long 30 degree cut

[sbryan]

I'm attempting to make a triangular floor lamp. My current design calls for making the three sides separately, then joining them with 30 degree beveled edges. I'm having difficulty finding the best way to make a cut of this angle. I currently don't have a table saw, so in my first "prototype", I set up a complex jig to hold each end piece (a 1-1/2" x 2" x 12" board) upright so that I could cut a 60 degree angle using my circular saw. It did it, but it wasn't very clean.

My latest thought is to purchase a 30 degree chamfer (?) bit for my router, but so far haven't found one in the local HW stores. If this is the way to go, then I think I can order one online, but would like some advice first. Is this the best option? As I mentioned I have a circular saw and a router as well as a 12" compound miter saw and a not so great jig saw. The final version of the lamp will be about 6' tall (therefore a 6' long cut), so I think the miter saw is out!

[MadMark]

Borrow a TS.

Seriously.

The bit angle is 60° and that is a steep chop on a router. Plus the slightest shift will show.

See if you can't beg, borrow, or steal a TS from someone. There are some jobs you just can't do without the right tool and this is one of them.

M

[woodspinner]

[font size="1" color="#FF0000"]LAST EDITED ON Dec-19-00 AT 02:28AM (CDT)[/font][p][font size="1" color="#FF0000"]LAST EDITED ON Dec-19-00 AT 02:27*AM (CDT)[/font]

OK if you can not borrow Mark's saw ;) then here is what you might try:

create a jig in the following manner:

it will be longer than your needed length.

It will be wider than your saws base is wide by several inches.

It will be shaped like an "L" and be a real accurate 90 degree angle support it underneath with angled brace if needed.

And now you will need to "calibrate" it:

Adjust your saw blade to the needed angle, remember you have added in the 90 degree angle: that will help make setting your saw easier.... place it on your jig, right up tight to the edge of your jig, with the saw blade guard "UP" and mark your jig at the edge of your saw's base, better yet, take a piece of scrap and set it next to the base and clamp it in place. Remove saw. MARK next to the scrap of wood and measure that to the edge of jig, and then measure and mark that same distance on the other end.

Attach a very straight 1X2 as long as your jig, and screw it onto your jig on the marks use enough screws to keep it from shifting as this will be your saws fence!

Now to test your jig, attach it to a piece of old particle board, scrap ply etc. the same size as your desired "real wood" using "C" clamps on both ends set far enough down that your saw blade will of course clear it when you cut... <you have of course drawn the needed line "as if" it was what you wanted> SET TO THAT LINE.

Clamp your test pice so that it is now vertical to any solid item that you can: do you have a work bench???? it must be solidly mounted. your jigs "table" and fence are now horizontal and you can safely run your saw on the "table" next to your fence and you will have your angle!

The extra length should be at the start end of you cut, and will allow your saws guard to be lifted and for you to "get straight" onto your board.

It should run along your drawn line where you will want your angle cut. you will have an accurate fence to run next to allowing you to do your cut.

AFTER you test cut, check to see how close you are to your line!!

YOU may have to adjust the fence, probably away from your line a little bit, but you will not be able to know that until you actually do a test cut!

I know that all sounds like a lot of work, but without that table saw of Marks ;) you need to make do, and if you follow those instructions and have a good sharp blade, you will have better results than "free hand" ANYTHING!

I hope that helps... and remember "where there is a will, there is a WAY!!!!"

Phil

[Glen]

I'm in disagreance with 'madmark' here. I would go with a chamfer bit.If you use a router table and a fence with hold downs and feather boards you'll get much better results. The key is the hold-downs/featherboards to keep your work flat on the table and snug against the fence. Make a series of passes, don't try to take it all off in one bite, maybe even rough it out on a table saw.
Oh and a source for your bit is EAGLE tools....very quick to
ship. They have bits for hex, oct, pent etc. etc.

Glen

[MadMark]

A router bit is NOT the answer!

Problem is that the angle is a 30º cut (reference a straight cutter at 90°). That makes the router bit at least 3½" in diameter for cutting ¾" stock. (a 30° angle is a 2:1 run:rise, so if his stock {rise} is ¾" then his run {depth of cut} is 1½" x 2 for the diameter of the bit is 3" plus a ½" shank - you're certainly not going to find a 3" cutter on a ¼" shank - makes a total tool diameter of 3½") I don't think you'll find a 30° cutter. This is essentially a panel raising bit.

Now using a 60° cutter and cutting with the stock against the fence instead of the table is going to make using featherboards and holddowns essentially impossible.

I don't think you're visualizing this setup properly. He is trying to remove 60° of the stock so there is only 30° relative to the face! This will require an "against the fence" cut no matter what he cuts it with.

There is an alternative.

Instead of mitering both sides of the angle to form an equalateral triangle with the edge in the corner, Bevel the edges of the board at 30° and put the edge of one against the *face* of the other. The seam moves off the corner and 1" or so into the face of the triangle, but the cut suddenly gets a *lot* simpler.

M

[sbryan]

You're right, Mark. That's where I keep getting cloudy. The cut is actually 60 degrees to leave 30 degrees. I think I will try your last alternative. Unfortunately I don't think I can make all the sides look the same, but it shouldn't be that noticable.

Thanks to everyone for their input (not that I'm suggesting it stop - more opinions are welcome). This is my first posting to this forum and I'm amazed at the great and quick responses!

[woodspinner]

Mark, I agree with your statements about router bits on this... and the zero angle right off from the fence is a no no when you own one of those fancey Incra fences like you do... <read great levels of jelousy there> :7

However... neither on the posts after mine said anything about the jig I suggested... I have used it before, not for as many cuts as he has to do (two per side, six total) but what it is is a zero fit to the edge of the wood... and allows the 30 degree needed angle to be cut....

When I used this jig, the set up crew had borrowed my posrtable table saw... and I was "stuck" in "do this now mode" I placed the wood to be cut in my Black and Decker Work Mate (the poster did say he was short on tools... I did not ask him if that was one he owned...) and made the cut... worked fine.... It would not be my FIRST choice <first choice go to Mark's Shop and use his TS>

But in the field... make do with what we have is the rule!

phil

[MadMark]

Here is my analysis of what you're trying to make and how to cut on both the router and the TS.

http://www.netexperts.cc/~lambertm/Wood/triangle.gif

I hope this clears up what I'm trying to point out. In some cases a picture is really worth a thousand words. I assumed you'ld need a ½" threaded rod for the wiring down the center of the lamp. It's a LOT easier to attach the lamp parts if you use a threaded rod. I also assumed ¾" stock thickness. Note that by repositioning the mitre you not only make it a lot easier to build but you also can use less stock for the SAME amount of wood.

M

[Lou_williams]

Mark,

I for one can't see your picture. My Brouser can't find the Server.

[MadMark]

We had a crash last night 'cause of the cold. We should be back on the air later tonight or tomorrow AM at the latest.

M