Riving knife pain

[monkeybiter]

http://www.axminster.co.uk/media/downloads/501242_manual.pdf

FYI

EDIT:- The site seems to be experiencing difficulties at the moment.

 

[blackrodd]

http://www.axminster.co.uk/media/downloads/501242_manual.pdf

FYI

EDIT:- The site seems to be experiencing difficulties at the moment.

Excellent! just the very thing.
Rodders

 

[MickCheese]

The saw is provided with a perfectly good straight edge in the form of the fence. Push it against the blade and it should make judging if the knife is straight easy.

5mm seems to me to be such a large discrepancy that I would be looking for a missing washer or bush in either the riving knife or the blade.

Mick

 

[paulm]

Sounds like you may have missed parts 29 or 31 on the drawing on page 28 of the manual linked to above, or assembled them incorrectly ?

Still worth checking the riving knive is flat to start with though and not twisted, and that the blade is also seated correctly and the flange (part 24) used correctly.

Cheers, Paul

 

[DiscoStu]

Thanks for all the help and replies so far. I've been out and made some measurements and taken some photos which might help.

So firstly the RK seems not to be parallel to the blade and fence.

So here are two measurements from the RK at the front and back of the side next to the table:

The third photo is of a straight edge line up with the RK, as you'll see with the blade at full height the edge starts to drift out and at the front of the blade it's 3.6mm - it is quite a lot more when the blade is lower

If we then look at the verticals it also appears to be out

The RK is is 1.87mm thick, yet if I measure the RK and the blade together (without moving the RK) the combined thickness is 3.48mm which shows it is quite a long way off the blade.

 

[Steve Maskery]

Stu
Can you remove the throat plate and photograph how the RK is attached?

You have shown that the RK is not vertical. Is the blade vertical, or is that out as well?

If you remove the RK and lay it on the CI table, does it rock or it it completely flat?

S

 

[DiscoStu]

I can confirm that the knife is completely flat as I checked that yesterday and I compared it to the previous knife and that was also perfectly flat. The riving knife has a large slot at the bottom and it slides onto two bolts. It's not out of vertical buy much. I think the main issue is, is that it isn't parallel to the fence or the blade. The blade appears to parallel with the fence. I will check though. as I'd gone to the "hassle" of taking photos and measurements I have just emailed Axminster as well with the same info to see what they say.

 

[Rhossydd]

It's not out of vertical buy much.

You need to compare it to the blade. They should both be at the same vertical angle.

The blade appears to parallel with the fence.

It's better to check that it's parallel to the mitre slot, rather than the fence. The slot is the one part that can't be adjusted, so everything should reference to that.

I think the main issue is, is that it isn't parallel to the fence or the blade.

Have you double checked the blade is correctly mounted ?
Whilst you have the table insert out, get a torch and make sure the correct washers are in place holding the RK correctly. It might also be worth looking at the whole carriage assembly to see if there's any obvious signs of damage too.

 

[blackrodd]

The saw is provided with a perfectly good straight edge in the form of the fence. Push it against the blade and it should make judging if the knife is straight easy.

5mm seems to me to be such a large discrepancy that I would be looking for a missing washer or bush in either the riving knife or the blade.

Mick

FWIW.
The fence is unreliable, as in so many posts regarding fence's being out of parallel, etc, are likely to be a problem unto themselves!
As previously mentioned, the mitre slot is constant and the saw blade, riving knife and fence should be referenced to that.
but, A decent straight edge, in this instance, would clearly demonstrate the alignment problem across the front, back, and riving knife for photographic evidence to the seller, to fully understand the issues at hand and give any advice.
It looks, at a glance to be something akin to a washer in the wrong place or not in order, that's fixing the riving knife in place regards Rodders

 

[Steve Maskery]

Is your blade parallel to the mitre slots? That should be your first reference when fettling your saw.
That is nothing to do with this problem, though.
S

 

[Myfordman]

It looks to me like the mounting block for the RK has been fitted/welded out of truth with the spindle axis. It only needs to be a fraction of a degree out and the error is magnified by the RK.
Should be down to Axi to fix either by having an engineer come out to fettle it or to replace the machine and they can fettle the old one in their workshops.

Good Luck

 

[DiscoStu]

Well once again I have been impressed with axminster customer services. They are going to collect the saw and get one of their engineers to look at it.