Can anyone explain???

May be caused from the belt slipping as the board is being passed over the blade. this would cause the the knifes to rotate as they are supposed to, This will cause the board not to get surfaced properly.
 
I know the belt on my jointer is loose because the board comes out with a twist in it...I just can't wrap my head around why.:huh: :dunno:

Anybody?

I have pondered this and I cannot make a "cause and effect" link between the 2 things. Has this happened more than once? If not, I'd mark it up to coincidence.

If the bearings on your jointer failed terribly, It's possible that low tension on the belt would cause deeper cutting on the belt side. But if the bearings were that bad, the first thing you'd probably notice would be an earthquake-like shaking and some very loud noise. And then the cutter head might fly out of the machine. You would definitely know you had a problem.

.02
 
It's happened a number of times. The bearings are fine...that's the thing.:huh: The belt is slipping. This I know, because the solution works every time...I tighten the belt and all is well. In my mind...the only way to get a twisted piece of wood out of the outfeed table of the jointer is for the knives to be somehow lifting up, or twisting. But the only thing that is changing is the speed of the cut, when the belt slips.
:dunno:

Plus I think I posted this in the wrong forum :doh: Oh well.
 
Thanks Vaughn. And I really don't consider it a jointer "problem" though. I think it is more of a direct cause and effect...I just can't figure out why. Maybe this is a bit of a warning as well as a question.

Warning: if your jointer belt is loose, your boards will come out twisted.

But is almost doesn't make sense right? And I see this happening long before I would've known about the belt from hearing it or otherwise. I spend a lot of time on the jointer...sometimes days at a time.
 
If you ever do figure this out please post it!! I have been thinking on this and thinking on this and I am stumped. Unless there is something loose or some play where I can't figure it out. It just not make any sense. But I have seen some strange things in the factory that once you FINALLY found it made sense. But finding the problem was near impossible.

Recently my jointer started making wedges but they were tapered across the side, not end to end. That has me stumped why it suddenly started doing this. Of course it didn't take to long to find it, it was a loose knife.

Jeff
 
Hi Craig,
I sure hope you figure this out because something is wrong and it could be a very hazardous situation you are working in. If something is wrong there is a reason, like Jeff said, with him it was a loose knife:eek: :eek: :eek: . Ive seen results from a loose knife on a northfield jointer. It can tear up some steel.
Hope it is just the belt but best be sure and safe. Figure it out SOON and let us know.
Shaz
 
Craig, I know you said the bearings are fine...but having some "play" in the mechanical connection from the belt to the knife head is the only plausible reason I can think of that would cause one side to go off plane.

Looks like we're all stumped....good luck.
 
Craig.......If tightening the belt makes the twist go away...the knife head must be moving. Tightening the belt puts more pressure on one side of the knife head. If it was just a loose blade, I don't think tightening the belt would have any effect on the twist. That would be my guess....JMHO.
 
Craig

I think you really ought to find a qualified technician in your area to look at this thing. Visit the manufacturer's website to see who they use for warranty service and get in touch with them.

The forces you're dealing with are very strong - I would unplug the power cord right now and get it serviced.
 
Craig, there must be some play as others have said in the cutterhead. This could be internally in the bearings, or perhaps there is some wear in the casting (or bearing block) that the cutterhead bearing fits into on the jointer body. One way to check this is, if possible, to lock the cutterhead in place with one of the knives at TDC (like you would when setting the knives) and place a magnetic base & dial indicator on each side of the bed and the Dial indicator stem on the top of the blade. Zero both dial indicators, and then either tighten or loosen the belt, (depending on whether you start with a tight or loose belt), watch the indicators as you make the belt adjustment. Any deviation from the zero setting on either dial indicator whether + or - will show if there is any play in the bearings or bearing blocks and how much play there is.

Hope this helps.
 
Craig, there must be some play as others have said in the cutterhead. ....

Thats what I am leaning toward also. And there is nothing wrong with using some leverage to check for play. Of course use common sense when prying on the any machine part too! But it may be that the play doesn't show up without some force, and there is a lot of force on a spinning cutter head.

Jeff
 
All great suggestions, and I'll be sure to check each and every one. But its cutting fine now that the belt is re-tightendThe knoves are not loose or moving. And it has definitely loosened over time as I'm almost out of adjustment. Next time I'll have to replace the belt. It's a DJ 20, good machine, but I use it pretty hard. Just past up a great deal on some old arn too. :( 12" Casadei for a song.
 
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