I have worked out how to do everything except the top curve. My plans so far:
1. build the matrix bracing, which will also form a template for the curves
2. flat MDF sheets will be added for the top and bottom and the front baffle
3. 3mm sheets of MDF will be bent around the matrix bracing to form the curved sides and rear of the box
The construction will include constrained layer damping - a box within a box with liquid nails between. I won't go into this as I have resolved how I want to achieve this. The most difficult part is:
4. adding the top curve. Moving along the top of the box from the front baffle to the rear there is a gentle curve reaching a peak in the middle so that the edges around the box are at the same height (excluding at the front) but the middle is raised. Note: very similar to B&W subwoofers.
My query: how to get the top curve
* I don't want to do it by planing a single flat sheet of MDF with a belt sander or any similar technique! I have done this before, the results are less than ideal, and it is extremely time consuming. I can live with tedious if the result is just right, but not if it doesn't look quite right.
* The finish is piano gloss black so accuracy is important
Suggestions? ......
1. build the matrix bracing, which will also form a template for the curves
2. flat MDF sheets will be added for the top and bottom and the front baffle
3. 3mm sheets of MDF will be bent around the matrix bracing to form the curved sides and rear of the box
The construction will include constrained layer damping - a box within a box with liquid nails between. I won't go into this as I have resolved how I want to achieve this. The most difficult part is:
4. adding the top curve. Moving along the top of the box from the front baffle to the rear there is a gentle curve reaching a peak in the middle so that the edges around the box are at the same height (excluding at the front) but the middle is raised. Note: very similar to B&W subwoofers.
My query: how to get the top curve
* I don't want to do it by planing a single flat sheet of MDF with a belt sander or any similar technique! I have done this before, the results are less than ideal, and it is extremely time consuming. I can live with tedious if the result is just right, but not if it doesn't look quite right.
* The finish is piano gloss black so accuracy is important
Suggestions? ......
Banned
Joined 2002
im probably gong to copy your idea but as mine will be ported out the rear : O) my ideas
First making the box out of 1" mdf. getting it to the closest shape as possible with all teh fiulling and glueing i can.
then adding 1/2 " to the sides maybe thicker depending on teh curve after doing that sanding it down with rough sand paper. after having it nearly the shape i would apply fibre glass after doing layers and getting it to the thickness i needed and teh smooth surface i would take it to a paint shop to get painted hi hi hi gloss black or a blue. i have not decided if i want to build the power amps into the box or not but a ported box is definate for me : O) as ill build 2 of these with 10" hi excersion but low fs drivers : O )
Jason
First making the box out of 1" mdf. getting it to the closest shape as possible with all teh fiulling and glueing i can.
then adding 1/2 " to the sides maybe thicker depending on teh curve after doing that sanding it down with rough sand paper. after having it nearly the shape i would apply fibre glass after doing layers and getting it to the thickness i needed and teh smooth surface i would take it to a paint shop to get painted hi hi hi gloss black or a blue. i have not decided if i want to build the power amps into the box or not but a ported box is definate for me : O) as ill build 2 of these with 10" hi excersion but low fs drivers : O )
Jason
http://www.hurdygurdy.com/progress/030428.htm
http://memimage.cardomain.net/member_images/2/web/338000-338999/338577_242.jpg
http://memimage.cardomain.net/member_images/2/web/338000-338999/338577_234.jpg
http://www.woodbenders.co.nz/company info/ttf.htm
or buy a sono tube and cut it,then steam it to bend
use bender board stapled around the inside edge of sono tube to hold stick/cleats for support. cut a thick mdf front with the face shape you want,and staple to the claets,for shape,
then fiber glass the top ands bottom
then bondo gel coat ,sand and finish it.
http://memimage.cardomain.net/member_images/2/web/338000-338999/338577_242.jpg
http://memimage.cardomain.net/member_images/2/web/338000-338999/338577_234.jpg
http://www.woodbenders.co.nz/company info/ttf.htm
or buy a sono tube and cut it,then steam it to bend
use bender board stapled around the inside edge of sono tube to hold stick/cleats for support. cut a thick mdf front with the face shape you want,and staple to the claets,for shape,
then fiber glass the top ands bottom
then bondo gel coat ,sand and finish it.
Bill Fitzpatrick said:
Bill,
To my eyes, sites with black text in white background is very glary and hard on the eyes. I find mine easier to look at, and it also has the kind of look that I want. If you can't make sense of the image, then perhaps you could adjust monitor settings. I have noticed a lot of people have their monitors set so that they lose shadow detail.
But still Bill, I changed the image for you and still no response to the actual question!
bigmike216 said:I think fiberglass is the answer
I have discussed fibreglass with someone who has built a fibreglass boat before, but I can't see any advantages in performance, finish or ease of construction. I have considered using some kind of outer epoxy coating for extra toughness (MDF could take dents).
Jason,
Your method sounds a little bit arbitrary - ie sounds a bit like how you would create a sculpture, not the level of accuracy and precision I'm looking for. I have already worked out a way to do all of the box except the top. A piano gloss finish means I need to achieve this, as the reflections will show up imperfections readily.
did you scroll down and look at any of the pictures of forming shapes ?
try this site and scroll down and see a shiny custom car finish don't look real good at first,til sanded
and a fiberglass boat holds and takes alot of abuse
http://www.dennistaylorsreproductions.com/SHOP TOUR.htm
try this site and scroll down and see a shiny custom car finish don't look real good at first,til sanded
and a fiberglass boat holds and takes alot of abuse
http://www.dennistaylorsreproductions.com/SHOP TOUR.htm
Zuki,
Thanks for all the links, I have spent quite some time looking through them. The idea of fibreglass with a mould does seem fairly involved and difficult. My impression is I can get the result I want more easily with MDF, however, I can also see it could be good to use the outer resin layer of fibreglass for its hardness and finish.
Fibreglass with a mould looks like extra work. ... I'm stil trying to grasp how Hurdy Gurdy managed to get the curve in two dimensions with timber bending ....
Thanks for all the links, I have spent quite some time looking through them. The idea of fibreglass with a mould does seem fairly involved and difficult. My impression is I can get the result I want more easily with MDF, however, I can also see it could be good to use the outer resin layer of fibreglass for its hardness and finish.
Fibreglass with a mould looks like extra work. ... I'm stil trying to grasp how Hurdy Gurdy managed to get the curve in two dimensions with timber bending ....
Paul,
I don't understand the problem. Do it the same way you are doing the rest of the cab, by using braces to get the proper bend. It's only a slight bend, so having different degrees of curvature shouldn't prove too difficult. Experiment with a thin piece of plywood and mdf first to see which works better.
I don't understand the problem. Do it the same way you are doing the rest of the cab, by using braces to get the proper bend. It's only a slight bend, so having different degrees of curvature shouldn't prove too difficult. Experiment with a thin piece of plywood and mdf first to see which works better.
stack 1/8 sheets of maso nite , bending each thin sheet to the shape you want and add another atop it til it gets 1/2" or 3/4" thick ?
or bend any thin wood material,fasten in place, mix fiberglass resin ,cover thin wood with glass cloth and pour/brush the resin over it, let dry a day/then sand it
i could show better than type what i mean, it is really not hard
or bend any thin wood material,fasten in place, mix fiberglass resin ,cover thin wood with glass cloth and pour/brush the resin over it, let dry a day/then sand it
i could show better than type what i mean, it is really not hard
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