Jointer Struggles, Need Technique Advice

[Paul Richard]

Hey All,

A couple of the fine folks here gave me some good advice a few weeks back which resulted in me buying my first new woodworking machine, a Jet 12" jointer/planer. Everything I have was effectively broken or missing parts when I bought it. I've enjoyed getting them working, but my skills are getting such that I want to move to the next level, which to me starts with better equipment. One thing I HATE is tuning a machine - I like to do something with them, not fiddle with them.

I've had the Jet machine in my garage for the last few weeks and just moved it into my basement this past week. I took great care to minimize any table readjustment, but I'm struggling with it already. I got it hooked up and it seems to work fine for face jointing and planing, but edge jointing does not seem to work well at all. After edge jointing a 4' board and putting it on a piece of glass I find that the left most and right most points contact the glass, but the middle 2/3 of the board are arced, in the neighborhood of almost 1/32. An 18" board is nearly perfect, but anything beyond that just has too much of a gap for my intended use. It may very well be (perhaps even likely) user error. My approach is to use my left hand to hold the stock against the fence and down on the outfeed table, with my right pushing the stock. I've tried with varying levels of pressure, both down and back, but after say 30 repeated joints of an edge I wound up with a board that looks like a trapezoid of sorts (3" at one end, 5" at the other).

Does anyone have a repeatable technique that would yield good jointed edges over an 4' or ideally 8' board? I'm not looking for NASA level tolerances, I'm just a homeowner hack that wants to build some furniture, but many of the projects I have in mind are more than 18" so I'll need to fix this problem.

Any ideas? I've googled the heck out of the Internet and have yet to find a good site or set of videos that help with technique and tuning of machines. Most manuals are weak at best.

Can anyone help? If you are local to me and are willing to show me a few things, I'll treat for a burger and a beer (after any tool use, of course). :-)

Thanks!

- Paul

[Hoang N Nguyen]

Have you checked to see if your tables are in plan with each other? If either infeed or outfeed tables are sagging at its outer edges, it would cause what you are experiencing.

I'm not sure how long the beds are with your jointer, but I have to use roller stands on both infeed and outfeed to help support the work piece when I'm jointing. Otherwise I get the same results as you.

[Paul Richard]

Tables are 27" each, for a total of 55 3/4" bed size.

I've not checked the tables being co-planar with the exception of using a digital angle (Wixey) tool. They vary about 1/10 of a degree, which I'm thinking should not produce the results I'm seeing. Am I off to even use that kind of tool to check the tables? I know that I need to by an accurate straight edge to do some further inspection. That is next on my list of tools. How does my technique sound?

[Mel Fulks]

I would not use the glass ,or even a precise straight edge for checking the wood. Only the machine itself. Your description of method sounds right. I think the out feed table is a little high,"little " meaning possibly only 1 or 2 thousandths. On a lot of the machines making adjustments that small is difficult, IMO the ones having an adjustment wheel instead of a stick lever are easier to use. The jigs used to set the knives in cutter head "top dead center" do a better job of getting all the knives same height than than getting them level with outfeed table. I would drop outfeed table a little ,then test cut and check two pieces together until result is good. Snipe at trailing end of material is a sure indication that outfeed table is too low,so you then know UP ,in small increments, is the right direction for outfeed table.

[Hoang N Nguyen]

I've noticed the wixey tools to be off enough to make a difference. I have one, but rarely use it and never use it to set up tools. It's not meant for that. You need a reliable straight edge. Lee valley has a good one that is affordable, around 100 bucks for a 50" one.

[Richard McComas]

http://www.newwoodworker.com/jntrprobfxs.html

[Matt Day]

There's a good jointer setup video by the woodwhisperer you should watch. You'll need a good straightedge. Sorry you hate setting up machines, but that's part of owning machinery. Maybe you know someone locally that could help you?

[Danny Hamsley]

When I had this problem, the knives or cutters were not set correctly to the outfeed table. Get a 6' straight edge and lay it on the outfeed table with the straight edge over the infeed table and set the infeed table so that the straight edge is flat on both tables. Do it along each edge of the tables, in the center of the tables, and diagonally from each side. The straightedge should be flat to both tables in each position. You need a straight edge that will extend over both tables. Once you do this, set the knives to just kiss the straight edge when it is laid flat on the outfeed table. When set right, they should kiss the straight edge exactly the same from one side of the knives to the other.

[NICK BARBOZA]

This was a good one over at The Wood Whisperer:
http://www.thewoodwhisperer.com/videos/jointer-setup/

Good Luck,
NWB

[Bill Orbine]

Are you sure your glass is flat? Glass can flex....to a certain point, you know! Joint a couple pieces of 4' board and then butt the two edges together. See what gaps you have in the center. If your glass is anything at all accurate, then your gaps at the center of two boards should be double. It's a waste of time fine tuning machines on the basis of assumption.

[Matt Day]

This was a good one over at The Wood Whisperer:
http://www.thewoodwhisperer.com/videos/jointer-setup/

Good Luck,
NWB

Is there an echo in here?

[Paul Richard]

OK, so first, THANKS for the ongoing help! I am going to purchase a straightedge today - I'm sure that will help a little. Any opinions on steel vs. aluminum? Lee Valley has a 50" at $90. The steel ones are bit more than I want to spend to tune a machine I just dropped almost $2K on.

I'll read the link and watch the video as well.

Definitely hope to find someone locally who can just help me with the process once. I'm reasonably handy, from cars to furnaces to home appliances, but I'm baffled here because it's not about repair, it's about accuracy and/or technique. With a hammer and vise grips I can fix almost anything. :-)

Thanks again all!

[Chris Fournier]

Tuning machines is a way of life if you are serious about getting good results. This goes for very expensive machines as well as fixeruppers.

[Warren Lake]

Read what Mel said he told you the problem and how to identify it, he knows more about material and how it works than internet gurus Ive seen. ive read enough of his posts that clearly show that. I use the two board method because it doubles what is out, a dial indicator if need be can show you half a thou easy as you raise and lower your rear table, I hardly do that but its a great visual indicator to know how much you are moving things Got to snipe and come back up. I do level my knives to both the cutter head and to the rear table in set up so its all on the same plane then I just run it and raise my table up and down to get the result I need. Some old school guys deliberately put a slight hollow in their boards when jointing them say on a table top.

this is assuming your machine is set up correctly and that you are using it correctly,

[Tom M King]

I'm a little confused by the "hold down with left hand, and push with right". I hand over hand over the outfeed table right past the cutter head with constant hold down, hold against fence, and feed pressure. A lot is said about board lengths and bed lengths. With good technique, neither matter much. You can straighten any length board on any length jointer. Longer beds just make it easier.

You don't need an expensive straight edge. I use a thin strip of very hard wood to set knives flush with the outfeed table. You can feel if a knife brushes the piece of wood, or see if it pushes it up, or see if the knives don't touch, so it's a good way to check knife height any time.