LumberJocks

How to cut a tapered arc?

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by kme3113 posted 09-16-2014 06:20 PM 1235 views 0 times favorited 22 replies Add to Favorites Watch
View kme3113's profile

kme3113

5 posts in 814 days


09-16-2014 06:20 PM

I have been starting at these two pictures for what seems like an hour trying to figure out how you would be able to cut a tapered arc like this? I thought maybe a band saw and then the cut the board lenth wise at an angle. That would still not work since the arc would be the same all the way through. Any ideas how to do something like this? Hopefully this is not something requiring a lathe. Thanks for the help.


22 replies so far

View firefighterontheside's profile

firefighterontheside

13511 posts in 1323 days


#1 posted 09-16-2014 06:30 PM

I would think you could make a jig to do this on the tablesaw. It’s hard to say how they did it. The guy appears to be about to push that piece thru the tablesaw free handed and there does not appear to be a blade in the bandsaw. I would say make a long cove in a long piece and then cut them into smaller pieces, but then the grain would be running the wrong way in comparison to these pieces. I bet they were done by a cnc or some other piece of machinery like that.

-- Bill M. "People change, walnut doesn't" by Gene.

View BinghamtonEd's profile

BinghamtonEd

2281 posts in 1836 days


#2 posted 09-16-2014 06:31 PM

Looks like they cut the arch at the table saw (google “cove molding on table saw”), then cut the resulting piece at an angle on the bandsaw, either by tilting the table, or with a jig, or both.

Edit : I don’t think the grain direction is wrong, it would probably just indicate that the stock was cut down to smaller blanks before making the arch in it.

-- - The mightiest oak in the forest is just a little nut that held its ground.

View firefighterontheside's profile

firefighterontheside

13511 posts in 1323 days


#3 posted 09-16-2014 06:35 PM

I know Ed, just would be hesitant about doing that cove at the saw with such a small piece.

-- Bill M. "People change, walnut doesn't" by Gene.

View kme3113's profile

kme3113

5 posts in 814 days


#4 posted 09-16-2014 06:35 PM

Thanks for the replies, I was thinking the cove molding as well but think where it tapers in towards the top in the second picture would not work. I am assuming its some CNC but was hoping for someway to replicate it at home without a huge piece of machinery.

View Loren's profile (online now)

Loren

8313 posts in 3114 days


#5 posted 09-16-2014 06:36 PM

Looking at the grain direction I think the simplest
way to do it would be to bevel the end and cut
the cove on the band saw. You might be able
to concoct a jig to move the work in an arc.
It will have saw marks though which will be
difficult to sand to a flawless curve.

Alternately, cut all your blanks, bevel the ends and
glue them together in a sawtooth pattern to
make a long cross-grain board. Wedges may
be glued into the saw-tooth for support. Then
cove it out on the table saw, cut the parts
apart and remove the wedges.

The “wedges” could also be replaced by attaching
a board to each side of the sawtooth pattern. It’s
just there to bear against the surface of the table
saw. Carpet tape wold probably be adequate…
and clamps would not necessarily interfere.

Such thing can be made with a copy router as
well. There are plans for ones you can build.

View kme3113's profile

kme3113

5 posts in 814 days


#6 posted 09-16-2014 09:05 PM

I think maybe a jig that holds the board at an angle… that way as it runs throught the tabel saw the cove cut starts with a big chunk of the wood and then tapers as less of the wood is touching the blade. I will give it a go this evening. Hopefully it works. I have a lot to learn and looking through this forum is amazing. Amazing what you guys can do.

View bigblockyeti's profile

bigblockyeti

3668 posts in 1187 days


#7 posted 09-16-2014 09:15 PM

I second (or third) what Ed mentioned cutting the cove on the tablesaw. I’ve done this with the grain, across it I would first cut the pieces to length and attach them in some form to a board where many could be fed through at once. Then cut the taper on the bandsaw and sand the tapered face smooth on a belt or disc sander. Just guessing on the size, looks to be about 4” x 5” x 1 1/2-2”. You could safely cut the cove on 8-10 depending on the length of your jig fence and the size of your out feed table. I would be interested to see what these are used for.

View kme3113's profile

kme3113

5 posts in 814 days


#8 posted 09-16-2014 09:46 PM

its a passive amplifier for your phone. I was thinking about making one for myself and stumbled across this one. Though it was fairly unique and in the process would learn something new trying to build it. Have yet to attempt any cove cuts at this point.

View Rick M's profile

Rick M

7929 posts in 1846 days


#9 posted 09-17-2014 02:49 AM

The guys in the picture are just posing, the bandsaw doesn’t even have a blade. The people running that website are shamming the public into believing these are handmade by craftsman. My guess is they are CNC’d or simply drilled at an angle.

-- http://thewoodknack.blogspot.com/

View Steve Peterson's profile

Steve Peterson

325 posts in 2548 days


#10 posted 09-17-2014 03:05 AM

I agree with Rick. The pictures look fake. The table saw blade is too high and way to dangerous to cut a cove like they show. And the bandsaw has no blade.

-- Steve

View Yonak's profile

Yonak

979 posts in 987 days


#11 posted 09-17-2014 04:10 AM

I think this could easily be done with a band saw and a spindle sander. Starting with a square block, cut and sand the arc first. Then cut the angle off the block. Forget the table saw. That’s a ruse.

View BinghamtonEd's profile

BinghamtonEd

2281 posts in 1836 days


#12 posted 09-17-2014 12:02 PM

People keep pointing out that there’s no blade in the bandsaw. Hasn’t it occurred to anyone that it has a really, really, really, really, really super think kerf blade?

Edit : Wait a minute, I recognize that technique!

-- - The mightiest oak in the forest is just a little nut that held its ground.

View bigblockyeti's profile

bigblockyeti

3668 posts in 1187 days


#13 posted 09-17-2014 12:08 PM

I too agree with the posing, no bandsaw blade, wearing gloves, no splitter, guard or riving knife on the tablesaw, not to mention no fence. Definitely marketing geared more toward those more interested in the latest offering from Apple than actually knowing how things are made.

View MadJester's profile

MadJester

1947 posts in 1896 days


#14 posted 09-17-2014 12:25 PM

Well, the pics you have there are obviously a set up…they are clearly fake…blade too high on the table saw, no blade on the band saw…etc…..but then I remembered this video from the Wood Whisperer that I ran across a few months back…

http://www.thewoodwhisperer.com/videos/coves-on-the-tablesaw-the-parallelogram-cove-jig/

It shows both a straight cove and an offset cove…so I suppose that you could then go to the band saw and cut at an angle to get the pieces shown in the pics you have….but I really think the pics are just poorly laid out marketing pics or something like that….

-- Sue~ Mad Jester Woodworks, "Not what I have, but what I do is my kingdom" Thomas Carlyle

View Jim Jakosh's profile

Jim Jakosh

17172 posts in 2571 days


#15 posted 09-17-2014 12:38 PM

I would use a band saw and spindle sander.

-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!! Variety is the Spice of Life!!

showing 1 through 15 of 22 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com