How Do I Route a Rectanguar Hole

[Jerry Murray]

I am toying around with the idea of routing a rectangular pattern into a gun grip blank. I want to set a burl inside the rectangle, glue up and then shape for a gun grip.

I am at a loss as how to build a jig to do this.

Any thoughts?

[David DeCristoforo]

There is really no way to rout a square inside corner with a round bit. You can make a template to rout a rectangle but you will need to make the inside corners square with chisels or a small saw.

[Lee Schierer]

Because router bits are round, you cannot route a square hole. It will have rounded corners. They make a template bit for inlays that does a good job for making mating sized parts for inlays however you still need to trim corners to square.

[David Keller NC]

Well, 'suppose this is obvious, but you cannot rout a completely rectangular hole - the best you can get is a rectangular shape with rounded corners that you will then have to chisel square by hand.

There are a couple of easy routes to your goal that I can think of. If you want to use a router to do it, you'll probably need to build a fixture to hold the gun stock firmly and to give the router a flat surface to ride on. Then one uses a plywood template and a pattern bit to get the shape you want. Another route to the same thing is a pattern and a pattern sleeve that mounts in the hole in your router's base plate.

Another way to do this would be with a hollow chisel mortiser, though again, you will likely have to build a fixture to hold the complex shape of the blank still while you use the mortiser to create a rectangular/square hole.

[Jerry Murray]

There are a couple of easy routes to your goal that I can think of. If you want to use a router to do it, you'll probably need to build a fixture to hold the gun stock firmly and to give the router a flat surface to ride on. Then one uses a plywood template and a pattern bit to get the shape you want. Another route to the same thing is a pattern and a pattern sleeve that mounts in the hole in your router's base plate.



I have an accessory that came with my router. http://www.amazon.com/gp/product/B000BGKIJ6/ref=ox_ya_oh_product I wonder if this could be of some help?

I would like to see a setup that is already working so i can get some ideas.

[Chris Padilla]

This is simple, Folks, he needs a SQUARE bit!!!












:D

[Jerry Murray]

LOL...

I think I have an idea about how to do this.

I take a rough outline of a grip and cut out a piece of MDF so that the grip fits perfectly inside the cut out. I then cut the hole I want to rout...sandwich the two together and rout out.

What do you think?



This is simple, Folks, he needs a SQUARE bit!!!












:D

[Mr. Jeff Smith]

Because router bits are round, you cannot route a square hole. It will have rounded corners. ...

Actually that's not true. Its because the router has a center shaft and rotates, that is what makes it round. The bit could be square, triangular, whatever and it would still result in a round cut because the mechanics of a router.

Not trying to be smart, just saying.:D

[David Keller NC]

I have an accessory that came with my router. http://www.amazon.com/gp/product/B000BGKIJ6/ref=ox_ya_oh_product I wonder if this could be of some help?

I would like to see a setup that is already working so i can get some ideas.

The little thing that looks a bit like a t-nut with a round top with serrations is the pattern-routing sleeve. You can mount that accessory in the base of your router, then put a straight bit through it. The sleeve rides around the inside of a hole cut out of a piece of plywood or mdf (your template), while the bit cuts out a slightly smaller hole in the workpiece.

In fact, this "slightly smaller" feature is used to route both the recess and the insert with a bit more sophisticated pattern-routing bearing set. The sets have differently sized sleeves so that with one size, you route the recess, and with a smaller sleeve, you cut the insert out of a solid block of wood.

[Jerry Murray]

The little thing that looks a bit like a t-nut with a round top with serrations is the pattern-routing sleeve. You can mount that accessory in the base of your router, then put a straight bit through it. The sleeve rides around the inside of a hole cut out of a piece of plywood or mdf (your template), while the bit cuts out a slightly smaller hole in the workpiece.

In fact, this "slightly smaller" feature is used to route both the recess and the insert with a bit more sophisticated pattern-routing bearing set. The sets have differently sized sleeves so that with one size, you route the recess, and with a smaller sleeve, you cut the insert out of a solid block of wood.

cool...I'll have to check that out. I wondered what all that stuff was.:D

[Nathan Callender]

If you're only doing one, it may just be easier to get out a sharp knife and chisel, especially since whatever patterning setup you use with a router is going to require some type of jig to hold the setup. If you have a dremel and base, you may be able to use that and might not have to build a jig.

[Jason White]

An expensive way to go for one job -- but you could make a series of passes with a dedicated mortising machine. They come with a special bit that makes square holes. Or, they make a drill press attachment that does the same thing.

Jason


I am toying around with the idea of routing a rectangular pattern into a gun grip blank. I want to set a burl inside the rectangle, glue up and then shape for a gun grip.

I am at a loss as how to build a jig to do this.

Any thoughts?

[george wilson]

I is possible to rout a square hole,if you are a machinist. On my Bridgeport,I can put an adjustable angle head on the quill (Quillmaster).Then,using a flat sided 60 degree pointed carbide cutter,looking straight down,the cutter is angled at 45 degrees into the corners,in turn,of the round cornered rectangular or square hole just milled. If the 60 degree cutter is also angled downwards at the correct angle,the cutting edge of the cutter will rest flat on each side of the corner once it has milled,or "routed" its way just enough to get the "round" corner milled out fully. In actual practice,this does not make a seamlessly milled out corner,perfectly blended with the inside sides of the hole. it does get you close enough to touch up with a file. This process also can square up the bottom corners of a blind hole without further angle adjustment.

Maybe some woodworker can cobble up a jig to hold a router at the vertical and horizontal angles required,and also have a vertical slide on the router to enter the hole with. There are angular tip router bits sold. They do have to be 60 degree.

[Myk Rian]

I just made grips for my 45. I traced the outline on the new wood and cut them out with the band saw. Then I screwed the old grips to the blanks and used the sander to shape them. I thought of using the router but nixed the idea.

[Bruce Wrenn]

First, make your inlay blank. It will need to have radiused corners that match your pattern bit( usually 1/4".) Next, take four pieces of wood, and surround pattern, pocket screw them together. Then take this assembly and use to guide the pattern bit. I like to use a 1/4" shank, 1/2" dia, 1/2" pattern bit from MLCS for this operation. You will be doing the same operation as fitting a router plate into a top. If corners have to be square, then inlay can be square, but some chisel work will be necessary to square the corners in gun stock.

[Floyd Mah]

Machinists do have a bit that will cut a square hole. I've seen pictures of it, but I don't fully understand how it works. It is, as described above, a triangular cutting bit. It oscillates in such a way that its' straight sides travel to cut out a square hole. I was under the impression that the bit had to be positioned vertically so that the hole's walls are also vertical. It is probably geared so that its' movement is predescribed as a square.

I found a link to the watts drill http://toolmonger.com/2006/11/30/tool-tech-square-drill-bits/ and then another to this article "Drilling Square Holes" http://upper.us.edu/faculty/smith/reuleaux.htm.

[Billy Chambless]

I am toying around with the idea of routing a rectangular pattern into a gun grip blank. I want to set a burl inside the rectangle, glue up and then shape for a gun grip.

I am at a loss as how to build a jig to do this.

Any thoughts?


I would leave the router on the shelf and chisel out the rectangle.

[george wilson]

Floyd,I have one of those too. It is called a watts bit. It is a triangular drill ground to cut only on the bottom edge. It is set in a round disc up above that allows the bit to slide sideways in every direction. There are hardened steel templates that are fixed over the work,which the rotating,sideways flopping triangular bit runs in,covering every ounce of territory inside the square template by just moving here and there sideways as it revolves.

Everything is very rigidly held in place.The triangular bit can move sideways,buy its verticallity is strictly maintained.

I didn't mention it because of this device's esoteric nature. Many machinists don't know of it,let alone woodworkers.

I thought perhaps someone might be able to rig up a home made wooden version of the other device I described. Certainly,they couldn't make up a watts drill setup.

THERE IS an 18th.C. device for automatically routing out smallish odd shaped cavities,such as for escutcheons for the keyholes of boxes. It is bow operated,and has a handle at the top,and a pulley right below. Sticking down,are 2 spread out legs,made of ,say,1/8" square spring steel. These steel legs are filed triangular near the bottom,and the part that contacts the wood is ground to a double beveled chisel edge. There is a hardened steel template that is clamped right over where you want to rout the shape. The legs of the device are squeezed together,and inserted into the template. When the bow is pulled to and fro,the legs dance around back and forth,springing around,and finding every corner of the template's shape,while the chisel edges scrape the wood away to about 1/16" depth. Then,you can fit your inlaid part right into the hole,gluing it in.

This device was common among makers of small boxes like drafting tool boxes,that had a shield shaped plate around the keyhole.

The escutcheon plates,or whatever, need to have been pre stamped to exactly the same shape every time. They were usually brass.

[David Keller NC]

George - That particular device was featured on a relatively recent Woodwright's Shop episode. The original was recovered from the Marples company when a lot of their stuff was liquidated and the factory modernized in the 1960's. They used it to form the little triangular escutcheons in rosewood stocked squares that are familiar to woodworkers. I believe it was called a "Passer's Drill".

[Floyd Mah]

George, the description of the watts bit sounds like an experience that I once had cutting with a spade bit. I was repairing a window for my mother and I needed to recess a round washer into the wood, but the bit was much smaller than the washer. What I did was hammer the washer into the wood just enough to create a slight recess. Then when I started drilling, the bit stayed within the borders of the recess, but was able to remove enough wood that I could fit the washer without any trouble. It might be interesting to fit a metal template to your workpiece and then use a modified spade bit to carve the recess under power.