Computer desk on hold...need ideas for cutting large cove on leg.

[Jim O'Dell]

Well,Ken, I guess you're off the hook for a while. :D I'm redesigning the computer desk idea..changing from a corner desk with a 45 cut on the business side, to an L shape. And I'm going to wait for the wood. I don't have enough money saved for the all of the wood I need. I'd rather it not sit out in the shop for too long in this heat and end up only being usable for water skis. :rolleyes: Plus there are a couple accessories I need to get to do this right. Which brings me to this post.
I will need to cut a cove in the inside corner of the leg in the L. The wood will be 2 pieces of QSWO planed down to about 1 1/2"and glued together to make to make a roughly 3X3 post. I'd like it to be a 2 1/2" radius to closely approximate the outside curves in the furniture I'm trying to blend into, but that is going to be pretty tough to do. Is my best bet going to be a crown molding bit, like this: 198969 and make several passes to get the complete inside curve? Is there a better/cheaper way? I considered using the saw blade, but don't think I could get a tight enough radii. I also thought about using the nose of my belt sander, but man, that would take a while!! Any ideas would be appreciated! Jim.

[Rod Sheridan]

Hi Jim, rough it out by grooving on the tablesaw, then refine the cove with a scraper.........Rod.

[Jim O'Dell]

Rod, if I were to try this on the saw (the looks of it has always scared me) I know I'd have to make a sled, or clamp down a guide to push the wood against at the proper angle to get the smaller than blade diameter for my cove cut, but how high should the blade be? And what type of blade should I use? I guess a scraper can be purchased of the right diameter? And would probably be less than the router bit pictured above. Good place for scrapers? Jim.

[dave toney]

I think Rod may have been suggesting to make multiple cuts lengthwise so that you have a stepped profile and then removing the peaks with a scraper.
draw the cove on the end of the piece of wood and raise the blade to cut to the line and keep shifting the fence and changing the depth of cut.
The peaks will scrape off fairly quickly or you can use a curved sanding block and coarse sandpaper.
Dave

[Jim O'Dell]

Thanks Dave. Guess my mind jumped to the technique I've seen on videos where the wood is pushed through the blade at an angle to make the cove, knowing you would have to go up in small increments so the body of the blade isn't hitting the wood, since no cutting action would take place. I like the nibble away idea, and that may very well be what Rob was talking about. I did find Woodcraft has a set of curved scrapers on sale for 11.99. Might be the best way to attack this without creating an extra expense. Thanks for the clarification. Rob, let us know if this is what you were talking about. Jim.

[Brian Tymchak]

Jim,

I can't offer any practical advice, but I bookmarked this page (http://woodgears.ca/cove/calculate.html) on cutting coves with the TS a while back thinking I might someday need it. It has a calculator to figure out the angle of the fence and blade heights. I think you can do some pretty narrow coves by using less fence angle.

I was also thinking that maybe a stair rail bit in a shaper could make that cut for you but I couldn't come up with any in my relatively quick search that cut the shape you need.

Brian

[Rod Sheridan]

Jim, I was suggesting cutting grooves using a rip blade in the conventional manner, not diagonally, as Dave indicated.

I would use an old card scraper and just grind it to the profile, or turn a sanding block in the lathe to the correct radius..........Regards, Rod.

[Ryan Hellmer]

I've had good luck with the diagonal feed on tablesaw method. It's really not as scary as you'd think. Just raise the blade incrementally to prevent issues (1/16-1/8" at a time) The resulting profile is easy to finish with sandpaper or a scraper. I've heard more teeth is better but I've only ever used a 40T combo blade on it. CMT also makes a cove blade for tablesaws. It looks like a shaper cutter (a big one) and has rounded tops. Finish is supposed to be really good. Just FYI

Ryan

[Jim O'Dell]

Thanks guys. Great information. The calculator is especially neat. Wish it was in inches instead of metric for my old brain!! :p But it wouldn't be hard to figure it out and get close.
But as fate has it, after drawing up the second set of plans, looks like plans will change again. LOML wants the computer case hidden. Doesn't like my blue lights I guess.:cool: So we may be rearranging the bedroom furniture to accommodate a normal shaped desk with storage. Now to see if I can get all that out of one sheet of ply, and still have enough left over for repairing the damaged top fields of the dresser and night stand. Guess I could still make it L shaped and modify the plans I already have. :rolleyes:

[Bob Wingard]

+1 on using the angle-cutting method. I've done it several times, and never felt uneasy about it. There is a program out (I THINK it's free or share ware) called COVECUT ... it shows what the profile will look like using various angle & blade heights, and allows for asymetrical work, as well.

Go here .....

http://www.woodcentral.com/bparticles/bpindex2.shtml#downloads

and, in the middle of the page you will find a link to "COVECUTTER.EXE 1.0"