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I've decided to move along on this project as I want to listen for a possible improvement in the sound. The extension will nearly complete the original output end of the transmission line, but will be about 24" short of that, and the original terminus dia. was 64" or 68" as I recall, and I'll have only 30". I think I read that 78RPM records do not play low enough to justify the additional TL 2' length and larger exit dia.
I also plan to cut away excess foam at 2 of the corners letting the block lines more closely follow the spiral. The block will then be encased in painted Masonite and the top and bottom surfaces covered in about ¾" panels.
Questions Regarding Horn Design and Dimensions
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TN Allen
- Victor O
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- Location: Blue Hill, Maine
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Inigo
- Victor Monarch
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Re: Questions Regarding Horn Design and Dimensions
Very interesting, thanks for reporting. Will follow your progress with illusion... I am humbly also thinking of making one of these horns since I read Wilson book... But my project is still in infancy, and I've only made calculations, which still need to be matured and reviewed. So these projects are very funny for me. Thanks again.
Inigo
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TN Allen
- Victor O
- Posts: 53
- Joined: Sat Sep 22, 2018 11:24 am
- Location: Blue Hill, Maine
Re: Questions Regarding Horn Design and Dimensions
It is pleasant knowing another person may produce a new Wilson & Webb(?) player. If I can assist please let me know.
I am retired from teaching as of today and no longer have access to the CAD software and Haas CNC machine I used, but will have time to continue projects and assist others.
I am retired from teaching as of today and no longer have access to the CAD software and Haas CNC machine I used, but will have time to continue projects and assist others.
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dzavracky
- Victor IV
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Re: Questions Regarding Horn Design and Dimensions
TN Allen,
What a fascinating project. I have always wanted to make something like this; for the eventual possibility that I will own a home
. I have always thought it would be cool to build the horn into the wall and just have the mouth of the horn showing. Good job with the HAAS CNC machine... I wouldn't have considered cutting foam in one. I wonder if my boss would let me use ours to make something like this in the TM-1 
. What software did you use to draft/code this project?
Hope you can finish this as I am interested to see the final result!
I made something like this awhile back, but calling it a rough first attempt would certainly be a generous take I didn't get very good adhesion for the inner layers of the bell; but even in its rough condition I gotta say it still sounded pretty darn good! I want to return to this project at some point in the future... hopefully to create a mold that will allow me to fabricate the horn out of wood. Imagine how pretty a walnut bell would be 
Cheers,
David
What a fascinating project. I have always wanted to make something like this; for the eventual possibility that I will own a home
. I have always thought it would be cool to build the horn into the wall and just have the mouth of the horn showing. Good job with the HAAS CNC machine... I wouldn't have considered cutting foam in one. I wonder if my boss would let me use ours to make something like this in the TM-1 . What software did you use to draft/code this project? Hope you can finish this as I am interested to see the final result!
I made something like this awhile back, but calling it a rough first attempt would certainly be a generous take
I didn't get very good adhesion for the inner layers of the bell; but even in its rough condition I gotta say it still sounded pretty darn good! I want to return to this project at some point in the future... hopefully to create a mold that will allow me to fabricate the horn out of wood. Imagine how pretty a walnut bell would be Cheers,
David
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TN Allen
- Victor O
- Posts: 53
- Joined: Sat Sep 22, 2018 11:24 am
- Location: Blue Hill, Maine
Re: Questions Regarding Horn Design and Dimensions
Thank you. I used Kubotek's KeyCreator, which was Cadkey years ago. KC had recently added a few new tools that made locating the circles specified in W&W on a spiral easier. Once the circles were located I converted the wire frame to a solid, then subtracted the solid from a block a generated the tool paths. The foam blocks were about 24" X 8" X 48" so I milled segments of the horn in different setups.
Finding a suitable cutter to mill foam is difficult, but I found ~1" dia. spherical burrs for carving wood on Amazon. I inserted one of these in a ¾" X 8" rod to make a cutter long enough to clear the depth in the deeper parts of the design. This all worked well enough given it was stretching the design and Haas capabilities.
Finding a suitable cutter to mill foam is difficult, but I found ~1" dia. spherical burrs for carving wood on Amazon. I inserted one of these in a ¾" X 8" rod to make a cutter long enough to clear the depth in the deeper parts of the design. This all worked well enough given it was stretching the design and Haas capabilities.
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TN Allen
- Victor O
- Posts: 53
- Joined: Sat Sep 22, 2018 11:24 am
- Location: Blue Hill, Maine
Re: Questions Regarding Horn Design and Dimensions
The last post in the #3 segment of this series of posts shows the cutter.
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TN Allen
- Victor O
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- Joined: Sat Sep 22, 2018 11:24 am
- Location: Blue Hill, Maine
Re: Questions Regarding Horn Design and Dimensions
The extension is glued together with Gorilla Glue. It seems to adhere quite well to the cut foam but not well to the manufactured face surfaces.
I plan to "turn" the inside surface round and with about a 9/16" internal convex curve or flare. This will be like the curve in a bell rather than a cone and closely follow the W&W exponential horn dimensions.
I suspect the hardness of the cured Gorilla Glue compared to the foam may be a problem. I intend to grind the surface and I may be able to find a solution to potential problems. If not I'll leave it as is, and paint over the foam and "frozen snot" irregularities.
If I cannot turn/gring the internal surface because of the difference between the hardness of the foam and Gorilla Glue, perhaps the multi-facet(18 panels) surface will not make too much difference in sound compared to a turned surface following the W&W configuration, as it is at the end of the transmission line. Perhaps someone with a better understanding of the dynamics can provide a better evaluation of the difference in surface configuration. No doubt there is an advantage to a better surface consistent with the W&W dimensions.
I plan to "turn" the inside surface round and with about a 9/16" internal convex curve or flare. This will be like the curve in a bell rather than a cone and closely follow the W&W exponential horn dimensions.
I suspect the hardness of the cured Gorilla Glue compared to the foam may be a problem. I intend to grind the surface and I may be able to find a solution to potential problems. If not I'll leave it as is, and paint over the foam and "frozen snot" irregularities.
If I cannot turn/gring the internal surface because of the difference between the hardness of the foam and Gorilla Glue, perhaps the multi-facet(18 panels) surface will not make too much difference in sound compared to a turned surface following the W&W configuration, as it is at the end of the transmission line. Perhaps someone with a better understanding of the dynamics can provide a better evaluation of the difference in surface configuration. No doubt there is an advantage to a better surface consistent with the W&W dimensions.
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