Thread: Spiral Head and When to Rotate the Cutters

Similarly to you Chris, i've had my jointer for about 4 years, and the previous owners have had it for about 3 before that, still on the original surfaces. From what i've been told by my local saw doctor is when you're unhappy with the surface is when you rotate and rotate all of them. The reason being is if you rotate a couple here or there you end up with the newly rotated blade being ever so slightly longer than the used ones and you end up with lines on your board, obviously not a big deal as you'll most probably be sanding afterwards. Same goes if you break one of the cutters.

I have a lot of spare cutters but given that I have three more sides to go the original ones should outlast me with ordinary use. I machined a lot of blue gum a while ago and that is tough stuff and I can't see any drop in finish quality.

When the Shelix heads at work were due for rotation you could see the surface finish had lost the "glassy" sheen that comes with fresh edges and sometimes the surface was rough to touch as well from fibres being compressed and springing back instead of being cut. Because the wear is so slow, it can be hard to tell when it's due, but once you rotate to fresh edges you wonder why you waited so long.

We'd get 3-6 months per side, depending on what timbers we'd been running, but only rotate every second row so you effectively double the life of a set while maintaining 80-90% of the finish you'd get from rotating all the inserts.

Originally Posted by tonzeyd

The reason being is if you rotate a couple here or there you end up with the newly rotated blade being ever so slightly longer than the used ones and you end up with lines on your board

Didn't see that when I first replied, but it has come up before and I was highly sceptical of that claim, so I did the measurements and can confirm it's not a thing replacement cutters for spiral head

The only reason for visible lines is if the inserts aren't seated properly.

Chris
perhaps you could be guided in part by Elan's response

Originally Posted by elanjacobs

We'd get 3-6 months per side -- that's 12 to 24 months per set of cutters -- depending on what timbers we'd been running, but only rotate every second row so you effectively double the life of a set [to 2 to 4 years] while maintaining 80-90% of the finish you'd get from rotating all the inserts.

given the thousands of metres that Elan would have put through his former work's thicknesser, five years on, your original cutters are still probably near new.

Perhaps as Elan suggests rotate half of the cutters and see if there is any difference in surface appearance. If yes, rotate the ones you haven't rotated to bring up fresh faces. If the answer is you can't see a difference, rotate the original cutters back to their original edges and keep going.

bought my AD951 with spiral cutter block maybe 2 years ago now. rotated a number of them, I notice I have to rotate a couple of knives 3-4 times in the past 2 years and some of them never rotated! probably due the way the stock is fed...

If I get the time I might rotate them to answer my own question and to see if a visible improvement is the result. I doubt if mine had done anywhere near the work that Elan would have done in just a few weeks, in fact I am sure of it.

Originally Posted by Chris Parks

If I get the time I might rotate them to answer my own question and to see if a visible improvement is the result. I doubt if mine had done anywhere near the work that Elan would have done in just a few weeks, in fact I am sure of it.

I only get lines on mine if the knives are damaged. otherwise visually they are all good. sometimes I am lazy or just one or two small pieces needs sizing I dial the speed all the way down and just give it a light sand afterwards. but most of the time for bulk jobs they get properly sanded through the WBS.

Albert, what time is it in NZ?

Originally Posted by Chris Parks

Albert, what time is it in NZ?

New Zealand is still only 2 hours ahead of New South Wales.

Daylight saving time 2020 in New Zealand will begin at 2:00 a.m. on Sunday, September 27

and ends at 3:00 a.m. on Sunday, April 4, 2021

All times are in New Zealand Time.


Where you are Chris, the corresponding dates are:

Daylight saving time 2020 in New South Wales will begin at 2:00 a.m. on Sunday, October 4

and ends at 3:00 a.m. on Sunday, April 4, 2021

All times are in Eastern Australia Time


So for a week New Zealand will be 3 hours ahead of New South Wales.
But for now, it was almost 2 AM when Albert posted.

Queensland, as we all know by now is getting ready to get out of the Australia.

I have had the A3-31 some 5 years. In that time I have turned the blades once, this being about 18 months ago. Note that I work with only hardwoods, some of which are quite abrasive. One and a half years into the second face, the edges are still sharp and leaving a good finish.

Regards from Perth

Derek

Originally Posted by ian

New Zealand is still only 2 hours ahead of New South Wales.

Daylight saving time 2020 in New Zealand will begin at 2:00 a.m. on Sunday, September 27

and ends at 3:00 a.m. on Sunday, April 4, 2021

All times are in New Zealand Time.


Where you are Chris, the corresponding dates are:

Daylight saving time 2020 in New South Wales will begin at 2:00 a.m. on Sunday, October 4

and ends at 3:00 a.m. on Sunday, April 4, 2021

All times are in Eastern Australia Time


So for a week New Zealand will be 3 hours ahead of New South Wales.
But for now, it was almost 2 AM when Albert posted.

Queensland, as we all know by now is getting ready to get out of the Australia.

Ian, it was a tongue in the cheek question because of the time it was in NZ.

Originally Posted by Chris Parks

Ian, it was a tongue in the cheek question because of the time it was in NZ.

I realised you were posting "tongue-in-cheek" a couple of hours after you asked Albert the rhetorical "question"



DUH to me, me thinks

We have a powermatic 15" thicknesser with a spiral head. It gets used about 6 hours a day 6 days a week. In practice it seems we rotate the full set of blade's faces around 6 to 9 months, but then, its a shared resource among 400 people so I am not all that fussy mostly. What we usually notice is that there is an increase in the amount of noise coming from the cutters a couple of weeks before the deterioration in cut quality becomes obvious. When people start complaining about the increase in noise, I start paying some serious attention to the quality of cut.

best
Brendan