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Oblate Spheroid Waveguide - Consolidated Construction Thread
Oblate Spheroid Waveguide - Consolidated Construction Thread
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Old 19th July 2008, 06:11 PM   #11
BHTX is offline BHTX  United States
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Quote:
Originally posted by Wayne Parham
Notice the dip in beamwidth at LF just before the rise as pattern control is lost. This is the behavior of single slit diffraction, a result of the dimensions of the mouth.
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Old 20th July 2008, 12:26 AM   #12
jcx is offline jcx  United States
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could carve boards to stack to get full waveguide?

http://www.sears.com/shc/s/p_10153_12605_00921754000P


elsewhere I pointed to Rapid Prototyping as an option, many techs, all pricey - as long as he keeps working so cheap you may as well get Geddes to make you a new Summa

http://home.att.net/~castleisland/rp_int1.htm
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Old 27th July 2008, 04:35 PM   #13
JLH is offline JLH  United States
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Iím bumping this thread up because there might be a little action coming soon. I have about 5 different off-line conversations going right now. Depending on how they go, I might be moving forward on actually building some waveguides. Donít get too excited, it will still take some good time and planning to pull this off with my busy schedule.

Rgs, JLH
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Old 27th July 2008, 05:00 PM   #14
LineSource is offline LineSource  United States
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Originally posted by JLH
II might be moving forward on actually building some waveguides. Rgs, JLH

Does anyone have the CAD tools to generate a 3D rendering and tooling file for the 18" OS waveguide sized for a 1" compression driver? It would be very valuable to get a group review before anyone invests in plastic production tooling, or starts carving wood or mixing concrete. Plus some 3D pictures would be COOL!
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Old 27th July 2008, 05:19 PM   #15
gedlee is offline gedlee  United States
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Ineresting thread - thanks for the interest. Several comments.

1) the waveguide is a start, but the system involves a lot more, like the woofer, crossover, enclosure, oh and the crossover, and did I mention the crossover?

2) foam plugs are required for the very best performance. I can make and will sell those in any size that is axisymmetric. They are patented and as such only I can sell them.

3) I have a batch of ten 15" waveguides coming soon. I will sell those, with foam plugs and mounting plates, $350.

4) I think that the 18" idea is being taken too seriously as it will be very difficult and expensive and its not clear that there will be any significant advantage over the 15", which, as I said, I already make.

5) casting in poly is how I make the 10" and 12" but I am convinced that the 15" would be too big and that I could not do a casting in this size. Not in one part at least. The 15"s that I sell will be fiberglass.

6) casting in epoxy is not viable because of the heat in such a large volume.
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Old 27th July 2008, 05:48 PM   #16
soongsc is offline soongsc  Taiwan
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Quote:
Originally posted by LineSource



Does anyone have the CAD tools to generate a 3D rendering and tooling file for the 18" OS waveguide sized for a 1" compression driver? It would be very valuable to get a group review before anyone invests in plastic production tooling, or starts carving wood or mixing concrete. Plus some 3D pictures would be COOL!
Generate the points from the spreadsheets, import them to a CAD program using some tool like "Points Import", and work the CAD program from there. If anyone has a more direct way of working it, please let us know.
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Old 27th July 2008, 06:21 PM   #17
MartinQ is offline MartinQ  Canada
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Originally posted by gedlee
3) I have a batch of ten 15" waveguides coming soon. I will sell those, with foam plugs and mounting plates, $350.
This is great news. Any idea how the shipping costs would compare for a 12" baffle vs the 15" waveguide? I'm assuming the 15" waveguide would be smaller and lighter than the 12" waveguide/baffle.
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Old 27th July 2008, 07:02 PM   #18
gedlee is offline gedlee  United States
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I would not expect much difference as the weight will not be that much different. Shipping costs in any case tend to be pretty small if in North America.
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Old 27th July 2008, 07:15 PM   #19
MEH is offline MEH  United States
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Has anyone gone so far as to get a price quote on an 18" waveguide done with stereolithography? There are rapid prototyping services available that can handle a part that large while using high-temperature resin (temperature stable enough to use under the hood of a car). While such 3D-printing is usually only used for prototyping, it can sometimes be more cost effective for very limited serial production than would be investing in all of the tooling needed for larger scale production.
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Old 27th July 2008, 07:18 PM   #20
gedlee is offline gedlee  United States
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My experince with stereolith was not good. The parts were very brittle and delicate, not at all suitable for actual use for extended periods. They worked well enough to test, but thats about all. And they were very very expensive.
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