# sharp square corners?



## spidennis (May 29, 2011)

I have to cut out a small repeatable rectangle and need to sharpen up the corners somehow. It's a 1" x 2 1/2" hole in 23/32" ply (3/4). I want those corners square. Any thoughts about what bit to use and how to do it?

I can use a 1" forstner bit against the fence on my drill press to remove the bulk but haven't found a small enough bit to clean up the edges and get into the corners well enough. 

I have to do a lot of these so a powered option is what I'm hoping for.


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## jschaben (Jun 21, 2009)

spidennis said:


> I have to cut out a small repeatable rectangle and need to sharpen up the corners somehow. It's a 1" x 2 1/2" hole in 23/32" ply (3/4). I want those corners square. Any thoughts about what bit to use and how to do it?
> 
> I can use a 1" forstner bit against the fence on my drill press to remove the bulk but haven't found a small enough bit to clean up the edges and get into the corners well enough.
> 
> I have to do a lot of these so a powered option is what I'm hoping for.


Hi Dennis - tough to get square corners with a round bit. What is the smallest radius you can deal with? 1/8" bit will leave a 1/16" radius corner which is pretty tight. 1/16" bit is even tighter but the bits are pretty fragile. Other than that, corner chisel, hand chisel, mortise chisel. Somewhere here there is a thread on a trilobe bit to leave square corners but I don't know if it's a real product or not. Theoretically it should work, practically,,, I dunno and likely pricey.
A little more info on your project could lead to other suggestions, ie, would it be feasable to soften the edges of whatever is going into these reliefs?


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## bobj3 (Jan 17, 2006)

Cutting square corners easy with tool below,no need to make a easy job into a hard one.

Multifunction Oscillating Power Tool - 1.6 Amp, 120 Volt

==


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## berry (Oct 17, 2005)

If you don't have one of those fancy multi-purpose oscillating tools I'd think you could do it with a saber saw (aka jig saw). You could make a template to guide it if there are lots to do.


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## MikeMa (Jul 27, 2006)

Would a mortiser be feasible?


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## spidennis (May 29, 2011)

good ideas guys! thinking of other options is important ......

I have some pics I'll add soon to help make this clearer.

Possibly I could change up the design just a bit?
then the corners wouldn't be all that important ....

Like I said, I have a bunch to do ..... 
16 per every project so the easier the better.


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## spidennis (May 29, 2011)

*photos of "landing gear"*

An example work piece on the left and my latest prototype piece on the right.
You can see that a 23/32" birch ply shaft that's 2" wide goes thru the hole




























Don't mind the inaccurate details of this prototype .....
it carries all my mistakes and the learning curve with it.


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## walowan (Jan 21, 2011)

Instead of trying for a square hole how about radiusing (round over the edges) of the piece that goes into the hole? Then use a jig to make the hole with the appropiate size bit for the smallest radius you are comfortable with on the "inserted" piece.


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## spidennis (May 29, 2011)

walowan said:


> Instead of trying for a square hole how about radiusing (round over the edges) of the piece that goes into the hole? Then use a jig to make the hole with the appropiate size bit for the smallest radius you are comfortable with on the "inserted" piece.


I'm thinking along these lines too, so it's nice that someone is on the same page as I.
The top edge isn't too much of a problem as that could be above the "bottom" panel and not really be affected. The bottom part of the square hole I'll use the smallest bit I can find, so far it's a 1/4" , but I can widen the hole just a bit, plus radius the 2" shaft a bit. 

I'm not sure wether to use a top or bottom bearing bit to do this, so I ordered one of each to see how it plays out. 

It's nice to have a sounding board sometimes instead of my own ideas bouncing back and forth between my own ears. :help:


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## Cherryville Chuck (Sep 28, 2010)

It doesn't appear that it needs to be a perfect fit/ perfect finish solution so you could drill out the corners past your hole dimensions before you rout out the hole. A good sharp rasp would also square up the corners enough to slide the board through the hole.


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## spidennis (May 29, 2011)

Cherryville Chuck said:


> It doesn't appear that it needs to be a perfect fit/ perfect finish solution so you could drill out the corners past your hole dimensions before you rout out the hole. A good sharp rasp would also square up the corners enough to slide the board through the hole.


I like that idea! a small pilot hole at the corners would get in there. I think I like this idea better. I can stay on the same pieces to finish it, not go on the shafts to modify them. 

I actually use the small pilot holes for marking lots of other things like this. Hummm, and I somehow forgot about that?


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## me5269 (Jun 2, 2011)

I use my scroll saw for small pc's and a jig saw for large pc's. I just picked up a multifunction tool, but have not tried to clean up corners with it (thanks for the idea BJ).


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## spidennis (May 29, 2011)

I have a Harbor Freight osc tool, it's by far the most loud tool I have! I try not to use it ...... it has it's uses though. I could try it out in this case ...... eek, the noise ..... it's like grinding teeth .....


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## spidennis (May 29, 2011)

another idea?
I mounted my router upside down, so why not a jigsaw?
I'd have to remove the blade every time if I was to use a scroll saw ......
Is there a jigsaw filing attachment for corners?
seems like a good idea?

edit: seems there's a patent on this already.


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## Gaffboat (Mar 11, 2012)

Okay Dennis, I can't stand it anymore. You've gotten lots of good advice but haven't given us the answer I'm looking for. In one post you referred to your project as "Landing Gear" and I'm dying to know what it is/does. Can you tell us? Pleeeezzzzze. Inquiring minds need to know!


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## spidennis (May 29, 2011)

Gaffboat said:


> Okay Dennis, I can't stand it anymore. You've gotten lots of good advice but haven't given us the answer I'm looking for. In one post you referred to your project as "Landing Gear" and I'm dying to know what it is/does. Can you tell us? Pleeeezzzzze. Inquiring minds need to know!


I call it "landing gear" only because that is what it resembles. It's a handle holder. More details will come! I promise!! And a video! 

Presently I'm waiting on bits to come from MLCS via mail ...... so I have to go on to other parts of the project while I wait. MLCS has pretty good prices, plus free shipping!

I got lots of good ideas to pull from which is really nice!

There's a saying ....... If you can only figure out one way to do something then are most likely doing it WRONG! ....... so I like to have my options. 

So you can tell that I'm not an experienced wood worker, but I did stay in a Holiday Inn at some time in my life ...... yeah, that doesn't really help me out much, but I do have an idea ....... and a growing shop of tools, and making a lot of sawdust! ..... and hopefully not firewood ....... I did make some pykrete which is some interesting stuff! Still working on the formula, size and shape, and resulting end use. Think ice with an R factor. If it lasts longer than regular ice then maybe it'll be something cool for our hot texas summers? Maybe keep fish cold longer? I do live in a very good fishing location .........


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## Willway (Aug 16, 2012)

Hi Dennis does it have to be square? If I were doing this I think I would look at a 3/4 bullnose bit (or use a 3/8 round over bit on both sides) on the piece of ply that has to go through the hole. Then simply drill 2 holes with 3/4 Forstner bit (with exact spacing), and then use a jig saw between the holes. This should give a nice looking fit.


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## spidennis (May 29, 2011)

Here is a scroll saw version of my inverted mounted jigsaw sanding blade idea.

Sanding Belts for Scroll Saws - Lee Valley Tools

edit:
here's a diy of it on youtube


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## spidennis (May 29, 2011)

Willway said:


> Hi Dennis does it have to be square? If I were doing this I think I would look at a 3/4 bullnose bit (or use a 3/8 round over bit on both sides) on the piece of ply that has to go through the hole. Then simply drill 2 holes with 3/4 Forstner bit (with exact spacing), and then use a jig saw between the holes. This should give a nice looking fit.


I have another piece to this part that is similar in requirements, it's the bottom cover part, basically a rectangle cut out and another to fit into it's place. Again, I have lots of these to do so fast and simple is the way to go.


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## TinyTiger (Mar 9, 2013)

It sounds like outting a radius on the insert piece would indeed be the easiest way. If you _had_ to have a square hole, a mortiser or mortising attachment on a drill press would probably be the easiest (since the pieces can index off a fence).


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