Using a pre-fabbed baffle - how do I get 90* corners so it fits properly? - AVS Forum
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post #1 of 23 Old 01-22-2013, 07:52 AM - Thread Starter
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I am building some boxes for my front speakers and decided to use a pre-fabbed baffle (mainly to try something different) which has a routed lip around the entire perimeter (11/32" wide by 15/32" deep area removed along the outer perimeter of the baffle). This requires a recessed "channel" to be routed along the inner edge of the front face of the speaker box so the baffle fits properly. The picture below shows the type of cut I need to rout into the front face of the speaker box. The red dotted line represents the outer edge of the recessed cutout area I need to make in the speaker box. I have not assembled the panels yet, fyi.

How do I get 90* corners to match the sharp 90* corners of the baffles? Obviously the router bit will leave the corners rounded. The problem is only with the top and bottom panels - the side panel cuts are straightforward based on how I am assembling the cabinet. I could do 45* bevel cuts for the corners of the top, bottom and side panels but would rather not go that route.

Another option would be to slightly round over the corners of the baffle.

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post #2 of 23 Old 01-22-2013, 07:56 AM
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Originally Posted by Aaron_G View Post

How do I get 90* corners to match the sharp 90* corners of the baffles? Obviously the router bit will leave the corners rounded.
Use a chisel.

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post #3 of 23 Old 01-22-2013, 07:59 AM - Thread Starter
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Is it really that simple? I was thinking I needed to achieve this via some machined option but if it's that simple then I feel really foolish asking redface.gif
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post #4 of 23 Old 01-22-2013, 08:03 AM
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Originally Posted by Aaron_G View Post

Is it really that simple? I was thinking I needed to achieve this via some machined option but if it's that simple then I feel really foolish asking
These days guys don't think about using hand tools; give them a chisel and many would be puzzled as to where to find the 'on/off' switch. rolleyes.gif

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post #5 of 23 Old 01-22-2013, 08:08 AM - Thread Starter
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My first thought was to just use some a chisel since the material that needs to be removed is relatively small but just assumed there was some "trick" I was missing. biggrin.gif
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post #6 of 23 Old 01-22-2013, 08:38 AM
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Despite having over 50K in woodworking machines for that job I would reach for a chisel, more specifically a corner chisel. To do a "perfect" job without a corner chisel (which I assume you do not have) you need a SHARP chisel (bench or paring it doesn't matter). The problem is most woodworkers don't have a good chisel and almost never have a sharp one. A well sharpened chisel with a micro-bevel will cut paper like a razor blade but most woodworkers with a bent toward hand tools (I do both) will have hundreds of dollars invested in sharpening implements alone. I say all this to make a wild guess you may not have a proper chisel available, even buying a (good) chisel would not work since it will need to be lapped, sharpened and honed. The best solution is a flat "chisel" Xacto blade and taking your time. Score the wood first so you are less likely to have tear out and take your time and you can get a nice near perfect corner. The best blade would be an Xacto #18 but a #17 would work in a pinch.
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post #7 of 23 Old 01-22-2013, 08:52 AM
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Originally Posted by Bill Fitzmaurice View Post

These days guys don't think about using hand tools; give them a chisel and many would be puzzled as to where to find the 'on/off' switch. rolleyes.gif

And how in the heck do I get the bit out of this wooden chuck?

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post #8 of 23 Old 01-22-2013, 09:00 AM
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Originally Posted by JD in NJ View Post

And how in the heck do I get the bit out of this wooden chuck?

Or wonder where the battery charger was since without a cord it must be battery powered...
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post #9 of 23 Old 01-22-2013, 09:01 AM - Thread Starter
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Originally Posted by PsychoM3 View Post

Despite having over 50K in woodworking machines for that job I would reach for a chisel, more specifically a corner chisel. To do a "perfect" job without a corner chisel (which I assume you do not have) you need a SHARP chisel (bench or paring it doesn't matter). The problem is most woodworkers don't have a good chisel and almost never have a sharp one. A well sharpened chisel with a micro-bevel will cut paper like a razor blade but most woodworkers with a bent toward hand tools (I do both) will have hundreds of dollars invested in sharpening implements alone. I say all this to make a wild guess you may not have a proper chisel available, even buying a (good) chisel would not work since it will need to be lapped, sharpened and honed. The best solution is a flat "chisel" Xacto blade and taking your time. Score the wood first so you are less likely to have tear out and take your time and you can get a nice near perfect corner. The best blade would be an Xacto #18 but a #17 would work in a pinch.

Well, anything that requires me to buy some new tools is OK in my book smile.gif

While I could come to my own conclusions eventually, what are some good brands of chisels to consider? My brother and I want to get into woodworking so we'll need some good chisels at some stage.

Good info on the other option of using an Xacto blade. I have time to do it right so at the very worst I can go this route. But I want to explore acquiring some quality chisels in general.
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post #10 of 23 Old 01-22-2013, 09:03 AM - Thread Starter
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BTW, I am currently reading Tage Frid's book on woodworking (the first two books) and it's definitely got some throwback info in it, like cutting dove tails by hand, etc.
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post #11 of 23 Old 01-22-2013, 10:36 AM
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Quote:
Originally Posted by Aaron_G View Post

Well, anything that requires me to buy some new tools is OK in my book smile.gif

While I could come to my own conclusions eventually, what are some good brands of chisels to consider? My brother and I want to get into woodworking so we'll need some good chisels at some stage.

Good info on the other option of using an Xacto blade. I have time to do it right so at the very worst I can go this route. But I want to explore acquiring some quality chisels in general.

I am a big fan of Lie-Nielsen hand tools. There are also some quality chisels available from Lee Valley, but I don't have much personal experience with them.

That being said, learn to sharpen your blades and a package of Stanley chisels from the local hardware store will do the job quite well, although you may need to hone them more often.

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post #12 of 23 Old 01-22-2013, 01:07 PM
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When you put it that way, I've got to wonder why you wouldn't just round the corners of the baffle.
Quote:
Originally Posted by PsychoM3 View Post

Despite having over 50K in woodworking machines for that job I would reach for a chisel, more specifically a corner chisel. To do a "perfect" job without a corner chisel (which I assume you do not have) you need a SHARP chisel (bench or paring it doesn't matter). The problem is most woodworkers don't have a good chisel and almost never have a sharp one. A well sharpened chisel with a micro-bevel will cut paper like a razor blade but most woodworkers with a bent toward hand tools (I do both) will have hundreds of dollars invested in sharpening implements alone. I say all this to make a wild guess you may not have a proper chisel available, even buying a (good) chisel would not work since it will need to be lapped, sharpened and honed. The best solution is a flat "chisel" Xacto blade and taking your time. Score the wood first so you are less likely to have tear out and take your time and you can get a nice near perfect corner. The best blade would be an Xacto #18 but a #17 would work in a pinch.

Noah
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post #13 of 23 Old 01-22-2013, 01:46 PM - Thread Starter
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Originally Posted by noah katz View Post

When you put it that way, I've got to wonder why you wouldn't just round the corners of the baffle.

I'll admit, rounding the corners of the baffle is still an option at this point, but I'd have to do a test run to make sure it was correct. Either way will require some time to make sure it's correct.
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post #14 of 23 Old 01-22-2013, 02:09 PM
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When you put it that way, I've got to wonder why you wouldn't just round the corners of the baffle.

I'd probably still reach for a chisel to do that. Setting up a jig to round the corners with a router would probably take me longer than doing it by hand unless it was a big production run.

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post #15 of 23 Old 01-23-2013, 05:42 AM
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I am confused about this.....Is the original problem that the edges of the (pre-fab) baffle are but at angles, ie similar to what you would cut into a piece of crown molding with a miter saw? If so, would you not just run the boards for the top/bottom & sides through a table saw set to an angle that matches up with the baffle? Is a chisel really capible of cutting a precise angle like this? If so, any tips on how to do it correctly? (I am a total newbe and apologize if these are stupid questions).
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post #16 of 23 Old 01-23-2013, 05:59 AM
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You guys are over thinking this. It's all going to be covered by the baffle if I understand the OP correctly. So you have options: hack out the 90 w/ a chisel, knock off the corners of the baffle at a 45 w/ a chisel, or drill the box at each dashed line intersection with a 1/4" bit.

I use this to sharpen chisels:

http://www.amazon.com/DMT-D6FC-6-Inch-Dia-Sharp-Double-Sided/dp/B000GD8WHY/ref=sr_1_27?ie=UTF8&qid=1358949350&sr=8-27&keywords=dmt+diamond+sharpening+stone

This is my chisel set:

http://www.homedepot.com/h_d1/N-5yc1v/R-100067444/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=chisel&storeId=10051#.UP_sMB3nXSg
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post #17 of 23 Old 01-23-2013, 06:14 AM
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Quote:
Originally Posted by Martycool007 View Post

I am confused about this.....Is the original problem that the edges of the (pre-fab) baffle are but at angles, ie similar to what you would cut into a piece of crown molding with a miter saw? If so, would you not just run the boards for the top/bottom & sides through a table saw set to an angle that matches up with the baffle? Is a chisel really capible of cutting a precise angle like this? If so, any tips on how to do it correctly? (I am a total newbe and apologize if these are stupid questions).

Think about the simplest case of this, which is a stopped dado for a shelf.

If you use a router to cut the dado, at the end of its travel it will leave a semi-circular end, that is the nature of using a round bit.

So your shelf, which is squared off, won't slide all the way forward, and there will be a big ugly gap in the side just in front of the shelf.

Your options in that case are:
  • Use a mortising tool or chisel of some sort to square the end of the dado
  • Use a router or chisel to round off the end of the shelf
  • Use a saw or router to notch the shelf so it can be slid forward further

This case is similar to that, in that a channel is being routed, and the 90 degree turns are only sharp on the inside, not the outside. The panels intended to fit into them will interfere.

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post #18 of 23 Old 01-23-2013, 10:46 AM
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I was thinking about this earlier and it hit me their is a cheaper corner chisel. Whiteside makes an excellent small corner chisel that would work well in this senario, should run $20 or so. You will still need to use a chisel or similar implement to cut the waste out from the bottom.

As for chisels in general I have used them all, from Blue Spruce to Harbor Freight specials, save the new Lee Valley PM versions. Lie Nielson makes an excellent chisel and even at their price I suggest them to new hand tool workers since they come ready to use out of the box. If you don't have a mentor it is hard to know what a good chisel can do until you have had one in your hands. That said most people, even long time woodworkers don't want to pop for Blue Spruce or LN chisels. By far the best value in western chisels are Narex, Highland and Lee Valley both sell them but I would go with the imperial bench chisels from Lee Valley (Highland only has the metric last time I checked). That and one of the sharpening kits from Lee Valley (I would go with the one with the Veritas MkII jig) and one can do a lot. If you want to save even more money on sharpening google scary sharp and look at the sandpaper sharpening approach. On my point about imperial bench chisels vs metric, with a bench chisel it makes no difference really but with the option I tend to go with imperial.

Sorby and LN sell good corner chisels but the Whiteside would be the cheapest way to have a corner chisel that would work well here. If you decide on one of these small corner chisels do NOT get one of the cheaper versions like Porter Cable and Grizzly sell both are garbage IMHO.

Even the most ardent power tool woodworker needs some good handtools, the three essentials that pop to mind are a small set (4) bench chisels, scrapers and a high angle block plane. I do caution as handtools can be a vortex for money, the next thing you know you will have 20 hand planes, a wall full of saws, 30+ chisels and be arguing over oil stones, water stones and diamond stones... You know you are completely off the deep end when you have a 2 and three jaw brace, actually use gimlets, start a rounds and hollows collection and start thinking of taking out a second mortgage to have Karl Holtey build you a custom infill plane... http://www.holteyplanes.com/


One other thought if you happen to have access to a square chisel mortiser you can use that to square the edges. Ha I figured out a way to use a power tool after all.
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post #19 of 23 Old 01-23-2013, 12:53 PM - Thread Starter
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Originally Posted by PsychoM3 View Post

*snip*

One other thought if you happen to have access to a square chisel mortiser you can use that to square the edges. Ha I figured out a way to use a power tool after all.

Thanks for the input on the chisels, it gives me some great info.

As far as a mortiser, I don't have one (yet). I am going to find a good corner chisel and clean up the corners that way, I think it will be the most efficient path.
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post #20 of 23 Old 01-24-2013, 04:30 AM
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Originally Posted by JD in NJ View Post

Think about the simplest case of this, which is a stopped dado for a shelf.

If you use a router to cut the dado, at the end of its travel it will leave a semi-circular end, that is the nature of using a round bit.

So your shelf, which is squared off, won't slide all the way forward, and there will be a big ugly gap in the side just in front of the shelf.

Your options in that case are:
  • Use a mortising tool or chisel of some sort to square the end of the dado
  • Use a router or chisel to round off the end of the shelf
  • Use a saw or router to notch the shelf so it can be slid forward further

This case is similar to that, in that a channel is being routed, and the 90 degree turns are only sharp on the inside, not the outside. The panels intended to fit into them will interfere.

Ok, this just confused me like a trillion times more, but, I appreciate you taking the time to try and help me! LoL. What is a dado? What are you referring to as the shelf? I have never really used a router, so I am not sure what is "at the end of its travel". Also, what do you mean by "square the end of the dado"? Please bear with me as I am a total woodworking newbe, but with that being said, I am also very serious about learning how to do this stuff. Any further attempts to educate me would also be greatly appreciated! Thanks!
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post #21 of 23 Old 01-24-2013, 05:00 AM
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A dado is a square-bottomed groove cut into a piece of wood. Here's an article all about making dadoes with a router. The referenced article will tell you more than I can and has pictures, too. smile.gif

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post #22 of 23 Old 01-24-2013, 08:11 AM
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Thanks JD! That was a great instructional. I will definitely be building a dual fence jig.
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post #23 of 23 Old 01-29-2013, 10:30 AM - Thread Starter
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FYI, after all that hoopla I was able to cut the corners using an Xacto knife and taking my time. They turned out just fine. If I had a lot of these to do, I would throw down on a good chisel.
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