Mitre saw issues

[quixoticgeek]

I have a manual mitre saw (similar to this one). Unfortunately it doesn't seem to cut straight. I'm trying to cut a piece of 100mm wide 9mm thick ply (along the 100mm length). But it doesn't give me a 90° cut. I've tried tensioning the blade. I've checked everything is assembled properly.

What have I missed? Do I just have a heavy inaccurate paper weight or is there something I can do to make this saw cut straight?

Cheers

J

 

[bugbear]

Was the workpiece standing vertically against the rear fence when cut, or lying flat on the bed (so did did you cut down though 100mm or 9mm)?

When you say it's not 90°, how far out is it? Was the cut straight, albeit at the wrong angle?

I had a CK saw of this style, and after a fair bit of testing and shimming, I managed to persuade it to cut straight and square.

it certainly wasn't as accurate as I needed "as supplied".

BugBear

 

[AndyT]

You don't say how old the saw is. Is the blade sharp? Do the points catch at your skin if you (carefully) press your hand against the teeth?

Replacement blades are available at your local tool shop.

 

[quixoticgeek]

Was the workpiece standing vertically against the rear fence when cut, or lying flat on the bed (so did did you cut down though 100mm or 9mm)?

When you say it's not 90°, how far out is it? Was the cut straight, albeit at the wrong angle?

I was trying to put a 15 degree mitre on the end of a 100mm wide bit of 9mm ply. So the ply was stood up against the back rest, and then cut downwards. Making a 100mm long cut. The cut seems close to straight but at about 20 degrees to the verticle.

I had a CK saw of this style, and after a fair bit of testing and shimming, I managed to persuade it to cut straight and square.

it certainly wasn't as accurate as I needed "as supplied".

Oh. what did you do to make it accurate?

Thanks

J

 

[quixoticgeek]

You don't say how old the saw is. Is the blade sharp? Do the points catch at your skin if you (carefully) press your hand against the teeth?

Replacement blades are available at your local tool shop.

The saw is 15 months old, but this is the first time I've used it.

J

 

[bugbear]

Was the workpiece standing vertically against the rear fence when cut, or lying flat on the bed (so did did you cut down though 100mm or 9mm)?

When you say it's not 90°, how far out is it? Was the cut straight, albeit at the wrong angle?

I was trying to put a 15 degree mitre on the end of a 100mm wide bit of 9mm ply. So the ply was stood up against the back rest, and then cut downwards. Making a 100mm long cut. The cut seems close to straight but at about 20 degrees to the verticle.

Ouch. Wow! I was expecting errors in the 1-5 range at most.

I don't see how that is even possible - a 20 degree error. Surely the saw must have jammed solid eventually, as the line of the cut and the position of the saw-frame diverged?

I think a photo is needed to help you further. Something is very wrong.

BugBear

 

[xy mosian]

I have Nobex and found that a number of snags similar to yours were down to the workpiece slipping along the bed during the cut. I know it is not easy to do but try clamping the workpiece to the bed, G - clamp, F - clamp, etc.. I could never provide enough clamping manually.
HTH xy

 

[quixoticgeek]

Ouch. Wow! I was expecting errors in the 1-5 range at most.

I don't see how that is even possible - a 20 degree error. Surely the saw must have jammed solid eventually, as the line of the cut and the position of the saw-frame diverged?

Slight error of judgement on my part. It's a 5° error. Having sat there and had a play and worked it through with a friend, we've concluded that the issue is that the vertical backrest isn't vertical, so when you clamp the piece to this and start cutting that inaccuracy multiplies out across the piece. In short, I have a paperweight.

Will be writing a snotty mail to the manufacturer later.

I think a photo is needed to help you further. Something is very wrong.

BugBear

Thanks for your help.

This issue made me dig out the circular mitre saw, but it turns out that doesn't cut straight either due to play in the mechanism. Nowhere near as much as on the manual saw, but enough to make a visible gap that causes problems. Time to look at alternatives.

Thank you everyone for your help.

J

 

[memzey]

Do you have a shooting board and plane? Perhaps your saw could get you close enough to finish off that way?

 

[quixoticgeek]

Do you have a shooting board and plane? Perhaps your saw could get you close enough to finish off that way?

What's a shooting board?

I have a plane.

J

 

[memzey]

Hi J,

A shooting board is a small appliance used at the bench to ensure that certain edge and end planing tasks are done in a controlled and precise way. There are plenty of videos on utube explaining it with video better than I ever could with words! Timothy Rousseau of FWW magazine shows one that looks very good and is adjustable for irregular angles and odd mitres. I'll probably make one to that pattern in the next week or so.