Board rocking on jointer


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17 hours ago, MikeHoncho said:

you always want to plane the face with the low spots on the ends.  If you run it with the low spot in the middle you will be indexing it different every time unless you are super consistent (which doesn't happen in my world). 

I find it easier to do it the other way around.  When I doit your way, I find that I often put too much pressure in the middle, forcing the middle against the tables/cutterheads (i.e., forcing the bow out with my hands).  If you plane it the other way around (like a smile) that problem doesn't exist.  

I don't find the consistency to be an issue.  You pass it over once and you have created a flat spot, so then you use that flat spot to reference for each successive pass, and the flat spot gets larger and larger and it thus becomes easier and easier.  

Different strokes for different folks and all - just saying what's worked for me.

In fact, as I think more about it - doing it your way could create a problem if the board is longer than the infeed table.  With the low spots on the ends, the board will be starting with the tail end below the infeed table, and as you move it forward the board will move upward until the trailing end finally gets on the infeed table, which has changed the registration with the front of the board.  Hard to explain without pictures, but I'm not sure that's what you want.

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Hi Everyone,

I think (fingers crossed) I figured out what was wrong and just wanted to post the solution for any other newbies who run into this later.

I checked for co-planer tables as best I could with the cheap levels you can get at home improvement stores (was going to go to woodcraft this weekend for a better one) but as I was going through and checking everything again I noticed the stock wasn't sitting well against the fence when I was feeding the board through. (This is the first tool I have that's fence guided like this, so I initially wasn't sure what to expect).  I'm not sure if I failed to lock the fence properly or what happened but long story short my fence was off of 90 degrees by between 1/8 and 1/4 of an inch. 

After re-aligning the fence I ran through a couple of boards and the jointer is making contact with the entire board and the rocking is gone. 

As I suspected it was a newbie mistake :-/

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I don't know what the fence has to do with anything.  The fence only assures that the edge will be 90* to the face.  It has nothing to do with flatness.  Maybe I'm misunderstanding you...I don't see how realigning the fence to 90* would make any difference with your problem.

Also, levels are not good enough to check for coplanarity on a jointer.  You really do need a good straight edge for that.  You'll only be able to test within the flatness of the level...and the level isn't really flat...enough.

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Eric, I had a similar situation once. I think with the fence out of square, and the user trying to register againt it (I know, unnecessary for flattening the face), he may be pushing against the fence so that the board rocks up and off the tables, actually producing a twisted face.

So, to the OP, don't worry about the fence when planing the face of a board. Push down, not sideways.

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I don't know what the fence has to do with anything.  The fence only assures that the edge will be 90* to the face.  It has nothing to do with flatness.  Maybe I'm misunderstanding you...I don't see how realigning the fence to 90* would make any difference with your problem.

Also, levels are not good enough to check for coplanarity on a jointer.  You really do need a good straight edge for that.  You'll only be able to test within the flatness of the level...and the level isn't really flat...enough.

Exactly what i was thinking when i read it. Either we don't understand or he doesnt understand. Miscommunication somewhere.

Sent from my SGH-I337M using Tapatalk

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Coplanar aside, don't forget to check the infeed and outfeed table individually for dips or humps.

I had a similar jointer problem that drove me bananas...tables were coplanar...took me months to realize that I had a dip in my outfeed table....

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When flattening the face, don't push it against the fence. As others have said, the fence is used for a different operation (edge jointing, not face flattening).

What happens when you try it without pushing against the fence? 

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There are numerous video and web-procedure setup guides... Get yourself a decent straight edge (50" or so) plus a set of feeler gauges and have at it... It's really not hard... But there are no shortcuts -- get the tools and follow the process -- done. Find a procedure that leaves the outfeed table about a thou below the cutterhead arc... Those are the procedures that typically work best...

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Best video I've seen for a jointer with dovetailed ways (not sure if this is what you have) is the one made by Grizzley.

Generally speaking is there any other product that has to be so precise... And is not cheap by any means... in which the manufacturer suggests that after taking it out of the box you cut up pieces of a Tab Cola can to set it up so it works properly?????.... If all woodworking tools were that complex, I would not be woodworking today.

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  • 4 weeks later...
On 12/24/2015 at 6:15 PM, vinnyjojo said:

 

Best video I've seen for a jointer with dovetailed ways (not sure if this is what you have) is the one made by Grizzley.

Generally speaking is there any other product that has to be so precise... And is not cheap by any means... in which the manufacturer suggests that after taking it out of the box you cut up pieces of a Tab Cola can to set it up so it works properly?????.... If all woodworking tools were that complex, I would not be woodworking today.

I picked my 8 inch jointer up at the Bellingham shop.  I was met by the actual owner (be was a member of a ww forum i was on)  and he gave me a tour of the place including the boardroom and guitars he made.  Got it home,  cleaned it up,  assembled it and haven't had a issue for about 10 years. 

 

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I had a similar problem before and found it was the position of the outfeed table. Theoretically it's supposed to be exactly even with the knives when they're top dead center but in practice I found it works better when the knives are a few thou higher. 

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On 12/22/2015 at 0:56 PM, bgreenb said:

I find it easier to do it the other way around.  When I doit your way, I find that I often put too much pressure in the middle, forcing the middle against the tables/cutterheads (i.e., forcing the bow out with my hands).  If you plane it the other way around (like a smile) that problem doesn't exist.  

I don't find the consistency to be an issue.  You pass it over once and you have created a flat spot, so then you use that flat spot to reference for each successive pass, and the flat spot gets larger and larger and it thus becomes easier and easier.  

Different strokes for different folks and all - just saying what's worked for me.

In fact, as I think more about it - doing it your way could create a problem if the board is longer than the infeed table.  With the low spots on the ends, the board will be starting with the tail end below the infeed table, and as you move it forward the board will move upward until the trailing end finally gets on the infeed table, which has changed the registration with the front of the board.  Hard to explain without pictures, but I'm not sure that's what you want.

Your assuming the crown is in the middle.  And even then your index to where you want the board to flatten out changes with every pass ending up with a thin board on one end and a thick board on the other.  Running a board with high spots on the ends( jointed on the table side)  through a planer is a real pain. 

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11 hours ago, MikeHoncho said:

Your assuming the crown is in the middle. 

I'm making no such assumption.  My method works for an asymmetrical crown unless you have a weird board where the crown is severely to one side or the other, in which case you probably should be using a different board and cutting this one down to use for smaller parts (since you'd maximize yield by just lopping off the end where the crown is).

 

11 hours ago, MikeHoncho said:

And even then your index to where you want the board to flatten out changes with every pass ending up with a thin board on one end and a thick board on the other.  Running a board with high spots on the ends( jointed on the table side)  through a planer is a real pain. 

The index doesn't change. You create a flat spot on the first pass.  That becomes your index.  That index grows with every pass because you're keeping pressure there.  Eventually that index is the whole board, which means the board is flat.  Each successive pass is easier because that index (flat spot) gets larger and larger.

Edit:  Not even sure I understand what you're getting at here.  You seem to be saying two different things.  First you say you end up with a thin board on one end and thick board on the other.  Not so - you'll end up with a thin board in the middle (where you're taking off most material) and a thick board on the ends, which seems to be what you acknowledge in the next sentence.  As for running that type of board through the planer, I don't have a problem with it.  I'd also much rather have the challenge be during the planing operation, which is much more controlled and less beholden to technique, than on the jointer, where the operation is more finicky.  

Like I said, to each his own, and I have no problem with other people doing it differently - just saying my method works.

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