Turning boxes?

[Eric Thumb]

I am making smallish boxes (cigar box sized) and I posted a question a few days ago in the woodworking section about how to make the sides slightly curved (and uniform). One of the responses that I received told me to put the box sides on a 4x4 post and turn them. I was amazed. It never crossed my mind that you could do that with a lathe. I have never owned a lathe because I have really only seen bowls, pens and maybe a table leg made on a lathe and I have no interest (at this time) in making them.

I've searched the turners forum a little and have not seen anything referring to making boxes with the lathe so I am wondering if this is something that is not very common or maybe the last guy that tried it got killed by a piece of lumber flying off of the thing.

The sides of the boxes that I am making are around 3 1/4" tall and the wood that I am using is 3/4" thick. I am trying to get a gradual curve on the sides and shooting for 3/8" on the top and bottom and leaving it close to the 3/4" in the middle.

I got to thinking about the 4x4 post and (correct me if I am wrong) but I don't think that i would be able to get what I am after with that. The post would be too small, waaaay too small. I drew the curve on the side of the board tonight and figured it to be around a 6" radius (12" circle). So would I need to put a 12x12 post on a lathe to do this? That sounds like a BIG piece of wood. Would I need to get a second mortgage to buy a lathe that could do that?

Anyway I figured that I would ask tonight because I don't think that my arms will be working tomorrow. I spent about two hours tonight HEAVY sanding the radius on a board with a homemade sanding block that I had cut the curve out with on my bandsaw.

266940

Thanks!

[Lyndon Coad]

Just a thought, check out http://www.sawmillcreek.org/showthread.php?196231-Pterocarpus-Rex-drum-set&p=2103588&highlight=#post2103588

check out his jig for turning drum shells. maybe you could set up a similar, but obviously very different jig for a router.
maybe a sliding router cutter up and have your timber on a swing arm above (literally like a swing)
thoughts?

[Eric Holmquist]

I've seen the basic idea demoed at some Symposiums where they either use a wooden core like you suggest, or use a jig that holds the pieces sort of like barrel staves to get a larger radius of curvature on the outer face.

[Robert Henrickson]

Google "therming", e.g.,

http://www.iwgnortheast.com/May-2011.html
http://www.thamesvalleywoodturners.com/docs/Turn-54MarApril2008.pdf [see p4]

If you are member of AAW, look at the article by Art Liestman
Art Liestman “Beyond Round: Therming” American Woodturner 25.2 [2010] 48-52

[Grant Wilkinson]

If you mount the box sides to a square column to turn them, wouldn't the thickness of the box side turn out to be consistent throughout? The OP wants the sides to be thicker in the middle than at the top and bottom, if I read him correctly?

[Thom Sturgill]

There are several options
1) have a shaper bit made $$$$ We had one for cutting guitar fingerboards bought from a company that went out of business.
2) make a swing arm that will pass the pieces over a belt sander at the right radius. I have done this manually, again for fingerboards.
3) make a carrier for the lathe.

I would make an octagonal box the length of the longest sides plus some for waste. the corners of the carrier should fit a 12" circle. The endcaps will fit to the centers - mount a faceplate on one end. Mill a 5/32" deep groove lengthwise centered on each face wide enough to hold the blank snugly. Attach the blank at the ends with recessed screws or glue - be careful turning it metal is used.

Do at least in pairs, on opposite sides to maintain balance. You can do two complete sets with this jig at the same time.

turn it until the face cuts just touch the corners of the jig. Sand. This jig could also be used with a router as shown above in the drum reference.

If you are not an experienced turner, I would recommend the second option, or the router jig.

[Jeff Nicol]

I guess depending on how many boxes you plan to make with the same profile it would be better to find a way to make longer lengths or a simple jig that could be used again and again to create the profile with a router. Another way would to get an powered hand planer and use it to cut close to the profile and then use the sanding block to finish them. This could be done also with the lathe by turning a drum shape with a cove profile cut around it to the desired shape, then either glue sandpaper into the cove around the drum or use velcro to attach different grits of hook and loop paper to it. With that you could start with a coarse grit and work your way through to a finished piece no matter the length needed.

Just some ideas,

Jeff

[Eric Thumb]

Well after mulling over all of your suggestions (which I really appreciate by the way) I have come to the conclusion that I have no idea what I am doing on a lathe and I can foresee numerous bad things happening if I try to go with a three foot long 12" octagon. I am also too lazy to make a router jig BUT I have thought of another solution.

If I mounted a short section (10" long) of say a 6x6 or 8x8 on the lathe (which I don't have yet) and carved my radius into that could I line it with sandpaper and make into a sanding jig? Has anyone ever tried that? I'm not sure how hard it would be to get the sandpaper to conform to the inside of the jig.

[Bob Hamilton]

If I mounted a short section (10" long) of say a 6x6 or 8x8 on the lathe (which I don't have yet) and carved my radius into that could I line it with sandpaper and make into a sanding jig? Has anyone ever tried that? I'm not sure how hard it would be to get the sandpaper to conform to the inside of the jig.

That would only work if the piece you wanted to make was concave rather than convex. The link about therming showed a solution that would work well for short pieces that wouldn't flex much. A disk of the required diameter at each end with the pieces mounted between them. You would need to make the pieces a bit wider than the finished width because there would be tear out along the edges that would need to be trimmed off after turning.

Good Luck!
Bob

[Eric Thumb]

Bob I must have explained it backwards. I am making the radius an innie, not and outtie. something like this

!\___/!
! -----!
! -----!
!/----\!

If you can imagine a spindle or an hourglass on it's side. Anyway that's my technical drawing..... and probably what my first try at making it would look like. Also I would be able to sand with the grain instead of against it like I would if I tried the therming technique. But I'm not sure how much difference that would make when all was said and done. I've never sanded against the grain on purpose. Maybe it doesnt make much difference if you can sand against the grain with a super fine grit.

[Bob Hamilton]

Hi, Eric:
Yeah, I had completely misunderstood what you were describing when I was responding. So you are thinking of something like a shaped drum sander? I would think it would be difficult to get consistent results without some elaborate jigging. With regard to the cross grain sanding that is pretty much the way all spindle work is sanded. Once you get it sanded to your final grit on the lathe you can take it off and hand sand along the length. Backing up one grit makes it pretty quick to eliminate any cross grain scratches.

Good Luck!
Bob

[Allan Ferguson]

Make a molding plane with the proper profile. Do the grunt work and you will have your box sides. Check with he Neanderthals forum.

[Eric Thumb]

Jeff I just noticed that you posted the same idea that I had. I must have been typing (I'm slow) when you put that on here. Didn't mean to seem like I was ignoring you.

Allan I know less about hand planes than I do about lathes. I am still looking into all my options though. I did use a block plane that I had bought a few years ago to take down the corners some. It was quicker than sanding but I would have ran into trouble fast if I went much further with it.

[Jeffrey J Smith]

I've come to this late, but couldn't you do this on the table saw the same way cove moldings are cut? Google it. Clamp a fence at an angle to the blade and make multiple cuts, raising the blade until the depth of cut is achieved. The blade acts more like a horizontal shaper to cut a cove any depth and width you determine with your fence.

For a cove the size you're describing, seems like the best way.

I've done this for wide cove moldinds for cabinet cornices. The cut can be rough, but sands easily to a good finish if you're patient.