Thread: Jointer Knife Setting Jig

I never had any luck with the first one/pair.

I guess I've always emulated the second one with a flat bit of hardwood and lots of swearing.
Drives me mad how that last tiny little turn of the bolts lifts the blades.

I have used the 2 nd one for about 4 years now and have found it does the job well.

I use a bit of wood also. That said instinct says the second one is likely the best bet as it is referencing off the outfeed table.
Regards
John

For a 6" jointer the two bits of wood is simple, cheap and quick. Once the knives have been set to the underside of the timbers, a slow rotation of the head will cause the knives to move the timbers forward slightly. If this movement of the timbers is exactly equal your knives are set spot on.

The answer to the question really is in the descriptions of the two links provided.

The first link is a unit for a thicknesser/planer, and references the blade protrusion to the cutter head, which is significantly exposed on a thicky when the guards are removed sufficiently to be setting the blades. For a jointer, you either reference of the head by virtually removing the tables to access enough of the head to fit the jigs, or reference to the tables and hope that the micrometer has enough travel to set the blades correctly from an elevated position which may not always be the case.

The second link is a unit for a jointer and references the blade protrusion from the outfeed table, so it does not need to be adjusted from optimum position to set the knives. It is however fairly useless for setting knives in a thicky as there is nothing like an outfeed table to reference from. In the pics in the link they are showing the jig effectively bridging the infeed and outfeed tables with the knives hanging from the centre magnets. I believe this to be incorrect as the infeed table setting will influence protrusion, which is wrong. I believe that the correct use of this jig is to have the centre magnet and the one furthest from it on the outfeed table and hang the blade from the magnet nearer the centre magnet. This way the blade should be positioned relative to the outfeed table, and be completely independent of the infeed table position, whose adjustment sets the depth of cut.

The two sticks method mentioned is a valid approach to verify knife position relative to the outfeed table, but often lacks magnets to hold the knives in position while the fixing screws are tightened.

As melb says the one that sets to the outfeed table is fine for a jointer but will give you issues if it is a combination thicknesser/jointer
This I found out after fitting new blades and using the two bar gauge, they cut ok in the jointer mode but would not cut in the thicky mode because the blades were too low below the drive rollers in the thickness mode
The gauge that attaches with magnets to the cutting head are the way to go,set the blades to the height specs in the manual
Set up the gauge as instructed,this will be a once only set up

As Malb said, the second one is what you want for the jointer. Set the blades from the outfeed table only, I have been using one for about 10 years and is very easy.
I do not experience any movement of the blades when tightening, for those who do it might be more to do with their jointer rather than the jig.

Regards
Keith

I have a set of the first ones if you want to give them a go.

You could try something like this. Pick up some magnets from Bunnings, a few bits of plywood or timber and you're good to go.

Originally Posted by NCArcher

I have a set of the first ones if you want to give them a go.

Thanks for the offer NCArcher!

Based on the feedback, I might have a crack and making a simple magnet jig and see how I go.

Failing that, I might take you up on the offer.

Thanks all for your comments.

Those micrometer type are available on ebay cheap as chips.

My jointer/thicknesser has aluminium tables so the magnets are useless. I've done my best with a straight edge but I've got about 0.2mm I can't get out.

Maybe I'll try the micrometer type.

https://www.ebay.com.au/itm/2pcs-Mag...frcectupt=true

Hi Pach

I have the Rockler one and it works really well Rockler part number 34099.
I also have the ones in your first link but I only use them on my thicknesser

Originally Posted by damian

My jointer/thicknesser has aluminium tables

Aluminium tables?? Sacrilege

A problem that some people come up against is the blades moving when the screw is tightened, this can be avoided by filing the end of the screw flat or quicker still put it in a lathe and flatten it or machine to a very slight convex shape.

Wadkin had a very simple method of setting knives that could be made and used on any machine. It was two segments that had a curve cut out of them at the height the blades should be set at. The segments were joined by two bars so it was one assembly, put it on the drum, lift the blades so they contacted it at both ends and tighten. If DaveTTC sees this he might take a photo and post it. It didn't have magnets because on the Wadkin the blades sat on springs and were pushed against the jig but magnets could be used instead.