Careful with that belt-sander, Eugene
(er, Michael)
Careful with that belt-sander, Eugene
(er, Michael)
Point taken.
Also thanks for the Westlake alum bracket posting John,Ifelt like a blonde with my ruler on the monitor
Michael
Finished my first go at the 1200hz horns in mdf.
Here are a couple shots from the construction.
I started with a full size pattern of the horn in 1/4 hardboard, carefully getting the arc to plan, but leaving a little more than the 135 degrees so I could screw it down during forming.
Using a pattern bit on the router I made the initial arcs.
Next I made a 90 jig for cutting a precise contour to the horn. Mounting the jig a little forward of the center-line of the blade on the table saw, I carefully made 4 passes in a slow arc to follow the profile of the plan. The horn pivots down into the blade from the center of the circle.
Feathered in the curves with a hand plane.
I also used a router jig to shape the vanes. Basically the same method. There are two holes on the top positioned by a couple nails to center the vane and help hold in place.
I cut the back off a little further than on the plan so I could make a clean transition to the compression driver.
They sound great. I hooked them up to the midrange on my L222 Disco’s. A little out of balance for now, but for vocals very natural and engaging.
Next step is a walnut version. My plan is to incorporate them into their own three-way.
Fantastic!
Those look "SLICK"
Excellent
Johnny Haugen Sørgård
Oh My - Those are Nice !
You Guys are Masters of the DIY Kingdom.
Very nice. Please make mine in walnut.
John
Nice job John! I like the jig for the vanes. That just happened to be my next project. Very timely. Keep up the good work!
Woody
I'm envious as I have little to no woodworking skills at all.
Ron
Looks very nice! What did you use to seal the MDF?
Is your horn based on Johnny's drawing or is it different? I notice the mounting/throat adapter is different.
Widget
I sealed the mdf with a couple coats of automotive primer, then sanded smooth and finished off with Krylon black semi-gloss.
I did deviate from the plan around the throat. I cut it back about 1/2in, and shaped a smooth transition from the 1in driver to the horn out of a 3/4 piece of mdf. This piece screws into the horn and has a couple of square nuts captured on the back side. There is a 7/16 piece of oak that bolts onto the driver and then from the otherside onto the horn.
On the vanes, I built the pattern and drilled two holes in the top along the center line the, same diameter as a couple 8p nails. I tapped the nails through the holes on the blank I was shaping, then drilled into the marks that were registered. This way they could be flipped end to end and still line up correctly.
Very nice John. I was going to use the two pin registration (nail) method for the vanes as well, but make a pivot or arm to mount on a bandsaw. The 8 inch vane has a beautiful 24 inch radius on it. Swing through the bandsaw, flip the piece over and swing through again. Then it's done, except for final sanding and finishing for each vane.
Bruce
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