Depth, Centered, Screws?

[Steve Kwon]

Is there a quick tutorial about the settings and the screws?  

I get that the depth collar bit controls the depth of the hole.  

I get that drill guide moving up and down controls how at some point the screw gets centered.

But how does it relate?  

I built the frame for my workbench today with 2x4's... came out great... but without the plans... I would've been so confused!

[Steve Kwon]

Thank you James for your reply and the article... helps a ton...

My only question to your reply is... can you think of any instance where you would set the depth collar and drill guide to be different?

[Steve Kwon]

Thanks James!!!

[James Andrew]

I understand the basics, but here's where I get confuzzled:

Using 3/4" birch ply (that is 1/16"-1/8" shy of 3/4") and using the 3/4" setting on the jig, the screw exits a good distance off center bringing the screw tip closer to exiting the joined panel.  You can back off the drill bit to keep the screw from exiting, but this means less screw in the joined piece.  

I am thinking that shimming the jig by an amount equal to that of the defect between 3/4" and the real thickness is the only way to correct the exit point of the screw.  

Has anyone come up with a better answer than this??  

James Waller said:

Yes, some plywood's thickness might be less than what is stated, so you would set your depth collar back about 1/8" to avoid drilling the screw through the mating piece.  If possible use some scraps to test your setting and adjust accordingly until you feel its safe to make the pocket holes on your project wood.

If you plane your boards to a different thickness than it originally was, then you need to adjust your depth collar here also. Again try to use scraps to test your adjustments.

James :)

[Rick]

James, if you try to locate the drill guide in-betwixt the 1/2" and 3/4" indents, how will you lock it in position since that brass screw lock will be useless?

James Andrew said:

I understand the basics, but here's where I get confuzzled:

Using 3/4" birch ply (that is 1/16"-1/8" shy of 3/4") and using the 3/4" setting on the jig, the screw exits a good distance off center bringing the screw tip closer to exiting the joined panel.  You can back off the drill bit to keep the screw from exiting, but this means less screw in the joined piece.  

I am thinking that shimming the jig by an amount equal to that of the defect between 3/4" and the real thickness is the only way to correct the exit point of the screw.  

Has anyone come up with a better answer than this??  

[James Andrew]

My current thought is to place a few rubber bands around the vertical part of the jig that would provide the thickness lost by the undersized wood. When the clamp is closed, the rubber bands will be between the jig and the wood thus making the wood "seem" thicker...

[Malcolm Turton]

James Andrew said:

"My current thought is to place a few rubber bands around the vertical part of the jig that would provide the thickness lost by the undersized wood. When the clamp is closed, the rubber bands will be between the jig and the wood thus making the wood "seem" thicker..."

 

I would have thought a rigid plastic packer would be more suitable, having said that I would set the jig to a measurement below the thickness of timber and maybe set the drill coller slightly deeper (test before drilling that the drill dosen't foul on the jig"

[James Andrew]

this is why these discussions are useful.  Running the jig undersized and maximizing the screw depth is probably best...  fewer things that can go wrong.