Joiner "snipe"

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I am using an 8" Delta jointer, and am experiencing "snipe" at the end of each pass. For some reason the last 1.5" or so of board gets a deeper cut, giving me an uneven board.
I've checked the Delta docs with no luck; any ideas on how to correct this would be most appreciated.
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If the rear table is adjustable the rear table needs to be adjusted up to be level with the knives. disconect power loosen locknut on outfeed table gibs (ususlly centre bolt) place straight edge on outfeed table and over knives adjust rear table up untill you can rotate the cutter block by hand and knives just touch straightedge when at top dead centre tighten locknut on outfeed table gibs
If the outfeed table is not adjustable the knives need to be adjusted to be set level with outfeed table. disconect power place straight edge on outfeed table and over knives rotate the cutter block by hand and adjust all knives to just touch straightedge when at top dead centre tighten gibs
away you go and all should be well

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Don't you have to measure how far off it is with a dial indicator first?
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Why? Who cares if its .001" , .025", 3/16", 2mm or 1/2 a pubic hair off ..... ? It's either right or wrong. You simply adjust as required to match straight edge. It doesn't matter how much you adjusted it unless for some strange reason you like to keep statistical maintenance records of how often and how far out it is.
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wrote:

I think that comment was intended mostly in jest, referring to another thread we had a month ago about setting jointer knives.
However...
"Simply adjust as required" is just another name for "trial and error". While trial and error does work (not the best way IMO, but it does work) for setting the height of the outfeed table relative to the knives, it's a *lousy* way of making sure that the knives are all at the same height relative to each other. That's where the dial indicator is really useful.
--
Regards,
Doug Miller (alphageek at milmac dot com)
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While
setting
of
other.
Ugh-oh.....
--

-Mike-
snipped-for-privacy@alltel.net
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Sure. Because you can then use the built-in microadjust capability to raise or lower the knives precisely the required amount.
For those of you who have that capability. What brand of jointer is that, anyway? The one with the auto-adjust which compensates for blade wear?
LOL
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Well, yes, that's kind of the point.

I'm not sure just what you find confusing here. I have a Delta DJ-15, just your basic run-of-the-mill 6" jointer, nothing particularly special about it. Each knife has two height-adjusting screws. With a dial indicator and an Allen wrench, it's a pretty simple operation to adjust each knife to exactly the same height. What brand of jointer is it, anyway, that does *not* have height-adjusting screws for the knives?
--
Regards,
Doug Miller (alphageek at milmac dot com)
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first?
?
straight
how
thread
Sorry George.

While
setting
of
other.
I dont think we need to go down this track again but there is no trial and error about it if its done right. The measurement is of no paractical use unless you happen have a microadjust scale on jointer as George mentions little firther down.

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wrote:

It's not entirely clear to me exactly what you mean here, at two points:
Which measurement is "of no practical use"?
And what, exactly, do you mean by "a microadjust scale" on the jointer? Are you talking about adjusting the infeed, the outfeed, the knife height, or what?
--
Regards,
Doug Miller (alphageek at milmac dot com)
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wrote:

Simple concept. Of what value is a precise measurement of error when you have no precise corrective adjustment? How many turns, after you take out the inevitable backlash, does it take on the knife elevating screws if so equipped? If you think that butting the knife up against a gage with a dial attached is significantly different than butting it up to a block referenced to the outfeed table, there's no help for you. The knives can be perfectly level to the outfeed and still be in error as far as the operation of the tool is concerned.
If the wood passes the knives, which are the cut limiters, and catches on the table, lower the table until the new surface just touches it. If feeding while referencing the outfeed produces a snipe on the trailing edge, lower the table until it does neither.
A good way to figure how low you have to go is to extend your outfeed table with a block and bring the knives up until they kiss it at the top of their arc. Pretty much what you'd do whether you knew how far you needed to go or not.
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Simple concept indeed -- but you seem to have missed it. The "precise corrective adjustment" with respect to using a dial indicator consists of turning the elevating screws while watching the dial indicator. It doesn't matter how many turns it takes.

Well, we don't see it the same way at all. I'd say quite the opposite: if you think it's *not* significantly different, there's no help for you.

Explain that one, please: if all three knives are "perfectly level to the outfeed", what is the source of error?

.. then the knives aren't "perfectly level to the outfeed" .

Trial and error...

.. then the knives aren't "perfectly level to the outfeed" .

Trial and error again.
Or you could use a dial indicator, or a straightedge and feeler gauges, to set the height precisely -- and eliminate the trial and error steps you've just described.

If that works for you, fine. I've done it that way, and I find it to be a PITA. I find it a lot simpler to use a dial indicator: pick one knife, any knife, and set it so it's the same height above the outfeed table all the way across. Or below the table; it doesn't matter at this point. Then set the other two knives to the same height. Note that so far, it doesn't matter what that height is -- just as long as it's the same height for all three, all the way across. Finally, I adjust the outfeed table so that it's one-thou below one of the knives (any of the three will do, since they're all the same now), and go to work. No trial and error, no catches on the outfeed, no snipe on the trailing end, just a nice clean cut.
--
Regards,
Doug Miller (alphageek at milmac dot com)
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way
what
the
below
now),
the
if you use straight edge method and you don't have to adjust outfeed after inserting and adjusting knives because it's all done in one step. One of the reasons I prefer my method is that it works with all cutter systems.
How well does a dial indicator work * on a set of scew mounted jointer knives? (no constant top centre) * on a spiral cut rebating head ? (no straight edge to measure off) * on a set of knives for a spindle collar ? (usually referenced of a point or a radiused edge) * on a tennoner head? (no straight edge to measure off)
Every one seems to carry on about the number of test cuts. 99.9% of teh time I have enough confidence in the setup that I simply go straight back to what I was doing.It would only be in an extreme situation that I would even bother to do a test cut.
When talking about standard jointer cutter block both methods are essentiall the same. The only difference is that you work in a specific measurement (thou) and set to zero thou. The straight edge system works in an 'universal' measuring system. It makes no diff if your talking metric, imperial or hair thicknesses you just set it to zero whatever units you ar working in.
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Paul D wrote:

    > * on a spiral cut rebating head ? (no straight edge to measure off)     

    
     Every cutter head that I am familiar with (except a B&D mounted router bit) cuts with reference to a fixed point and can be adjusted with reference to that fixed point. Find the fixed point, extend it if needed, and you've located one end of the indicator set up. The point being measured is, by definition, the other end. There is NO NEED for a straight edge at the measured surface ... none.
Indicators measure points, one at a time. When the points no longer vary, the line is straight, the circle round and concentric, the surface flat. You need TDC when using a straight edge because you have no other reference point. An indicator is not thus limited ... but can readily find that point, too, if desired.
With an indicator, the element of guesswork in 'trusting' a set up disappears. With proper use of an indicator you KNOW where the cutting edge is and you KNOW the amount of error you are accepting. From that, you can decide to trust or not based on knowledge. If I am cutting a groove and it is .002" deeper than intended, nearly always that is no problem and I would go ahead and make the cut ... but that is my choice based on knowledge, not guesswork.
--
There are two kinds of light--the glow that illuminates, and the glare
that obscures.
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Put your feed pressure against the fence and then on the outfeed side.....take less off in each pass as well. Your most likely at the end of the cut pushing down on the infeed side and rocking the board into the blades......when I changed methods mine magically fixed itself....Rod
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of
Yours was definatly a user error problem and a safety issue Safety Rule Number 1 Your hands should never pass over the cutter head.
To place enough pressure above cutter block to force timber down into knives would take considerable pressure. Your purpose at the driving end is simply to guide the piece through. Only light downward pressure is required. The size of each pass will not stop snipe, except a deeper cut will result in a deeper snipe and a shallower cut a shalower snipe. Only light pressure is required against teh fence to keep the piece in contact with fence. Exerting more pressure than necessary only serves to increase the seriousnous of the injury if something does go wrong ..... more pressure and fingers travel further into cutter ....
A gentle hand is all that is needed to keep things flowing smoothly
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Yep, my RIDGID model propels the stock through after I simply get it started.
Not sure why anyone would need to "exert" pressure or get one's digits near the cutterhead while the machine was operating.

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On Wed, 20 Dec 2006 15:12:38 +0000, resrfglc wrote:

That's a mighty fancy jointer that you have there if it has a power feed. Didn't know Ridgid made anything that sophisticated.
Perhaps you're thinking of a planer <http://www.ridgid.com/MenuDriver.asp?ParentID -Thickness-Planer> and not a jointer <http://www.ridgid.com/MenuDriver.asp?ParentID=6-18-Jointer--Planer ?

--
--John
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Nah, He's just running his wood across it backwards. It'll feed itself pretty well in that direction.
DonkeyHody "Even if you're on the right track, you'll get run over if you just sit there." - Will Rogers
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"Perhaps you're thinking of a planer"
Yep - Duh!

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