Page 4 of 14

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 7:10 am
by biggerrigger
That's good to hear. I have a 10" 60 tooth that I was going to use to cut 60 tweeters with in the next two days. Thanks for the heads up.

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 8:21 am
by Grant Bunter
biggerrigger wrote:That's good to hear. I have a 10" 60 tooth that I was going to use to cut 60 tweeters with in the next two days. Thanks for the heads up.
I reckon the I can place the time when the tooth got chipped!
I dived in a bit hard on one cut and on that particular piezo it took more of the barrel and consequently bit into the screw more as well...
Blew that one to pieces :shock:

So, slow and steady and all you may see is the odd spark.

I finished off the barrels with my angle grinder with slim steel cutting blade. Quick and neat with a few well placed swipes...

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 1:19 pm
by SirNickity
Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 4:03 pm
by Bill Fitzmaurice
SirNickity wrote:Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!
Ever made one? If you had it would be instantly obvious.

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 4:13 pm
by Grant Bunter
SirNickity wrote:Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!
Fair call!
It becomes more obvious when you build a melded array.
Part of cutting up the piezo's is taking a slice off the outer part of the barrel, and sometimes, not always, part of the screw head (due to manufacturing variances). This is so the piezo's will butt up to the one beside it (on either side) when assembling/glueing the array. Not doing this adequately leads to gaps in the array, and the array not being the correct length in total. If you take off the piezo and remove the screws, then all you may trim is the half of the barrel. You would then have to readdress the screws and the remainder of the barrel after reassembly, meaning more steps to achieve the same result...
Does that make sense?

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 5:49 pm
by Bruce Weldy
I didn't have a choice.....mine were from that batch that were glued down tight. :)

Re: 2 x DR250 build, based on March 2012 plans

Posted: Wed Jul 25, 2012 6:01 pm
by SirNickity
No, I've never made a melded array -- hence the question. I'm making the 6-piezo line array for the SLAP's -- and the piezo came right off so I didn't get crap in them while gluing and sanding and painting them.

Looks like these have an entirely different set of challenges. Makes sense now. Thanks Grant. :-)

Re: 2 x DR250 build, based on March 2012 plans

Posted: Thu Jul 26, 2012 3:00 am
by rogerc
I rotated every other tweeter so the screws don't clash

Re: 2 x DR250 build, based on March 2012 plans

Posted: Thu Jul 26, 2012 3:30 am
by Grant Bunter
rogerc wrote:I rotated every other tweeter so the screws don't clash
I guess that would work as well. After my error, I'm just following the plans (not that I wasn't trying to do so before)

Re: 2 x DR250 build, based on March 2012 plans

Posted: Thu Jul 26, 2012 4:08 pm
by AntonZ
rogerc wrote:I rotated every other tweeter so the screws don't clash
That's exactly what I did. Take the elements out when cutting & gluiing, then install the elements a bit different:
Image

And wire like so.
Image

Re: 2 x DR250 build, based on March 2012 plans

Posted: Thu Jul 26, 2012 7:06 pm
by biggerrigger
And this works with the tweeters cut at 2.0"?

Re: 2 x DR250 build, based on March 2012 plans

Posted: Fri Jul 27, 2012 1:58 am
by Grant Bunter
This may seem like an odd question...

Arrays are done, but it occurred to me as I was checking over the plans:
Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...

Re: 2 x DR250 build, based on March 2012 plans

Posted: Fri Jul 27, 2012 6:34 am
by Bill Fitzmaurice
Grant Bunter wrote: Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...
It doesn't, that's one of the advantages to the new DR revision. I don't recall if I changed the array section of the plans to reflect that, I'll take a look today.

Re: 2 x DR250 build, based on March 2012 plans

Posted: Fri Jul 27, 2012 7:54 am
by Grant Bunter
Bill Fitzmaurice wrote:
Grant Bunter wrote: Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...
It doesn't, that's one of the advantages to the new DR revision. I don't recall if I changed the array section of the plans to reflect that, I'll take a look today.
No worries Bill,
Thank you.
I was only wondering, regarding not having to worry about sealing the array, and a couple of coats saved = less time...

Re: 2 x DR250 build, based on March 2012 plans

Posted: Sat Jul 28, 2012 1:23 am
by SeisTres
Very nice. Didn't know the new plan didn't need airtight tweets. Mhh, this and the no access covers just might win me over instead of ot12's if i get into building again. But then again, ot12's are just a breeze and do everything i need. we'll see :D