# cutting 1/2 plywood



## littlejoe (Oct 22, 2015)

Hello,

I have a metal shop and I make a product that I need a crate to ship in. I have just recently started making my own crates which has proven to be laborious.

I need to cut rectangles out of 1/2" plywood, actually 15/32 plywood, on a production basis. Time is money. Measuring each cut takes too long so I want to use a template.

Finish on the cut is not important.

A table saw is not an option for me.

A jig saw is not an option because my arms would get too tired. Too much cutting.

A circular saw will work but I would have to start each cut with the saw base not touching the template and I would have to plunge cut on two corners.

I have never used a router and don't own one. 

I am assuming the high speed of a router will make cutting through 1/2" plywood easy and my arms won't get tired. Am I right?

Will a router cut through 1/2" ply in one pass? If so, what horsepower should I get?

The finished sheet sizes are 12" x 38", 20" x 39", and 15" x 20". 

I will usually buy 5 to 10 4' x 8' sheets and cut them up all at once so there is a lot of cutting. I will be making these crates for years.

Thanks in advance for your help.


----------



## furboo (Oct 12, 2015)

Welcome!

Aside from the plunge cut, a panel saw would sound like your best bet. A track saw is a cheaper option, which is what I use to break down sheet goods. But a track saw takes a bit more setup time. A homemade jig for a circular saw (track or not) is another option to consider.

I guess I'd strongly consider all of these before a router. Saws for cuts are faster and make a lot less dust and noise.


----------



## RainMan 2.0 (May 6, 2014)

What Rob said . I'm liking the track saw , and if that's not a go then building a track for your skill saw.
Can't see a router working for this application at all .
Btw welcome to the forum


----------



## Nickp (Dec 4, 2012)

Littlejoe...looks like your circular is your best option...try something like this to guide the saw...

50 In Clamp and Cut Edge Guide

You would first make the short cuts and then the longs...HF makes a shorter one...if you don't like the HF quality other manufacturers make same...

Router is out of the question...jig saw would take too long...jigs would help but would only emulate the off the shelf guides...

Set your sequence so you don't need to plunge...

If you will be doing this for years, invest in a used table saw...

Welcome to the forum...


----------



## MT Stringer (Aug 15, 2012)

Search You Tube for "circular saw guide".

Easy to make and should work almost as good as a track saw. Make a long one and a shorter one.

Notes:
1) Place a piece of insulation foam board under your plywood and set you saw so it just barely cuts through the plywood. See pic below.

2) After you determine a cut list, ask the lumber yard to cut each sheet at least once. That will give you a head start on the break down.

3) Stack three sheets together and cut them all at once! :surprise:

Good luck.
Mike


----------



## tomp913 (Mar 7, 2014)

Something like this guide How to Build a Simple Circular Saw Guide for Straighter Cuts is quick, easy and cheap to build. Lay out your rectangle on the sheet of plywood, clamp at either end and cut - as Mike said, you could cut 3 sheets at once. just screw them together so they don't slip as you're cutting. If you consistently cut just the these sizes, make a pattern for each size that you can drop on the sheets of plywood, mark the edges to be cut, clamp the guide and go for it - saves the time needed to measure and mark each time. If it doesn't matter which way the grain runs, layout the patterns to maximize yield from the sheet.


----------



## DaninVan (Jan 1, 2012)

An 8 1/4" DeWalt or Bosch Builders saw will easily cut through 3 OR 4 stacked sheets at one pass.
This isn't furniture, a 24tooth blade is what you need.
All of what the other comments said.
Personally, I'd do the 8' cuts first...just easier to work with 8' x 15+" pieces rather than 4' sections.
You know, this is the perfect job for a radial arm saw. Just sayin'...


----------



## old55 (Aug 11, 2013)

Welcome to the forum.


----------



## Cherryville Chuck (Sep 28, 2010)

Since you say finish is not an isue I don't think you need a straight edge. Cut a pattern out of something hard, thin, and light like masonite for a template. Throw itt on top of the sheet of 1/2" and mark your lines out. Then plunge cut. 

However, the description you give of how you plunge cut scares the crap out of me. You should never, and I mean not ever, hold the entire saw above the sheet and then dropit into the cut. The way to plunge cut is to tip the saw forward onto the front edge of the sole plate and then ease it down into the cut. Having the front edge sitting on the sheet gives way more stability and helps the saw blade enter the cut square so that it doesn't bind which can cause a kickback.


----------



## DesertRatTom (Jul 3, 2012)

One advantage of a shop made saw guide is that after you connect the straight piece the saw butss against, you then cut off the overhang. What you're left with is a guide piece you can set on the cut line. In addition, making the guide a foot or so longer than your cut supports the saw from start to finish so you don't have to plunge the saw at all. A clamp on each end to hold everything together during the cut and hold the guide in place and you're set. A sheet of insulating foam just makes it easy to make the cut without having to mess around with saw horses and 2x4s. You can cut on the floor if you wish. Half inch ply is pretty thin stuff, so 3 layers should be a snap.

I also think you should lay out on graph paper the sizes you need so that you get the most from every sheet. You don't need a very high grade of ply for crates, so you can use construction grade stuff with no finished surface. Glue your labels on for shipping purposes. If possible, have the lumber yard cut the piece down so you don't have to handle 4x8 sheets. If you order in bulk, they will probably do the cuts free. Much easier to deal with smaller pieces.


----------



## Bricknhank (Dec 28, 2013)

I know that you said that a table saw is not an option so I won't ask why however, even if it is a matter of space or finances (if it were me) I would find some way to utilize a small portable used table saw. I could set the fence and make many production cuts instead of setting up sawhorses or crawling around on the floor, laying down foam insulation, clamping and unclamping straightedges etc. If time is money and you want the best bang for the buck in my opinion a table saw is the way to go. But that's just me.


----------



## herrwood (Apr 19, 2014)

As the boxes are all a set size an you do not want to invest in extra equipment and i do understand the time involved, maybe you can make a deal with you wood supplier to precut to the size you want.


----------



## WizardLV (Mar 28, 2014)

Cutting down sheet goods is time consuming and does take up a lot of shop space. Most big box stores will allow several free cuts on their panel saw. However, if you wish to do this yourself, I also recommend a plunge cut track saw like the Festool TS 55. Great for the job and takes up very little shop space. A couple of saw horses and two by four's, you're all set. I would also invest in a good rip saw for the TS 55, and there are several available. You could still easily make template pieces for use with the track saw to eliminate measuring, as well. You would need a track of at least 106" (they make them), or you can also connect two 55" tracks together. I use my track saw way more often than my table saw these days, and using a table saw to cut down sheet goods is difficult, without the right setup. Better to move the saw, rather than the sheet in my opinion on these larger sheets. You could easily make dozens of crates in an afternoon with such a setup. Good luck!


----------



## OPG3 (Jan 9, 2011)

Many of my products go to all "corners" of the world. Different destinations have differing requirements. As an example, when we send products to Hawaii, Australia, Japan & Taiwan - we have to have our products stacked atop of PRESSURE TREATED PALLETS and then BOXED-IN with MARINE PLYWOOD. I have "people" that handle freight concerns, but if you're using INTERMODAL FREIGHT HANDLERS - They can provide you with the specifics. 

If I were cutting-out a lot of the same dimension pieces, I would make ONE PERFECT PIECE (the TEMPLATE) OFFSET by the saw's sole plate to blade dimension and clamp-it-down to my workpiece and follow the edges and "kill several birds with one stone". Obviously, the longest straight edges would be aligned prior to this template cut. 

Otis Guillebeau from Auburn, Georgia


----------



## john60 (Aug 30, 2014)

I assume you are in the metal working business and not wood working. Where do you buy your ply. Have you looked in to buying it cut to size. If you are buying quanity you may get it done for nothing. Also you might try a cabinet shop. Have them make crates when they are not busy.


----------



## timbertailor (Oct 4, 2009)

I would built a template that your circular saw would fit in since you have to build one anyway. A jig saw for the detail work. Let us know what you decide on and good luck.


----------



## mgmine (Jan 16, 2012)

Of all the methods that you mentioned the router is the worst way to do it. Why is a table saw not an option? Maybe there is a way to make it one.


----------



## knickam (Aug 31, 2015)

Not Cheap, But this might suit you






Can be extended to cut a full 8' by joining 2 rails


----------



## The Hobbyist (Apr 25, 2015)

Hi Little Joe,

I used to work for a plexiglass fabrication shop. I noticed that the boss was wasting a LOT of material, so I wrote a small computer program in BASIC to use his dimensions and get a higher yield out of any sheet of material. It would take his piece dimensions, and plot out the cuts efficiently in any size of material, allowing for blade width in the calculations. Where he was once using 20 sheets to do a job, I was able to show him how to get *all* of the pieces for a run out of only 14 sheets of plexiglass. The six-sheet-$aving$-per-production cycle earned me a nice rai$e!

I am trying to visualize your situation. Can you post a couple of photos, or sketches of the *finished* crates? Post a couple of photos with the crates, and showing the machines IN the crates so I can see what room you have inside between the machines and the plywood.

Are ALL of the crates the same size and dimensions? From your measurements, it seems as if you may be wasting a lot of material.

How are you cutting your 4x8 sheets now, to get the (6) pieces you need to make the crate? What is the layout of the cuts on a 4x8 sheet,* to minimize waste? *_What do you DO with the cutoffs?_If you are producing stacks of cutoffs all the same dimensions, you may be able to SELL them to recoup some of your plywood crate costs.
Would you be opposed to making your crate out of (8) or even (12) pieces of plywood with a closed seam in the center(s) of two or more sides,* if I could show you how to get more than five crates out of five sheets of plywood?*

Are you cutting all of these pieces (I ASSUME two of each dimension) to get ONE crate out of ONE sheet of plywood? You may be able to get a higher yield by thinking outside of the box! :nerd: 

The dimensions you posted do not *make* a box, unless your 15"x20" pieces extend beyond one (or both) edge(s) of the 20" ... at the bottom, for forklift blades??



littlejoe said:


> A table saw is not an option for me.


Since all of your crates are the same size, you can make an inexpensive cutting jig that will store against a wall, and allow one man to cut your pieces using an ordinary circular saw.



> A circular saw will work but I would have to start each cut with the saw base not touching the *template* and I would have to plunge cut on two corners.


This is REALLY scary! Are you saying you cut a hole of some sort into one or more sides? I'd really like to see some photos of these machines and crates!

What TEMPLATE are you using to cut the plywood? Please post photos ....



> The finished sheet sizes are 12" x 38", 20" x 39", and 15" x 20".


With a little *out-of-the-box thinking*, :wink: you can make those crates more efficiently by perhaps working with different dimensions that TOTAL UP to the panel sizes you need. 



> I will usually buy 5 to 10 4' x 8' sheets and cut them up all at once


If you have Skype on your computer, we can work out your issues over the computer. I have a program that automatically "nests" pieces for 'best fit'. We could work together to figure out the best and most efficient way to make your crates without using a table saw, and without wasting a lot of material.

ASSUMING the dimensions you gave are two sides, the top, the bottom, and two ends, you are using 2,448 square inches of plywood for a crate. A sheet is 4.608 sq. in., so I HOPE you are not wasting 2,160 sq. inches of plywood per crate! We can do much better than that!

If I could produce (7) or (8) crates out of five sheets of plywood, would that interest you? It would reduce your crate building costs.

My Skype I.D. is "joejinky". *I make no promises*, but my help would be FREE, so it may turn out to be worth exactly what you paid for it .:grin:


----------



## DesertRatTom (Jul 3, 2012)

I'd take up Joe's offer if I were you, particularly if you are having to use high grade ply for your crates.


----------



## The Hobbyist (Apr 25, 2015)

I believe I have worked out eight crates from six sheets of plywood. Is that of any benefit to you?


----------



## MT Stringer (Aug 15, 2012)

I use Cutlist Plus fx for my projects. I take the hard copies with me to the store. The guys will cut the plywood once for free and sometimes I get them cut twice. Really makes handling the sheets a lot easier, especially for an old guy like me.

Also, I use either a track saw or table saw, and sometimes both. It just depends on what I am cutting. Repeated rips on the table saw are a breeze.

My track saw is a cheap Scheppach model, which is identical to the Grizzly model. No Festool for me. In my opinion, their prices are outrageous. That's my take from a hobbyist view.


----------



## littlejoe (Oct 22, 2015)

Thanks for all the advice. One thing is for sure I will not use a router for this job. Everyone here agrees on this. Thanks for saving me the money that I didn’t spend on a router.

I tried out using templates over the weekend and it didn’t turn out to be as easy as I thought. 

As a machinist I am going to do what I would do with a piece of metal in my machine shop. Set up a “stop” on a bench, clamp the wood down, and use a home-made track saw guide to cut the plywood with a circular saw. I will make a spacer the exact size of the wood I am cutting to set the track saw so I won’t have to measure before every cut. The simplest solution is always the best. I can’t believe I didn’t think of this before. 

Having someone cut up the wood for me is the ideal answer if they can do it accurately. I am still trying to find someone in Somerset county NJ and will keep looking. 

My local lumber yard does not want to do all this cutting even though they advertise they will. I got them to do it once but they practically chased me out of the place the second time I showed up. LOL

Lowes/Home Depot will do the cutting in theory but in practice it is not practical. I have to wait there while they do it which would take forever. My local Lowes panel saw cuts ¼” too big and the operators don’t want to take the time or effort to adjust for the ¼” error. I did this once as well but don’t want to do it anymore.

Someone mentioned having a cabinet maker make the crates in their down time. In fact I had a cabinet maker making my crates for me but he passed away. I will keep looking into this option as well.

Anyway, since we are off this forum’s specified topic of routers I am starting to feel guilty taking up all your time. Thanks again to everyone for helping me out.


----------



## The Hobbyist (Apr 25, 2015)

What is your crate-per-4x8 sheet of plywood yield now? Are you using *one sheet per crate?* Is all of the plywood the same, or do you have to mix thicknesses and grades?

MOST important ... what flexibility do you have to* increase or reduce the dimensions you posted?* Would an inch shorter or longer on a couple of dimensions be a deal breaker? Or is the crate already a "glove fit" to the machine? Are we LOCKED IN on the dimensions you posted?


----------



## MT Stringer (Aug 15, 2012)

> Anyway, since we are off this forum’s specified topic of routers I am starting to feel guilty taking up all your time.


 @littlejoe - don't worry about that. It happens all the time. We have a lot of members and their experience varies from beginner to expert. Members come from all walks of life, and all over the world, and are good at some things and not so good at others.

I personally feel you can ask just about any question you can think of, and somebody will have an answer or a suggestion pertaining to the subject.

Mike


----------



## The Hobbyist (Apr 25, 2015)

You said you will be making these crates for years. I believe I can get *56 crates out of 43 sheets of plywood.* I will have to double-check my math.


----------



## Frankj3 (Oct 6, 2014)

I built me a jig exactly like the one Tom is showing in the photo above. I use it all the time for precise, quick cuts.

You mark the plywood where you want to cut, lay the edge of the guide down on the line, clamp it in place, then cut a perfectly straight line. Take the 15-20 minutes needed to build this jig. You probably have enough scraps to build one. You will be glad you did.

We ship a lot of items in crates at my job. We build our own too. We use C-D plywood and ship world wide.

Frank


----------



## littlejoe (Oct 22, 2015)

Since it is easier to cut one size at a time I am only cutting one size out of each sheet. I do cut some of the smaller pieces out of scrap left over for better yield.

The exact sizes are:
Top: 1 piece - 20 x 39
Bottom: 1 piece - 19 x 38
Sides: 2 pieces - 12-1/2 x 38
Ends: 2 pieces - 15-1/4 x 20

The 15-1/4 extend below the crate for forklift forks.

I get 4 crates out of 4 sheets with a few extra ends and sides left over which is okay because I will adjust quantities the next time I buy wood.

I am not allowed to upload pictures yet on this forum so I can't upload a drawing.

Thanks again for all the help


----------



## The Hobbyist (Apr 25, 2015)

littlejoe said:


> Since it is easier to cut one size at a time I am only cutting one size out of each sheet. I do cut some of the smaller pieces out of scrap left over for better yield.
> 
> The exact sizes are:
> Top: 1 piece - 20 x 39
> ...


Now you are changing the dimensions. :surprise:

I will ask again, are these dimensions carved in stone, or do you have some flexibility in changing them? 

What is INSIDE the crate? Are you using 2x2s to joint the edges, or just tack nailing the plywood edges and perhaps gluing them? 

If the crate is a glove fit to the machine with these _amended_ dimensions you have posted, then no dimensions can be changed 

However, if you can take off 1/2 to 3/4" here and there, you will get a much higher yield out of your plywood. ESPECIALLY if you can put the joint timber on the OUTside of the crate rather than INside.

You are wasting a lot of plywood with your current technique, and I can't see these crates being very strong. Are you using short 20" pieces of 2x4 under the crate to allow for forklift blades? Or are you relying strictly on the 1/2" plywood sides extending down to support the weight of the contents?

I really shouldn't care ... but I think I could save you a lot of money by rethinking these crates.

Is this what you are currently building?











.


----------



## DaninVan (Jan 1, 2012)

Littlejoe;
"I am not allowed to upload pictures yet on this forum so I can't upload a drawing."

If they're on your _own_ hard drive, you should be able to upload the pics. It's stuff that you want to take off the 'net that's restricted, as an anti-spam measure.


----------



## littlejoe (Oct 22, 2015)

The Hobbyist, thanks for all the effort you put into this. Yes when I originally put the sizes up on the forum I was going by memory and they weren't exact, sorry. So these new dimensions are accurate. The crate is built around my product and can't change in size or design. Yes the picture you put up is exactly what my crate looks like. Yes I have 4 twenty inch 2x4's under the crate for support, 2 on each side. I also have 4 twelve inch 2x4's inside in each corner and everything is screwed to the these.

You wrote you could get 56 crates from 43 sheets. Thanks for the info, but that is way too much inventory for me. I only have room to store about ten assembled crates and 20 if they are knocked down.

The assembled crate drawing and how I cut them out of the sheets is attached.


----------



## DaninVan (Jan 1, 2012)

Lj; I think Joe, The Hobbyist, was suggesting *the plywood to product ratio,* not that you should make them/cut them all at the same time.
If he'd said you need .75 sheets per crate, the obvious conclusion is that you still need to buy a full sheet. Extrapolated, you'd need 3 full sheets to make 4 crates for example...just an illustration.
I'd personally take up Joe on his offer to produce a cut list for you. You won't be buying 43 sheets!


----------



## The Hobbyist (Apr 25, 2015)

littlejoe said:


> You wrote you could get 56 crates from 43 sheets. Thanks for the info, but that is way too much inventory for me. I only have room to store about ten assembled crates and 20 if they are knocked down.


You would not have to cut all 56 crates at once. If you use a different cut pattern, you could cut enough for say, three crates, with some parts left over. Next, you cut three more sheets, and using the extra parts, you make three more crates with some parts left over. You continue until you have realized a yield of (x + (?) add'l crates) per  sheets of plywood.

It could happen over time, but you would end up with a dozen FREE crates that way.

If you changed the 12.5" dimension to 12" and changed the bottom width from 19" to 20" wide, it would do two things for you. First, it would allow the bottom to provide lifting force across the entire lower edges of the sides. Right now you are lifting the crate by the sides, since the bottom is BETWEEN, rather than BENEATH the sides. Changing the 12.5" dimension to 12" (actually 11.9", you will reduce your plywood use per  crates A LOT while only reducing the height of the lid 1/8"

Can you tell me of the regions between the 2x4 studs are use by the machine? You have two spaces that are 12" wide x 12" tall x 1.5" deep, and two spaces that are 35" wide x 12" tall x 3.5" deep. Does the machine occupy this space?

Can you take a photo of the machine in a crate with the top off and looking straight down onto the crate? 

It is all up to you. It is your company. I just hate to see you pay for a dozen (or more) sheets of plywood that you might not have to purchase, every time you have shipped out 5 of these machines!

The 2x4s inside could be ripped into two pieces, reducing your vertical interior frame costs by 50%.

Your dimensions changed, so I will play with the new numbers a bit. *I still believe I can save you a lot of money* (over time) :wink:


----------



## The Hobbyist (Apr 25, 2015)

By the way ... cutting them as you do now, what do you do with the 9"x96" and 10"x96" strips of plywood scrap that you produce?

How many machines do you ship in a month? Are we talking "one or two, and sometimes three," or are we talking "50 or 60 every month?"


----------



## littlejoe (Oct 22, 2015)

I will use the 9" and 10" drops for making Bottom pieces even though it would 2 pieces instead of one. This will cut scrap down to almost nothing. Once again, thanks for all the effort and help from everyone, especially The Hobbyist.


----------



## The Hobbyist (Apr 25, 2015)

okay.


----------

