Wave guide blanks glued up, 6 layers MDF. Turn them tomorrow and assemble the cabinet. Determined to dem o this on Superbowl Sunday.
TIP: assembling and glueing 6 layers at once is less of a nightmare if you use a couple brads in each layer as you stack the glue-up. Then clamp, no floating. Since I will be hollowing these out, I didn't want brads in the way, so I stacked them on the 1/8 inch centerhole using a heavy wire, clamp, then remove the wire.
TIP: assembling and glueing 6 layers at once is less of a nightmare if you use a couple brads in each layer as you stack the glue-up. Then clamp, no floating. Since I will be hollowing these out, I didn't want brads in the way, so I stacked them on the 1/8 inch centerhole using a heavy wire, clamp, then remove the wire.
Attachments
Wow, no that’s a project after my own heart!
Good work, finally someone has the gumption to actually build one of these, I’ve read many posts with the musings and ponderings of the how’s and what’s of a Polk Power Port, but you are actually doing it, I admire a man who sticks to his ideas. Looks like your close to actually testing this ,I can’t wait to hear how it goes, either way kudos to you and your excellent effort.
Good work, finally someone has the gumption to actually build one of these, I’ve read many posts with the musings and ponderings of the how’s and what’s of a Polk Power Port, but you are actually doing it, I admire a man who sticks to his ideas. Looks like your close to actually testing this ,I can’t wait to hear how it goes, either way kudos to you and your excellent effort.
Thanks for the encouragement. I sure hope this works. Here are the turned external wave guides, 2.75" radius. These took about 4 hours to make on the lathe.
Tip correction: these wobbled like crazy on the lathe because I didn't use the brad nailer to align each layer. If you must go without brads, then I don't recommend using anything flexible to thread.
Tip correction: these wobbled like crazy on the lathe because I didn't use the brad nailer to align each layer. If you must go without brads, then I don't recommend using anything flexible to thread.
Attachments
A complete waveguide assembly. Missing is the 6" pipe that surrounds it. Now all I need to do is assemble the cabinet around them.
I filled the 3" PVC with expansion foam to eliminate dead air. Don't know if this is necessary, but it sounded intelligent, besides I probably won't be able to do it later.
I filled the 3" PVC with expansion foam to eliminate dead air. Don't know if this is necessary, but it sounded intelligent, besides I probably won't be able to do it later.
Attachments
Today or tomorrow I'll hook this thing up. Here is view from the top with the top removed. The top is left unglued while I correctly size the PVC for fit, and later for tuning possibly (if the results are far off). I will be happy with anything from 17HZ to 23HZ. That is a huge range of pipe length, so it would be hard to miss that target. We'll see if Matt Polk had good engineers doing his empirical formulas. I have adhered precisely to the Powerport formula, tolerances +/- 1/16th in all aspects of construction. A math error seems the only likely source of significant error. BTW, this cabinet was not easy, but with another person it glued up smoothly using the slow set Type II stuff. It took 15 minutes to get clamps on and all glue squeezed. Also a brad nailer is worth 5 pairs of hands holding. With 10 panels in a single glue up, a plan of attack was key. I still have several braces to go.
Thanks Ampman for the salute. I hope I won't need a box of tissues.
Thanks Ampman for the salute. I hope I won't need a box of tissues.
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.