Squaring the router with the sacrifice board

[bill z]

While adding my sacrifice boards and squaring up the sacrifice board to the router, I discovered a problem. I purchased a 1.5 inch surfacing bit to make sure the sacrifice board is truly flat with respect to the router. What I got was something like a saw tooth on the sacrifice board. Maybe you can see the result of my surfacing in the picture.

Seems the router is tilted just a little. I read on the forum that a wedge can be placed in the mount that holds the router.

My question is how do I know that the router is really perpendicular to the sacrifice board without resurfacing after resurfacing? Is there a 90 degree tool that I can put in the router culet, swing around the sacrifice board to see if the distance from the tool to the sacrifice board is even all around? If so, what is it called and where can I find one?

[NewAgent45]

This is not unusual. Using a large surface planning bit is the best way to tell if your spindle is perpendicular to the table. If you see the "striping" you described. pay special attention to which side of the bit is cutting deeper. Then add pieces of plastic shim stock under this side of the router clamp. My machine was cutting deeper on the front side in the y direction indicating to add shims under the front of the clamp.

You can get and assortment of various thickness shim stock form any industrial supplier like McMaster-Carr.
http://www.mcmaster.com/#shim-stock/=105i344

Hope this helps!

.... Rod

[McBuster]

If you have an 1/8" Collette, you can take wire that size, make it like an "L". About 2-3" on the vertical and 1 1/2 - 2" on the horizontal. Bend it to 90 degrees. Then, relax it a bit to 92 degrees. Or so. Lock it in the Collette and move it to the center of you bed. Bring this down on the Z Axis to "Just About" the bed surface. Rotate it by hand. There should be some variance. Make adjustments to make the Left/Right and Front/Back equal. The Fr/Bk adjustment is at the top of the Z Axis Carrier. Hard to describe and, there are 2-3 Threads already on how to do this. The L/R probably best to use some kind of shim. Then repeat this for Lower Left, Lower Center, Lower Right, Center ... and Top ... You can also use Feller Guages to determine and variances.

[bill z]

Thanks McBuster and Rod.

I'll try it and get back to you with the results. I was thinking of making the horizontal some 3 or 4 inches to really square it up.

I'll take pictures.

[TomTurner]

Bill,

A good first step is to use a large square (12 by 18 inch) and verify that the Z-axis carriage assembly is orthogonal to the bed. On my shark I had about a 3 degree error on this. The result was that from top to bottom of the Z-axis carriage I had over an eighth of an inch error (in fact almost a quarter inch) Shimming the router mount alone didn't work for me since I use my Shark for a lot of Mortise and Tenon joints on furniture and the error resulted in furniture being out of square. I had to put shims on the outboard ends do the X-axis carriage assembly at the bottom. Once I had it close then I added shims to take out the final errors ( in both directions ) at the router mount.

I determined the error by creating two pockets ( one in X and one in Y direction) and adjusting the shims until I had a smooth surface.

Tom

[bill z]

Due to the holidays, aligning my router took a lower priority. But, I did it. Took quite more shimming than I originally thought.

First I took some ¼ inch rod stock I had and welded it at a 90 degree angle. Double checked the angle with 2 different speed squares. The bottom piece is 6 inches long so I can really get accurate.

Placing this in the router, I was able to rotate the square around 360 degrees using some MDF as a reference.

Shimming in just one place exposed some errors in other places in the circle.

I got it just right with several attempts.

After reading Tom’s posting here, I tried to check if there was any variances when I raised my router. Big problem here is the measuring device. But, I think it is still real close to perpendicular to the mdf board.

Here are some pictures to show what I did to figure this all out.

[tradewinds]

Great idea Bill, it would come in handy. Are you willing to create such a tool for sale to others?

[bill z]

I suppose I could.

I'm guessing that not many have access to a welder.

I'm not great at welding or CNC.

If anyone is interested, they could PM me and we can discuss.

Thanks for the suggestion Tradewinds.

[rinkmik]

your squaring tool looks alot like a allen wrench .......jsut sittin here i wonder how square they are ill check that in the morning first thing.