One option would be to use the PETG to create a mold in plaster. Then you can bake the plaster but as you write that would work for short membranes but would be a pain since I assume you don't have access to an industrial sized oven 🙂
Yes, plaster would work. I'm not sure that the local pizzeria will let me use their oven though.
I just ordered some 0.1 and 0.2 mm aluminium foil. Let's see what they can do.
I just ordered some 0.1 and 0.2 mm aluminium foil. Let's see what they can do.
I made some AMT´s with 0,03mm adhesive foil. I cut the traces on Silhouette camaro.
Best sound subjektive .Tested fullrange .
Bernt
Best sound subjektive .Tested fullrange .
Bernt
Yes, I remember that.
But I'm gonna corrugate the 0.1 or 0.2 mm aluminium foil/sheet and interleave it with the corrugated membrane so that I can bake it.
But I'm gonna corrugate the 0.1 or 0.2 mm aluminium foil/sheet and interleave it with the corrugated membrane so that I can bake it.
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So for the full length membranes I need the Silouette Cameo 5 to cut 2440 mm to get a 2200 mm corrugated membrane.
The problem with that is that there's is no control in which order the machine will cut if I just export the design as dxf from Fusion:
The result is that the membrane goes back and forth while cutting the full length a lot. The chance of failures is very high if not certain.
Thanks to OllBoll I now have the solution.
More to follow.
The problem with that is that there's is no control in which order the machine will cut if I just export the design as dxf from Fusion:
The result is that the membrane goes back and forth while cutting the full length a lot. The chance of failures is very high if not certain.
Thanks to OllBoll I now have the solution.
More to follow.
2440 mm divided by 40 gives 61 mm chunks, it'll be tedious to CAD and take a long time to cut but hopefully the yield will be satisfying.
First I draw lines cross over the membrane at every 61 mm using rectangular pattern:
Then insert a Break at every intersection, this is the tedious part.
Be sure to select the vertical line and not the horizontal as in below:
One can see that the line is broken by selecting the lines above and below the break:
Compare to the next line which is yet not broken:
Break the rest of the vertical lines in that row, then remove the horizontal line.
Do this for the other 38 horizontal lines.
First I draw lines cross over the membrane at every 61 mm using rectangular pattern:
Then insert a Break at every intersection, this is the tedious part.
Be sure to select the vertical line and not the horizontal as in below:
One can see that the line is broken by selecting the lines above and below the break:
Compare to the next line which is yet not broken:
Break the rest of the vertical lines in that row, then remove the horizontal line.
Do this for the other 38 horizontal lines.
I found an easier way.
Just do the bottom segment and one more at the top.
Then select the second from the top and copy it using rectangular pattern, done in no time!
Then I export the design as a dxf-file and import it to Silhouette Studio where I assign every segment to an unique color:
There must be a better way to do this, why use colors?
I can then in the Send/Line determine the order of the cuts.
And then hopefully the membrane while cutting only will be moving 61 mm at the time.
Just do the bottom segment and one more at the top.
Then select the second from the top and copy it using rectangular pattern, done in no time!
Then I export the design as a dxf-file and import it to Silhouette Studio where I assign every segment to an unique color:
There must be a better way to do this, why use colors?
I can then in the Send/Line determine the order of the cuts.
And then hopefully the membrane while cutting only will be moving 61 mm at the time.
Well, it didn't work as expected. The cutter jumped one segment or two on occasion.
So I added a pause after every segment to force the cutter to cut the segments in sequence.
It could be good to also use the pause to check the cuts and perhaps clean the knife from time to time.
I also mounted the roll feeder to better align my cutting "mat":
And that worked!
Sadly I had made a couple of mistakes when prepairing the segment; those colors can really confuse you.
So at 1750 mm of perfectly cutting the membrane, the whole mat rolled back to cut the first line that accedentely had gotten the same color as that current segment. The line didn't end up in the right place and the whole membrane lost its alignment.
I also had a constrution line at the end, so I need to redo the whole from the export from Fusion.
But this time I shall use the hex representation of the colors starting at $000001 and adding 1 for each following segment:
So I added a pause after every segment to force the cutter to cut the segments in sequence.
It could be good to also use the pause to check the cuts and perhaps clean the knife from time to time.
I also mounted the roll feeder to better align my cutting "mat":
And that worked!
Sadly I had made a couple of mistakes when prepairing the segment; those colors can really confuse you.
So at 1750 mm of perfectly cutting the membrane, the whole mat rolled back to cut the first line that accedentely had gotten the same color as that current segment. The line didn't end up in the right place and the whole membrane lost its alignment.
I also had a constrution line at the end, so I need to redo the whole from the export from Fusion.
But this time I shall use the hex representation of the colors starting at $000001 and adding 1 for each following segment:
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Nice work!
It confuses me too that they only allow colors and not numbered ordering of the items to cut.
It confuses me too that they only allow colors and not numbered ordering of the items to cut.
I guess we're are pushing any normal UX out of bounds.
Thank you again OllBoll for leading me in the right direction!
Now I think that I finally can see the light in the tunnel.
Thank you again OllBoll for leading me in the right direction!
Now I think that I finally can see the light in the tunnel.
Some improvements:
Use odd vertical cuts, that way the cutter will not do a fast feed forward when the next segment starts.
I'd to add a dummy cut as the number of vertical traces were even.
Enter the hex color in actual hex number when assighning colors.
During cutting the decimal number is displayed.
Remove roller when cutting the final segments.
Otherwise the cutting mat will hit the roller on the way back and ruin the last cuts.
The first 2440 mm long mid membrane was finally successfully cut:
The calculated 11.5 ohms was in reality 13.3 ohms.
So unless I take a leap of faith and go wide as OllBoll with 7 mm instead of my 3 mm conductor traces, I'll have to take a mirror of the above membrane and glue it to the other side of the mylar film.
Use odd vertical cuts, that way the cutter will not do a fast feed forward when the next segment starts.
I'd to add a dummy cut as the number of vertical traces were even.
Enter the hex color in actual hex number when assighning colors.
During cutting the decimal number is displayed.
Remove roller when cutting the final segments.
Otherwise the cutting mat will hit the roller on the way back and ruin the last cuts.
The first 2440 mm long mid membrane was finally successfully cut:
The calculated 11.5 ohms was in reality 13.3 ohms.
So unless I take a leap of faith and go wide as OllBoll with 7 mm instead of my 3 mm conductor traces, I'll have to take a mirror of the above membrane and glue it to the other side of the mylar film.
If I understood correctly you use very thin aluminum foil, 5-10 micron? What supplier / brand do you use? I'm looking at buying some 6-9 micron foil. I can get 14 micron from Clas Ohlson but I can't seem to find thinner foil. Or at least I can't seem to find foil in that thickness where they list the thickness.
Outside Denmark, that thin foil is a scarce commodity.
At least the one with paper backing which is a necessity with foil that thin; 6 µm.
They used to be obtainable in any Danish grocery store as "Madpakkefolie", but as far as I know you'll need to buy wholesale nowadays.
And they only ship within Danmark. I haven't found any wholesale or retailer in Sweden.
At least the one with paper backing which is a necessity with foil that thin; 6 µm.
They used to be obtainable in any Danish grocery store as "Madpakkefolie", but as far as I know you'll need to buy wholesale nowadays.
And they only ship within Danmark. I haven't found any wholesale or retailer in Sweden.
I ran into some trouble with the makings of the steel plates, so I've order laser cut plates from Fractory.
They'll arrive in the beginning of next week.
Meanwhile I've done some dispersion measurements on the mini SMAPPP:
I've applied some PEQ In the measurements below to mitigate the effects of the Helmholtz' resonance.
Dispersion for Mid at one meter, 0 till 30°:
Dispersion for Top at one meter, 0 till 30°:
This looks really good!
They'll arrive in the beginning of next week.
Meanwhile I've done some dispersion measurements on the mini SMAPPP:
I've applied some PEQ In the measurements below to mitigate the effects of the Helmholtz' resonance.
Dispersion for Mid at one meter, 0 till 30°:
Dispersion for Top at one meter, 0 till 30°:
This looks really good!
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