Paul Carmody's OS Center Build - I may have cocked this up...

[Bearforce One]

Hold that thought! Found a YouTube video by a guy called Paul Sellers. Using his advice as best I could, it’s much better. These blocks for the insert nuts aren’t perfect, but they’re close enough (for government work).

I was pleasantly surprised. Tried relaxing on the saw too, lighter pressure, and changing my stance a little. Happy days!

That little Stanley table vice, attached onto my dining table (wife in bed, of course ) was a great buy! Great bit of kit to get you going.

[Bearforce One]

I now have my box frame. But with a tiny lip on the right side.

How do I best take this out? If I sand it, I risk rounding off somewhere. I don’t have a plane, but I could borrow one. Not sure what’s best 🤔

Any ideas?

[JensToft91]

Looks small (?).. Have you tried placing the panel on it, to see if it will gap?

[JensToft91]

I can't recommend this method, but i did use it on a speaker, where a mistake couldn't be seen.

If you decide to do it, practice first, and go slow!

Press a handsaw against the lower surface, and trim the lip.

[JensToft91]

You also risk pulling the outer layer of ply off. So don't saw "outwards"

[Bearforce One]

Apologies for late reply - for some reason I didn’t receive a notification.

Turned out when I offered in the back panel, which didn’t fit as the lengths were bowed, I followed the “if it don’t fit, force it” method.

And split the box apart

Long story short, I couldn’t unbend the bow, so the shop I bought from recut me new lengths for free, so it’s third time lucky!

Current dilemma: I bought a nice 70mm
Starrett hole saw for my woofers. Tried it out on a practice piece and it worked well - nice clean cut.

Dropped a woofer in and all good! But now I’m wondering, instead of a close-fitting hole and chamfering, wouldn’t the woofer be able to breathe better if I made a larger hole, maybe even 80mm?? Bearing in mind I’m using 3/4” ply too..

I’ll post some pics when I have chance. In the meantime, grateful as always for comments (Jens thanks for yours!)

[buggers]

No it will not breathe better with a bigger hole...

[tomzarbo]

Something I've done with boo-boos in thickness is to glue a large piece, or pieces of sandpaper on a large scrap panel, clamp that panel to a worktable, and carefully sand the area flush. I used a big belt sander loop, it was 6" wide and 4 feet or so long... a belt from my HFT sander. Cut in thirds, glue, overlap on the sides and staple for insurance. I've used this one panel for several years and its still in tact.

Regarding clearance for drivers, in my opinion the best practice is to keep the opening tight to the driver, and chamfer the "breathy" areas. This keeps as much material as possible for the driver to mount against.

I use a file or Dremel with a drum sander to do this quickly. For larger drivers, Javad has designed a perfect router bit for this for after construction use.

I'm a hack woodworker, so I just get it done however.

Glad you're staying with it. Think of how much you're learning! Next one will be a breeze!

TomZ

[tomzarbo]

Forgot the pic.

[Bearforce One]

Thanks for comments gents.

Here are some pics of the driver in a scrap piece. Maybe I’m being dumb, but I’m not seeing how a chamfer, to maybe half the depth of the ply, will help the driver breathe better than an enlarged hole overall. To my mind, a chamfer still leaves a bottleneck. What am I missing??

Tom I did use your idea, or a smaller version of it, to flatten off some of my edges, so thank you for that.

[djg]

Put a 3/8" 45 degree chamfer on the back and you'll see. You need the strength of the plywood for the mounting holes. Putting mounting screws in 1/8" from the edge of a hole in plywood is problematic.

[Bearforce One]

Here’s a pic of the driver

[Bearforce One]

For you, Tom, a few pics of the new cabinet and endcap. Better than my first attempt, for sure!

[Bearforce One]

And one from behind. I didn’t know the size of the terminal plate before placing the insert nuts, so had to improvise some new ones further apart so the terminal plate would clear the furniture screws at the back. A good chance to try out some new epoxy wood glue I’d bought..

[Chris Roemer]

Yeah, you need a small enough through hole to get a good seal between the driver flange and the baffle.
You can chamfer three-fourths of the way through, but don't do it completely around. Leave the meat by the screw holes.
From the backside it'll end up looking nearly like a "Club" (from a card deck).
SOMEone here had excellent pics of their method a few wks (or more) ago. Wish I had a link to the pics for you.

[JensToft91]

Thanks for comments gents.

Here are some pics of the driver in a scrap piece. Maybe I’m being dumb, but I’m not seeing how a chamfer, to maybe half the depth of the ply, will help the driver breathe better than an enlarged hole overall. To my mind, a chamfer still leaves a bottleneck. What am I missing??

Tom I did use your idea, or a smaller version of it, to flatten off some of my edges, so thank you for that.

You're not missing anything. That hole NEEDS to be chamfered. Look here:

chamfering driver holes (troelsgravesen.dk)

If the link doesn't work, search for: The Importance of Chamfering Driver Holes troels gravesen

[davidroberts]

This is the post Chris was referring to.

http://techtalk.parts-express.com/fo...96#post1454896

[tomzarbo]

For you, Tom, a few pics of the new cabinet and endcap. Better than my first attempt, for sure!

That's looking good, nothing wrong with that at all. I like the diagram for the crossover too. I should probably try doing that.

TomZ