Considering a Byrd for my Jet JPP-12

[Mike Cornelsen]

I'm thinking about throwing my income tax return at a Byrd Shelix for my Jet JPP-12 combo machine and I was wondering if anyone who has done it have any issues. Big discussion a couple of years ago (before Jet came out with the JPP-12HH, http://www.sawmillcreek.org/showthread.php?p=796586). No need to discuss pros/cons of knives/spiral cutters, etc. I'm getting by with the knives and I don't need the shelix, I just want one. Thanks.

[Jeffrey Makiel]

When I looked into buying a JJP-12 (before the helical head option was sold by Jet), I contacted Byrd. They stated that they sold many helical heads for the JJP-12 and have had no complaints. The cost (14 months ago) was $1095.00 plus additional $ if bearings are needed.

However, when Jet introduced the JJP-12HH, I believe they slowed the feed rate down from 20 fpm to 12 fpm. I believe this modification also delayed the JJP-12HH's introduction by 6+ months.

The feed rate info is hard to find for the JJP-12HH. It's not in Jet's product specs on their website. However, some folks here at SMC that have the JJP-12HH provided feedback.

If Jet did reduce the feed rate, why did they do it?

Just a thought.

-Jeff :)

[Van Huskey]

If Jet did reduce the feed rate, why did they do it?

Just a thought.

-Jeff :)


Didn't Jet have an issue with overloading the motor/breaker with the HH when the originally started the process of adding the HH?

[Mike Cornelsen]

That is exactly the sort of issue that has me hesitating. I'm not trying to resolve any issues with my JJP-12. It's a fine machine and I'm happy with it. This is probably a good time to follow the old adage, "If it ain't broke..."

[Mike Zilis]

I'd love to add a Byrd head to my JJP-12 too. The price makes me choke and I'm still having trouble justifying the upgrade, but if I can get past the cost my next concern is what's involved in installing it and if it would over-tax the motor. I tend to only take very light cuts anyway and as a hobbyist I doubt that my amount of usage taxes this machine.

I hope someone who has performed this upgrade can chime in with some first hand experience.

-Mike

[Mike Weaver]

Mike,
Though I can't help with the experience itself, I can tell you that Holbren.com is a great company & with the "SMC10" discount code, the price comes down to $985.50 w/ free S/H as far as I know.
-Mike

[Mike Zilis]

Mike,

That's excellent news indeed. Much appreciated.

[Curt Harms]

This is confusing to me. I was participating in a thread about this topic some months ago. Rick Lisek(?) from Massachusetts who has worked on woodworking machinery for years stated that it was common knowledge in the business that helical heads require less power than conventional cutterheads of the same size. I too would be interested in the feed rate for the JJP-12HH vs. JJP-12. The Grizzly helical head machine (G0634) is 5 h.p. but so is the 3 knife cutterhead machine (G0633). Somebody's just gotta buy one.

[Van Huskey]

This is confusing to me. I was participating in a thread about this topic some months ago. Rick Lisek(?) from Massachusetts who has worked on woodworking machinery for years stated that it was common knowledge in the business that helical heads require less power than conventional cutterheads of the same size. I too would be interested in the feed rate for the JJP-12HH vs. JJP-12. The Grizzly helical head machine (G0634) is 5 h.p. but so is the 3 knife cutterhead machine (G0633). Somebody's just gotta buy one.

I think there is a different issue going on besides raw power. I think the number and placement of cutters could have something to do with it. The other discussion used a phrase like the feed rate got the wood "ahead" of the cutter. In any case though HH by common knowledge should use less power than knives it does not seem universal, many Dewalt owners claim their machines labors more once a HH is installed.

I would also like to know if the feed rate was lowered, if so we can pretty much bet there was a serious reason behind it.

[Van Huskey]

This is confusing to me. I was participating in a thread about this topic some months ago. Rick Lisek(?) from Massachusetts who has worked on woodworking machinery for years stated that it was common knowledge in the business that helical heads require less power than conventional cutterheads of the same size. I too would be interested in the feed rate for the JJP-12HH vs. JJP-12. The Grizzly helical head machine (G0634) is 5 h.p. but so is the 3 knife cutterhead machine (G0633). Somebody's just gotta buy one.

This is a quote from Wood magazine March 2009:

" You also have to factor in the cutterhead when figuring cutting power because spiral models with carbide cutters require greater oomph to power through cuts. (This happens because two to three cutters are always in contact with the wood; straight knives have intervals—albeit split-second ones—between knife cuts.) "

Although contrary to popular opinion it certainly is logical, but would also depend on the number of cutters and their spacing, but I think this explains the extra power needed with some HH replacements.

[Mike Konobeck]

I don't think that these companies slow down the feed rate because the motors can't handle it. My theory is that they slow down the feed rate so that the teeth make more contact with the wood. At least a full revolution per tooth width from front to back. I am thinking that because of the shape of the Byrd teeth you need to get that tooth to crest the plane or you will end up with the well documented scalloping. Once the teeth cross the plane then the tops of the teeth are flat. The more teeth you can have hitting the wood the more flat the surface. This may be a completely false assumption but I just can't think why they would do it. Taking small chunks consistently would put a consistent load on the motor which these machines should handle just fine. A fellow woodworker put one on a Hammer A3-31. While the motor is 4hp, he didn't mention having any problems with the cut quality or taxing the motor. This may be due to the fact that the head was at a high enough RPM that the feed rate was ok. The math can be done by much smarter people than myself on how many times the teeth would break plane. Longwinded theory and please feel free to shoot holes in it.

[Jeffrey Makiel]

Mike, I like your theory. A slight deviation of it may be that the higher feed rate changes the effective shear cut's angle of attack. That is, with faster feed speed, the shear cut of each tooth must cut more linear feet of wood and is thus less effective at achieving a smooth cut.

Another theory is that a helical head is less efficient at clearing the chips. So, one must either slow the feed rate down or derate the maximum cutting depth.

-Jeff :)

[Curt Harms]

I remain interested in this thread because I've had the same thoughts about eventually adding a helical head. Given the feed roller drive train I don't see a way to slow the feed rate without some major revamping. I recall when the JJP-12HH first appeared on Jet's web site mentioning a feed rate of 20 feet/minute, same as the JJP-12. Now there is no feed rate mentioned. I wonder if the original entry was an edited JJP-12 page and they forgot to remove the feed rate line.

[John Harden]

I'm not trying to resolve any issues with my JJP-12. It's a fine machine and I'm happy with it. This is probably a good time to follow the old adage, "If it ain't broke..."

I'm confused. If your J/P is performing just fine, why would you want to change out the cutterhead???

I wouldn't consider a helical cutterhead an "upgrade" to a machine that is operating well. More like a waste of money.

Regards,

John

[Daryl Negley]

Has anyone on here actually replaced a head on a jointer. I have a Jet 6" jointer and would like to put the Byrd cutter head on as a replacement. ANYONE???

[Mike Goetzke]

This is a quote from Wood magazine March 2009:

" You also have to factor in the cutterhead when figuring cutting power because spiral models with carbide cutters require greater oomph to power through cuts. (This happens because two to three cutters are always in contact with the wood; straight knives have intervals—albeit split-second ones—between knife cuts.) "

Although contrary to popular opinion it certainly is logical, but would also depend on the number of cutters and their spacing, but I think this explains the extra power needed with some HH replacements.

I questioned this too. True there are always cutterheads on the wood with the spiral but they are taking up much less area than a bladed head. I would think the motor and drive gear would like a constant load better that a highly fluctuating one.

[Eddie Darby]

Looking at the Grizzly site, their 12" combo machines all have the same 22 FPM feed rate whether the head has insert or blade cutters.


http://www.grizzly.com/products/mach-specs.aspx?key=450000


If you slow down the feed rate you should get a better finish.
Finishing cuts should always be very light cuts.
5 HP is way more HP than my bench-top Delta planer, so I don't think it's an issue with HP.

[Jeffrey Makiel]

I believe the Grizzly model had an index head option right around the introduction of the machine, or soon afterwards, which may have been accounted for in its base power design.

The Jet model added this option some time later, and this machine previously existing in Europe for some time with straight knives. So, it may not have had the provision of an oversized motor to support an indexed head at its conception.

I'm also not sure if having three indexed cutters entering the wood at the same makes an impact to power requirements because the cutters only are 1/2" or so wide and don't go the full linear length along the axis of the cutterhead. That is, there are large gaps between adjacent indexed cutters in the axial length of the cutter head that are not in contact with the wood. I guess one would have to add up all the linear inches of each indexed cutter contacting the wood at one time and compare it to one straight knife edge to determine this though.

-Jeff :)

[Chip Lindley]

Mike, thats BIG BUCKS for a helical head, even at 10% off! Part of Me wants helical heads for my 20" planer and 8" jointer. But I just cannot justify that major expense. What small amount of chipout I suffer is sanded out with drum sander. But, IF the helical head eliminated a need for the big drum sander altogether.....Hmmm....(Doubtful!)

IMHO, if you are not suffering from specific problems (tearout of figured woods, or chipout of brittle woods).....If It Ain't Broke Don't Fix it! (is there an echo in here?)

But, its your hard-earned BIG BUCKS!

[Curt Harms]

I questioned this too. True there are always cutterheads on the wood with the spiral but they are taking up much less area than a bladed head. I would think the motor and drive gear would like a constant load better that a highly fluctuating one.

Right, and the Byrd head cutters operate on a skew vs. head-on attack like straight knives or the Grizzly-style cutter heads. I don't know if or how much that would influence power requirements.

[Van Huskey]

Mike, thats BIG BUCKS for a helical head, even at 10% off! Part of Me wants helical heads for my 20" planer and 8" jointer. But I just cannot justify that major expense. What small amount of chipout I suffer is sanded out with drum sander. But, IF the helical head eliminated a need for the big drum sander altogether.....Hmmm....(Doubtful!)

IMHO, if you are not suffering from specific problems (tearout of figured woods, or chipout of brittle woods).....If It Ain't Broke Don't Fix it! (is there an echo in here?)

But, its your hard-earned BIG BUCKS!

Depends on how much you use your planer/jointer. In the long run the helical heads will save money on sharpening and blades. For me it is much more economical just to pay up front and get a better finish plus significantly reduced tearout. I have yet to see a finish ready face come out of any planer but then again I have yet to see a finish ready face come out of a drum sander either.

[Derby Matthews]

When angle of attack was mentioned above, it occured to me that perhaps the problem might not not simply the also-aforementioned scalloping, but what about tearout trouble as a potential motivation to reduce the feed ratio? It occurs to me that if the cutter blade is doing a significant portion of it's work on the upstroke as it were, it would logically follow that the chance of chipping into the workpiece above the cut line would increase in some formulaic proportion to feed rate, perhaps even more so since the blades on the helical concentrate their force on a significantly smaller unit area than do straight blades, which tend to "hammer" more than simply "scoop".

As to motor/ breaker overload, I would think that unless some form of resonance were achieved (implausible) that straight blades would tax a motor every bit as much, if not more so, than individual cutters. One factor that might occasionally argue against this point is that we all know that carbide simply cannot be made/kept as absolutely razor sharp as HS Steel blades out of the box, and this might cause them to collectively use additional motive power (or a need for reduced feed rate. This would be moot against a slightly (equivalently) "dulled" straight knife, of course.


However, like many here I've over the years routinely noticed a significant drop in ease of feed, and motor lugging, and breaker tripping, and tearout, and hammering, and excessive sniping, and burning of sugary woods, and infeed roller-marks-because-I've-tried-to-reduce-depth-of-cut-too-much-because-of-all-these-other-annoyances - in my erstwhile beloved Parks just before sighing (or swearing) and stopping work for an hour to change my knives at midnight in the middle of a project that's already behind schedule! Phew!

For the record. My JJP-12H has ended all that. I love the machine, have no tearout trouble, am (un-academically speaking) unconcerned with whatever the feed rate the slide-rule folks have deemed works best. I now love my infrequent blade changes, and no more swearing at midnight....at least not about my now-favorite jointer-planer. One Guy in Oregon and another in Washington (who bought my old beloved Porter 300C jointer) now have the midnight-cuss-words honor since I passed my two old friends on to them. I rarely look back, but do so with bemused affection, like to my long-gone MG that was also all over the road when on it. Please tear this post apart at will, as it's a very interesting topic. The word of someone who actually knows calculus and run some numbers would make for great reading and comment.