# Budget spiral cutterhead upgrade for 6" jointer



## runswithscissors (Nov 8, 2012)

I has been noted by others that spiral or helical heads do take a bit more power. One LJ compared amperage draw with knives vs. helical, and it did take more juice. I surmise that there are constantly cutters engaging the wood, with no "resting" period that the motor gets with 3 knives making intermittent cuts. Not that those periods of no-load would be more than a micro second.

I have the Jet 12" jointer-planer combo, with helical head, and would not want to go back to straight knives.

I'm glad it is working out for you.


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## robscastle (May 13, 2012)

Hello Mike 
Looks like a good sales pitch for the upgrade, and at possibly around 50% dixcount its a real no brainer.
Setting the knives on a jointer has got to be one of the most time consuming maintenance activites of all the woodworking suite going.

I think I have spent hours when I cannot get the required result first up, and even then have concerns to everything being at the same level.

The "Uses more Power" hype has been a talking point for a while, I personally believe its not supportable and it may be the result of the helical head working so well its removing additional material than the fixed blades were.

Regardless the advantages outway the disadvantages by far.

I had a look at your pictures and i assume there is four rows of inserts I can see 7 inserts visible in your pcture and assume the next row is staggered and has 8 inserts in it?


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## jonah (May 15, 2009)

Anyone heard of someone installing the 8" version of this on a Powermatic Model 60? At ~$260, it's a lot more palatable than a $450 Byrd head.


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## Mike_D_S (May 3, 2012)

Robert,

Yes, four rows with staggered cutters. I'll post a few additional pics this evening. That's not an ideal pic as it doesn't show the end cutters. One each end of the head, there is an end cutter with a square set to the rotation plan, which I'm assuming is to insure the end of the cut is flat for sure.

I never took current readings on the old jointer, so a measurement now won't mean much, but I never really take heavy cuts. Heavy for me is 1/16" as I'm usually quite happy to make multiple passes. So I don't think cut depth is the cause of the perceived load.

While it's counter intuitive if you think about blade contact, from the little use I've had it does seem this head is a bigger load. I think it's likely a combination of things. I'd have to measure to say exactly, but I think the diameter of the body for the spiral cutterhead is a little smaller than the 3 knife head, so less rotational momentum. Then we'd have to think about belt stretch where I would expect the 3 knife head intermittent contact to potentially not reduce the motor speed as much correspondingly. The spiral head would be stretching the belt, but with the more continuous contact, the belt stretch would tend to be more consistent meaning the load on the motor would be steadier.

Conceptually, I can rationalize the spiral head drawing more power for the same cut.

Mike


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## Kelster58 (Dec 2, 2016)

Thanks for posting this. You have imagination and skill. This will be a big help to many!


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## Mike_D_S (May 3, 2012)

While I'd like to take credit for being imaginative and skilled, really the only risk I had was the restocking and return shipping costs.

If it hadn't been a drop in fit, I wouldn't have tried to make it fit.

Mike


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## russde (Aug 17, 2010)

Mike,
Any chance you could measure and post the specs? I've got an old Atlas 6001 that would really benefit from an upgrade like this.
Thanks


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## Mike_D_S (May 3, 2012)

I added the measurements I had above and will fill in the rest when I get home tonight. I also listed the generic bearing sizes.

Actual dimensional information is very hard to come by online and even calling Grizzly doesn't get you much more than what is in the manual. We should have a thread for people to put in their measured dimensions from these heads for others to use as a reference.

Mike


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