Gettin' Jiggy Widdit -> Squeezing Plastic Pieces Into Brackets

I'm prototyping more stuff at TechShop.

Since I need some plastic brackets, I decided to make them consistently to my specs by building a jig to make the bending go smoothly.

Of Course... I like to use MDF to build stuff, so I based my design on 1/4" MDF to be laser cut.  I used Autodesk Inventor 2014 for the whole design process.

Step 1: I Made the Mold Body and Ram

I will include a copy of the file I used to cut these.  

Reality is, though, if you would like to reproduce the jig, you'll need to tweak some of the rectangles to match with your MDF thickness.

Here you can see the face of the mold, and the rear end of the driving ram that will shape the heated plastic into a bracket with two flanges.

I made an alignment channel in the base, and a slide which attaches to the ram and slides down the channel.

The second photo shows the ram and slide assembly.

Step 2: The Base Accommodates the Ram Slide, and Holds the Mold

This top view shows the whole assembly, and the details of how the parts go together.  

The splines I used to attach the different layers together are 1" long, and 2, 3, 4, and 5 thicknesses (MDF thickness) wide to fit into the appropriate slots.

Step 3: Here Are All the Pieces...

In this shot, you can see all the pieces, and an approximate layout of their locations.

Yup. That's my foot and my usb-stick that holds my files...

Step 4: Here's the File That Generates the Pieces

Step 5: Notes on the Point That Holds the Plastic

I may have to modify this part a bit.  I found that it wears down pretty easily.  

For now, I will not glue it in, so I can easily replace it as need be...

Step 6: The Finished Product...

Comments

[chifin]

Interesting project. How do you heat the plastic to the correct temperature to allow the bending of the item?

[togo1919]

Search for Plastic Bender, and you'll see many options.

[berserk]

Do you use anything to actually power the bending process, or is it just muscle? And, do you heat the plastic? How, how much?

[togo1919]

Just muscle - it is easy enough. I had considered adding a lever to this, but it's not really necessary.

I set it in the bending heater for 7 to 10 minutes. That number is not set in stone, since any bender will be different from the next. I had to use trial-and-error on the machine I use.

Plastic is not my favorite stuff, so I don't have a lot of experience. This is working for my needs.

[iburrow]

oh I do love a good jig! well done, it's well worth it. keep up the good work. got any more sensible jig designs?

[togo1919]

I'll put more Gettin' Jiggies as they come along. I have some additional plastic bends to make coming up on my present project.

A bit of a note. The height of the mold and of the ram were important to get clean bends of the plastic blanks. Also, holding the plastic blank against the face of the ram was important to help maintain alignment during the bend.

I'll try to get a video out later this week.

[togo1919]

And Thank You Very Much for checking-in, folks...

[njc121983]

It is a good design, but may I suggest using aluminum, to prevent quick wear and tear on the jig itself. As I understand it, the tech shops have milling machines. A good design plus durable material would give you the long life of the jig that you are looking for.

[togo1919]

Not looking for long life here.

[momsnacher]

so, what is this for. is this a mold of some sort or a tool to assemble parts?

[kshowell]

It is a bending/forming tool. In Step 6 picture the flat blank is to the left, and the formed U bracket is to the right. Very good for short run quantities where uniform parts are desired.