Miters on big pieces

[Kenneth Walton]

I'm making a case piece and I want to miter the corners. The problem I see is size - the sides will be about 3/4 x 18 x 48. I have a crosscut sled, but cutting with the blade at 45 degrees throws off my zero clearance cut. I'd rather not make a new one! I also have a chamfer bit and a track saw. Thoughts?!?

[Kevin Jenness]

Cut the pieces to size with square edges and then cut the bevels using the rip fence.

[Mark W Pugh]

Add a 45 deg fence to your crosscut sled.

[Kenneth Walton]

Maybe I'm using the wrong terminology - bevel might be a better descriptor? Think like a mitered box only bigger.

The problem with my rip fence is that I've only got 36" capacity and need to cut a couple of 48" pieces. I might be able to go off the left side of my saw if I move my bandsaw, but I'd also have to make a new crosscut sled. Sounds like I just have to man up and do it!

[Warren Wilson]

I have made some 36"-long edge cuts at 45 degrees on 3/4" plywood using a track saw. They came out sharp and precise.

[Max Neu]

Since you don't really have sufficient equipment like a slider, I would take the tool to the work piece.A track saw or just a straight edge with a power saw and good blade would be your best bet.

[Peter Quinn]

I'd use the track saw if you don't want to make the sled, either should work fine.

[Tom Ewell]

18" cut, use new sled, box shape
48" cut, use track saw, column shape
Or maybe precut the 45's on large stock with track saw, then rip the width (depth) of the box on the table saw. IE. two sheets, 36-1/4" with miters cut to 48", rip to 18"

[Patrick Walsh]

Just did this an hour ago with a mft/3 and a track saw with some Azek for header on a front entry door.

The miters came out razor sharp and perfectly square...

[Kenneth Walton]

Ok. Track saw it is!

[Rich Engelhardt]

I have a crosscut sled, but cutting with the blade at 45 degrees throws off my zero clearance cut. I'd rather not make a new one! I also have a chamfer bit and a track saw. Thoughts?!?
You could always pick up a lock miter bit/set?

Personally, I'd wimp out and use my track saw...however.....adding a lock miter to one's arsenal of techniques isn't a bad idea.

[ian maybury]

A lot depends on the ability of the track saw to deliver a clean cut at 45 deg. Even a Festool will possibly struggle without a fresh blade and making sure that the hold down strip (zero clearance equivalent) is working properly...

[Martin Wasner]

If the track saw is up to it, that seems like your only option really.

I would cut a piece of scrap whatever to act as a spacer to bump the track for the saw into. Clamp it down to the piece you want to cut, bump the track up to it, and make your cut. Repeat on the otherside. So long as you don't change the size of the spacer and it's cut squarely, you should get four pieces that are as close as you're going to need them. Figuring out how big the spacer needs to be might take some fiddling around, but it be more repeatable, and quicker than marking everything out.

[Curt Harms]

I'm making a case piece and I want to miter the corners. The problem I see is size - the sides will be about 3/4 x 18 x 48. I have a crosscut sled, but cutting with the blade at 45 degrees throws off my zero clearance cut. I'd rather not make a new one! I also have a chamfer bit and a track saw. Thoughts?!?

I made a microwave cabinet to hang on the wall out of 3/4" borg oak plywood. I cut the miters on the table saw using a good miter gauge and dado insert. Reinforced the joints with biscuits (before I knew they didn't add any strength to a joint:p). I did have a little bit of a gap on one section so moistened the edges and rolled 'em together with a smooth screwdriver shaft. Still good after 10+ years. I should make a zero clearance 45o zero clearance insert one day.

[Brian W Smith]

You can conceivably write a mathematical formula for the ratio of a panels flatness(during the cut) and the size of the contact patch of whatever pce of equipment your debating.

Another way of looking at it is;using a combination sq vs a framing square to check the end of a board.The first is only using a 4" base and the other is utilizing a much longer one.Which is more accurate?It would be the latter under "most" circumstances but there are exceptions.....it IS these exceptions that the above formula could resolute.

Whatever method(tool) you decide on or have available....look at the panel like it wants to be assembled.IOW's you "may" need to brace it straight before making the cut,determined by the tool's base size,N'est-ce Pas?