Router lift and reverse glue joint bit.

[Bill Huber]

There was a thread not long ago about why would you need a lift if you had a base that had though the table adjustment.

Well I don't see how in the world you could set up a reverse glue joint bit with out a good lift.

At the WoodWorking show a week ago I picked up a cabinet set from Woodline, one of the bits in the set is the Reverse Glue Joint bit. So today I had noting going and decided to learn to use it on a bunch of scrap.

To start the bit is an excellent bit and cuts a very clean joint, it is a 3 flute bit.

It came with a set up block which gets you close but not there. Now you have to get it adjust spot on, so if the edge of the face up board is high then you raise the bit, I think. I am still not sure and have to stand there and look at it for awhile before I make the adjustment.

I have the Remote Digital Readout, from Wixey on a Jessem Master R II and I don't see how I could have got the thing set up with out both. You get it close but there is still a small ridge you can feel. So you raise the bit .002 and try again. Now you can feel one on the other side and you lower it .001. That to me is just a little to fine for a base with though the table adjustment. I had that set up at one time with a Bosch base and I don't think I could have done it.

How can you set one of these things up with out a good lift, I don't see how in the world you could do it.

[Neil Brooks]

I'm 2wks into using my Amana reversible glue joint bit.

My Mil 5625 doesn't sit in a lift ... yet.

I had no problem _making my own_ setup blocks (out of scrap UHMW I bought, CHEAP !).

I just hope that the PRL that I ordered ... makes it _easier_ to set up the bit for sizes other than the 3/4" that I did, first.

FWIW, I have a Wixey height gauge AND a set of gauge blocks. Between the two, getting precise setups ... while not _easy_ ... isn't that tough.

Like I said, though: I anticipate the PRL making is that much easier.

OhByTheWay: I got thoroughly razzed for buying that bit, but ... don't you just love it ? :cool:

Dead flat panels, AND ... the theoretical extra strength of more surface area to glue.

I'm a convert !

[Josiah Bartlett]

I use a DW621 in my table with a fine adjust accessory that replaces the plunge rod. This allows you to adjust the router up and down with screw threads, albeit from beneath the table. It works pretty well. I have a shaper too so I don't usually use the router table for enough precision work to justify buying an expensive lift.

[Steve Schoene]

More surface area to glue, but not really more strength, since a straight edge joint executed well is as strong as the wood already.

What I don't see is how the "glue joint" edge allows you to tweak the fit of the joint. Even jointers usually require a bit of fidding to get a truely straight joint that won't pass light before it is clamped. You can't do that with the glue line joint. I'd guess there will be places where the glue line can be detected without looking at the ends.

[pat warner]

I'm guessing the problem is in the Y dimension and the work nests east/west.
A simple calibration requires a caliper measured in .001's.
Set the height arbitrarily and rout a 16" piece if scrap.
Whack the scrap in half and assemble (work must be of uniform thickiness).
Measure the up/down error; divide/2, change cutter height x that much.
Repeat on same thickness stock. If that doesn't work, it's method, lousy mishapen stock or a bad cutter.
Designed a few of GJ cutters (http://patwarner.com/images/798m.jpg).

[Neil Brooks]

Said it before, Pat, and I'll say it again.

Wish I'd been into woodworking when I lived on Mountain View ... a stone's throw from you.

Love to have tapped your brain, here and there :)

[Neil Brooks]

More surface area to glue, but not really more strength, since a straight edge joint executed well is as strong as the wood already.

What I don't see is how the "glue joint" edge allows you to tweak the fit of the joint. Even jointers usually require a bit of fidding to get a truely straight joint that won't pass light before it is clamped. You can't do that with the glue line joint. I'd guess there will be places where the glue line can be detected without looking at the ends.

a) I would argue that it actually IS more strength, but ... that the extra strength isn't really needed (for the reasons you gave) :)

b) My joints are seamless. I run the panels through my Jet 16-32, at P150, and ... poof ... the seams are gone.

Seriously. Gone :cool:

I would _imagine_ that it's all a matter of nailing the alignment, when you first use the bit.

That's why -- IMO -- the setup blocks are SO critical: invest the time once, and then ... easy-peasy, from then on.

I had to re-make one of my 3/4" panels, and had already changed out the bit. From time of collet tightening to time of running the board through was about two minutes. Slap a UHMW spacer block in place, tweak the height until the fit into the UHMW is optimal, run the fence up to it, ta-da !

Setup blocks are everything. Without them, I'd use the bit to toast marshmallows -- BIG marshmallows :p

[Bill Huber]

OhByTheWay: I got thoroughly razzed for buying that bit, but ... don't you just love it ? :cool:

Dead flat panels, AND ... the theoretical extra strength of more surface area to glue.

I'm a convert !

I will sure agree with that, after I got it set and put a 3 board panel together and saw how flat and nice it fit together I will be using this bit a lot.

[Bill Huber]

More surface area to glue, but not really more strength, since a straight edge joint executed well is as strong as the wood already.

What I don't see is how the "glue joint" edge allows you to tweak the fit of the joint. Even jointers usually require a bit of fidding to get a truely straight joint that won't pass light before it is clamped. You can't do that with the glue line joint. I'd guess there will be places where the glue line can be detected without looking at the ends.

I can not really comment on if the joint is stronger or not but there is a lot of glue area that is covered. Another thing is that they fit together so good I have to knock them apart to put the glue in.

I am not sure I understand what you are talking about tweaking the joint. What I was talking about is getting the bit height just at the right point so that the 2 boards when put together are exactly the same. Once that is done and you are running the same thickness boards they will all be alike, the panel will be flat and glue up quick and easy.

[Bill Huber]

I'm guessing the problem is in the Y dimension and the work nests east/west.
A simple calibration requires a caliper measured in .001's.
Set the height arbitrarily and rout a 16" piece if scrap.
Whack the scrap in half and assemble (work must be of uniform thickiness).
Measure the up/down error; divide/2, change cutter height x that much.
Repeat on same thickness stock. If that doesn't work, it's method, lousy mishapen stock or a bad cutter.
Designed a few of GJ cutters (http://patwarner.com/images/798m.jpg).

I understand how to set up the bit, that is half the of the measurement but it is adjusting the router for just that small of an amount. That is where a good lift comes in and the digital read out is great.