Circular saw recommendations (for cutting facets)?

[---k---]

Other than only have two drivers holes , looks good to me. :T

[JonW]

Other than only have two drivers holes , looks good to me. :T

I've got a 3 way in mind. That's my next project. :twisted:

[JRT]

I’ll be cutting facets into the front baffle of my ongoing project. After reading and thinking about it, the circular saw method, as shown below from jquin, might be the best way to go.

If you are only going to occasionally make cuts like this, instead of using a power tool, consider using a frame saw. The frame saw would be a lot safer,and it will also give you more control over the cut. And if you are going to have to build special saw guide jigs and fuss with setups on the circular saw, the handsaw might not take a lot more time as you would only need to make a few layout lines to cut parallel to.

(edit) I found another link, a closeout deal at Woodcraft.

http://www.woodcraft.com/family.aspx?familyid=4608&mode=details#tabs

http://www.traditionalwoodworker.com/default.php/cPath/37_126_570

Image not available

[chasw98]

You definitely DO NOT have a stable enough surface for the saw to sit on. I can see from the pictures that the 'non edge guide' part of the saw board needs to be closer to the sawboard actually providing the guide and needs better support so that you do not sag or move in the horizontal plane. A picture is worth a thousand words in this case. If you look at my pictures I had a much smaller gap between the sawboard and the supporting sawboard to make my cuts. Oh well, good practice and a way to get a feeel for how the saw handles. BTW, did it cut deep enough?

Chuck

[JonW]

JRT,

Interesting idea. I hadn't thought of that. Do you think there is a good way to align things such that you could get a good cut of the facet?


Chuck,

I think you're right. I need to get everything more solid and stable. Not sure how I'll do that. Maybe use the test baffle as my support for the second, non-cutting side of the saw. That might be more solid and less mobile. And I'll move the second, non-cutting saw board closer to the blade. Good ideas. Any others?

[JRT]

JRT,

Interesting idea. I hadn't thought of that. Do you think there is a good way to align things such that you could get a good cut of the facet?

I suggest cutting a couple of under sized facets for practice. You can make those practice cuts in the waste portion of the facet cut. Just mark the three edges of the final facet, then make some parallel markings for smaller practice facets. Make sharp lines. Make the cuts to the outside of the lines, leaving the lines intact on the loudspeaker cabinet.

When you are done with the cutting, sand to the line, with a hardwood sanding block, starting with very coarse open coat garnet sand paper. Then move up progressively to finer grits of open coat garnet. Don't go beyond 320. The more different grades of sandpaper you use, the more grits you use, the quicker it will go. It really will not take much effort to get it flat and smooth this way. it will add effort and time if you skip grits and try to do too much sanding with an excessively fine grade.

[JonW]

I made my “real” fact cuts. Here’s what I found…
I used the method that Chuck and I both posted photos of, above. JRT- your method may be something to try in the future. For now here’s what I did.

I made some more practice cuts and could not get things to align perfectly when I made a cut on one side, then tried to do the same on the other. So here’s what I found to work OK:

Start with the cut you’ll make with the saw in the middle. You’ll be pulling the saw out toward you to make this cut. (Not really pulling the saw toward you- that would be dangerous. But for the sake of orientation here, from where the photo is taken.) Let’s say this will be the top left corner of the baffle, when looking at it.





See how deep the cut was made. Then, on the other corner, mark an equivalent cut with a pencil. We’re on the top right corner now. Make the pencil mark on the top edge of the baffle, that you are looking at when looking from the ceiling down onto the speaker, if it were standing up.

I used a three-sided ruler to mark the cut line- that makes it easy for drawing the 45 degree cut line. This isn’t the one I used but it’s about the right idea:



Then align the saw boards and put the saw up to the baffle. Here the cut will be made standing where I was when taking the photo. I will push the saw forward. I arranged the saw boards and saw such that I could see the blade lined up right onto the cut line I made with the pencil. This photo doesn’t really show it well. But the idea is that you kneel down and look along the edge of the saw blade. Make sure it’s aligned with your cut line that is on the top edge of the baffle. Then make the cut. (Note this photo was from practice, not the real cut.)




If that makes any sense I hope it might be useful to others.

And the final product:

[ColoradoTom]

Jon.....

Here's another option using a table saw. Look about mid-way through the thread.

https://www.htguide.com/forum/showthread.php?p=250091&highlight=facet+jig#post2 50091

The jig holds the baffle at 45 degrees so that you can get the maximum depth from the table saw blade. With a 10" saw you should be able to get 3 inches deep.


ColoradoTom

[Paul Ebert]

I plan to use a jig like yours, Tom. Did you consider attaching a runner on the bottom (at the appropriate angle) to ride in the t-slot, rather than the angle jig against the fence? That's what I'm leaning toward.

[CraigJ]

Jon,
Here is a picture of the All-in-One Clamp and saw guide that I use. Not only is it an excellent and safer setup for facet cutting, you can even use it for ripping your full sheets of BB. More info can be found here; https://www.bt3central.com/showthrea...023#post234023
Good luck and thanks for sharing.
Craig

[JonW]

Jon.....

Here's another option using a table saw. Look about mid-way through the thread.

https://www.htguide.com/forum/showthread.php?p=250091&highlight=facet+jig#post2 50091

The jig holds the baffle at 45 degrees so that you can get the maximum depth from the table saw blade. With a 10" saw you should be able to get 3 inches deep.


ColoradoTom

Hi Tom,

I actually looked at your sled setup many times before trying what I did. Thanks for posting the details way back when you did. I tried something different for 2 main reasons. First, I don't think that my table saw is big enough to support the whole setup well. Second, you said you were going to try something different next time.

Jon,
Here is a picture of the All-in-One Clamp and saw guide that I use. Not only is it an excellent and safer setup for facet cutting, you can even use it for ripping your full sheets of BB. More info can be found here; https://www.bt3central.com/showthrea...023#post234023
Good luck and thanks for sharing.
Craig

Hi Craig,

Thanks for posting that again. Now that I tried the regular saw board, those clamps look more interesting. Using the saw boards, things did turnout OK. But could be a little better. I'm done for now with cutting facets for these 2 way speakers. But I've got a 3 way project in mind. So I'm on the lookout for future facet cutting ideas there.

For those All-in-One clamps can you clamp down onto the work piece at an angle? If everything has to be clamped at 90 degrees it might not be so good for cutting facets.

In your link they also discuss the EurekaZone setup. That might be even better. It looks like it has a good way to keep the saw running straight alongside of the clamp, minimizing any unwanted movement of the saw, etc. Not sure if that will clamp at non-90 degree angles. Something for me to consider for the next project, along with the All-in-One clamps. Link here:

http://www.eurekazone.com/index.html

[CraigJ]

For those All-in-One clamps can you clamp down onto the work piece at an angle? If everything has to be clamped at 90 degrees it might not be so good for cutting facets. Link here:
http://www.eurekazone.com/index.html

Good question regarding the non 90 degree cuts. I suppose an 80 degree and 10 degree block (assuming a 10 degree angle), either hot glued or held on with a brad, could be attached to the side and top of the baffle. Any other woodworkers have a suggestion? Also, did you clamp your baffle to the BT3100's sled when cross-cutting? If my memory is correct, Jon purchased the BT3100 because it could cut the facets on the M8ta with one cut. Lots of interesting was to cut a facet. Tell us more about your planned 3 way.
Craig

[ColoradoTom]

I plan to use a jig like yours, Tom. Did you consider attaching a runner on the bottom (at the appropriate angle) to ride in the t-slot, rather than the angle jig against the fence? That's what I'm leaning toward.

Good idea...but be careful because you have to run the baffle through opposite sides of the saw blade to cut the facets on both sides of the baffel. With the setup I had I just unscrewed the handle and attached it to the other side, moved the fence to the exact same distance on the opposite side of blade, and made the second cut.

Tip: Draw the facet cuts on the baffle before you cut... that way you'll be able to look at your setup prior to actually cutting to be sure you've aligned everythin properly!! You'll also be able to see the blade track the lines you've drawn as you make you cuts!

Tom

[Paul Ebert]

Good points, Tom. My first reaction was that I could flip the jig and run it in the slot on the other side of the blade, but they are not equidistant from the blade (one is 4", the other 5). I wonder why they did that?

Of course, there are four facets to cut per baffle. I'll have to think about this some more (when I'm not so tired).

However I make the cuts, I will certainly mark out the cut and make test cuts. Fortunately, I have a good bit of scrap for such a purpose.

[JonW]

Good question regarding the non 90 degree cuts. I suppose an 80 degree and 10 degree block (assuming a 10 degree angle), either hot glued or held on with a brad, could be attached to the side and top of the baffle. Any other woodworkers have a suggestion? Also, did you clamp your baffle to the BT3100's sled when cross-cutting? If my memory is correct, Jon purchased the BT3100 because it could cut the facets on the M8ta with one cut. Lots of interesting was to cut a facet.

OK, so those All-in-One clamps might not be ideal for this job. I'll look more at that EurekaZone setup. When Tom mentioned his Festool, I looked at that. It seems the really great thing about the Festool is the guide/rail. And, basically, that's what the EurekaZone thing is. If it can be clamped at an angle, that is something I'll consider for my next project. I quite like the idea of a guide/rail for the circular saw that doesn't allow for any significant play or movement.

Tell us more about your planned 3 way.

It's still in the planning stages. I first need to finish my Spassvogel MT's, for which much work remains. But the general idea of the 3 way is to take a similar approach to the MT's: a very "high end" speaker, top notch drivers, lots of effort into the cabinet and crossover designs, etc. Basically make the best speaker possible. The current thought, subject to change, is all Scanspeak drivers. So it won't be even close to cheap. But my efforts with the MT's, so far, look like things are coming together well. Even in the flimsy test cabinets, the MT's sound very nice. To my ears, that is, so all disclaimers apply. Everyone else might hate them, etc.

[David Meek]

Jon,

What blade are you using on the Makita? I just quickly scanned the earlier posts, so my apologies if I missed this.

[peter_m]

Faceted enclosures... What's the advantage?

[JRT]

Faceted enclosures... What's the advantage?

It can help reduce ripple associated with edge diffraction, though not as well as large edge radii.

You can play with this simulation tool to see how things are affected.

http://www.pvconsultants.com/audio/diffraction/downloadbds.htm

Edge treatments well away from the tweeter or small midrange are just for aesthetics.

[peter_m]

And round-overs? Are they also for mid-range and highs?

[JonW]

Jon,

What blade are you using on the Makita? I just quickly scanned the earlier posts, so my apologies if I missed this.

Hi David,

I'm using the stock blade that came with the saw. It's brand new- I've only used it for cutting these facets so far, so it's nice and sharp. It cuts through just fine as is. And it seems to have an easier time of it that the blade in my table saw. Details on that are here, post 400:

https://www.htguide.com/forum/showthread.php?t=25031&page=12

[JonW]

Faceted enclosures... What's the advantage?

Hi Peter,

If you just have square edges to your cabinet, sound can come from the tweeter, bound across the face of the baffle, and then load up at the edges. The result is some frequencies will be more pronounced than others. So smoothing out the edges with a roundover or facet,etc. will help some. Do a search on "baffle diffraction" and you will find a lot of reading on the topic. If you want to play around with some simulations and learn for yourself, look for the programs "Baffle Diffraction Simulator" or "Edge."

I used BDS and came up with some interesting tidbits that helped me understand things:

https://www.htguide.com/forum/showthread.php?t=24931

And if you want to see actual measured data, I tried a few different cabinet configurations and the results are here, on pages 10 and 11:

https://www.htguide.com/forum/showthread.php?t=25031&page=10&pp=35

[Dryseals]

I may have pssed it up, but has anyone suggested using a radial arm saw, it's perfect for cuts like your making. I know a lot of folks don't like them, but I love mine.

[Ray Collins]

I had a radial arm saw during the 1970's and loved it; built a small sailboat with it(Pumpkin Seed from Popular Science Magazine). I never nicked my fingers using one but I have hurt my hands twice in the one year that I have owned my table saw. Seems that the sliding compound miter saw may have influenced the waining popularity of the radial arm saw??

Ray

[chasw98]

I may have pssed it up, but has anyone suggested using a radial arm saw, it's perfect for cuts like your making. I know a lot of folks don't like them, but I love mine.

I have a radial arm saw and use it quite a bit. When I was helping Jon figure out how to make the cuts I attempted to use the RAS for some of the cuts and it does not like doing 45 degree cuts through 2 1/4 inch thick material. Either the motor would bog down or the motor would get in the way when doing a compound cut. Worked great when the material wasn't so thick.

[chasw98]

I had a radial arm saw during the 1970's and loved it; built a small sailboat with it(Pumpkin Seed from Popular Science Magazine). I never nicked my fingers using one but I have hurt my hands twice in the one year that I have owned my table saw. Seems that the sliding compound miter saw may have influenced the waining popularity of the radial arm saw??

Ray

Lawsuits had a very great influence on the popularity and profitability of the RAS. When I bought my 20 year old saw 3 years ago, there was still and still is a class action lawsuit concerning kick back mechanisms and the table to the point that if you sign up or call, the company taking care of the recalls and lawsuits will send you a complete new table (with cnc milled 1 inch thick MDF) and a whole new kickback assembly. Right now, I think only Delta still makes one that is generally available.

[Dennis H]

The biggest problem with radial saws (and sliding miter saws) is that the blade is climb cutting when you pull it toward you so it tends to bind. It can be dangerous and can give you a wavy cut when the blade binds and flexes the arm and head assembly. Of course the better (stiffer) the saw and the sharper the blade, the less of a problem the normal climb cutting is. A way around the binding problem, when you want precision cuts, is to pull the blade toward you, slip the wood in behind it, and cut with a pushing stroke just like with a handheld circular saw.

[chasw98]

Jon.....

Here's another option using a table saw. Look about mid-way through the thread.

https://www.htguide.com/forum/showthread.php?p=250091&highlight=facet+jig#post2 50091

The jig holds the baffle at 45 degrees so that you can get the maximum depth from the table saw blade. With a 10" saw you should be able to get 3 inches deep.


ColoradoTom

Well, I was making some test cabinets today and they are faceted. I finally gave up, admitted defeat, and took Tom's advice. In the end I do not know why I wasted my time with a sawboard and radial arm saw, etc. I was able to make a 'compound sled' in less than an hour and then have accurate facets cut in less than 15 minutes. I made it out of old wood lying around the shop and it works great. If I were going to make a permanent unit, I would change some things, but for ease of use this is it. Thanks Tom!

Top view of Jig



End view of Jig.



Bottom view of Jig.



Results!







Chuck

[JonW]

Looks good. :T And good to see exactly how you did it so well. For my next project (the 3 ways) I will explore different ways to cut the facets from what I did with the Spassvogels. I'll give a shot to what Chuck did here.

But I've got to call Chuck (aka Cadillac Saw, aka Mr. Fancy Pants) on one thing: He recently got a cabinet saw with a 3 HP motor. So I am wondering how well this sled method will work with a smaller table saw like the one I have (Ryobi BT3100).

For the top facet cut on my speakers I used the table saw, rather than the circular saw and saw board. My saw had a very difficult time cutting through 3 layers of birch ply at a 45 degree angle. A new blade might help a little. But I feared burning out my motor. And the surfaces of my saw are much smaller than a cabinet saw. I wonder how the sled approach will work with a large (~40" long) and heavy (3 layer) baffle on a small table saw.