# Parallelogram Jointer



## stvchmn (Feb 14, 2010)

What does this mean? What makes a jointer a parallelogram jointer?


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## phinds (Mar 25, 2009)

*parallelogram jointer* --- A standard *jointer* but with an adjustable *fence*, thus allowing one to edge boards at an angle other than 90 degrees. 

from:

http://www.hobbithouseinc.com/personal/woodpics/_g_P.htm


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## woodnthings (Jan 24, 2009)

*Not so sure paul*

Check this out:
*Parallelogram Tables*







 Cams at each corner of the tables makes adjusting the PJ-882 simple and fast. If this machine is not coplanar it is because you are exceptionally lazy!
Click image to enlarge​ For a jointer to be accurate the infeed and outfeed tables must be coplanar - perfectly aligned with each other side-to-side and front-to-back. The tables on the *PJ-882HH 8" Parallelogram Jointer* have been precisely aligned at the factory but could need adjustment in the future. To make that an easier chore the *PJ-882HH 8" Parallelogram Jointer* has special cams built into each corner of the tables, two on the front and two on the rear of each table. These cams allow the user to make corrections to the tables easily and quickly.
The mechanisms that move the tables up and down actually moves them through a small arc that keeps their edge close to the cutterhead regardless of vertical position. Maintaining that small gap between the table and cutterhead produces cleaner, more accurate cuts.


The fence is a separate issue from the tables.  bill

*
*


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## phinds (Mar 25, 2009)

Hm ... not sure where I got that definition but it made sense to me. I see what you mean though ... sounds like I'm either completely wrong or there are two definitions floating around, one for the adjustment mechanism, another for the kind of cut it makes. I'll have to dig further.

Now that I think about it, I seem to recall seeing a pic of one that fits the definition I gave, which further solidified my belief that it was correct, but I don't have that pic so I could well be wrong about that. I've got a memory like an elephant but I do sometimes forget where I put the peanuts.

Thanks for pointing that out Bill.

Paul


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## phinds (Mar 25, 2009)

No, I looked into it further and I believe I have it right, including on the specific model you quoted. You'll note in the specs that the fence can be tilted over up to 45 degrees, either inwards or outwards, specificallly to accomodate any bevel up to 45 degrees. I believe that IS what makes it a parallelogram jointer.

I'm NOT 100% sure on this, however, because I found at least one jointer that has the plus or minus 45 degree fence tilt but is NOT listed as a parallelogram jointer.

At this point, I'm not sure what to think. I'm going to call an equipment manufacturer and see if they can tell me, unless you or anyone else here can add more to the discussion.

Thanks again for bringing it up.

Paul


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## phinds (Mar 25, 2009)

Yeah, the more I look into it the more I think that you have it right --- the "parallelogram" seems to be pretty universally used to refer to the table adjustment mechanism, not the fence.


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## phinds (Mar 25, 2009)

OK, I'm convinced. You've got it right, Bill.

stvchmn, it seems that it means that there is a particular kind of adjustment mechanism that assures good alignment of the table ... has nothing to do with the kind of bevel cut it may or may not be able to make, as I originally thought it did.

Have changed the glossary to say:

*parallelogram jointer* --- A *jointer* with a particular kind of precision adjustment mechanism for the table that is advertised to provide very accurate table adjustment over a long life, so that the infeed and outfeed surfaces remain coplanar, which is crucial to accurate surfacing. 

Paul


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## Colt W. Knight (Nov 29, 2009)

Yup. Pstrallelogram refers to how the jointer tables are aligned. The base and table make one set of parallel lines and a series of connectors which all are connected and parallel will raise or lower the table from the base. Since they are all connected and should stay parallel. The table should remain straight . Grizzly has a great cutaway to show how the internal mechanism works.


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## stvchmn (Feb 14, 2010)

Thank you all very much for clearing that up for me.


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## woodnthings (Jan 24, 2009)

*Where did you find it?*



Colt W. Knight said:


> Yup. Pstrallelogram refers to how the jointer tables are aligned. The base and table make one set of parallel lines and a series of connectors which all are connected and parallel will raise or lower the table from the base. Since they are all connected and should stay parallel. The table should remain straight .* Grizzly has a great cutaway to show how the internal mechanism works.*


*
* I looked but didn't come up with anything. Can you post a link? bill


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## Colt W. Knight (Nov 29, 2009)

Sorry Bill, those pictures are no longer up on the grizzly website. When I first started looking at jointers last year, they had some nice cut away diagrams and drawings showing how the parrallelogram mechanism works.


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## Colt W. Knight (Nov 29, 2009)

Let's see if this helps. 









Imagine that each cam is parallel, and that are all connected by links that keep them all parallel if you were to move one. 

The lever will make one swing, and since they are connected, they all swing at once. Since they are all connected at the bottom, as they swing to the right they will get higher, and lower if they swing to the left. They will be fitted with a stop that wont allow them to swing any higher than a 90 degree angle. 

The infeed and out feed table will be fitted with the same length cams and mechanisms, so theoretically, the two tables will always remain parallel to each other. Where as the old style wedge and dovetail adjustments could deviate along the horizontal plane of the the infeed/outfeed tables. So with a Parallelogram jointer, you only need to set your fence 90 degrees and the depth of cut, and you wont have to worry about making sure the two table are parallel to each other.


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## Colt W. Knight (Nov 29, 2009)

They do still have one picture in their catalogue though.


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