Whenever I needed to drill some holes for dowels I would make a template usually from oak, usually L shape thing with two holes and cut the width to what my application needed. It worked exceptionally good. The results were repeatable and accurate and oak was hard enough to withstand several hundred drillings, i.e. enough for any project.
It takes 15 minutes to make ( plus gluing time) but very inflexible, One needs to make a new one if the hole pattern is different.
So I decided to buy a factory made jig to save those 15 minutes. Following the rule "greedy pays twice" I skipped cheap jigs and bought more expensive Jessem Doweling jig.
So far my experience was awful. I wish I bought some cheaper self centering jig, or stick with shop made as before.
First of all no matter how hard I try the holes are about 1mm off to where they should be. I align the center line of the jig to the center line of the board as careful as I can, Use caliper to make sure my center line is in the center and use two clamps to ensure the jig does not move. It is repeatably 1 mm off.
But that's not all. You can only adjust to the thickness of the board in some pretty large detents. It is impossible in most cases to have holes exactly at the center of the board. So if you need to have dowels on both sides of the board ( such as bed slats) you need to position the board on the same side without turning it over. But doing so your 1 mm error ( see above ) is doubled now.
What an incredibly bad design !
If you need one time dowel it might work for you, provided you manage to align it correctly ( I could not ) but if you need repeatable results forget it.
It takes 15 minutes to make ( plus gluing time) but very inflexible, One needs to make a new one if the hole pattern is different.
So I decided to buy a factory made jig to save those 15 minutes. Following the rule "greedy pays twice" I skipped cheap jigs and bought more expensive Jessem Doweling jig.
So far my experience was awful. I wish I bought some cheaper self centering jig, or stick with shop made as before.
First of all no matter how hard I try the holes are about 1mm off to where they should be. I align the center line of the jig to the center line of the board as careful as I can, Use caliper to make sure my center line is in the center and use two clamps to ensure the jig does not move. It is repeatably 1 mm off.
But that's not all. You can only adjust to the thickness of the board in some pretty large detents. It is impossible in most cases to have holes exactly at the center of the board. So if you need to have dowels on both sides of the board ( such as bed slats) you need to position the board on the same side without turning it over. But doing so your 1 mm error ( see above ) is doubled now.
What an incredibly bad design !
If you need one time dowel it might work for you, provided you manage to align it correctly ( I could not ) but if you need repeatable results forget it.