Trouble breaking insert carbide teeth on planer
Howdy all,
Howdy all,
Well, i’ve been running into a lot of trouble with my old powermatic 20″ planer that has been outfitted with a USA made head.(Don’t know if brand name makes a difference, i’ll leave off) I’ve never heard much about running these things a lot and only hear about how great they are for edge wear, but my teeth break constantly and when they do they take out 20 other teeth when the carbide bounces around inside the planer. I spend a good 1/2 hour hunting down the offending chipped teeth and some seem to break after running the planer for a few more minuetes after putting it all back together again. I’ve found these teeth have little hairline cracks but they are hard to see before they blow up and chip more teeth. Needless to say its a chore to keep turning the machine on and off and hunting the problem teeth all b/c of a loose knot or chip of wood. I was wondering if this is common for folks running these? Its most common when a knot gets pulled loose and obviously it would be nice to run knot free lumber, but this is the real world. Its very expensive and time consuming to break 3 teeth and rotate 20 for every knot that comes loose. I’m thinking the best solution is to switch to a straight knife machine with built in grinder?
We are a small sawmill/mill works shop that planes 100’s of bd ft at a time. Not a giant factory running thousands of board feet. I love the wear properties of the carbide but the brittleness is killing me. Anybody have experience with this? Oh, and one more thing the journals are getting chipped up as well and often have to be repaired with a file so that any knicks left by the exploding carbide insert is smooth and doesn’t crack the replacement. I have not seen this problem mentioned in any of the reviews in all the woodworking magazines that are talking about how big an improvement the indexable head planer and jointer are.
Thanks
Kelvin
Replies
What torque ?
Replacement cutters should be torqued to 55 INCH/LBS. You may be inadvertantly cracking them during instalation.
have torque wrench, but could still be something...
Doesn't seem to be responsible for knots breaking the inserts. I did buy a 1/4" drive decent quality torque wrench for this exact purpose. The torque is suppose to be what you can achieve by hand tightening with a torx wrench. i've changed hundreds and hundreds of these inserts, i don't think i'm cracking them while installing unless these things are so sensitive its possible to wreck them with a very slight over or under torquing. I'm thinking that there might be something with retrofitting old planers with these heads as the chip breakers are designed for straight knives so maybe accounting for the broken inserts bouncing around inside the housing? Maybe a custom made planer with a insert head in it would be designed differently? I know these heads are used in large production machines and they can't possibly be stopping and reseting these things constantly in that type of enviroment.
I'm really curious if anyone had experience with a more production enviroment, planing 100's of bd ft at a time per day, is a straight knife machine with a built in knife grinder a more durable way to go?
Same Machine
Hello Kevin, I have basically the same machine The company that makes this cutter head told me to torque the inserts to 40 to 45 inch lbs and since then Ive never had another problem. just thought i woud share that with you I hope you get it figured out.. Christopher
If it is a Byrd head you could have the wrong inserts. Their have been discussions about this problem on various woodworking forums. If you have a Byrd shelix head call them.
http://www.sawmillcreek.org/showthread.php?100542-Byrd-Shelix-inserts-breaking&p=1027645#post1027645
Been running this planer for 6 years, just a loose knot problem
Thanks for the responses. I've been running this planer for about 6 years so its not a day to day problem with turning or torquing the inserts. If i'm running select cherry i'd say it would run forever with no problems. The problem lies in knots that pull loose. I am extra careful not to run things with loose knots but this planer tends to pull things out that i wouldn't call "loose". When the chunk of wood pops out, the pieces bounces around. I've read where you need to watch out for "loose" knots but that doesn't inform you what to expect in a day to day operation. Each pulled knot takes us down for an hour or so replacing and cleaning broken and chipped teeth, firing up, finding more problem teeth, fixing those etc. Its not something discussed much. Maybe its just a trade off in running carbide, its brittle. It could be the quality of my carbide, i put an email in to the company i bought from to see where they are made and if they have any helpful hints.
The teeth are very exposed on this type of journal. I've seen pictures of different brands styles and some of them have the tooth buried in the journal with only what appears to be the cutting edge sticking out. I'm wondering if this exposed Byrd style head has something to do with the broken inserts bouncing around and taking out a whole mess of others. The industry could not be running these heads in their giant machines with the trouble i'm putting up with b/c knots pulling are a fact of life.
Anyone here have experience running a planer with a built in grinder on straight knives? Wondering if i would have less downtime???
Thanks for any input,
kelvin
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