Cutting angled front baffles??

[Jim85IROC]

I believe this is JonMarsh's design?

My question is how do you cut the slanted portions of this front baffle? I am interested in a somewhat similar design for an RS180/27TDFC 2-way that I'm building, but I've struggled with ways to cut this type of angled front panel. The best I can think of is to set up a jig to pass it through my table saw or radial arm saw, but those blades aren't large enough for me to cut beyond a certain depth.

Anyway, any pointers would be greatly appreciated. Thanks!

[Paul H]

If I recall Jon cut that baffle on a larger table saw with a 12" blade.

It could be cut on a bandsaw with appropriate jigs, or cut part-way with a regular table saw and finished with a handsaw and plane.

But you're right - it's a difficult cut.

Paul

[taz13]

If you have a decent tool rental in the area you can rent large diameter circular saws that can do it. On my practice cuts I made a jig and used one of my Korean pull saws. Worked just fine. You could probably use a backless dovetail saw as well. Make your lines and use double sided tape to hold the jig on. All the jig is really, are 2 pieces of wood cut to the proper angle to guide the saw.

[ThomasW]

Actually Jon cut the bevels on a $300 Ryobi tablesaw, with a 10" blade. As I recall it was cut as two sections that were then glued together.

[JonMarsh]

Well, Thomas W mostly got it right...

It was cut on a Ryobi BT3100 table saw- the top and bottome bevels done in 2" thick sections, which were glued up from 1" thick sections, (which were routed individually for the required holes). Then, the complete 4" thick panel was clamped up from the 2" sections, and after setting, was sawed for the side and front bevels.

The Ryobi BT3100 has an unusual design, it's belt drive but with a wide, flat belt with a small diameter pulley. As a result, it will do depth of cut on angles which can only be matched by standard 12" saws, as Paul was surmising. The BT3100 also comes standard with a pretty decent sliding miter table. This is an accessory which can cost $300 to $800 for many saws. Now, I wouldn't say this is a "production shop" saw- it's built for a hobbyist duty cycle or work load. But with a very small effort, it can be setup to do some nice, accurate work- it's easy to square up to a high level of precision, and the standard fence is the best I've seen in a saw under $1,000.

I made some custom jigs to work with the sliding miter table for the cuts. Also, the cuts on one side are done with the front baffle flat, on the other with it at 90 degrees (side down). It took a bit of effort to work out... more a triumph of determination over tool time skills, as I'm more a wires and sparks kind of guy.

[Jim85IROC]

Thanks a ton for the info. I need to go home and measure my table saw... I think it's a 12", based just on the fact that the blades are too big to fit on my 10" radial arm saw.

Since my cuts won't need to be as deep as yours, as long as I can figure out how to make a jig to hold the panels properly, this might not be so impossible after all. Thanks for the info.

[Ten 99]

Not impossible Jim, but I'd be surprised. 10" Table saws are pretty standard issue, until you get into some higher dollar production machines in 12" and 14" setups. Unless you paid big bucks, or inherited a nice machine, I'm betting it's a 10" setup. With careful planning, good jig setups, and a dash of luck, a person can cut the baffles half thickness at a time, or even quarter thickness at a time, and then glue up the laminations after the bevel cuts are done. If doing quarter at a time cuts and then gluing the lams up afterwards, I would highly suggest the use of a plastic resin glue. The main reason is that this glue dries much slower than standard yellow wood glue, and will give you more working time to get the quarters stacked precisely and clamped down.

Jon, have you looked at some of the newest 10" contractor saws that are available from grizzly, bridgewood, etc? They offer some really nice units with Biesemeyer clone type fence systems, and at prices under $600 with cast iron extension wings, these are well made machines that will last a LOOOONG time. The BT3100 saws are great little saws, especially for the price. But that loud direct drive motor, and setup just has it's limitations. I guess in the end, it's all about what you need that TS to do for you.

[markrpaulson]

I'm also building the M8ta under Jon's intense tutelage.



I was very apprehensive about doing the cuts, but they actually turned out to be relatively easy, and were done on a 10" saw that's at least 30 years old. It still gave me 2" of vertical depth, or 2.828 inches of hypotenutal bevel width. I did all the cuts at 10 degrees, so I cut a wedge of MDF with a 10 degree taper that was as long as the baffle, screwed two blocks to the top that were flush with one edge, and then affixed said blocks to the back of the baffle (more screws). If you marked the cuts well, you just bump the fence up to where the cut begins and slide it through, detatch the jig, flip the baffle over, and do it again.

[Paul H]

Not their first cabinet project ...

Paul

[Ten 99]

Amatures....

[David Meek]

That had to be cast, right? Right? 8O

[Dennis H]

Nope, mostly wood. On the Mad board, Aaron said he built a rib framework and glued down 3 layers of 1/4" Masonite on the curved surfaces. Front and back baffles are 2 layers of 3/4" MDF. The tweeter enclosure is a PVC pipe. He didn't say but I assume he used something like Bondo to feather everything together.

[Davey]

Hideous looking. Seriously.

Davey.

[JonMarsh]

Hideous looking. Seriously.

Davey.

:rofl: :rofl: :rofl: :rofl:


:agree:



Well, it just depends on what you're into...

I like Kieth Kidder's Translams, for example.

Aaron's speakers are a little too Automotive and Wilson Audio for my personal taste... but I'm an old fogey of sorts, I guess. Still stuck on wood.

I wonder how the diffraction properties actually are?

But masonite walls? just three layers?


Well, variety is the spice of life!

[Paul H]

Hideous looking. Seriously.

Davey.

I was commenting favorably on the talent and care required for construction - I'm with you on the appearance. Although, beauty is in the eye ..

Paul

[Dennis H]

Geez, you guys are no fun. Square boxes and flat surfaces get boring after a while. I think he has some good construction techniques that could be translated to a veneer and solid wood box, with multiple curves, that would impress even the Luddites among us.

[JonMarsh]

Geez, you guys are no fun. Square boxes and flat surfaces get boring after a while. I think he has some good construction techniques that could be translated to a veneer and solid wood box, with multiple curves, that would impress even the Luddites among us.

Would you like to take that on as a homework assignment for now, Dennis? I've got my hands a little full at the moment... you know, my usual over extension based on ruthless otpimism...

[Dennis H]

Yeah, I'll whip something up today and post pics.

[Jim85IROC]

I checked the table saw over the weekend. It's a 12" Craftsman. I talked with my father (after all, it's his equipment), and he said that between the table saw and the radial arm saw, he's pretty sure we can come up with a jig to do what I'm looking for.

Here is a picture of what I'm basically trying to achieve. The main difference is, I intend to make the cuts flat instead of radiused like in the pic. At the most, I'll do a slight roundover just to smooth the transitions:

Image not available

[Ten 99]

Jim, your dad must have a nice vintage 12" Craftsman saw. Back when they actually made some power tools that were worth owning. Sad it isn't that way for them now. Although they have recently stepped up their game, they still have some room for improvement.

Looking at the picture that you attached above, I really get the sense that the cabinet construction methods used in the above picture have an MDF cabinet construction, with some hardwood lamination's over the top. The black parts are most assuredly MDF that has been painted black. If you look at the front section of the tower that is almost facing straight on, and look at the wood section below the black, you can see a clear edge line and some dimensional seem between it and the side panels. If I'm a guessing man, I'm betting that the section underneath the front of the black section is veneer. I can't see the rears, I won't venture to guess.

The danger with mounting wood panels to the sides of the enclosure, is that MDF will do little or no moving at all with regards to humidity and temperature. It is dimensionally stable. A real wood panel on the side (these look to be 1/2 to 3/4 of an inch thick) has wood fibers that will expand and contract with regards to humidity and temperature. Some species are more dimensionally stable than others (ie.. they won't expand / contract much). If you glue the panel to the MDF, and the panel is subject to normal expansion and contraction, you will eventually see that the wood may split, crack bow, etc. What you consider in a situation like this, is to secure the panel with screws. You can screw from the inside of the cabinet out. It would be best if the MDF had some slightly slotted holes for the screws to go through to allow for some slight wood movement, while one edge did not have the slotted holes to pin the edge more for holding the panel's place. I would also suggest that if this method is used, that you apply a finish to the back side of the panel (that is against the MDF) as well. This will make the absorption of moisture more uniform, and will prevent cupping or bowing.

That edge that is on the side panels above looks like it was done with a chamfering bit on a router or router table.



The curved angle on the black section would be much more difficult to replicate.

[Jim85IROC]

Here's the thread originally posted on madisound:

http://www.madisound.com/cgi-bin/discuss.cgi?read=327748

The front panel is covered in leather (ala Sonus Faber) and the cladding is solid hardwood. My version will be MDF with a cherry veneer. Before I decide on specifics, I'll angle cut some MDF and practice veneering it to see if I like the results. If not, I'll do a roundover instead of a chamfer.

I may also experiment with a version of Transverse Lamination to construct curved sides. Rather than build a template to cut out the entire shape of the enclosure, I may only cut out the sides in this method to cut down on waste. I can then build separate front and rear panels out of flat wood.



Similar to this, but only the sides will be cut this way.