What is my issue - jointer help

[brian cammarata]

I have a 1996 Reliant 39C jointer.

Got it at an auction at a bargain basement price.

Thought all was good in the world. Replaced the knives, checked for bed /fence for 90 degree. Set the out feed every way to Sunday based on the over abundance of youtube information. But long story short, taking multiple light passes and I cant get the edge of a board anywhere near flat /pass the light test. I am about wits end. What am I missing. I assume it is operator error, any further guidance for this newbie.

Thanks in advance

[Jeff Heath]

What is happening?

Are you getting a full length cut?

Are you only getting a cut about halfway down the board?

Are you creating an arch in the center of the board?

Is the new, flat edge twisted?

Lots of possibilities based on the answers you give. Have you checked to make sure the outfeed table is at TDC (top dead center) of the cutting circle? Answer the questions as best you can, and we'll figure out what is wrong.

[brian cammarata]

sorry should have included that. It seems I am making it worse in terms of getting a flat surface ad creating more of an arch in the board

[Ron Citerone]

Outfeed table must be even with the highest point of the blades rotation.........AND infeed and outfeed table must be parallel. My two pennies.

Good luck!

[Mel Fulks]

Ron is exactly right . I chime in only because it is a concept many find hard to grasp. I remember how difficult it was for me to understand even when it was carefully explained to me by the best architectural millwork guy around. Without "votes" the truth is often rejected on this one. Putting the machine in that particular adjustment is sometimes done to make a "hollow joint",unlikely to ever pop open at the ends. You might want to try that before adjusting to regular order.
take two pieces of flat dressed wood, and joint off about a whole 1/8 th inch from both,while holding down firmly on the
OUTfeed table. Then put the two surfaces together,to see if the middle of the joint is slightly open.

[Steve Rozmiarek]

Like Mel mentioned, mind your technique, down pressure on outfeed table only. 99% of my jointer issues come from screwing that up. Once the feed technique is consistent, then it's easier to diagnose the adjustment errors.

[Jeff Heath]

I should have mentioned that, as others hinted to, technique could be a problem. I did a "Jointer 101" video on my YouTube channel if a visual aid is better for you. Just search my name on YouTube, and you'll find the video in my video list.

You can use winding sticks on your infeed and outfeed table, in several locations on each table (back...middle....front) to see if the tables are coplaner. Very important that they are.

[Don Jarvie]

I had the same jointer and ran into a similar problem. It could be your technique, but you need to make sure the tables and knives are set up correctly. Bring both tables up even with the knives and as you rotate the head there should be no gaps across the head. If there is a gap you need to check to see if the knives need to be adjusted or if the table isn't dipping on one side. If it looks like the tables are dipping then remove the knives and set the tables to the head. You can shim the tables on either side to correct the dip.

Next is to check to see if the tables are dipping on the ends. If you have a long straight edge or long board that is flat check to see if the tables are level all the way across. If not shim accordingly. If the outfeed table is dipping on the end it will affect the edge of the board. Once the machine is set up correctly you can look at your technique and go from there.

My outfeed table dipped a bit so I had to shim it. Its not a bad jointer once its set up correctly. If you are ambitious enough you may want to take it apart and clean everything.

[Mel Fulks]

I need to stress that 1and 1/2 thousandths wear on the knives is all it takes for the wood to start "climbing". So they can continue to cut well though the wood is climbing. Never seen it mentioned in any manufacturor provided info. That's why I much prefer the jointers that are adjusted by hand wheels ...not "stick shifts". The wheels can be easily calibrated for
QUICK adjustment withithout dials, straight edges, feeler gauges,magnets, etc. This info needs to be in the jointer manuals. In a home there is no one to call you an idiot and give terse instruction. ....I know what you're thinking .But
your wife might not know anything about jointers !

[brian cammarata]

I had the same jointer and ran into a similar problem. It could be your technique, but you need to make sure the tables and knives are set up correctly. Bring both tables up even with the knives and as you rotate the head there should be no gaps across the head. If there is a gap you need to check to see if the knives need to be adjusted or if the table isn't dipping on one side. If it looks like the tables are dipping then remove the knives and set the tables to the head. You can shim the tables on either side to correct the dip.

Next is to check to see if the tables are dipping on the ends. If you have a long straight edge or long board that is flat check to see if the tables are level all the way across. If not shim accordingly. If the outfeed table is dipping on the end it will affect the edge of the board. Once the machine is set up correctly you can look at your technique and go from there.

My outfeed table dipped a bit so I had to shim it. Its not a bad jointer once its set up correctly. If you are ambitious enough you may want to take it apart and clean everything.

thanks...I hope to get home tonight and monkey around with this a bit more. Appreciate all the suggestions so far

[glenn bradley]

For such a fundamental machine, the jointer can give you fits even if it is functioning correctly. For the sake of this conversation, let’s assume that “Set the out feed every way to Sunday based on the over abundance of youtube information.” means:


You have a nice long straight edge.
Both the infeed and outfeed tables are aligned coplaner with each other.
All the knives are at the same height and even with the outfeed table along their length.
The outfeed table is even with Top-Dead-Center of the knives.

Assuming this, just as with hand planes, one can still get suboptimal results through improper technique. Technique is curable, I’m proof; even I learned to sharpen things and I would have thought that impossible.
Your goal is to make an un-flat surface, flat. This means that the surface resting against the infeed table will be irregular. Part of your technique is to choose or enforce a reference position for your first pass.

If the board is simply bowed . . .

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. . . I will knock down the leading and trailing edge with a hand plane to reduce the height of the “bridge” created when the board is set on a flat surface. If the bow is too great, the leading edge will pass over the cutter head and catch on the lip of the outfeed table. This is probably a good time to mention that the bow should arch up; jointing a convex surface is fraught with problems. Also, consider your grain direction.

<< sorry, no room to put more pictures in >>

Assuming the board will pass over the cutter head successfully, material control enters the picture. For the same reason you cannot joint with a planer (without some sort of jig) you must not alter the shape of the material while feeding it due to unnecessary pressure. If you flex the board while feeding the cut will be applied to the distorted shape and yield poor results.

You begin the cutting operation with your control pressure on the infeed table. Once a few inches are past the cutter head you now have a newly cut reference surface. You want to transfer material control effort to the material that has already past the cutterhead. This doesn’t mean there is no control at the infeed. You are just changing the nature of that control to a feeding effort allowing the material control effort at the outfeed to use the newly created reference surface to control the feed path.

That sounded more involved than it is.

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[Mark Hennebury]

Bruce Lee said that before he understood; a punch was just a punch; when he studied it a punch was incredibly complicated; after he mastered it, a punch was just a punch. A jointer is much the same.

It is the most simple of machines. That appears frustratingly complicated to understand, once you get it it is like breathing, you don't even think about it.

The simple; you just push wood over it.

The complicated;
Do you understand what you are trying to accomplish?
Do you understand flat?
Do you know how would you check flat with a straight edge?
Do you understand co-planer in relation to the tables?
Do you understand cutterhead geometry?
Do you know hook and relief angles?
How about the cutterhead axis in relation to the tables surfaces?
How about the knives at top dead center in relation to the table surfaces?
Do you understand the way that a circular cuttehead cuts?
Do you understand that top dead center of the knife circle is above the bottom face of the board when it is on the outfeed table?
do you know what a sharp blade is, how it feels when you run lumber over it, or how a dull blade feels?
How about wood?
Do you know about wood structure, moisture content, equilibrium, internal stress, unbalanced stress, fiber direction?
Do you understand your job, or how you can affect the out come.


Jointing lumber is a ballet, it is fluid, effortless and beautiful, when everything is right and you know what you are doing.

Lets Assume a lot; that the machines is in good working order, the blades are sharp and your lumber is at equilibrium and stress free.

Think about it this way:

Your job is to use the infeed table to provide a stable base of reference to present the wood gently and firmly without distortion or movement accept along the horizontal plane to the cutterhead.
As the wood passes over the cuttehead the knives remove some of the wood leaving a flat reference surface that is perfectly supported by the outfeed table.
Once enough of the newly machine surface is supported by the outfeed table, the infeed table is no longer needed, and theorectically could be removed.if you lumber is strong enough to support itself, if you lumber is Flat thin and flexible, that's a different story, then you need the infeed table to support it.

If you machine is not setup, then thee are a whole host of issues.
If your wood is not stable, then there are a whole host of issues.
If you don't know how to hold and move the wood, the same thing.

It takes a lot of hard work to make ballet look easy.


https://youtu.be/bQ0L24YbGGI

[Alan Schwabacher]

If it's just the outfeed height you are trying to set, and not the more difficult parallelism, try this. (The review on WoodCentral says both infeed and outfeed tables of your jointer have handwheel adjustment. This is good.)

1. Lower the outfeed table to below the top of the knives.
2. Using an already reasonably straight board held down tightly to the infeed table, slide it slowly into the running cutterhead and stop when it has reached only a couple inches over the outfeed table. Shut off the jointer. There will be a slight gap between the wood and the outfeed table.
3. Holding the wood down tightly to the infeed, carefully crank up the outfeed table until it just touches the stock without lifting it off the table. This should be very close to the correct setting.