Miter Cutting Precision

How to boost the accuracy of miter cuts for doors, without spending too much on equipment. July 28, 2012

We are having difficulty getting precise miter cuts for our mitered cabinet doors. I have checked out the Unique 245 machine that miters, finger joints and dowels all in one. It's an excellent machine that costs over $19K, which we can't get into right now (just took a lease of $22K for machinery a few months ago).

We use a shop made miter table saw sled to cut our 45s, but it's not precise. Is there an inexpensive miter saw/machine that is very precise? I wonder what frame makers use to cut their frames?

Forum Responses
(Cabinetmaking Forum)
From contributor J:
I've seen several Pistorious double miter saws going on online auctions for very reasonable prices. May be something to look into.

From contributor T:
How are you fastening your joints together? We use a double miter saw, then a kerf saw, then a clamp nail. It is a fast and accurate, indestructible joint. But you need 5/16 on the back side of your door rail.

From contributor C:
We use biscuits to join together, but we are looking into adding a dowel to the joints as well (since the dowel will keep the joint in line when we assemble on our Ritter door assembly machine).

I am pretty certain that the reason we are not getting perfect miters is our table saw miter sled has a little wiggle in it. I was thinking of trying a regular miter saw like a Dewalt or Bosch, and mounting a fixed miter jig on it. The miter saw will be fixed at 90 degrees, but the jig will have 45 angled fences on the left and right (sort of taking the shop made table saw miter sled and fixing it on a miter saw). What do you think?

From contributor K:
I asked the same thing last spring and what I came up with was to cut my miters on my Dewalt 10" miter saw. I used a J.A. Dawley stop system with a miter stop. Spot on cuts every time. I used an Amana, Prestige blade to first cut the miter, then shave it clean with a second cut. To join the miters, I used a Grizzly horizontal boring machine fitted with a router to cut 5 mm slots for Festool Dominos. This, surprisingly, worked extremely well. Yes, slower than a 20k machine, but you can't tell I only spent $500 on the setup.

From contributor M:
Sounds to me like you need new rails for the miter sled. I have a piece of 3/4" UHMW that I bought to make a miter sled, but haven't gotten to doing it yet. I figure the flat head screws countersunk into the plastic will make an adjustable rail rather like the Incra rails on my miter 5000. Incra markets the rails as an individual item as well. Go to their site and take a look at item 8A. For only 40 bucks it might be worth a try to fix the miter sled.

From contributor J:
Only problem I see with the jig mounted to the miter saw is you would have to have the pieces cut to length first. So it's adding an extra step. Besides that, if you have a good quality blade in there, it could do the trick.

From contributor L:
We've got an Omga miter saw, very good blades: slick, dead-on miters. The 14" Omga will most likely last you the rest of your life. No second shave cut needed! But costs more than several DeWalts.