Vitrex Ulitmate blade walks off line

[richard8688]

I am cutting 16mm porcelaine paving with a Vitrex bridge cutter.

I fitted a Vitrex Ultimate blade to replace the standard blade. It cuts better, with less chipping but on a 600mm cut it walks off line by 3mm.

The saw runs true and the standard blade cuts true but it chips like a MF.

So any reason why a blade would wander off by so much?

Any other blades I can try? 200x22.2 mm?

 

[richard8688]

I think that the blade is cutting more on one side which is making it flex? Does that sound possible?

 

[One Day]

It happens with some blades. Different reasons.
Have you tried a few light passes over the surface before fully cutting through?
(assuming you have a plunge facility on your saw)

 

[Old Mod]

Try cutting at a slower rate, sounds like blade is flexing because it’s being pulled too quickly.

 

[richard8688]

Will try a really really slow cut. I was really gentle and not pulling hard at all.

Don't really understand why it's head off sideways though. All the force is on the front edge and then on the side as it wanders off sideways. You'd think it would start to head back to the right line as the stresses build up. The blade must be flexing a lot towards the end of the cut... A good 3mm of bend


No plunge facility unfortunately....

 

[Old Mod]

what type of blade is it, continuous rim, or turbo type?
(Smooth blade or one with a serrated appearance)
A turbo is less likely to flex as it clears more material off the shoulder of the blade as it cuts causing a wider cut line allowing blade to move freely.
Continuous rim blade only cuts the actual width of the whole blade causing more friction, it heats quicker and can flex.
Like the reason a knife has a blood line, for want of a better example.
And as Mark suggests above, benefits from several passes over the cut rather than full depth.

 

[richard8688]

what type of blade is it, continuous rim, or turbo type?
(Smooth blade or one with a serrated appearance)
A turbo is less likely to flex as it clears more material off the shoulder of the blade as it cuts causing a wider cut line allowing blade to move freely.
Continuous rim blade only cuts the actual width of the whole blade causing more friction, it heats quicker and can flex.
Like the reason a knife has a blood line, for want of a better example.
And as Mark suggests above, benefits from several passes over the cut rather than full depth.

Its a continuous blade. Turbo blade is arriving today, so hopefully that will cut straight.

The vitrex machine has no plunge, so cant do a light cut, not without modifying the machine!

Initially the motor assembly was not square. Not by much, but enough the for the back edge of the blade to catch on the way back up past the tile and chip it to hell on one side...

You could see the blade was not square against a square set on the end fence.

I had to add a washer to each side of the motor to get the blade square.

It cut clean after that, just not straight. I am wondering if the blade got damaged while it was running out of square and now cuts more on ode side?

 

[One Day]

To be fair, Vitrex saws aren't top quality in build. It's good that you've managed to tweak it though.

 

[richard8688]

Spent some more time checking the blade/motor for square.

Took off the motor and shimmed it.

The blade had a runout of 1.2mm initially and not it's 0.2mm from front to back.

Also got a turbo blade from ATS to try...

 

[richard8688]

Spent today making more adjustments. The blade was measuring 1.2mm out of square and I got it down to 0.2mm. In the end I shimmed the motor face plate with 0.36mm of beer can

The ATS turbo blade arrived and cuts dead straight.

I think the vitrex blade was damaged by running so far out of square and was cutting more on one side which made is drift off to one side.

The only remaining issue is some chiping caused by the back of the blade catching the tile.

I think there is still some float in the carriage which allows it to go out of square. If the back of the blade is off centre even by 0.2mm, it will catch and chip the top surface of the tile.

So now it's down to handle technique and not applying too much sideways bias to keep the blade straight.