Blade starts to walk off centre?

[richard8688]

The cutting of Porcelain tiles, 16mm, with a Vitrex bridge saw, has been very successful, holding cuts of 900mm to 0.4mm.

BUT

All the blades I have tried, ATS, Marcrist and Rubi, have all started to cut off centre.

I have dressed the blade with a Rubi cleaning block and this will improve cutting but it doesn't seem to cure cutting off centre.

For some reason, after a load of cuts, the blade will start to deviate from where the machine carriage is going. At the end of a long cut, it can be as much as 2-3mm off centre and you can see the blade flexing sideways.

My theory as to why this is happening is that the edge of the blade, although 'sharp' with plenty of exposed diamonds, is no longer square. It's rounded and the rounded edge is not even.

Of all the blades I have tried, Rubi TVH was the worst. It cut the best, with lower noise, less chipping but didn't last half a day before it started to wander off.

So am I right is thinking I need to square up the blade? If so, how?

The blades seem to cut through the cleaning/dressing stone really easily. Do I need to make the cut into the dressing stone more quickly?

Do I need to dress the sides of the blade?

Is there some other way to recover the blades? Thay all have lots of edge left, it's just not square...

Any advise muchly appreciated!

 

[Concrete guy]

Are you sure it's the blade deflecting and not the entire axle on which the carriage is running? I used to own a RUBI bridge saw which was known for this, in fact I think they still do it.

It only needs to deflect slightly then the blade wants to wander off line. Once off line the blade will continue to wander and accentuate the problem.

The fact it's happening with all types of blade would suggest there's an outside factor involved.

16mm porcelain paving is about as hard as it gets for a tile saw. The Vitrex machine you have is entry level as far as bridge tile saws go, so I'd imagine you're at the limit or possibly beyond the limit of the machine. Specifically the power of the motor and blade diameter.

Try slowing down the cut speed, if this creates a straighter cut (even if it wanders less) then it points to the capability of the machine.

 

[Dumbo]

Tbf when I use a bridge saw I don't just set it and run it., I watch the blade through the cut and move the tile accordingly

 

[Dan]

I used to work at Topps tiles and as a newbie there you always did the wet cutting, which was a service they'd offer to DIY so they'd spend more on tiles.

I can't ever remember using the guide with success. Always had to free hand it and guide it myself.

Pushing too much will make the axel move eventually. So perhaps put a lot less pressure on it. The fact you've had the same results with loads of blades would suggest it's the machine and / or operator

 

[richard8688]

I used to work at Topps tiles and as a newbie there you always did the wet cutting, which was a service they'd offer to DIY so they'd spend more on tiles.

I can't ever remember using the guide with success. Always had to free hand it and guide it myself.

Pushing too much will make the axel move eventually. So perhaps put a lot less pressure on it. The fact you've had the same results with loads of blades would suggest it's the machine and / or operator

The machine cuts dead straight, to 0.4mm over 900mm, for maybe 20-30 cuts. Then the blade walks off to one side by 2-3mm.

At that point the blade is knackered. It will continue to produce curved cuts.

There's no way you could get a stright cut by 'moving the tile', it's 25 kg for a start!

The issue is the blade getting degraded.

I just don't yet know how to get the blades back to normal.

I suspect they need to be squared up somehow.

 

[Concrete guy]

So based on that I'd dress the blade every 10-15 cuts. See if that makes a difference.

 

[Unused Account 1]

Time for a new saw

 

[richard8688]

Time for a new saw

New saw blade? The machine cuts dead straight, the blades don't after a days's cutting....
[automerge]1562277818[/automerge]

So based on that I'd dress the blade every 10-15 cuts. See if that makes a difference.

Is there a specific technique for dressing the blade? Just take a cut straight through the cleaning block? Does it need to be a fast cut?

 

[Bopster]

I’d be looking at changing machine to a track saw system like TC 180.
That will give the result your after, zero run out and able to cut in depth increments to stop the blade degrading

 

[richard8688]

I’d be looking at changing machine to a track saw system like TC 180.
That will give the result your after, zero run out and able to cut in depth increments to stop the blade degrading

Hi Bopster,

I could, if I have to, make the machine settable with a shallow and full cut, if that helps.

But I really don't think it's the machine, as it runs true and with a fresh blade cuts perfectly.

Is there something about the machine that could make the bades decide to cut off line?

When the blade has gone off, the machine is still tracking straight. It's the blade that wants to cut off in one direction. At the end of the cut, the machine will be still bang on the line but the blade will be flexed over 2-3mm off to the side.

This is why I think the problem is something to do with how the blades wear in the really hard Porcelain. If the blade wear is uneven, it's going to start to want to track off sideways?

I noticed one blade had an edge that was off centre.

This is what the blade does. Initially the blade will cut straight be then gradually veer off until at the end of a long cut, it's flexed over. The machine tracks dead straight and the blade is dead square. I've checked it with a dial gauge.

This