# Cutting Square in plywood



## birdhousebarn (Feb 18, 2011)

Hello,

Attached is an image a lighted house we make. We make a ton of these in different sizes and designs.

We make them from 1/2" pine plywood. So that is what is used on the front of the house where the door, window, and cross is located.

Right now we trace the design (windows and doors) onto the cut plywood that already has the angle roof cut. Then we drill a 3/8" starter hole and the cutout it out with a handheld jigsaw.

This has worked for years but it is usually very time consuming and often the up and down motion of the jigsaw tends to leave some nasty splinters and guages now and then.

Any idea on what to use for speed and the best cut....

A router never worked for me very well. I tired a couple different setups and none of them worked. Router bits are just so delicate and I'm afraid we would go through so many of them in 1/2" ply.

I was thinking of using a mortising machine? Can this be done in plywood? I don't know anything about mortising. I have seen some videos online and it looks pretty simply to operate....I just think setting up the fence to cut the different areas would be impossible.

Any advice would be appreciated....Thanks! Fred


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## mikeintexas (Oct 25, 2011)

A Rotozip would be ideal for this, due to the small size of the cuts (openings) and right angle corners. Being that you make these houses in different sizes, you could make a template for each size board for the front of the house.

You have the windows, doors and cross cut out in the exact position where they go for each size "front of house", you use double-sided tape or clamps to align the two pieces together and just cut through your template.

You could also use a router with a template bit...I know that would work too. I'm not real smart on template bits though. I am sure someone else will chime in w/more info on that.

OR

You could use Forstner bits to hog-out the majority of material and then clean up the corners w/the jigsaw or Rotozip. For example, say your door opening is 2" x 4". Use a 1.75" bit and cut overlapping circles out of the door area. That would leave just a little bit of material left in the corners to clean up.


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## tcleve4911 (Dec 16, 2006)

What kind of jigsaw blade are you using?
I use a Bosch TB 101 which gives me a very clean cut in plywood.
You can also take a utility knife and score the outline to prevent tearout.

I don't think a router or drill press is the answer.
Better use of your jigsaw is....
Hope this helps.


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## Dave Paine (May 30, 2012)

I do not think a mortise machine would be good for your application.

With 1/2in ply I would have thought a scroll saw would be easier than a hand held jigsaw. Should give a better cut.


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## mikeintexas (Oct 25, 2011)

Scroll saw's an excellent idea; it's perfect for small-sized work like this. I didn't think about that as I don't own one. Outta sight, outta mind I guess.


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## Chris Curl (Jan 1, 2013)

there are multiple ways ... here are two that come to mind immediately

- a plunge cut with a sawsall
- drill a hole as a starter for a jig saw
- plunge router with a cleanup of the corners with a hand held saw or chisel


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## shopman (Feb 14, 2013)

I would make a template of the front of the different buildings you make. Something that could be slid right over the front and maybe have stops nailed to it to keep it from sliding around. Then drill a pilot hole through each opening near the center and use the smallest bearing guided patern bit in a small trim router. You could do all three openings without moving the template and it should be easy to square off the corners with a file.


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## mengtian (Nov 8, 2012)

+1 on the scroll saw. If you are doing these frequently it is well worth the money to get one off of CL. Even a new Craftsman is only 125 or so. Plus, yo can use it for soooo many other things.


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## birdhousebarn (Feb 18, 2011)

Hi Guys,

Thanks for the help. I never used a rotozip. I do have a router but clamping always seems to get in the way. With a scroll saw I would have to get inside each little window through a pilot hole....Some of the designs have as many as 14 windows so that would be really time consuming to set up.

I like the router pattern bit idea from shopman.

What exactly is a pattern bit? I've never used one of these before. How does it work?

The stops would eliminate the clamps...I never thought of that.

Thanks,
Fred


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## jschaben (Apr 1, 2010)

That's about the first job I've ever seen where I thought a Rockwell blade runner would be useful. Lacking that, I would mount a jig saw under a table with the blade sticking up. Jig saw usually cuts on the pull stroke so mounting upside down with a thin slot for the blade would give you a zci for the jigsaw blade. Just need to drill the starter holes. :smile:


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## MT Stringer (Jul 21, 2009)

My Dewalt jig saw came with a pack of blades, one of which is the DW3765H. It works great. I used it to rough cut out the pattern I was fixing to cut on the band saw. It is made of 5/4 Red Oak. I had no problem cutting through it. The resulting cut was smooth. Surprised me. No chipout.

I found the blade on the Internet so here is an example.

Hope this helps.
Mike


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## Chris Curl (Jan 1, 2013)

that blade runner thing is pretty cool. it's essentially a jigsaw or reciprocating saw built into a little table.

one could think of it as a poor man's band saw.


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## Pirate (Jul 23, 2009)

Chris Curl said:


> that blade runner thing is pretty cool. it's essentially a jigsaw or reciprocating saw built into a little table.
> 
> one could think of it as a poor man's band saw.


Not even close to what a band saw can do. Haven't heard anything good about the Blade runner.


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## Pirate (Jul 23, 2009)

I would use templates and a pattern router bit also.
Precise, smooth, and fast.
Another idea, which would let you use a small, straight bit, would be a pin router. 
With a small dia. bit, you could even make cathedral shaped windows, and less cleaning up on the corners.
I had a Craftsman ras, that I made into an overhead router, that could be used as a pin router.
Of course, you could also get a cnc machine and let the machine cut out a whole sheet of houses, while you had lunch!


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## rrich (Jun 24, 2009)

My solution would be 4 pieces of wood, TB-III glue and a dado blade. Cheap, quick, easy and you're not really looking for structural strength. If more strength is needed, a couple of cleats on the back.


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## jigs-n-fixtures (Apr 28, 2012)

Router with a Plunge panel bit, with a rear minted template. 

White side makes a nice one with down shear. 

The plunge panel bit is made for exactly this use.


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## Salmon_Ears (Mar 20, 2013)

Newbie wood-hack here, but wouldn't a reciprocating blade like a Ridgid JobMax do the trick?


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## 4DThinker (Mar 13, 2013)

I don't know how many of these you make, but the fronts would be trivial to cut out with a small CNC. With the software most come with you can usually import a sketch to turn into vectors to be cut. The router could cut the opening with the same "hand cut" look you are currently getting. Splinters are avoided by using a downcut spiral bit on the first pass, and an upcut spiral bit on remaining passes. You could use bits as small as 1/8" diameter in 1/2" plywood to end up with very tiny (1/16") radiused inside corners.

I if you can't afford a small CNC, then perhaps you could hire one to cut the fronts for you. Another option would be to have the templates CNC'd, then use a pattern bit with your now perfect templates. 

Rocker sells their small CNC Shark for $2,899: http://www.rockler.com/product.cfm?page=19441&site=ROCKLER


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## Cliff (Feb 5, 2012)

Is this your work?








Found here?
http://www.thebirdhousebarn.com/pinebirdhouses.htm

From the look of that you don't need to be told how to do much.
I'm confused. 

Anyway when I've done a doll house and I have to do the cut out for a window or door I use a rotary tool like a router. I guide it with a little fixture that just fits the job.

But it would more fun to use a mortiser like this:
http://youtu.be/kBPyrkwsjgU


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## Tman1 (Jan 14, 2013)

To answer your question on the template bit, it is a router bit with a bearing on top that can follow your template. It will exactly match your template, except on the inside corners. You would want one that could plunge so you could avoid pilot holes. 

Another option is a guide bushing set. This is a router base designed to have a guide bushing that goes around the router bit. A good quality one will have a special bit you can use to make sure the bushing is centered in the bushing. With a guide bushing, it would be the same as the template bit, except your hole needs to be bigger by the difference in diameter between the bushing and the bit. 

I would recommend over sizing the template so that the router never overhangs the edge of the template.


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