Typically, straight (non-staggered) holes are only used where the open area is below 40%. Most builders I've asked recommend 40%-61% open area. McMaster-Carr has great prices and fast shipping but last time I checked 40" was the largest dimension they sell. If you want taller panels for cheap, OnlineMetals.com has great prices and will cut to your dimensions. I bought some of their 20 gauge 48"x12" precut steel perf for $20 each.
I started with scissors with plastic handles then the plastic broke on one of the handles, could have been nasty, that's why I bought all steel scissors, no chance of any accidents when cutting perforated sheet. Still, I don't think you will be cutting as many sheets that I have.
That's safe then, about 50!! My 12 um mylar has just arrived so can carry on with rebuilds.The scissors are steel with a thin plastic covering. How many panels have you cut? Sounds like a friendly challenge
I think that you will have even more of a challenge getting those panels flat again.
The most tolerance of warpage tat you can ave for an ESL is about .010" and maybe up to .025" total for both sides if you are lucky.
Being slightly bent is not the same as having a panel with many large waves and creases.
Even some of the very slightest waves in a panel have been known to separate at the tape bonding.
One of Mavric's panel's did this there might be a picture of it in one of his threads back in early of the year 2010.
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-3.html#post2135155
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-4.html#post2142850
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-5.html#post2143819
Here is were it had separated,
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-6.html#post2157488
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-6.html#post2158568
http://www.diyaudio.com/forums/planars-exotics/158115-material-esl-4.html#post2093878
http://www.diyaudio.com/forums/planars-exotics/165495-start-finish-esl-hybrid.html#post2160924
And more,
http://www.diyaudio.com/forums/planars-exotics/164489-help-needed-esl.html#post2142437
http://www.diyaudio.com/forums/planars-exotics/134366-my-esl-attempt-2.html#post1942244
All of these treads are a must read from start to finish as there is a extreme wealth of info.
I have heard these panels and they sounded awesome and it took a lot of patients to get them done.
I do remember that they had a few quirps here and there, But were easily worked out as Charlie would know the details of what they were off hand.
For the most part they worked perfect on the first try.
Remember these are not the same as magnetic planar with the diagphram at least an 1/8" over the top of a layer of magnets.
The the tolerances are much much greater.
Only about 10% is about the max that you can have without worrying to much about stability problems.
At 10% that is only a 6mil (.006") difference with 1/16" D/S spacing.
As you have two Tremendous forces pulling on both sides of the diagphram and any deviations in the gap can/will cause an unbalance and unequal force to occur and cause the Diagphram to suck into one the the Stators and stay there until the bias voltage is removed and dissipated.
Not to mention the possibility of a slightly higher THD should they be stable otherwise.
I would hate to see you spend the money on coating them only to find that they may not work well or even at all.
I think that you might be able to salvage few pieces for some smaller panels or someting or maybe you will get lucky with A LOT of extra hard work and get them straight again.
But, all in all, They Must Be Flat!!!
Good Luck !!!
jer
The most tolerance of warpage tat you can ave for an ESL is about .010" and maybe up to .025" total for both sides if you are lucky.
Being slightly bent is not the same as having a panel with many large waves and creases.
Even some of the very slightest waves in a panel have been known to separate at the tape bonding.
One of Mavric's panel's did this there might be a picture of it in one of his threads back in early of the year 2010.
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-3.html#post2135155
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-4.html#post2142850
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-5.html#post2143819
Here is were it had separated,
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-6.html#post2157488
http://www.diyaudio.com/forums/planars-exotics/162127-different-ideas-esl-panels-6.html#post2158568
http://www.diyaudio.com/forums/planars-exotics/158115-material-esl-4.html#post2093878
http://www.diyaudio.com/forums/planars-exotics/165495-start-finish-esl-hybrid.html#post2160924
And more,
http://www.diyaudio.com/forums/planars-exotics/164489-help-needed-esl.html#post2142437
http://www.diyaudio.com/forums/planars-exotics/134366-my-esl-attempt-2.html#post1942244
All of these treads are a must read from start to finish as there is a extreme wealth of info.
I have heard these panels and they sounded awesome and it took a lot of patients to get them done.
I do remember that they had a few quirps here and there, But were easily worked out as Charlie would know the details of what they were off hand.
For the most part they worked perfect on the first try.
Remember these are not the same as magnetic planar with the diagphram at least an 1/8" over the top of a layer of magnets.
The the tolerances are much much greater.
Only about 10% is about the max that you can have without worrying to much about stability problems.
At 10% that is only a 6mil (.006") difference with 1/16" D/S spacing.
As you have two Tremendous forces pulling on both sides of the diagphram and any deviations in the gap can/will cause an unbalance and unequal force to occur and cause the Diagphram to suck into one the the Stators and stay there until the bias voltage is removed and dissipated.
Not to mention the possibility of a slightly higher THD should they be stable otherwise.
I would hate to see you spend the money on coating them only to find that they may not work well or even at all.
I think that you might be able to salvage few pieces for some smaller panels or someting or maybe you will get lucky with A LOT of extra hard work and get them straight again.
But, all in all, They Must Be Flat!!!
Good Luck !!!
jer
Last edited:
On my website (link below) view the "building the stators" link therein to see my method for straightening the stators by hand. I don't recommend using a metal hammer over a hard surface, as that would expand the metal and ruin the stator.
Thanks Charlie, I was looking for that picture to post for Shaunman !!
Jazzman's DIY Electrostatic Loudspeaker Page: Building the Stat Panels
jer
Jazzman's DIY Electrostatic Loudspeaker Page: Building the Stat Panels
jer
I picked up some of that soft rubbery drawer liner from Harbor Freight last night. I refer to Jazzman's entire site quite often... Great stuff, well documented build.
I asked how to straighten here only because the panels have more than just mild bending :-(.
I did find a very local perf metal supplier online yesterday. Hopefully, they will make a size I won't have to cut. It would be nice if the whole panel had a solid border, as someone pointed out here very recently.
I asked how to straighten here only because the panels have more than just mild bending :-(.
I did find a very local perf metal supplier online yesterday. Hopefully, they will make a size I won't have to cut. It would be nice if the whole panel had a solid border, as someone pointed out here very recently.
OnlineMetals.com has standard sizes like 12x48 but will also cut to any size you specify, and they're cheap too.
I checked their website a few minutes ago and it shows "0" quantity of the AN506's in stock so I'm guessing they haven't updated the quantities yet.... did you you call them to find that out?
The "33" quantity posted on their site earlier must have been an error. It seems finding a steady source is still hit and miss.... and $13 bucks each was almost too good to be true.
Spent an hour straightening the panels. They seem to be flat enough, and time will surely tell. After some bending back into shape on the drawer liner, I set each panel flat on the wood work surface I was using, and tapped along the width and height looking for high spots. Straightened even more, so, we'll see.
Also got the angle grinder out and started rounding off all the sharp edges. That will take a while--maybe get that done this weekend.
Thirdly, a friend had a tested set of electronics he was willing to part with, so that's on the way too. Been a good day of progress.
Also got the angle grinder out and started rounding off all the sharp edges. That will take a while--maybe get that done this weekend.
Thirdly, a friend had a tested set of electronics he was willing to part with, so that's on the way too. Been a good day of progress.
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