CECAA850 Posted September 1, 2012 Share Posted September 1, 2012 Seems I'm building more horn loaded subs these days. My latest build will be a BFM TableTuba for my back porch. Horn loaded subs have a LOT of panels on the inside of the box. The pic below shows the outline of the 13 panels that will have to be cut for this particular sub. I love building subs but don't really care for ripping all those panels. Every panel has to be exactly the same heigth or else the last panel won't fit flush and possibly leak. Beings that I'm generally lazy (and cheap), I wanted to find a method to rip the plywood that didn't involve spending any money and be very accurate. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 Once I determined how wide I wanted my sub to be, I subtracted the thickness of my saw guide and cut 2 pieces of scrap plywood to length. It's critical that these be EXACTLY the same length. I clamped 2 pieces of scrap together and cut both ends with one swipe of my saw. I then clamp those pieces flush to the end of my plywiood. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 Then it's just a matter of butting your guide up to your scrap spacers. My guide is made from a scrap piece of MDF. The sides are machine straight on MDF. I glued that to a piece of plywood for the saw to slide on. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 Lay another piece of scrap plywood down so the saw saw rides perfectly perpindicular to the piece you're cutting. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 Then just let er rip. There's no measurements to screw up and the cuts are repeatable and accurate........every time. Carl Quote Link to comment Share on other sites More sharing options...
Quiet_Hollow Posted September 1, 2012 Share Posted September 1, 2012 ooooo....Table Tuba. You'll enjoy that one! Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 ooooo....Table Tuba. You'll enjoy that one! Dual drivers[6]. Quote Link to comment Share on other sites More sharing options...
Coytee Posted September 1, 2012 Share Posted September 1, 2012 You're using a circular to make the cuts huh? Nice! Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 1, 2012 Author Share Posted September 1, 2012 You're using a circular to make the cuts huh? Nice! A 30 year old Craftsman to be exact. I'm also using it to cut all my bevels. I use a protractor to set the angles and run it along the guides. They come out perfect. Quote Link to comment Share on other sites More sharing options...
Turbox Posted September 1, 2012 Share Posted September 1, 2012 nice, keep the thread going with your build. Quote Link to comment Share on other sites More sharing options...
Schu Posted September 4, 2012 Share Posted September 4, 2012 I've always wondered... why do horn loadeds never use angled joints/corners on the interior tube structure? would there not be a benefit from angling the joints more subtly? Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 4, 2012 Author Share Posted September 4, 2012 I've always wondered... why do horn loadeds never use angled joints/corners on the interior tube structure? would there not be a benefit from angling the joints more subtly? If you're talking about rounding the corners in the horn path, I think it's been proven that there's no benefit to it and it would involve a lot more work. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted September 4, 2012 Moderators Share Posted September 4, 2012 Nice work, it's really the only way to get a straight cut on large pieces, without spending a ton of money. I did something similar, just clamped a large strait edge to run the saw guide/edge on. I couldn't do like you did there were no square angles on mwm tops and bottoms and each piece took up 3/4 sheet of plywood. After checking measurements a few times before cutting it worked great. At $50 a sheet for hardwood ply I did not want a silly mistake considering I needed 12 sheets without a mistake. Now you know we need you to have pics of this all the way to the end, it's only fair now that you got us started. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 4, 2012 Author Share Posted September 4, 2012 Now you know we need you to have pics of this all the way to the end, it's only fair now that you got us started. I'm normally pretty slow when building, so it may take a while but I am taking some pics as I go. This particular sub needs 15 seperate panels to be fabricated and most of them have bevels (or so it seems). There's also a lot of bracing that needs to be angle cut. I've got 6 panels cut so far. This coming weekend I need to drive over to FL (13 hrs 1 way) for my fathers memorial so it may be a couple more weekends before I can work on it. Carl Quote Link to comment Share on other sites More sharing options...
juniper8 Posted September 4, 2012 Share Posted September 4, 2012 Nice work and thanks for sharing, if you have a chance show us your bevel cutting technique.... Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 4, 2012 Author Share Posted September 4, 2012 Nice work and thanks for sharing, if you have a chance show us your bevel cutting technique.... The guide is set up the same way. I just take a protractor and set the angle on the saw bed before I make the cut. I'll look and see if I can find the pic that I posted in another thread. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 4, 2012 Author Share Posted September 4, 2012 Here it is. I believe this was a 7 degree bevel. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted September 4, 2012 Moderators Share Posted September 4, 2012 No rush just explaining what we want. [] Glad you got to spend some time with your Dad. Sorry Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted September 5, 2012 Author Share Posted September 5, 2012 Pics you will have, patience you must possess. There should be something for me to post in a couple weeks, stay tuned. Quote Link to comment Share on other sites More sharing options...
Schu Posted September 5, 2012 Share Posted September 5, 2012 I've always wondered... why do horn loadeds never use angled joints/corners on the interior tube structure? would there not be a benefit from angling the joints more subtly? If you're talking about rounding the corners in the horn path, I think it's been proven that there's no benefit to it and it would involve a lot more work. Interesting. thanks Quote Link to comment Share on other sites More sharing options...
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