Best way to measure mitre cuts on left tilt saw?

[sphell]

Hi everyone,

I'm hoping some of you experts can help me out. I work in car audio and make a bit of stuff on the table saw (panels, sub boxes etc). Most of the time the cuts are 90 degrees.

Yesterday I had to make an octagonal subwoofer box that fit inside a spare wheel. So I had to cut 8 side pieces with 22.5 degree opposing mitres on our left tilt table saw.

Each piece had to be 158mm long and the only way I measured each cut was to slide the piece through on the mitre gauge aligning the pencil mark by eye.

Got it done ok but I was wondering is there a quicker and more accurate way to measure mitre cuts on a left tilt saw using the fence?

[Arron]

I have to do a similar thing a fair bit and find the best way is to invest a little time in making a table saw sled for the job.

Mine is just a slab of mdf, with a runner underneath, a fence running perpendicular to the blade, a toggle clamp and a movable stop. Of course there is a blade guard too. The syntax is basically to cut the pieces a little long (say 165mm in your case), set the blade at whatever degrees, set the stop at (say) 161mm, cut all the left hand edges, set the stop to 158mm, then cut all the rights.

To make each cut I just settle them against the fence and the stop, activate the toggle clamp, and slide the sled through.

I generally find that if you have jobs to do routinely, or even occasionally, its worth making a sled for the job.

cheers
Arron

[DonIncognito]

Cut the first one by eye, then use that as a guide to set up a stop block for a mitre saw.

Whoops. Just saw the table saw bit. Can't help there sorry.

[sphell]

I have to do a similar thing a fair bit and find the best way is to invest a little time in making a table saw sled for the job.

Mine is just a slab of mdf, with a runner underneath, a fence running perpendicular to the blade, a toggle clamp and a movable stop. Of course there is a blade guard too. The syntax is basically to cut the pieces a little long (say 165mm in your case), set the blade at whatever degrees, set the stop at (say) 161mm, cut all the left hand edges, set the stop to 158mm, then cut all the rights.

To make each cut I just settle them against the fence and the stop, activate the toggle clamp, and slide the sled through.

I generally find that if you have jobs to do routinely, or even occasionally, its worth making a sled for the job.

cheers
Arron

Thanks Arron,

So I'm guessing the edge on your MDF base plate is the reference for measuring/setting the stop? (eg - that edge basically touches the side of the blade as you slide the sled through?)

Do you have a pic of the sled by any chance?

[Arron]

Photo attached. I have shown the blade position with a red line.

This is actually a sled dedicated to 45% cuts. I also have one for 90 degree and one for 60 degree cuts - well they are cheap and easy to make so why not. You could make an variable-angle one if you want. I didn't because an variable one would need a wider blade slot and so would provide less support below the cut, but its probably not that important given a sharp blade.

The stop on this one is micro-adjustable so its a bit more complicated then it need be - Otherwise just a block with a locking-screw and a runner underneath to keep it from turning sideways in the track is all that is needed.

The pointer is not really visible in this photo, but it gives me the measure without having to resort to trial cuts or pulling a ruler out. In this case I align the pointer with the vertical marks on the sled which represent things I often cut - but normally I would have a ruler drawn on the sled.

The forward edge of the stop is sloping at 45 degrees (ie in the same direction and to the same degree as the blade is tilted when the cut is made). This means that the distance from the point on the stop where the upper edge of the stock sits to the rhs of the sawcut remains the same regardless of the thickness of the stock used - so the pointer/scale always read true regardless of thickness of the stock.

On my left-tilt table saw, the stock is always on the right hand side of the blade - so the longest side of the stock is always uppermost. This gives a truer cut then cutting from the lhs, wherein the stock would be pinned below the blade.

One thing I would love to do is find some way of making flip-type stops. These are the sort which flip out of the way when not in use, and can be flipped back when needed and will go into exactly the same position. I've tried making them out of a variety of hinges and other fittings but never really got the repeatable accuracy needed out of home-made solutions.

I know my approach is crude, but its very accurate and the reduction in frigging-around time means it pays for itself very quickly.

cheers
Arron

sled.jpg