cutting height on a jointer.

[Ed_K]

 I bought a new set of jointer blades and tried to set the cutting height to use it. I used a magnetic dial indicator an got the blades all set to less than .003 then used a machinist straight edge an set the out feed table to equal the top of the blades.
 Then using the dial indicator set the in feed table to .062, the gage on the side of the in feed table is hard read.
 When I ran a board on edge a few times it started getting thinner for one side to the other.
 WHAT am I doing wrong. I've never used a jointer before.

[btulloh]

Re-check your alignment first.  You described the right method, but sometimes it can be tricky to get it right.  

The other thing about using a jointer is that how, when, and where you put pressure on the board you're feeding is a bit of a learning curve.  Usually a problem like that will result in a board that's curved end to end though.  Side to side variation can happen if you're board is got a twist though.  Flattening a twisted board takes a little practice with where you put the pressure and when.

Generally, you want to transfer your down pressure to the the outfeed table as soon as there's enough board on the outfeed table to allow that.  A twist can rock side to side if you're not real careful, and you end up with a mess.

Adjusting knives can be finicky, but it sounds like you're approaching it the right way.  Also check the alignment of your infeed and outfeed tables to make sure they are in the same plane.  Worn ways on either one can lead to a misalignment.

Patience and perserverance pays when adjusting a jointer.

[dougtrr2]

Advice given above is good.  Here are a couple other considerations.

Some set up instruction will have the outfield table slightly below the arc of the knives.  Like if you set the straight edge on the outfeed table and rotate the head, the straight edge is dragged forward a slight amount.

Any adjustments to the tables, especially the outfeed table should be done with the table going up.  That eliminated the effect of backlash on the screw raising mechanism.  To try to explain.  If you reverse the direction you have been cranking on the table, there is a lag before the table starts moving.  That is due to the slop in the screw threads.  So you want to be moving the outfeed table in an upward direction when you make adjustments so the the table is resting on the threads.  If you don't the table could drift down over time, even if you locked it down.  

Make a pass or two on a board so you have a reasonably straight edge.  Then make another pass paying very close attention as the board gets to the outfeed table.  There should be no "bump" as it hits the outfeed table.  If there is, that means your table is set too high.  If you are getting snipe on the tail end of the board your outfeed table is too low.  

Are the infeed and outfeed tables parallel to each other?

Joint a board about 12" and stop. There should be no gap between the board and the outfeed table. If there is it could mean the tables are not parallel.  The fix for that might be as easy as loosening the gibs, hold up on the outfeed table and retighten the gibs.

Good luck

Doug in SW IA

[btulloh]

the infeed and outfeed tables parallel to each other

Yes - that is correct.  When I said they should be in the same plane, I stated that incorrectly.  Parallel is the correct way.  

Good points from Doug and good advice on the backlash.

[alan gage]

Some set up instruction will have the outfield table slightly below the arc of the knives. Like if you set the straight edge on the outfeed table and rotate the head, the straight edge is dragged forward a slight amount.

I'm not jointer pro by any means but this made a big difference for me when I tried it. Otherwise I'd been getting a deeper cut on the leading edge of the board as opposed to the trailing edge. It also made a big difference when I started transferring my hold down weight to the outfeed table as soon as a jointed surface was resting on it.

In your original post I was a little unclear about where you were seeing the uneven thickness. Was it the long way from end to end or across the board the short way?

Depending on the shape of the board when you start it can be normal for it to come out tapered one way or the other. The jointers job is to make the surface flat and usually that means more wood will be removed from some parts of the board than others, resulting in uneven thickness. Then it's the planers job to even everything back out when the board is run through with the jointed face down.

Alan

[YellowHammer]

If you are going to be setting jointer blades often, it's a big help to get a magnetic blade setting gauge for a jointer.

Did the machine cut straight before you set the blades?

If you want to do a full alignment, raise both tables to zero, and rotate the cutters so they are shy of the table top. Get a long (as long as the bed) aluminum straightedge, I prefer an aluminum level, or 80/20, and place it flat on the table, from infeed to outfeed, full length.  Then take a flashlight and put it behind the straightedge and look for any light coming between straightedge and the table. Slide the straightedge inboard and outboard, diagonally, etc and look for any end droop, concavity, warp, anything and adjust it out until both tables are dead flat in all planes.  

Then rotate the cutter head and get the cutters adjusted to the outfeed table with them just barely ticking the straightedge all along the cutter length and for all cutters.  

Make adjustments to the height of the out feed table at this point to make sure the cutters and out feed table match up perfectly.  

At this point, get a piece of hardwood, like ash or white oak and put it in its edge instead of face and take a big bite, 1/8" or so and run a piece and watch how it engages the outfeed table.  If it bumps it or raises up the drop the outfeed a hair.  If there is a gap, raise the outfeed until the leading edge exactly engages the outfeed table lip.  Then finish jointing the piece and about halfway through, push down on the piece on the outfeed table and see if it causes the piece on the infeed to jack or rock.  If so, make the adjustments.

Do this in the near side of the cutter, then the far side of the cutter head.  Then take the board edge and place on the outfeed table and it should be dead flat.  If not, go back and make adjustments.

Then plane the face of a hardwood board, it should come out so flat it will vacuum down to the table, you should feel it suck down and when you pull it up, you should feel it release.  

[firefighter ontheside]

I'm not sure if anyone else said this, but you need to joint the side that is concave.  Jointing on the convex side will likely lead to what you are describing.  When jointing that side, you cannot push down in the middle or you will not remove the concave.  Hold down on the ends.  

I was using my jointer the other day and I was getting weird results like you.  I discovered that the outfeed table had sagged about 1/16", but you said that you have it set at the same height as the knives at their highest point already.

[kantuckid]

FWIW, I do my jointer blades using a VG Starrett straightedge not my dial indicator. That said I did machine setups for my job and well trained with using a dial indicator at that. 
I also found that my 8" jointer blades were cheaper to buy new on ebay than have sharpened. Not true for my planer blades which I use the solid metal gauge that came with it(bridges the blades using spring loaded pressure) to set the blades, not an indicator

[Ed_K]

 Thanks all, btulloh, I never thought about where to put pressure really but when there was enough on the out feed table I pushed there more.
 dougtrr2, I aligned the out feed table with the straight edge to the blade that was the highest. The lead screws have 1 1/2 turns to get rid of slop, I've run WW2 lathes that had 3 turns trying to hold +/- .005 :D. When I ran a board thru I didn't get any bump but on a couple there was snipe. I was running w/pine maybe I should do some ash to set up was just trying to do a job for Rita's niece. I think/wonder if I should pull to tables apart an see if the gibs need to be surface ground, it's hard to set them and get good slide from high to low on the lead screws.
 alan gage, the boards were uneven width wise, 6" boards and after a few passes one side would measure 5 15/16" the other 5 3/4". I ran them thru the planer first to 13/16 thick, I thought the jointer was to get the boards flat end to end for glueing and 90° to the flat side.
 Yellow Hammer the blades that came with it were sharpened on a table grinder by hand I think . I bought new ones thru amazon (big mistake) took 6 weeks an came from England :(. I checked the flatness/square of both tables but not across both, I'll use the 4' level but again wonder about the gibs.
 firefighter ontheside, I never thought about concave/convex just that run them thru and the jointer would take it out. The out feed table was still where I set it but I have to go back and check to see if it's square,side to side.
 kantuckid, Starrett was down rt 2, 25 mile from me wish they were still in business,probably made in china now. I used a starrett true square to set my fence to 90°,and that pointer wasn't right either. The blades were around $40. for 3 of them, when I need planer blades I'm changing to a helix cutter. I think this machine had a lot of use and abuse, came from a lumber yrd.

[YellowHammer]

If you are getting snipe on the rear of a board then the outfeed table is not adjusted. Typically it's because the outfeed is too low and as soon as the board comes off the end of the infeed and isn't supported, it drops to the height of the outfeed table and snipes.  I always use hardwood to tell how to make adjustments because it cuts precisely.  

If the gibs are worn it will cause end table droop or side sag, among other things.  If you have a gib jointer, once it's set correctly, take the outfeed table height knob off.  You should never have to adjust the outfeed table except if changing knives.  That's one reason it's so important to test for flatness and planarity across both the infeed and outfeed at the same time.  Here's a 6 foot aluminum straight edge on mine.  I bridged the cutterhead and if the straight edge rocks there's a problem.
 

If the tables are not adjusted correctly it will never perform well.  It's a quick check. Of the three jointer I've had, two needed adjustment from the factory.  

[Dan_Shade]

After you get it set up properly, keep a good coat of paste wax on the beds, it makes a big difference in use.

You know the board is flat if it sticks to the outfeed table..... I'm like a kid and always play with a board for a bit when that happens.   The board will "float" as it's set down, and then "stick" . 

[Ed_K]

 I'm almost betting the gibs are bad. And if I try to repair them I'll find their to far gone. That'll be a hunt 60 ? yr old mach.

[Don P]

Put 2 jointed edges together, are you getting a straight edge?

[btulloh]

Even if the gibs are worn some it should be possible to make it work right.  Just a bit more fiddly.  There's just not much occasion to get a lot of wear on the jibs though.  My bet is that it can be adjusted to work fine, just takes a little more re-tweaking.

After re-reading your first post, I understand now you're running the edge.  When you say it's getting thinner end to end does that mean narrower?  Is the edge straight or curved after you run it?  That would be indicative of the infeed and outfeed tables not being parallel or the outfeed table being below the blade height.

The only jointer I've ever seen that couldn't be made to work right is one of these little bench-top things they sell now with short cast aluminum tables.

[kantuckid]

My jointer is a Sprunger, once made in IN, they were VG machines. I bought it from an English professor up around Lima, OH who did machine rebuilds as his sideline. Interesting combo huh?
 
Mine has had the gibs resurfaced and I've been using it for over 40 years as it is. I also bought a Sprunger wood lathe from him which I extended the bed for my back rocker posts. It sits on large wooden beams now which dampen vibration well. I use the storage shelf/brace underneath to store nails and to add weight. 
The older, well built, designed machines can be freshened via generic parts and basic trade skills. 

[Ed_K]

 Sorry not to get back to everyone, it got short of breath from my new chemo meds and found out I have blood clots ing my lungs. Getting some better now and will try to work on realigning it.

[Don P]

No hurry on our end Ed, take care of yourself. I sawed in a bad cloud of dry locust dust the other day and have been wiped out for 2 days, got my partner's cold on top of it. Nothing compared to yours, take care of the important stuff and play when you feel better.

[PC-Urban-Sawyer]

Glad you got treated for the pulmonary embolism(s)... They can be killers. I had major clots in both lungs a couple of years ago. I'm still on a blood thinner (Eliquis) but a very small dose. 

Take care.