planer catastrophe, knives contacted chipbreaker

[Jeffrey Spitler]

i have a powermatic 209 with straight blades.
last night i was planing some pecan, a 50mm wide piece, a full-thickness knot shattered below the cutterhead. the resulting loose pieces managed to wedge themselves somewhere between the cutterhead and chipbreaker (approx 3/16" welded steel). the chipbreaker mounts on a 5/8 steel shaft.
the shaft deflected to the point of bending, about 3/4 " out of center at midpoint. the chipbreaker and rear guard bent and the knives made contact with the steel chipbreaker.
all the knives folded back and shattered, sending out shrapnel.
the guards kept it all contained with the machine.
the cutterhead bearing is ruined as well.

mmtoolparts and ereplacement parts are great.
ordered all new components and a byrd cutterhead.

[Mike Henderson]

Wow, that's some damage from a knot. Glad to hear the machine contained the damage and you're okay.

Mike

[Marty Tippin]

I had a similar explosion several months ago on my Grizzly 15" with the spiral head - one or two of the cutters shattered and it was a chain reaction that destroyed more than half of the cutters, the chip breaker and a pair of underwear...

Glad you're not injured and hope you get everything back in shape before long. You'll like the spiral cutter head!

[Stan Krupowies]

the chip breaker and a pair of underwear...

Glad you're not injured and hope you get everything back in shape before long. You'll like the spiral cutter head!

What was your underwear doing in the planer? :D

[Ken Fitzgerald]

As stated by others, I am glad to hear you weren't injured!

[Kent Adams]

i have a powermatic 209 with straight blades.
last night i was planing some pecan, a 50mm wide piece, a full-thickness knot shattered below the cutterhead. the resulting loose pieces managed to wedge themselves somewhere between the cutterhead and chipbreaker (approx 3/16" welded steel). the chipbreaker mounts on a 5/8 steel shaft.
the shaft deflected to the point of bending, about 3/4 " out of center at midpoint. the chipbreaker and rear guard bent and the knives made contact with the steel chipbreaker.
all the knives folded back and shattered, sending out shrapnel.
the guards kept it all contained with the machine.
the cutterhead bearing is ruined as well.

mmtoolparts and ereplacement parts are great.
ordered all new components and a byrd cutterhead.

You have a great sense of proportionality. I'd be madder than hell if that happened to me.

[Larry Frank]

The bottom line is knots are very dangerous in a planer......or in other equipment.

[Bill Orbine]

The bottom line is knots are very dangerous in a planer......or in other equipment.

And....end grain cutting boards. Planers tend to blow-out the last inch of cutting board and it ruins your underwear!

[Peter Kelly]

Sounds spectacular. What type of planer is it?

Edit: just noticed PM 209.

[Jeff Duncan]

I keep a large flat head screwdriver on the top of my planer just for those little buggers….loose knots are not allowed through it ever! You've learned a lesson the hard way, but I'll bet you won't make that mistake again;)

good luck,
JeffD

[John Schweikert]

Bought my Jet jointer from someone who had same experience. I installed a Byrd head and used JB Weld to fill in the cast iron chip breaker area. All works perfectly now for much cheaper than new.

[Bill Orbine]

Sounds spectacular. What type of planer is it?

You asking me?? The spectacular show never happened to me but there has been a thread or two on here of other member trashing their planers surfacing end cutting board. Anyway....... my planer is the 209HH (Byrd head) and never had an incident...knock on wood (got lot's of it).

[Ben Rivel]

Huh, I dont have much experience yet with planers and jointers, so Im wondering, this was caused by having a knot in the board and the planer trying to plane it? Will/can the same type of thing happen running a board with a knot in it through a jointer?

[Peter Kelly]

It's probably a lot less likely with a jointer since the board isn't being pinched between the feed rollers and bed. I imagine a through knot would probably just pop loose out of the top when jointing.

[Andrew Hughes]

I had a similar experience this past summer working with hickory.Most of my boards were clear some had funny reversing grain.I did have one piece of wood pop out and make the oliver ring like a bell and dent the infeed table lip.My jointer weighs about 1800#s.
I also broke several carbide inserts in the planer not sure when.

[Allan Speers]

Geez, I never heard of this before, but talk about scary...


Suppose you had a board with a knot that just HAD to be planed. (forgetting hand tools for a moment, which would be the obvious solution if you have agood bench) Could you safely plane it by simply taking lots of shallow passes, or is it still dangerous?

[Marty Tippin]

Geez, I never heard of this before, but talk about scary... Suppose you had a board with a knot that just HAD to be planed. (forgetting hand tools for a moment, which would be the obvious solution if you have agood bench) Could you safely plane it by simply taking lots of shallow passes, or is it still dangerous?

The reason the knot caused a problem for the OP is because it was loose and came out of the board when the knives hit it.

If it's just your typical knotty area, you probably won't have much trouble. If there's any chance it could come loose, think twice before sending through the planer.

[Jeff Duncan]

Huh, I dont have much experience yet with planers and jointers, so Im wondering, this was caused by having a knot in the board and the planer trying to plane it? Will/can the same type of thing happen running a board with a knot in it through a jointer?

You never want to run a board with a loose knot in it through anything, planer, jointer, table saw etc etc... Ever. Not even once. Nope. Don't do it! Either remove the knot with a screwdriver, or other implement of choice, or cut that section of board out altogether. Tight knots are generally not problematic and will got through just fine.

good luck,
JeffD

[Rod Sheridan]

Jeffery, glad to hear you're OK.

I had a moulder do that once, bent the knives into a U shape, ejected one from the cutterblock and shattered the cast iron housing. No injuries on that one either.

Knots that appear even the least bit loose should never be sawn, jointed or planed..........Regards, Rod.

[Rod Sheridan]

Huh, I dont have much experience yet with planers and jointers, so Im wondering, this was caused by having a knot in the board and the planer trying to plane it? Will/can the same type of thing happen running a board with a knot in it through a jointer?

Yes, and your likely hood of injury is far higher as you're feeding the material.

This sort of incident can result in a kickback and contact with the cutter head by your hands..............Regards, Rod.

[Erik Loza]

Always morbidly fascinating to hear all these "And THIS happened" stories. Glad you weren't hurt.

Erik

[Ben Rivel]

You never want to run a board with a loose knot in it through anything, planer, jointer, table saw etc etc... Ever. Not even once. Nope. Don't do it! Either remove the knot with a screwdriver, or other implement of choice, or cut that section of board out altogether. Tight knots are generally not problematic and will got through just fine.

good luck,
JeffD


Yes, and your likely hood of injury is far higher as you're feeding the material.

This sort of incident can result in a kickback and contact with the cutter head by your hands..............Regards, Rod.
Thanks guys. Ill just keep a screwdriver near the planer and new jointer when I get it and take a jab at knots when I see them to see if they move or come out.

[Jim Andrew]

When I have a knot I wish to stay in the board while planing, I squirt some superglue gel around the knot, and allow the glue to dry before planing. If it comes loose, it will be on the last cut.

[Ben Rivel]

When I have a knot I wish to stay in the board while planing, I squirt some superglue gel around the knot, and allow the glue to dry before planing. If it comes loose, it will be on the last cut.
What about using epoxy like some West System?