SLA pro

[AntonZ]

I have had most of the parts in stock for a pair of SLA pro's for quite a while now (couple of years?). I may be very very busy in the near future, so the options are build now or postpone yet a few more years. OK, so here goes. Got me a sheet of decent poplar ply and had the shop rip it small enough so I could get it in the car. Then got out the table saw and trusty old panel jig. Love that panel jig, so easy to make square cuts every time. This is after the first session with the table saw and jig. All major parts cut to size here. Sides, baffles, rears, top, bottom and a few internal braces and supports.


Marked the baffle and started to cut holes for the tweets. I use the router circle cutting jig. Rather easy to make a number of identical holes.


And rather easy to mess up, too. I've been lucky here, next step will be to cut away the straight lines. So this is not really a problem. Just a warning: don't mess around with routers. Powerful buggers they are.


All the holes on the baffle done. I did two of these. Holes not cut all the way through. Just nearly through so I can see light shining through when I hold them up. That way the center piece will not move, as that would cause the router to wander away freely and do yet more harm. I will cut them out with a knife and sand the edges.


With the "miniature table saw panel jig" it is dead easy to cut 12 pizzers to size. Here they are mostly glued up to make two 6-driver straight arrays. For glue I have a jar (seen on the left) with a few cut-offs, add a little aceton, come back next morning and you have nice thick and gap filling glue for pizzer arrays.

[miked]

Very nice. Looking great so far. You have more finesse with your router than I do. I don't think I could cut something so that it's not cut out, but I can see thru the material. Pretty impressive! I cut things out in 1/8" deep increments. When it busts through, it busts through. I always make sure I have a backer board on the workbench and I don't worry about it.

This is the first time I've actually seen the "acetone and pizzer cutoffs makes glue" in action...it's cool to see that it actually works. AFA I'm concerned, if you're making piezo arrays, you MUST make the cutting/glue-up jigs. It's just so difficult to do without them, and it is so easy to do WITH them...a no-brainer. Keep the pics coming and good luck.

[Chris_Allen]

I notice you have 5 piezos but 6 piezo holes.

[AntonZ]

This is the first time I've actually seen the "acetone and pizzer cutoffs makes glue" in action...it's cool to see that it actually works.

It works very well actually. For my first piezo arrays I used model airplane glue. It does work, but fills no gaps. So every cut has to be spot on and dead straight, or it takes quite a bit longer to get the array right. This is no PL glue, it does not expand, but it fills the small gaps anyway. Very nice. Have no illusions about keeping some of it ready to go in the jar - even with the lid on all aceton evaporates within a few days. Keep the work area well ventilated.

I notice you have 5 piezos but 6 piezo holes.

Well spotted. Nothing I can get away with here I am using my old melded array jig to make two straight arrays. The jig is not long enough for a straight array of 6. It will only support 5 piezo's. So what you see here is the glue drying after number 5 was added. Once it is dried (and some more added again, to make sure) I can shift the whole thing to the right and add the last piezo. You can see it sitting waiting already, next to the jar. Number 6 for the 2nd array is out of sight on the pic.


Thanks for the encouragement. To be continued next weekend.

[AntonZ]

You cut the piezo circles with a router? Well fair play....
To me nothing can beat a jig saw with a fine laminate blade: cut my top hat holes with that and all! (Unfortunately the blade snapped - doh!)

Much faster with the router, all the exact same size with the ole brain almost on autopilot. Completely autopilot not recommended, as the router can f#$% it up rather fast too

[88h88]

We have the exact same jar.

[miked]

We have the exact same jar.

No, no, no. HIS is tilted the other way. Reminds me of this. http://www.youtube.com/watch?v=zNCrMEOqHpc

[AntonZ]

Progress is slow, but the holes for drivers and tweeter arrays are now done.



Next I made a template for the handles. To be used with the router and pattern following bit. I have not used it yet, next week hopefully.

[AntonZ]

Today I used the new handle template. Draw the handle shape through the template. Remove template and make a rough cut with the jig saw, making sure to stay inside the lines. Clamp the template back in place and run the router with pattern following bit. It takes a little effort to make a decent template, after that it's all dead easy.



You may have noticed the corners have already been rounded over. I used my dirt cheap crappy router table. Changing the bit or setting the height is a disaster on this thing, yet it still is a great addition to the shop. Dead easy to round corners with this thing. There is a 12" ruler for an idea of the size.



Preparing some simple braces. Easier than the folded horn cabs, these are all square cuts.

[AntonZ]

Brace pieces done. These go inside the cab, half way, supporting the outside panels. You can tell where I lost attention for a split second and cut too far on the table saw.

[AntonZ]

Now some fun for those who like a bit of router work. The cabs will have dual speakons on the rear and top hats in the bottom. One could simply drill a few holes, screw in the speakons plus hats and call it a day. But I do like the recessed mounts. So I spent way too much time here.

There is less "meat" for the screws to bite into once you route away the recessed parts. So first I glued pieces of scrap ply to the back. This is where the speakons will go. Same principle for the top hats, just slightly larger pieces.


Several passes before a speakon can be mounted. First I route a circle with the circle jig, seen on the left here. Then I route away the center, so we get the one on the right. Last bit is drilling the hole. Didn't get around to that just yet.


Same approach for the hats. Route a circle, a tad larger than the diameter of the top hat mount (taking into account that paint takes a bit of room, too - if the fit is tight, it will be too tight after painting).


Route away the rest free hand, leaving a tiny island in the middle as that is where the jig center pin goes. Then apply the circle jig again, this time to make the hole for center part of the hat to stick through. Note that it does not go all the way through at max depth.


This is the other side, this bit will be on the inside of the finished cab. Note the extra piece of ply. The 3mm hole for the center pin is all the way through, so I use the router circle jig again.


A tad deeper and we are through. Tidy up the hole with the top bearing bit until the hat fits through the hole. A very tight fit here. No problem, as I will not paint here.


From the inside.


Route away a tiny bit with the 45 degree top bearing bit and we are done.


I still need to come up with the template for some recessed logo router work (I did receive help by email from another board member), so there is yet more to come.

[miked]

Glad to see you backed up the tophat recess with another piece of wood. Once you route out the recess for the tophat, your 1/2" ply is now roughly 3/8" thick. An over-enthusiastic "slam" down onto a stand might be enough to crack the bottom of the cab. So that backing piece is a really good idea.

So you decided to go with a routed logo huh? Cool. Don't see too many of those. Cutting out the template will be fun. And by fun I mean "PITA." This MIGHT be a case where paying for a CNC'd template w/the cutout appropriately oversized to compensate for the collar on the router would be worth it. Maybe. Just something to consider. My drawing/drafting skills are laughable. I couldn't draw a logo template on my own. Then of course, cutting OUT the template calls for perfection and nothing less. Possibly the board member that built the first T45 and CNC'd the whole thing might be able to lend a hand? Not throwing you under the bus, T45-guy...you just popped into mind.

Looking forward to more progress/pics!

[AntonZ]

Glad to see you backed up the tophat recess with another piece of wood. Once you route out the recess for the tophat, your 1/2" ply is now roughly 3/8" thick. An over-enthusiastic "slam" down onto a stand might be enough to crack the bottom of the cab. So that backing piece is a really good idea.

My thoughts exactly. Same goes for the speakons. I want them recessed, but they shouldn't break out of the cab when force is applied inadvertently to the sockets.

So you decided to go with a routed logo huh? Cool. Don't see too many of those. Cutting out the template will be fun. And by fun I mean "PITA." This MIGHT be a case where paying for a CNC'd template w/the cutout appropriately oversized to compensate for the collar on the router would be worth it. Maybe. Just something to consider. My drawing/drafting skills are laughable. I couldn't draw a logo template on my own. Then of course, cutting OUT the template calls for perfection and nothing less. Possibly the board member that built the first T45 and CNC'd the whole thing might be able to lend a hand? Not throwing you under the bus, T45-guy...you just popped into mind.

Looking forward to more progress/pics!

Thanks. Not sure about the exact logo yet. But both Daniel and escapemc have given me nice ideas. I will create the template myself. Have done so for my wedgehorns before and I enjoy it, even though it is time consuming. I'm still waiting for a new jigsaw to arrive.

[AntonZ]

So this week the new jig saw came in. The logo's that I wanted to do cannot be made small enough to fit the SLA sides and still be used with my router pattern following insert. So I printed a few characters in a large font. A few mods were needed to fit the 17mm insert. Then hit it with the jig saw. Much smoother than the old saw, nice tool.



Hopefully doing some test runs with the router tomorrow.

[AntonZ]

Screw the template to a piece of scrap ply and pass the router with pattern following insert in order to determine the correct depth. This looks about right, so on to the cab side panels.




The poplar ply tends to pull threads at the edges, more so than birch in my experience.




Sand paper to the rescue. Good enough for me.