i’m sitting here with a broken thumb cause my planer seems to want to kickback wood. In fact it did…took a huge gouge out of the front of a piece of ash. it acts like the front roller is higher than the cutterhead but i’m not sure.
the rear roller is the only one that’s adjustable though. replacing the blades made little difference. Any ideas?
oh yea, it’s the typical 2 speed 13″ delta planer
Replies
Sorry to hear about your thumb. How long was the piece the kicked back?
moderately short - say 12"
That may be the issue. Planers don't usually do well with short stock. Try a 3 or 4' board and see if the issue repeats....feed carefully and standback of course!
i'm too skiddish now. I'm taking this thing to the shop. I've run lots of shorter stock before and never had this issue. I'd noticed that even before it was starting to grab the end of a board some and then once it started feeding it was OK.
Perhaps you could stand off to the side, set the board on the infeed, and coax it through using a another board to keep your hands out of the way. I've had kickback one time with my planer and it was on a short piece. No harm done by having it checked out though...
I saw somewhere in a woodshop textbook that 14 inches is minimum length to safely run through a planer. However, since then , we have portables available that will safely plane somewhat shorter lengths. I just took the time to look it up in two books. One said 14 and the other said 12. As long as a board is a little longer than the distance between the feed rolls, it should work fine. However, if you have a very wide planer, run the board near one side so that it cannot twist as it is fed. This would cause the length to be reduced to less that the distance between the feed rolls and jamb your machine. Check your manual to see if you can adjust a pressure bar. Another thing that will cause a kickback is if your board is thinner than your planer setting and you continue pushing it past the infeed rollers. The leading end can be tilted up by applying pressure to the trailing end. This can cause a violent kickback when contacting the knives.
Edited 7/12/2007 8:56 pm ET by wdrite
Thankfully it was just a broken thumb. The spec on this planer is a minimum board size of 1/8 inch thick and 10" long. Any chance the infeed rollers are out of alignment?
Greg
•••••••
Exo 35:30-35
Edited 7/3/2007 4:37 am by Cincinnati
Did you check the blades to make sure they are seated properly and aligned? Is this a new tool? Feed rollers can age, shrink and harden, losing their "grip". That said, 12" is pretty short for a planer.
Mike Hennessy
Pittsburgh, PA
First time this happened to me I tried to plane end grain. Failed! but no breaks. second time blunt blades.
it's not new...probably a couple years old. Actually the infeed roller "feels" to be in pretty good shape.
as far as the blades being aligned. They seem to be..that is, the posts do in fact poke through the blades and the blades are sitting flush against the head. I didn't really do anything else to align them, ... just set them into place.
BTW, i dropped the planer off this morning and won't get it back for a week :( Right when i desperately need one the most. Thumbs feeling a little better though.
I really think it was the piece itself and not the planer set-up. Though I've never had a kickback, I've had similar problems with short pieces. When the piece is too short to hold down well on the infeed side, it has a natural tendency to lift up on the back end when it comes in contact with the knives.
you could be right on the actual kickback but before this...even w/long 6' pieces, for a while i've had trouble with planer wanting to bite down and shutter...kind of pushing back sometimes...on the board when i first put it in. this is especially true if i make it a light pass through.
Thanks Bob for sharing the story. I've seen short boards launched out of the planer before, so I don't stand behind it. Doesn't sound like you were behind the board, just your thumb was. I guess I'll add use a push stick to my procedure for short boards. Would a sled with a backer board to abut the end of the short board help? Or would it just launch the sled too?
Ken
yep, just the thumb. I'm not sure a sled would help i think just keep in mind that planers *can* kick back so it's best to stand aside when you start a board. BTW i just ordered a big 20" industrial (3 phase) planer and i notice that it does have anti-kickback hardware. Since it's 5HP i'd really hate to be hit by a board coming out of this thing.
Bob,
I've been following this thread, and haven't offered any opinion, because I'm not familiar with your machine. The times my 12" Parks has offered to kickback, have been when for one reason or another, the stock has been too thin for the infeed roller to properly engage. Offering it a thinner piece of stock while it is already feeding one slightly thicker, for instance. The Parks has a metal, serrated, but not segmented, infeed roller.
It seems that the light machines don't like to take big bites, I read here about owners typically taking cuts of less than 1/16". I wonder if there isn't a smaller margin of error with them, wherein taking too light a cut, will increase the likelihood of insufficient infeed roller pressure, and thus, of kickback?
Ray
I can't see where a sled would make any difference at all in the case of short stock. Seems like the most likely candidate for a solution would be to have a leading and following board butted against the ends of the short one.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
This is a problem with the hobbyist type equipment now prevalent. They just don't have the safety built into them that more robust equipment would have as mandatory. Industrial planers all have a row of anti- kickback fingers, a segmented and serrated infeed roller, and adjustable pressures and travels on all infeed and outfeed rollers. In 35 years of industrial planing, I have never seen a kickback from a planer, despite some pretty stupid moves by myself and others.
When I see a post asking "Best planer for under $600" I cringe. There is none, I want to shout. But, this being one of America's fastest growing hobbies, and the benchtop planer manufacturers being a good part of the advertisers in FW, they are here to stay.
The best thing you can do if you stick with this equipment is to know and understand it. Know where that infeed roller is and where it needs to be. Try different pressure settings. Find out what a waxed infeed table does. A shop tech may or may not know (or care) about these things. I trust my thumbs and fingers only to myself.
One would think with lawyers/insurance dictating so many things today, that they would limit their liability in these machines with good safety equipment. It still must be cheaper to litigate than to manufacture responsible safety.
Dave S
acornwoodworks.com
yep and the difference a waxed bed makes, as far as the effectiveness of the rollers, is pretty dramatic.
BTW, nice web site. I like the style of the user interface.
I saw this post last week but I was traveling and didn't have time to pursue it then. Now that I'm back at work I have a few questions, because something doesn't sound quite right about your experience:
1. What were all three dimensions of the board, was it straight grained at the end you were feeding in first, was there a knot there?
2. How thick of a cut were you taking?
3. Were you having feeding problems and having to push hard to get the stock to feed through?
4. Have you been having problems with the two speed transmission jumping out of gear which would cause the rollers not be engaged.
5. Is there any chance that you used a spray lubricant on the table surfaces?
John White, Shop Manager, Fine Woodworking Magazine
John:
well, it's been a while now but i'll try and answer the best i can. But let me give you some background that could be insightful (or not).
For a while i've been having an issue where almost no matter what board i put in, the planer would tend to want to kind of snipe the end. several times i've had it start to push back. I did notice that if i fed the board with the back slightly elevated it seemed to behave a little better.
So i noticed that the back roller was really smooth on one side and more coarse on the other so i thought that that *could* have something to do with it, so i took the planer apart and removed the rear roller. i took the rear roller to the local repair shop and asked them if they thought it needed replacing. The technician measured it for flatness and said that he thought it was ok. So i bought a new set of blades and put everything back together. The other thing that was not working on the planer was the two speed controller. It just wouldn't move over to the slower speed setting. so while i had it apart i clearned out that and got it to where the lever would more easily move over. I put it all back together and grabbed the piece of ash.
The piece of wood was probably 7" x 13" x 1". First pass though worked great and i thought..ahh problem solved. (memory??) i lowered it 1/2 crank (1/32") and put it through again and i think it pushed back some on the input side. at that time it's a little unclear what i did about lowering the height but all i recall is that the next pass caused the wood to shoot out. The gouge it took out of the end of the wood was probably 1/8" and when i looked in the planer i coudl see that wood had lodged between the planer knife and (memory?) the bar that holds it down.
Actually my biggest question is what would cause the planer to originally kind of snipe the ends of boards..more so than the kickback <-- that could have just been stupid operator error though i've never had any issue like this before so i think they are somewhat related.
More background info. I'm building timberframe house and my planer did get used some by the workers to plane some large timbers -- like 6"x8"x10'. None of these symptoms started until after the planer was used out at the construction site some.
answering your other questions
3. No...i haven't had to push hard
4. never jumping out but it was stuck in one speed
5. i did use spray lubricant on much of it while i had it apart and was cleaning it. Mostly WD40. On the table bed though i use topcoat.
Without actually seeing the machine it isn't possible to know exactly what the problem is, but the history certainly suggests that the machine was probably damaged and that the kick back was the result of a mechanical problem.
Running a very large beam through the machine could easily have bent the entire frame of the tool causing all sorts of alignment problems that would be hard to diagnose and impossible to repair.
To be blunt, the machine was abused and it has been taken apart twice, it is time to throw it out.
John W.
"...and i think it pushed back some on the input side." With all due respect, that should have made alarms go off and little voices chorus mightily, especially given the problems you had earlier. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Bob,
I have been thinking about this.
I usually push the board till the infeed roller grabs and let it do his job.
For you to have suffered the consequences of a kick back you must have HAD to push it further.
Assuming that your rollers are chain driven, the only possibility I can imagine, is a broken sprocket pin. The roller turns but just by friction and doesn't have the power to push the lumber through the cutter. When the blade hits the board the roller is free to reverse direction.
The length of the board is not relevant.
C.
P.S.
Let's play "stump the chumps" here !
Edited 7/12/2007 6:01 pm ET by citrouille
That's in line with my thinking and why I just posted some questions about the details of the accident.
I'm wondering if the two speed drive had slipped into the neutral position with neither gear engaged, a common complaint with these machines, allowing the rollers to freewheel.
The size of the board could be relevant if only because a short board will be fired back with greater speed.
John W.
Edited 7/12/2007 7:12 pm ET by JohnWW
Bob ???John,What I meant is that the length of the board, or the lack of it, is not the cause of kick back.C.
C.
Sorry, you're not Bob, fixed the error.
Board length probably wasn't the primary cause of the kickback, but it can contribute to the speed of the kickback and the chance that there will be an injury.
John W.
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