Thread: Mitre Gauge ????

From my experience....if you buy an Incra, adjust the fit to the mitre slot properly, and take the time to align it with your blade accurately, the answer to your question is YES.

Best upgrade I've done to my JET ProShop saw. The mitre gauge that came with it was a piece of junk IMHO.

I have an Incra mitre gauge. I re-set it each time. It gets close, but not close enough. Even with clamping the piece to the gauge, there is some movement, and you will not end up with tight edges.

I use a vintage Stanley mitre (hand) saw and then plane the edges on a shooting board.

Regards from Perth

Derek

Interesting to get two opposing answers

Cheers Jerry

When cutting angled pieces for use in segmented turnings, I use a custom made sled with the fence adjusted by test cuts until exact. The fence is then screwed permanently in place.
Result is repeatable, accurate angles.
Downside is, you really need a separate sled for each angle.

Originally Posted by Mr Brush

, adjust the fit to the mitre slot properly, and take the time to align it with your blade accurately,.

.....which is why I said this

Your mileage may vary I guess.

There is a video at Stu's Shed. I think this is the link Saw Alignment and Incra Miter Express Stu's Shed

I'm probably as much of a perfectionist as anyone, and I reckon once the Incra's properly set up it's unbeatable ... and setting it up is no big deal.

AlexS - glad to hear I'm not the only one who thinks the Incra gauges work as their maker intended.....

Important issues are

Take the time to set up the mitre bar adjustment screws one by one as you feed the bar into the slot. Each one should be wound out until the bar just binds in the slot, then wound back a touch to allow free movement without any play. If this is done properly for all of the adjustment screws, there will be no side-to-side movement of the bar in the slot at all.

Use the board end-over-end method to set up the 90 degree position of the mitre gauge as accurately as possible. I'm talking using a vernier caliper to measure the two sides of the test board until the edge lengths are within 0.05mm of each other.

Once this is done, I've found all the laser cut detent positions on the mitre gauge to be spot on. Take a look at the specifications for ALL the Incra gauges (I only have the cheaper V27); they quote an absolute accuracy of 0.02 degrees, with repeatability of 0.01 degrees. That's more than good enough for any joinery I do !

Thanks for all the replies.
Mr Brush what does board over end meean ??

I am a big fan of my Incra 1000S and it should provide the accurate mitres required for picture frames.

However, that is only part of the story. You will also need a tablesaw, and blade, that will give you a very clean cut. It is for this reason that most picture framing places use a guillotine, it can cut omplex mouldings, most already finished with intricate finishes, without damage. They also cut a right and a left hand mitre at the same, giving a perfect match.

Jerryj - its just method of exaggerating any error in the mitre gauge setting (at a nominal 90 degrees).

I usually use a piece of scrap MDF or ply, but you can use a solid board. Prepare a piece long enough to register accurately against your mitre gauge fence (i.e. at least 200mm), and reasonably wide (maybe 120mm or more). The board should have parallel sides, but the ends don't matter because you are going to cut both of them anyway. Board can be any thickness you like.

With mitre gauge set to 90 degrees, place your board against the mitre gauge fence (mark this reference edge) and make a cut across the end of the board. Then, keeping the same edge against the fence, flip the board end over end (so that the opposite face is upwards). Make another cut across the other end of the board.

If you measure the two long sides of the board, the difference in length is twice the misalignment of the mitre gauge to the blade. Adjust the gauge a bit, then repeat (making small cuts off the same board) until the two edge measurements come out the same. The ends of the board are now exactly 90 degrees to the reference edge, your mitre gauge is set up, and all other angles will be as set. There is a video somewhere on FWW or something showing how to do this - I couldn't find it with a quick search. Obviously, the wider your board, the more the mitre gauge error is exaggerated. I keep the length of my board short enough that I can compare the two edges using a vernier caliper for greater accuracy.

Big Shed - I agree. The Infinity Combo blade I have leaves a glass-smooth finish on end grain. Its also a good idea to have a strip of fine sandpaper glued to your mitre gauge fence to prevent the workpiece slipping - even tiny movement of the workpiece as the blade cuts will stuff up your mitre.

Many years ago I actually used an industrial picture frame mitre cutter. It had two saw blades arranged in a V-formation rather than a guillotine, but the blades were at least 80 tooth giving a very fine cut. Only problem was that it had no clamps near the blades to hold the frame molding flat against the fence, so even a slight bow resulted in a crappy cut. Rather than spend the money on the optional clamps, the owner had simply removed the guards (and nobbled the cutout microswitches ) so that the operator could hold the molding a bit closer to the blades and pull it into the fence......sigh

Needless to say, after 2 days of this I quit. I told him that my fingers were worth more than $15/hour.......

I might be a bit late on this thread but I agree that the incra properly set up with a decent blade and well tuned table is spot on. In order to stop sideways movement on the sled I make sure the incra backstop is up against the timber hard so that it cant slip sideways during the cut. If you do this the timber cant move and the cut will be a true 45 (or whatever angle) without any sideways slack due to operator error and movement.

FWIW... my SCMS is the only machine that I have ever been able to "out of the box" cut a true and accurate compound cut (Mak LS1214).

I understand Derek is a bit of a purist however I cant comment on his failure to get a spot on cut. I can.... all the time! Perhaps he gets sideways play on the crosscut?? If thats the case the trick I suggest earlier in this post may be an answer for him/you.

As I said the incra and a well tuned setup CAN be set up to do a wonderful job. for the record I have a MSB300 a freud 72 (?) crosccut blade and I've tuned the table to be square to 0.003 (half a human hair!!) of an inch using the carbatec dial gauge. the incra I had to put a paper bush behind one of the lock screws to get it spot on... and IT IS spot on now.

Thanks very much for all the replies very interesting.

Cheers Jerry