Any designs for a husk box with soft, curved contours? Thanks for any leads!

Ted

Buy an old Porsche 356 and cut it in half......... :D

Well, that's one option...

Ted it will have to be custom. Remember balsa wood is very light and then balsa is flexable enough to make a temp frame to mock it up then you can measure and cut a suitable frame.

I am thinking of making a hushbox out of balsa frame and tehn wrapping it with fiberglass sheets (resin coated of course), then lining it with a few inches of dense fiberglass acoustic lining. Should work well, I can have the shape i want and it will be much lighter then most wood box type hushboxes.

My half built hushbox is fibreglass. I built an angled side wall, curved bottom, rounded corners (with lotsa bog) mould and glassed it. The world's dodgiest mould.

Destroyed the mould in the process, but got one hushbox out of it. I still have to cut it down to size and clean it up, paint it, hang it, admire it.

Oh well, one day, when I stop breaking my XG for fun..

I too would have loved more curves, but that's hard to fabricate.

Wood hush boxes need not be boxy, check out this one which has curved front edges, sloping top and interesting shapes:
http://www.avsforum.com/avs-vb/showthread.php?t=707451

THere is this one:

http://www.curtpalme.com/HushboxSupercooled1.shtm

Thanks for everyone's replies. JonFo that's a very handsome hush box. I see your point. I just have the curves in my mind :eek:

Jon and Mark, Any good tutorials for this activity? The building of the frame, the use of fiberglass, bondo. This is a free-form project so it could go badly if I can't measure / monitor symetry as I go.

Thanks a lot.

Not that I know of. IF someone has any idea please post it. I am not any kind of fiberglass expert. I know what I want, never said I am good at doing it :D

My totally curved fiberglass hushbox (http://gallery.avsforum.com/showphoto.php/photo/4435/cat/500/ppuser/7428372).

I have to say again, Ile's is the best looking hushbox I've ever seen. Also, for those of us that have to drop the PJ down from tall ceilings, this design works great and looks great. I just wish I had the fiberglas skills to make it. :(

Dave

I too would have loved more curves, but that's hard to fabricate.

Wood hush boxes need not be boxy, check out this one which has curved front edges, sloping top and interesting shapes:
http://www.avsforum.com/avs-vb/showthread.php?t=707451

Did you DIY the diffusor panel in the back? If so, what did you make it out of?

Dave

I have to say again, Ile's is the best looking hushbox I've ever seen. Also, for those of us that have to drop the PJ down from tall ceilings, this design works great and looks great. I just wish I had the fiberglas skills to make it. :(

DaveThanks,

I probably don't use it anymore ;), because I moved to row house and now I'm considering to build RP setup.

If I can't find good enough cheap RP-screen, then I cut that hushbox apart and make it 10" wider for BG1200. :)

Hello Ile,

You and I were talking back in '03 about this, believe it or not. The issue I'm having is getting the shape of this. It would have a tail like yours. Did you fabricate the mold all from foam, including the tail, and then line with fiberglass?

ILE

AWESOME box! I second that its its best looking I have ever seen!

Vic

Hello Ile,

You and I were talking back in '03 about this, believe it or not. The issue I'm having is getting the shape of this. It would have a tail like yours. Did you fabricate the mold all from foam, including the tail, and then line with fiberglass?I remember that we talked back then.

I piled some stuff (books, etc) behind projector to get rough shape for tail. Then I covered projector and that tail stack using plastic and alu-foil. Then I foamed whole thing and was using that foam lump as billet for mold.
Then I cutted shapes inside that mould using grinding machine and diy blade (http://archive.avsforum.com/avs-vb/attachment.php?postid=2849865&fullpage=1).

I would have to build the mold in place, since the hushbox would be sealed to the ceiling. Any thoughts on that? I could pull a vacuum on a plastic wrap, but the foam, or plaster would just fall off. I was thinking about installing a gauze or net over the plastic to give the plaster or foam something to grip to.

Any creative ideas along those lines?

How about using fish trap net (http://www.savenmaa.fi/tuotekuvat/suuri_834.jpg) to copy projector shape?

And then another net over it to make needed shape for hushbox. Then you can cover net with foil and start to laminate glass fiber over it...

Why I didn't get this idea back then, that would been saving about 50 working hours. :o

I've never done this stuff before, but the net would seem to capture an awfully crude shape, no? Doesn't the shape have to be more precise?

That's a great sounding idea, though. Really great!

Yes, it would be quite crude shape and in some point it's needed to finish surface to final form.

I'd do rough shaping after two layer of glass fibre using soft car polyester putty. It sounds quite a work, but using eccentric grinding machine (http://riemun.huuto.net/auctionimages/a/09/106714f8a3abb47105af24c714bf1-orig.jpg) it can be done quite fast. After that I'd add another two layer of glass fibre. Then it need to be finished for painting, that is hardest part...

But you can take it to nearest car painting shop. :)

Ile,

I'm envisioning a fine weave metal mesh that would bend and contour to the shape well. Don't know where I'd find this mesh, but let's say I did.

It seems like the mesh would have no structural strength once removed from the projector. Do you think the foam would stay up there with the wire? So the wire would be reinforced, then removed after the first layer of foam dried?

So wrap the projector in thin plastic, (coat with a release agent?). Wrap the wire around the projector and hope it doesn't tear the plastic. Spray with foam, let dry and remove mold from ceiling. Add more foam or fiberglass to reinforce. Then clean up the inside surface.

I have to say, if the right mesh could be found and could keep it's shape, that would be best. Maybe a layer of duct tape over the wire before removal would do the trick?

Just looked g90 pics in your gallery, but I couldn't see how hard it would be to remove those light gray and dark gray covers. It would be easier to make mould if you can remove those, it's just needed to measure front/back dimensions to ceiling before removing...

Did you DIY the diffusor panel in the back? If so, what did you make it out of?

Dave

No, those are commercial RPG Skyline diffusers.

ILE, excellent work on that fiberglass hushbox.

One other idea to make the base for the fiberglass would be to use blocks of Styrofoam glued together to give roughly the volume of the PJ. Then start carving down from there. Maybe hire a sculptor or automotive design student to come and do it for you. It requires some precision with measurements, but not critical.

IF DIY, any book or article on how to sculpt industrial molds would have plenty of pointers.

One other idea to make the base for the fiberglass would be to use blocks of Styrofoam glued together to give roughly the volume of the PJ. Then start carving down from there. Maybe hire a sculptor or automotive design student to come and do it for you. It requires some precision with measurements, but not critical.

IF DIY, any book or article on how to sculpt industrial molds would have plenty of pointers.When I was studying, one of my teachers was starting modeling company. We visited there once and their 5-axis CAM milling machine would be nice in this kind project. They make styrofoam modeling for industry.

Here is few photos of that shop.
http://www.toivakanmallinnus.fi/kuvat_en.shtml

Ile,

If you know what you're doing with the design tools, using a milling machine like that would AWESOME for making a mold and custom-fabricating your own super-high-tech hushbox. Unfortunately, unless your friend owns or runs the shop, you'd probably spend more on your hushbox than on your projector!!!!

SC

Curious if there has been any other developments

Mine is finished.

(The touch up roller marks are not really visible to the naked eye).

Mark, that's really nice! How did you accomplish the radius edges?

I made a mould out of 3mm melamine (white backed mdf), with more robust frame behind it.

Then bogged up the corners with lots of bog to get the radii.


Then applied mould-release and fibreglassed it.

Destroyed the mould getting it out....the corners stuck.


Then bogged and sanded and bogged and sanded as the corners didn't work as well as hopped.

Then undercoated it, fitted to the ceiling, and painted in place.


It's held up with bungy cords, so no hinges or clips are visible - got that idea from Gary.

It's lined with 50mm rockwool.

... Sounds simple enough:eek:

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I would love to do this. I have never worked with fiberglass, though.

It's the mold making part that gets me. You started with a square edge mold and ended up with a smooth product...

You started with a square edge mold and ended up with a smooth product...


Bog.

You bog the corners of the mould, and shape them with a bit of rounded wood. Then the mould has round corners.