

#26 Post by djohnson573 »

Perfect! :hyper: Thanks Harley. That is the approach I will take. Can't wait to build your jig. I even have a piece of that aluminum channel laying about.
Dennis

Built/Own:
- 4 x Titan 39 (14"W) BP102 loaded
- 2 x TLAH
- 4 x OT12 Deltalite 2512 loaded
On Deck:
- 3 Auto Tubas

DaveK
Posts: 735
Joined: Tue Dec 05, 2006 9:51 pm
Location: Sacramento CA

Re: Cutting piezos and not your fingers.

#27 Post by DaveK »

Another option is to alternate every other tweeter so their lugs don't interfere. I also think it's easier to wire them up that way because all the + terminals line up down the middle of the row and all the - terminals are on the outside.

However, alternating lugs is less attractive for models that have exposed tweeters mounted in the mouth (OT, Jack, etc.).

User avatar
Harley
Posts: 5763
Joined: Mon May 08, 2006 2:45 pm
Location: Christchurch, New Zealand - Authorised BFM Cab Builder

Re: Cutting piezos and not your fingers.

#28 Post by Harley »

DaveK wrote:However, alternating lugs is less attractive for models that have exposed tweeters mounted in the mouth (OT, Jack, etc.).
True...but a metex grille fixes that, and looks smarter as well.
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

User avatar
Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Cutting piezos and not your fingers.

#29 Post by Tom Smit »

You could put an abrasive blade on your mitre saw...that way you'll only cut, not through the screw heads. It's how I was able to accomplish the tweeter cuts. :)
TomS

phil
Posts: 159
Joined: Mon Feb 02, 2009 2:36 pm
Location: arcata, ca

Re: Cutting piezos and not your fingers.

#30 Post by phil »

How much pressure do the piezo's create? When I built my O10.5's it didn't look like I would be able to get the screws out if I needed to get a cap off, so I took the side screws out and hot glued the seam around the piezo and filled the screw holes with hot glue, figuring I could pry the cap off easier.

Seems to be holding up just fine so far, just wondering if it might not last.

Post Reply