Getting Perfect Edges with a Jointer

[yfs1]

I am fairly new to jointing but I am having a slight issue. When I run by boards through, and then put them next to each other they tend to be perfect on the ends and then a slight gap in the center (Maybe the thickness of a fingernail)

Between a hand planer and a sander I can usually get it near perfect but it takes loads of time.

Should I be getting perfect edges with just the power jointer?

If so, what is the most likely issue with my technique?

Thanks!!

 

[the_g_ster]

Hi,

I guess this depends what you are using the jointed boards for. If you are gluing them up for a table top or something then this slight bow will help you. A board shouldn't be dead straight when glued up, as when the end grain dries and moves you stand the risk of cracks at that joint. This should compensate for a small amount of movement.

If you need them dead straight then it's back to your technique. Don't take much off in a pass and concentrate on getting your pressure onto the outfeed and not on the infeed as this could cause a pivot and slight bow.

There's loads on here for technique, most people's bug bear is snipe at the end as you almost finish passing the board through, so you are not far off in which case.

Good luck, let us know how you go.

G

 

[motownmartin]

You might want to look at this thread there might be a few answers on there for you.

 

[BradNaylor]

If I want a dead straight edge on a board I don't use the jointer (planer) to get it. It is much easier and more reliable to use the table saw.

Simply take an 8' long x 6" wide piece of MDF and screw a batten along one edge and another one across one end. Place this jig over the plank of wood to be straightened and run the whole thing through the table saw. The sawn edge will be absolutely straight every time. Take a very fine cut on the planer to dress it up if necessary. For edge jointing there is no need to plane the edge so long as your saw blade is sharp.

Try it - it's foolproof!

Dan

 

[yfs1]

Thanks for all the tips!

I read the other thread and it seems that my infeed table is not level to my outfeed (I put down a straight edge and there is a tiny gap at the end furthest from the blades).

If only it had come with a manual, I could adjust it....Off to play trial and error.

I assume every planer/jointer's infeeds can be adjusted for level. (Its a Fox F22-563)

 

[motownmartin]

Thanks for all the tips!

I read the other thread and it seems that my infeed table is not level to my outfeed (I put down a straight edge and there is a tiny gap at the end furthest from the blades).

If only it had come with a manual, I could adjust it....Off to play trial and error.

I assume every planer/jointer's infeeds can be adjusted for level. (Its a Fox F22-563)

You might need a big hammer :lol: only joking

 

[bjm]

It sounds like your knives are set a fraction too low in relation to the outfeed table if you are getting a concave joint.

Brian

 

[yfs1]

It sounds like your knives are set a fraction too low in relation to the outfeed table if you are getting a concave joint.

Brian

I will try that first then (I have never adjusted them). Word back from the manufacturer is that no adjustment to the tables is possible. - So maybe the hammer wasn't too far off

Just out of curiousity if the knife adjustment doesn't change anything, it it worth my while using a bit of masking tape to build up the infeed table...We are only talking a fraction of a mm here.

 

[bjm]

When you set the knives they want to be fractionally (thous of an inch) higher than the outfeed table, not in line with it. If you place a straightedge on the outfeed table and turn the cutter block the knives should just pick up the straightedge and move it forward a few millimetres. You may have to fiddle with it but it will pay off. Good luck.

Brian

 

[WellsWood]

Your tables should be absolutely parallel to each other, although the infeed will be lower by the depth of your cut. If there is no facility for adjusting one or both the tables to correct this then you have 2 choices, figure out a way of shimming the tables till they're parallel, or send the whole thing back (assuming it's an option - how long have you had it?).
One thing is for certain, you will never get a straight edge from a machine with out of parallel tables. This is because the work will always rotate slightly as it goes from infeed to outfeed. You may get lucky from time to time when a particular combination of blade-height-to-outfeed-table and dullness of knives (both of which can have an effect on the result) conspires to cancel out the problem, but that's hardly a long term solution.
There is one thing which may work, try adjusting the cut depth in different directions to see if it makes a difference to the alignment of the tables, it may be a backlash issue in the rise and fall mechanism of the infeed table. I had a machine once that would only cut true if I adjusted "up to" rather than "down to" the required setting.
Oh and finally, make sure you use a known-to-be-accurate straightedge to do your checking. I once spent a considerable length of time trying to correct a problem just like this before discovering that bend was in the 1M steel rule I had been using and not the workpiece #-o