i forgot to add, the base i was useing was perfectly (enough within a 64th) straight i used mdf shevling stock

 

I made one of these things several yrs ago and have always had great success. 1/4" in 8'(?) that's quite a bit. Are you sure your blade is parallel to the fence? There's not to much else that will effect the cut.

 

now thinking of it the rip fence is was prob out of square i just have a cheap table saw and the rip fence is one that can lock at an angle

 

I (respectfully) disagree with that diagnosis

An out-of-line rip fence will produce a rough cut and/or burning, but if the workpiece is kept tight to the fence as it passes the blade, the two edges will be parallel, not tapered.

I think your work is either not placed in the jig parallel to the fence, or it is not staying in that position. Could it be shifting during processing? Or is the jig drifting away from the fence?

 

Jointing does not produce parallel sides, it makes something flat and/or perpendicular to an adjoining side. Joint first, then use just your TS to rip and make the edges parallel.

 

What are you referencing off of when you set the board to be jointed in the jig? The video you posted has the jig running in the miter track so assuming you are doing the same that is what establishes the reference edge. If you left the jig oversized and cut off the excess the first time you ran it though the blade than the edge against the blade should be parallel to that miter slot however the other right edge of the jig is probably not parallel and not a reference edge. When setting up your piece to be jointed measure off the left edge assuming you cut it parallel not the right edge. Is the spacing between the blade and the left edge of the jig consistent or does a gap open up as you push the jig by the blade?

Also as Rick M. said you only use this jig for one edge than flip the board around and use the freshly sawn edge against your rip fence to make two edges parallel to each other.

Hope this helps,

 

Jointing does not produce parallel sides, it makes something flat and/or perpendicular to an adjoining side. Joint first, then use just your TS to rip and make the edges parallel.

- Rick M.

Yes, but we're not talking about jointing on a jointer. We're talking about getting "jointed" edges on a tablesaw.

 

Are you using that jig to "joint" both sides of the same board?

 

Yes, but …
- jerryminer

There is no "but". It doesn't matter if you are using a jointer, a saw, or a hand plane; jointing does not produce parallel edges. The problem isn't the jig, it's a misunderstanding of the terminology and proper way to dress rough lumber.

Order of operations from rough stock, can be done with power or hand tools:
1) joint one face
2) joint one edge
3) plane faces parallel
4) cut edges parallel

 

Rick M-

Good point.

Joint first, then rip parallel

 

@alaskaguy, no, @richardh, no i do it along my fence

 

I agree with what many of the others have said already. If you're only using your jig to joint one edge of the board and using your TS fence to rip the opposite edge to width and you're ending up out of parallel, then the problem is unlikely in the jig but rather in the TS fence.

 

@alaskaguy, no, @richardh, no i do it along my fence

- Johnalan1

Explain your procedure and equipment used, be specific.