FWW Funny

[B a r r y B u r k e J r .]

Fine Woodworking has an article about cove cutting on tablesaws in the current issue. The article mentions that the spreadsheet will be available online.

On the FWW site, there's no sheet to download, as they say the macros will set off virus protection on some computers. It looks like someone rewrote the thing in Java or some other language that will run online. I really wanted the sheet, as I use a PDA in the shop that isn't connected, so I emailed FWW and asked for the formulae to make my own spreadsheet. I have this kick ass shop spreadsheet that includes my cut list generator, Cape Cod Bob's shellac sheet, some miter calculators, it's really handy. The cove calculator would have fit into it well.

The response was "The author dosen't want to make the data public".

I can fully respect that, maybe the guy wants to sell it as a stand alone app? No problem there.

Why not simply SAY THAT on the site?

Barry

[Bob S.]

Go to the page where the applet is running, right-click on the screen and select View Source. That will give you some clues as to the formula. You can save it to a file for viewing offline also.

Bob S.

[Greg G.]

Doesn't save the graphics or buttons, however. The calculator popup is supplied by an ASP script. Saving the page results in missing graphics. Oh, Look! There is a standalone post in A.B.P.W.

Greg G.

[B a r r y B u r k e J r .]

Right after I posted the original message, I realized that the applet was written in JavaScript, which is uncompiled, and did exactly as you suggest.

Barry

[Bob S.]

That Phantom guy sure is pretty smart.......:-)

Bob S.

[Mike in Mystic]

here's a downloadable cove calculator you could use offline:

's one of the programs in the list)

[B a r r y B u r k e J r .]

The attraction to the FWW version was that it would go into my Excel sheet, making it very easy to use across different platforms.

Thanks for the tip, though!

Barry

[Bob S.]

sheeeesh....there's just no pleasing some wooddorkers.

Live with it......;-)

Bob S.

[J Pagona aka Y.B.]

Actually, it all can be done with Trig functions, which can be put into an Excel worksheet. I roughly worked out the functions when driving to work this morning. I suppose I could take 15 minutes to work them out completely and post them here. Now if I can just get a spare 15 minutes. David

remove the key to email me.

[Bob S.]

Okay.... I'll give you 10 minutes.... anyone got a spare 5 minutes they can donate to David?

Bob S.

[J Pagona aka Y.B.]

OK, OK...here's what I've got.

Assuming a 10" diameter blade with an 1/8" kerf...

H=height of the cove and height of the blade.

W= the width of the cove

a=the angle of the fence. 0° is the fence perpendicular to the sawblade. 90° would be the fence in a normal rip cut position.

W=2*sqrt(10H-H*H)*cos(a)+0.125*sin(a)

My math skills are not up to solving for "a", so that you could plug in the desired height and width of the cove and get the angle. (What do you want, I'm a three time community college drop out.) But, you can put the formula into a spreadsheet where one column has angles increasing by one degree increments from 0° to 90°, and the next column has the formula with "H" as a constant reference to a cell where you input the height and "a" as the angle on the same line. This way, you could see for any given blade height what the cove width would be for any given angle.

Anybody still with me? David

remove the key to email me.

[B a r r y B u r k e J r .]

Yeah!

I'm going to test the calcs this weekend.

Barry

[Stephen M]

Me too.

I have always "snuck up" on that type of cut. I have to do this for a piece of crown this weekend. I'll do the imperical test.

[J Pagona aka Y.B.]

Well?

David

remove the key to email me.

[B a r r y B u r k e J r .]

Never got the chance to test it, got tied up working on a window seat / shelving unit. Not to mention two hockey games, a 7:05'er on Saturday night and a 4:05'er today. I'll do my best to try it this week.

I'd like to use some custom cove molding on the shelving unit, so we'll see how it goes.

Barry