Getting the mitre guage dead-on 45 ?

[wizer]

Hello

I'm mucking about with picture frames at the moment. I can't seem to get the mitre gauge (in this case the sliding table) to be exactly 45 degrees. I have tried using one of those perspex triangles from a stationary shop and also a roofer's square/triangle thingy. The weird thing is that I set the mitre fence on my shooting board with the roofer's square and that give near perfect results.

Is there a better way to do this? Do I need to invest in a good triangle?

I could just shoot the mitres, but having the TS setup for it would make things quicker and the shooting board only needed to clean up.

TIA

 

[Niki]

Hi Wizer

If you had one of those "Digital angle Gauge" (Wixey), it would be very easy (no, I also don't have but, I want )

I would first, check that the rip fence is in perfect parallel to the miter slot and then, set the miter gauge angle in reference to the rip fence.

Those perspex drafting triangles are usually very accurate, I use them for the 45° cutting sled.

Regards
niki

 

[wizer]

Thanks Niki. I am very suspicious of the drafting triangle. I am convinced it is not true 45. Is there a definitive test I can do on both triangles?

I do have a digital angle gauge actually, I didn't think of that.

 

[motownmartin]

I am very suspicious of the drafting triangle. I am convinced it is not true 45. Is there a definitive test I can do on both triangles?

If you put one of the square edges against a straight edge and draw a line then flip over the square and place the other square edge against the straight edge, if thr 45 deg edge lines up with the line then it is square.

I think :?

 

[wizer]

Thanks, that rings a bell. I will check them.

I do find the maths involved here a little taxing. Mathematics was non-existent for me at school. It's hard to visualise which way to shift the angle when the mitre does not align.

 

[motownmartin]

I hate doing mitres :twisted:

 

[wizer]

Indeed, but I like the look of a mitred joint.

 

[shim20]

nobex

 

[Niki]

Hi Wizer

As Martin said...

As for the Wixey, Put the miter gauge on the rip fence rail with the miter gauge bar facing (or pointing) down.

Put the Wixey on the rip fence rail and set it to Zero.

Move the Wixey and attach it to the miter gauge bar...turn the bar till you read 45° and lock the miter gauge.

And that's it...

Regards
niki

 

[Digit]

First things first wizer. Before that method can work, using what ever triangle you like, it is necessary to establish whether or not the mitre fence or sliding table is sliding parallel with the blade.
If it isn't you are wasting your time I'm afraid.

Roy.

 

[Niki]

I hate doing mitres :twisted:

I love to cut miters ...

For me, it's easier than to cut 90° frame...

The 45° just "click" together and produce a perfect square

Regards
niki

 

[wizer]

Will also check if the sliding table is parallel to the blade.

I'd like to make a mitre sled, but I can't imagine how to do it without the right hand mitre slot.

 

[Niki]

I'd like to make a mitre sled, but I can't imagine how to do it without the right hand mitre slot.

I also don't have the right miter slot, I'm using the left miter slot - with runner that is narrower than the slot and another runner that runs on the right table edge.

I made the miter slot runner narrower so in case of temp/humidity changes, it will not bind and I always can re-adjust the right runner.

https://www.ukworkshop.co.uk/forums/view ... highlight=

Regards
niki

 

[newt]

I dont think the relationship of the mitre slot to the blade will make any difference, I am prepared to be proved wrong.

 

[Digit]

If the slot isn't parallel to the blade using the blade as reference will guarantee an inaccurate cut Pete.

Roy.

 

[newt]

Roy I had a session on this subject a while back and did some tests for a 90 degree cut, the only thing that affected the angle of cut was the angle set on the mitre gauge, I have assumed the logic applies to any angle. Clearly the cut would not be very clean if it was way off. The same applies to a router table.

 

[Mr Ed]

I've found in the past that a sliding table slightly out of parallel to the blade can easily cause this issue. If that was the case however carefully you set up the initial 45 degrees it could drift away along the length of the table.

Cheers, Ed

 

[wizer]

Yes I wonder if I should always plan to do the initial cuts on the saw and then shoot to 'fit'. This seemed to work well today. The frame that I glued up had one corner with a slight gap.

More playing with this tomorrow. It's for the missus birthday, which is, er, tomorrow! :shock: :lol:

 

[Digit]

the only thing that affected the angle of cut was the angle set on the mitre gauge,

Exactly! Cos that means the reference is the slot, not the blade.

Roy.

 

[newt]

Roy I think thats what I am saying it the relationship of gauge to the slot not the slot to the blade.