I'm tuning up a 30" jointer. outfeed table is cast and does not adjust. I've adjustd the infeed table to as close as possible (i took the infeed table to a machine shop for flatness verification). When I run 6' long boards through, about 1 foot from the end I get no jointing (blades lose contact with the wood). When I put 2 jointed boards together I have a 1/16 gap in the middle. any suggestions or tips on how to align this thing. thanks
sounds like your outfeed table is to high. If you truly can not adjust it, perhaps the cutter head can be adjusted.
The most simple solution would be to loosen and reset the knives to the proper height.
30" jointer, nice drive by..you must have used a engine hoist or bobcat to remove the infeed table....Myx
adjust.
When you say you've adjusted the infeed table as close as possible what do you mean? Your knives should be adjusted to the outfeed table (dead bang, gnat's ass level) and the infeed table should be adjusted to be co-planer to the outfeed table.
Is that where you're at? And by 30" you're talking w i d e? If so, it must be an old machine so you might try
I know of only two errors in jointer setup that can produce the problem you describe: either the knives are set significantly below the outfeed table, or the tables are not coplanar.
"Coplanar" means "in the same plane". When talking about jointer tables, this means that (a) the tables are not twisted with respect to each other, and (b) they are dead parallel fore-and-aft. I think your tables are not coplanar. I think they're tilted like this: / \
Raise the infeed table until the inboard end of it (just before the cutter head) is at the same height as the inboard end of the outfeed table. Then lay a long straightedge along the infeed table, extending over the outfeed table. I think you will find that the outboard end of the outfeed table is significantly below the straightedge.
If this is the problem, it's best corrected by shimming the mounts of the outfeed table if possible. Since the outfeed table doesn't move, once shimmed properly, the setting should hold forever. If you shim the infeed table, repeated movement of the table could wear down the shim enough to eventually misalign the table again.
Good luck, and be sure to let us know what the trouble is.
-- Doug Miller (alphageek at milmac dot com)
How come we choose from just two people to run for president and 50 for Miss America?
Myx gave you the solution in the first reply. The outfeed table is higher than the cutters. It doesn't have to be by much, very little offset will do it. So make your adjustments very accureate. What happens is that you start off by cutting the depth you desire. But then the piece reaches the outfeed table and has to rise up onto the table. At that instant you are still cutting but now not at the depth you desire. As the piece continues through the planer the weight you shift to the front of the piece forces the very leading edge flat onto the outfeed table and lifts up the trailing edge to a height that is above the cutters. Try drawing this out on paper and you will see what is happening.
Joe....
Hi, 6' of timber that's a nice piece of timber to steady from the feed side of your planer! the timber may be just rising from the infeed table as the majority of the mass of timber passes of the outfeed table, you may just need additional support rollers after the out feed table to ensure contact with both tables during the planing process. Lew
As far as the straight edge your talking about, is it a STRAIGHT edge or something from borg. I've gone round and round with my jointer using a " sort of straight" edge. If you want that thing to do what it is supposed to you got to get a REAL STRAIGHT straight edge. Aligning your machine to a crooked straight edge is inducing error and it will haunt you forever. Just my .02
jack
I found that with my 6" Jet I had to have the outfeed table ever so slightly lower that the blade height. If I had everything dead even, I'd get the board rising above the outfeed table as it passed over the cutter. My only idea is that there is a degree of spring back from the cut (pine) which effectively reduces the cut depth.
-Bruce
Mcgyver wrote:
But did that result in the last *foot* of the board not touching the knives, as the OP noted? IME, that leads to missing an inch or so at the end, but an entire *foot*?
I still think his tables aren't parallel.
I haven't been following this thread closely,
Has anyone brought up the shapers gibs?
A lose gib will allow a table to sag, and the mass of the table would put enough force on the ways that looseness may not be noticed.
Just throwing out a thought.
About steel rules? The rules sold at the BORG are not steel rules, their strips of metal with numbers stamped on them. They *may* be OK for rough carpentry and of some use in fine(r) woodworking but suitable for machine setup? (lol)
No!
OR
He's trying to join an edge with a convexity by laying the leading edge on the table and holding everything down, instead of jointing the middle first..
Even with a drooping outfeed, proper hand position just after the knives would compensate. Of course, the board wouldn't be touching the end of same.
Basically from what I determined, table ends (either infeed or outfeed) that are too high (tables form a "U" shape) will make the board edge convex. table ends that are too low (sagging into an upside down "U") will make the board edge concave (OPs symptom). A cutter that is too high or too low relative to the outfeed table (tables are otherwise coplanar) will always result in a concave board end.
Non-coplanar tables would give the same symptoms but a lot would also depend on technique. Consider that with the outfeed table completely removed and the infeed table guiding the cut for the entire length (impossible I know, but...) the cut would be dead flat. With the outfeed table installed and used to guide the entire cut, the cut would also be dead flat. The problem arises when the transfer from the infeed table guiding the cut to the outfeed table doing the guiding. If either table was higher at the ends away from the cutter, the board would have a convex profile. If the table ends were lower, the board would take on a concave profile (and display symptoms like the OP describes). The alternative is if the cutter is too high, the outfeed edge of the board would "tip" down when guiding duties are transferred to the outfeed table (concave board edge results). If the cutter was too low the board would jump up onto the outfeed table at the start of the cut and likewise tip down when guiding pressure was transferred from infeed to outfeed.
Since the OP seems assured that the tables are coplanar, I'd suggest trying to nudge the outfeed table down a tiny bit and running some test cuts to see if the edge gets any straighter.
The tables certainly could be askew, but I think its easier to play with outfeed table height first before messing with table alignment.
-Bruce
Doug Miller wrote:
Hi, Mcgyver are you like your name sake " super human" almost lets get back to basics planer 30" to me that's 15" infeed 15" out feed, right? Board 6' that's 84" long, right ? how thick and wide is this 6' plank? Others can work out the figures but I recon with the forces lifting this plank off the cutterhead when 3' to 4' of timber is hanging off the out feed table you have to be Mcgyver!!
Do the math!!
So with out feed rollers or equivalent how do you support this mass and keep a clean even consistent cut?
Lew
My math has 6' as 72". And I did 2x10 birch on my old 4" Rockwell (30' table), so perhaps your arm is as weak as your math.
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