A true 45° angle with a Table saw.

Between the other things I have to do for spring cleanup around our little piece of heaven, I have been tasked to make some sliding, louvered doors to cover an 8 gang switch plate and a breaker box cover. The reason being, the Powers That Be, (from here on out referred to as the PTB’s), decided they wanted the stuff covered because it looked to ‘industrial’ in our faux rustic office.
In the last 3 years I’ve had to take my table saw down, or mostly, down 4 times. Every time I do, it get’s a bit more away from being accurate.
About 3 weeks ago I was trying to make some miter cuts to make the covers for the tracks on the doors. The first set looked like crap. The second set looked like you could slide the blade of a combination square through it on the back.
I decided to get the saw tuned up again, (it’s a Ryobi BT3100), and to do that I had to align the miter slots and the sliding miter sled.

I used an old plastic, 18” engineering square that I’ve had for about 10 years. It use to be dead nuts on, and I didn’t think anything of using it again.
Unfortunately, I let someone borrow it a few months ago and it seems they used it ad a speed square or a fence.
I aligned, adjusted, cussed and did it again and again, all the while making test cuts on scrape wood.
Each piece was off, each cut was off, I felt like my mind was coming off.

I finally decided to look at my wonderful, old engineering squre, and dammit! The person that borrowed it shaved about .05” in a taper on the edge.

I got out my new, Harbor Freight 16” adjustable square, checked it on a table that shows a straight edge, I adjusted it to the n’th degree and used it to align my miter slots. Wow! I made 12 cuts, flat and standing, (standing, just to see if I could)!
No matter how I swapped them and switched them, every miter came out almost perfect.
At most I could get a .0014 feeler gauge in the loose end.

This makes me a very happy camper and I have been doing my happy dance!

The moral of the story is, if something seems to not be working right, check every possible cause, don’t just accept that the square you have that was square yesterday will be square today.
DOn’t accept that your miter gauge is square, even if it is a high dollar Incra, if it bangs against something, it could be knocked out of alignment….......

Check, Check, Check, then do it all again!

-- Improvise.... Adapt...... Overcome!