delta 8 in. jointer

[Jack Gray]

What's the big advantage of deltas paralellogram 8 incher compared to the reg. "dovetail way" 8 incher? All other things aside, what's up with the p'gram tables?

jack

[Unisaw A100]

With the jointer the edge of the table acts as a chip breaker and it wants/needs to be as tight (within reason) as possible to the cutterhead. The bigger the gap the more likelihood that you'll experience greater (larger) tear-out. Its just like a hand plane in this respect.

With the "old style" dovetailed tables the table can only move along one line and is set up to clear the cutterhead at one point (tightest) and the gap opens as the table is moved onna 'count of the cutter head is round. For a graphic example of this take a 45 triangle and set it against a can of beans. Note where the triangle touches the mid-point of one of the quadrants. Notice where its farther apart.

Because of the geometry the "new style" parallelogram tables maintain a tighter (but not even) gap 'tween the edge of the table (the opening) and the cutterhead throughout its travels up and down. Please note, the gap isn't the same throughout the table's travel. That little trick would require a wee bit more injineering and moving parts.

Anyway, while this isn't possible with an "old style" system (though the "old style" system works pretty well) you do/should get a better cut/edge with the parallelogram tables.

UA100

[fun4usnow]

I never thought about the tables as chip breakers. I kinda figured it was for table adjustment or something.(advertising gimic)

Will the tables adjust for coplaner(?) better/as well as the dovetail style? Had a hell of a time getting my 6 in. jet outfeed table on the same plane as the infeed. I don't have a good straightedge yet.

Thanks very much for the lesson jack

[Dave Mundt]

As for the adjustment....I don't have one of these units (although if someone has a DJ-20 they want to contribute to a good home...) But it is my understanding that the table adjustment mechanism has eccentric cams that allow the angle of the tables to be adjusted to get them parallel. As for the straight edge...DAGS. Actually, you don't have to...here is my contribution to the discussion:

Within limits, you can get as LONG a straight edge as you are willing to deal with. However, note that the longer the edge the greater the chance that the flexibility of the material will take over and cause the test to fail. However, for lengths up to 5', I suspect that a 1x4 or 1x6 or so would be PLENTY stiff enough. Regards Dave Mundt

[Jack Gray]

Hello Dave,

That straight edge thing is One Helluva trick to know. Thanks very much. I'm about to go whoop me up a straight edge.

Gettin smarter all the time, Jack

[Jack Gray]

Hello Dave,

That straight edge thing is One Helluva trick to know. Thanks very much. I'm about to go whoop me up a straight edge.

Gettin smarter all the time, Jack

[Unisaw A100]

Don't know. The current crop of Deltas will have to age a couple/few more decades before I'll have one.

UA100

[CW]

Under a normal range of adjustment would make no difference. I wouldn't pay extra for it.