Gettin' Jiggy Widdit -> Squeezing Plastic Pieces Into Brackets




Introduction: Gettin' Jiggy Widdit -> Squeezing Plastic Pieces Into Brackets

About: Daddy-O...

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...



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    16 Discussions

    VERY cool... My metal milling skills are wimpy at best. I can see using a ShopBot to make your design in wood, though.

    I can see using a ShopBot to make your design in wood, though.

    Or a jigsaw and some sandpaper. Thinking about projects in terms of particular tools, especially those still rare and/or expensive, stifles the creative process.

    I think this design could be made with as simple or as fancy a toolbox as you have at your disposal. I think a drill and some sort of hand saw, band saw, jig saw or otherwise would work, and sandpaper or a sander. As far as materials go, a simple 2x4 scrap and maybe a plywood scrap should work.

    I get somewhat frustrated sometimes with the TechShop stuff on here because (mostly I'm jealous that I don't live near one) there is access to all sorts of fun toys. But, I think my design respects the humblest of tool availabilities.

    Agreed, I just don't want the less experienced to think that because they don't have a Techshop (which pegs my own jealousy meter) that they can't make something like this.

    Teddy Roosevelt said, "Do what you can, with what you have, where you are." My grandfather pretty much said the same thing. The programming god Donald Knuth said, "80% functionality now is better than 100% functionality never." Getting the job done is the important part, smoothing out the rough edges can come later, if ever.

    I grew up on farms and ranches in the 70s and early 80s with the nearest town 35 miles away and ordering parts took a good two weeks, assuming you could page through hundreds of pages of hardcopy binders of catalogs to find the part in the first place. Usually, though, the work couldn't wait even a few hours because farmers work for mother nature and she's a rather a stern boss.

    Instead, life on the farm is a constant exercise in technological improvisation. I didn't appreciate it until well into adulthood but my grandfather and uncles could improvise a fix or a solution to almost any technical issue that didn't require millimeter precision. They just looked at the problem, looked around at the tools and materials on hand and started banging away.

    I think we lost a lot of that skill when people moved off the farm and started to specialize in narrow technical domains or (increasingly) no technical domain at all. People think to much about how to do things like a dedicated specialist would instead of how they can do it with what they have.

    Part of the great value of Instructables is that it fights the tendency of people to think, "I do X because I don't have Y." I just wanted to reinforce the point.

    Great post and I love the quote "80% functionality now is better than 100% functionality never." I'm very guilty when it comes to that. I'll do lots of reading and planing on a project but when I find I don't have the tools, materials, money, or skills to make it as perfect as I want I usually give up. The truth is I would learn just as much (and still have fun) even if the final product isn't as pretty or only does 80% of what I set out to do. I hate letting that stuff hold me back.


    4 years ago

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

    1 reply

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

    1 reply

    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.

    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?

    2 replies

    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.

    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.

    1 reply

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

    1 reply

    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.