Bending Plywood With 3D Printer




Introduction: Bending Plywood With 3D Printer

About: Student, Maker, Designer

This is an experiment to bend plywood with 3D printed tool.

I have bent plywood before.The method used at that time is so-called molded plywood.

Apply glue to the plywood, pile several pieces and put them in the mold.

I was surprised at its very simple way.At the same time, I felt it was very hard to make the mold.

Since I was making in a workshop with various tools and facilities,I managed to make it well and I did not have to worry about the noise caused by the tool.

So, I will not try molded plywood at home.

Finally,a beautifully curved plywood and a mold that can only make it are completed.
Unless considering the production and disposal of the mold, the molded plywood is fun and you can easily create curved surfaces.

So I came to wonder if molded plywood could be made easier.

I am not very good at woodworking and I do not have much tools.

But I have a 3D printer. I made a simple tool with a 3D printer.

And with that tool I made this lamp experimentally.

I apologize in advance that English is not my first language

Step 1: Concept

First of all, let's briefly explain how to bend.

A mold is necessary for the molded plywood.

(This article is very easy to understand for molded plywood.People who try this experiment should read this article. Especially about veneer.)

Like the attached image, the mold consists of two parts.

I tried to simplify these two.

Make a frame with 1 * 4 spf lumber, and make a curve with a thin PP plate in it. Then put several pieces of plywood with adhesive in the frame.

Finally, put the ball in the gap and inflate it.

In short, it is a molded plywood made by the power of air.

And, this mold is repeatable deformable mold.

You do not need a great workshop or special tool.

Step 2: Materials

1×4 SPF lumber

Plywoods / Veneers (When I purchased this, I had it cut to a height of 87 mm at the store)

PP Sheet

M6-110mm bolts and nuts


Step 3: Tools

lubber ball (300mm)



(heatgun or iron)


wood glue


wood shaver


impact driver

Step 4: 3D Printing

First, print a joint that connects spf lumbers.

3D data is here.

There are two 3D models. 3 pairs are required.

Step 5: What Is This Tool?

As shown in the photo, fix the parts to the tip of the SPF.

This is the only preparation.

You can make a frame by combining SPF like the photo.

Step 6: Design

Because this is an experiment, I only want to see if it is possible to bend plywood in this way.

However, it is more fun to make things that can be used at home.

So, I decided to make a lamp that gently shines the room in the corner of the room.

A good thing about this method is that you do not need knowledge of 3D modeling, you can bend the plywood as if you were drawing a sketch.

Without determining the dimensions, I just drew a very rough sketch.

I will decide after bending the details, such as handling the code.

Step 7: Frame

Joints move freely.

This time, I need to make a triangle.

I adjusted the size and found the size I wanted to make.

Step 8: Curve

Use a sheet of polypropylene to determine the radius of the curve.

When the curve that I want to make is completed, I use tacker to fix the sheet to the board.

That is the completion of the mold. I can make a red line curve with this mold.

Step 9: Pre-Bend(extra)

In truth, I did not plan to do this work.

However, the 1.6 mm thick plywood I had prepared could not be bent small.

Plywood is only thin wooden film is overlaid with glue.

So I decided to bend the plywood a little in advance by softening the adhesive using a heat gun.

You can do the same thing with an iron.

Step 10: Glue

Before applying the glue, make sure that the plywood can fit in the mold without breaking.

Glue are those sold for woodworking. It is not a special glue.

Just apply and pile it. You need to do it quickly.

Using a roller, you can paint the glue very easily, quickly and uniformly.

I put plywood of 1.6 mm thickness on 5 layers.

Step 11: Insert Into Frame

This frame is assembling lumber with gaps.
You can insert plywood from this gap.

Depending on the shape, it may be easier for you to remove the bolt.

This time, remove the bolt of one joint in advance. Insert the stacked plywood inside, then return the bolt to the original position.

Insert the PP sheet in between so that the plywood will not stick to the SPF.

Step 12: Inflate

Using a vinyl string, hold down the corners, and inflated the rubber ball.

Look into the gaps and check that they are firmly sticking.

Step 13: Wait

It is truly a strange sight.

No balls are needed in the unbent portion. I only used 2 small clamps. I put a weight on the bottom.

I left it for 24 hours in this state.

Step 14: Release Air

Step 15: Disassemble Frame

Step 16: Success?

The part using the ball is perfect.

I could not apply a force well to the bent part at the top, so a gap was created.

Anyway, I could bend, so let's complete it.

Step 17: Clamping(Extra)

I thought that it might be possible to adhere to the part with a gap, I tried to fix with clamp after applying the glue in the gap.

Step 18: Cutting

Step 19: Shaving

Look at this picture!

I do like this line produced by molded plywood.

Step 20: Wiring

Just put a socket.

For now, I fixed it with double-sided tape.

Step 21: Lighting Up

Step 22: Adding Joints(Extra)

I made three additional joints.

In order to stabilize the frame you will need to create at least one triangle.

As shown in the photograph, when making one turn, it is necessary to align the plywood length beforehand.
It is thin so it is possible to cut easily if there is a cutter.

This form did not require pre-bend.

It seems to be important whether the length is exactly aligned or not.
There was a part which was doing well and a part which was not so. Again, I pinched the failed part with a clamp.

Step 23: Mounting to Wall(Extra)

Step 24: Insert Spray Can(Extra)

Of course, there are restrictions on the shape that can be made with this frame.

However, there are forms that can be made by modifying the frame a little.

Step 25: Mounting Wall(Extra)

Step 26: Fusion360(Extra)

I used fusion 360 for the design. This data is a joint only for 1 × 4 lumber, but if you edit the data you will be able to handle lumber of various sizes such as 2 × 4.

Step 27: Enjoy Bending

This is an experiment, and it can not be said that it was perfect.

There are some problems that need improvement.

However, using the SPF used for the frame, you can make something different by changing the angle and curve. Or you can duplicate the tool. This is not a mold. This is a reusable tool.

And, this experiment was done in a small room. There are no special facilities or tools.

Because there is no noise, neighbors do not get angry.

It is fun to bend the plywood without the workshop without the mold.

So, why do not you try it?

There is no need for a great workshop. Plywood can be bent in the living room.

More than anything, not only had my 3D printer run, it was fun to move my hands.

Anyway, enjoy bending.

Thank you for reading. If you have any questions or opinions, ask me anything.

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    4 years ago

    This is a very impressive and worthy process. I'm sure that many beautiful items can be made using your technique. There is only one thing I would suggest to make your work somewhat easier. Please consider applying an ammonia solution to the wood piece to be bent. This is an old method used by boat builders with to work some fairly thick wooden planks which cannot be bent as easily as thin sheets of plywood.. In fact, if you don't mind some temporary strong odors (which you can wash off after the wood has been shaped), your own urine will work well to soften the wood.

    The way the boat builders do it is to immerse the wood sheet or plank in a dilute ammonia solution until it is saturated. This makes the cellulose easily bendable without splitting. Then they remove the wood and place it among vertical wood rollers which can slide sideways to put pressure on the wood piece to be bent. It is an ancient technique. I read about over 20 years ago but have not done it myself.

    Good luck with your wood shaping.

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Thanks for your comment.

    That is very interesting information.I am going to try bending with steam in this way, but it seemed that a big pot would be needed. And hot wood will adversely affect the rubber balls and PP sheets.

    I did not know bending using ammonia. It seems easier than using glue. I will try. If it goes well, I will add pictures to this article or write a new article.

    Thank you!!.


    Reply 4 years ago

    You are most welcome. I forgot to mention that the old time fishing boat builders in the Northeast of the USA would actually ask the people from town to "donate" urine! They needed a lot of it to immerse the planks completely. LOL! I don't know what the ammonia concentration is in human urine. I assume you can Google it, but it probably is a weak solution. You probably do not want too much ammonia oversoftening the wood, of course. At any rate, being able to soften and bend wood at room temperature will ease your work.

    Here's an abstract from an article about softening wood with ammonia:

    Wood Softening and Forming with Ammonia

    Institut fur Microtechnologische Holzforschung, Eidgenossische Technische Hochschule, CH 8006 Zurich, Switzerland


    Department of Chemistry, S.U.N.Y. College of Environmental Science and Forestry, Syracuse, N.Y. 13210


    During sorption, softening and forming processes in woodwater-ammonia systems, changes occur on molecular to macroscopic levels . They are time-dependent and history-dependent functions of temperature, pressure, and system composition, and require definitionin terms ranging from molecular interactions to engineering properties. The influence of ammonia is comparable to but more extreme than that of water. At room temperature its effect is comparable to the effect of water alone at 200° C. In general the rate of diffusion of ammonia in wood is much faster than water; bound water is displaced by ammonia since ammonia sorption is more powerful; the fiber saturation capacity of the wood is much higher for ammonia; the wood can be more highly swollen. Ammonia-treated wood is less elastic and can undergo plastic flow and creep. The wood tends after drying to be more dense but less dimensionally stable. The processing characteristics and final properties of ammoniatreated wood cover a wide range depending on treatment conditions. At various stages of development are rapid ammonia treatments for wood forming, with results comparable in effect to steam bending (Zurich), modification of wood properties by compression (Riga), defiberization and pulping, wood slicing, adhesion of particles in molding, and applications in arts and crafts."

    Good luck to you.


    Reply 1 year ago

    I had never heard of using ammonia to bend wood, it sounds a lot easier than using and containing steam. I had heard of the roman laundries collecting urine to bleach robes white, I guess from the ammonia.

    Here is an article on softening wood using Ammonia, Lye and Urea. Again two chemicals in urine;
    Softening and Bending of Black Poplar (Populus nigra L.) Wood with Chemicals
    Author: Younis H. Suleman
    Journal: Tikrit Journal for Agricultural Sciences
    ISSN: 18131646 Year: 2015 Volume: 15 Issue: 4 Pages: 15-20
    Publisher: Tikrit University

    There is also an 8 minute Youtube video that says ;
    wood with ammonia is not really DIY, but I show the process, which is
    extremely effective. There is also a commercial product that is
    pre-treated flexible wood, which hardens after being clamped in the
    desired shape."

    Here is a 64 page manual from 1968 that
    contains several chapters on bending wood including one on using
    ammonia. the manual is titled Laminating
    and Bending, a Base Syllabus on Wood Technology. Prepared Institute
    Participants. N.D.E.A. Institute for Advanced Study in Industrial Arts, June 10 - August 2, 1968
    . (tell me that name wasn't created by committee!)

    two other citations;

    title={Plasticizing wood with ammonia - a progress report.},
    author={Ross W. Davidson and W. G. Baumgardt},

    author={Conrad. Schuerch},

    Thanks for the great idea. It's just another reason to figure out how to get my cheap monoprice printer to adhere to the bed.



    4 years ago

    This. is. AWESOME!


    4 years ago

    I never thought of using an inflatable ball to help pressure form shapes, thanks for sharing!

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Thank you.

    Depending on what you make, pressure may be insufficient.


    4 years ago

    Yikes, Ryo, I thought I was going see see you saw your thumb off in that one video! The way you were going to town on that board and the placement of your left hand made me *very* nervous.

    Aside from that, it's a very cool Instructable, thnx for sharing. :-)

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    I was lucky and I did not get hurt.

    I will be careful. Thank you.


    4 years ago

    Dude, this is amazing. I'm very impressed. Definitely trying this soon, I've always wanted to make a bent plywood chair without kerf cutting.

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Thank you!!

    I will also make a chair in this way, by improving the design of the bracket.


    4 years ago

    Really great work Ryo. I have been experimenting a bit with printed tooling myself recently. Hadn't thought of using it to shape plywood! Nice to see how you went about it. And I agree with randofo, great GIFs.

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Thanks for your comment.

    I like 3D printing and 3D modeling. However, I thought it would be nice to be able to make shapes without the limitation of the size of my small 3D printer. I wanted to create a tool that can compensate for the shortcomings of 3D printers using 3D printers.


    4 years ago

    Great instructable and intteresting technique!

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Thanks a lot.


    4 years ago

    Nice GIFs!

    Also, really appreciate the process you have created. I look forward to seeing what else you make with this technique.

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago


    I like GIF because it's handy when I explain something.

    Yes. Although it is the stage of the experiment now, I am going to rework and make bigger items such as chairs and tables.


    4 years ago

    You should try to make this and combine it with your lamp.
    I noticed the cord at the last GIF. this could solve it :D

    Ryo Kosaka
    Ryo Kosaka

    Reply 4 years ago

    Wow. cool!

    I also thought that if there was no code on this lamp.

    But the cordless socket was not sold anywhere.

    Thank you for telling me this article.


    4 years ago


    It is very imaginative to re-think a process like bending plywood so that it can be done in a small area and with less noise. I particularly like the flexibility of the brackets and the simplicity of the inflatable ball