Small router blade adjustment

[David Ragan]

Hi,

Thought I'd share a small gizmo that has probably been made before.

I was trying to take down the bottom of a dado, and found it difficult to gradually lower the blade incrementally:

395850

I'm also working on a jig featured in WoodSmith/ShopNotes years ago that features a threaded rod to advance a file along a saw blade (to cut new teeth).....so, the following little thing appeared in my mind:

395851

(No picture of the bottom-it has access to the head of the 10-24 brass machine screw.)

Here it is in action:

395853

All I have to do is put the router in place, turn the screw up a few turns, lower the blade, and get back to work.

My next modification will be a thumbscrew/wingnut that doesn't require a tool, and some type of friction hold on the little screw-this model's screw is too sloppy.

[David Eisenhauer]

And perhaps some way to quantify an adjustment, such as "one turn of the 10-24 screw = X amount of drop by the router iron"? Measure the resulting router iron drop with shims or something?

[David Bassett]

Not sure how much a number is worth in this situation, but:


... "one turn of the 10-24 screw = X amount of drop by the router iron"? ....

for that screw 1 turn would be 1/24", (or a little over 1mm.)

[Jim Koepke]

Hi David,

Interesting example of a threaded mechanism as a solution to a problem.

You may find some thing like a socket head screw or bolt with a 10-32 thread and a nyloc nut inserted into the wooden base as a good solution. The socket head would allow you to adjust from above with an allen wrench and a nyloc nut would keep it from being sloppy.

Here is something of mine written before retirement, it is slightly edited:

One full rotation of a 10-32 fastener will move it 1/32 of an inch or 0.03125". A half rotation will change the position of the end of the screw 0.0156", rounded for simplicity. A quarter turn will move it almost 0.008 of an inch.

On my router there are marks drawn on the adjustment nut to make it easy to judge 1/8th of a turn or to even land between them for 1/16th of a turn.

jtk

[Derek Cohen]

I was trying to take down the bottom of a dado, and found it difficult to gradually lower the blade incrementally:

There is a simple solution: use a depth stop. :)

1. Set the final depth of cut. Then return to the surface of the waste.

2. Use a hammer to tap the blade down. Think of the router plane as you would a plane without an adjuster. A hammer tap can provide a slightly deeper cut with more precision than an adjuster.

3. Keep increasing the depth of cut, as needed, until you reach the final depth determined by the depth stop at the outset.

If your LN (?) small router plane does not have a depth stop, make your own: http://www.inthewoodshop.com/ShopMadeTools/DepthStopsForVeritasRouterPlanes.html

Regards from Perth

Derek

[David Ragan]

Hi David,

Interesting example of a threaded mechanism as a solution to a problem.

You may find some thing like a socket head screw or bolt with a 10-32 thread and a nyloc nut inserted into the wooden base as a good solution. The socket head would allow you to adjust from above with an allen wrench and a nyloc nut would keep it from being sloppy.

Here is something of mine written before retirement, it is slightly edited:

One full rotation of a 10-32 fastener will move it 1/32 of an inch or 0.03125". A half rotation will change the position of the end of the screw 0.0156", rounded for simplicity. A quarter turn will move it almost 0.008 of an inch.

On my router there are marks drawn on the adjustment nut to make it easy to judge 1/8th of a turn or to even land between them for 1/16th of a turn.

jtk


This is a great improvement (Nylon nut).

I can't even say why I put the head on the bottom....makes more sense to counterbore the top and sink the head.

Only thing is-it's back to trigonometry class cause the amount of the screw turns and resulting effect on the blade is only a fraction of the distance that the cutter is from the screw. Pardon me for not articulating it very well. Mathematics is such a cool language-a pity I find it so difficult.


There is a simple solution: use a depth stop. :)

1. Set the final depth of cut. Then return to the surface of the waste.

2. Use a hammer to tap the blade down. Think of the router plane as you would a plane without an adjuster. A hammer tap can provide a slightly deeper cut with more precision than an adjuster.

3. Keep increasing the depth of cut, as needed, until you reach the final depth determined by the depth stop at the outset.

If your LN (?) small router plane does not have a depth stop, make your own: http://www.inthewoodshop.com/ShopMadeTools/DepthStopsForVeritasRouterPlanes.html

Regards from Perth

Derek

Another great idea.

A depth stop....just another thing to do instead of making an 'end product'