3D Objects, CNC and Machining, Creative, Engineering, Redesigning Something That Exists

Fidget

The 2010s can be divided into two eras — the time before and after fidget spinners came to existence. The weird part is that they came out of nowhere, and now they don’t seem to exist at all!

In fancy MakerSpaces, it is quite common to make these using 4 cylindrical ball bearings, and printing the shell. However, where’s the fun in boring old 3D printing? Besides, it takes quite a while to print. And not to mention, there is always going to be tolerance issues, because low fidelity printers are not supposed to be accurate.

Truth be told, using a thick piece of acrylic and laser cutting is perhaps the fastest way to do this. But a laser cutter is limited to cutting at most an eighth to a  quarter of an inch, beyond which one will have to repeat the trace on the piece of acrylic. And this would cost, surprise, surprise… the tolerance.

This slideshow requires JavaScript.

Regardless of the backstory, I was thinking of using multiple machines to make something. The plan was to use my trusty desktop CNC milling machine along with the water jet. I used delrin to make the case or the shell, and the caps. Then, I cut a thick piece of steel slab into circles, to give the spinner some weight.  All in all, it worked exceptionally well!

P.S. I’m not making another one, not in this way… ever. Also, I don’t think fidget spinners make good Christmas presents.

CNC and Machining, Engineering

Water-jet cutting

Water-jet machines are a special class of CNCs which use highly pressurized jets of a mixture of water and powdered abrasive, such as garnet. This can be assumed to be similar to Laser Cutters. They can only cut objects in 2 dimensions. However, unlike a laser cutter, the water-jet can cut through thick metals like steel, aluminum, and even carbon nano-fiber sheets!

Here is an example of a circular disc I cut from a steel slab for a funny little project, which uses the delrin from a previous post.

This slideshow requires JavaScript.

Here is another example of water-jet cutting to make a keychain.

CNC and Machining

Milling cylindrical objects

So, as previously shown, wood is an excellent material to machine into the desired form. It is possible to mill shapes using the tools of tiny sizes. In this case, a 1/32nd in. endmill. You simply need to be careful about the length of the flute of the tool.

Fusion 360 has a text feature in the model section. By selecting the desired font size, not too small for the endmill tool, and choosing the contour milling in the 2D section, it is possible to make appropriate alpha-numeric shapes onto almost any right kind of piece of material.

Ideally, I would have milled an actual cylindrical piece of object, but i found this weird wooden, plain looking keychain. Just so you know, the shape of the wooden part of the keychain is almost cylindrical. So it is better to select a cylindrical stock to make the CAM file.

This slideshow requires JavaScript.

Another reason why I milled this keychain was because we used to have an incredibly boring acrylic keychain, badly cut using a laser cutter (and not the one I had milled a while ago).

I’m really glad that I was able to fit the logo and all the letters on the keychain!

3D Objects, CNC and Machining, Engineering

Delrin

Although, it sounds like someone’s name, Delrin is actually the name of a plastic brand. The plastic itself is called polyoxymethylene, which happens to be a thermoplastic. It is relatively soft when you compare with metals and wood, however, tougher than ABS, making it an excellent machining material. Ever seen a  white colored gear? It is made of delrin. The plastic can also be used to make other objects like handles, guitar plectrums, toys, machine parts etc.

I was working on a CNC based project, and has to mill parts for the final product. In this post, there are only two milled caps. I will make another post on the giant flower-shaped hole in the middle, and the completed project in the future. So, for now, there is this video with royalty free YouTube music and some background noise. The video below shows the milling of delrin, using the circular milling method.

CNC and Machining, Creative, Engineering

Engraving Aluminum

I wanted to see if it was a good idea to engrave soft metals. Turns out, it’s a great idea. Not only is it easy, but also incredibly fast.

Even better is creating gcodes. In fusion 360, even though there is an option for engraving, it is not possible to use this with an engraving tool, because engraving is still considered milling by the software.

An easy way to get around that is by using the Trace option. And since I was using a simple sketches, it was extremely convenient to select the tool-paths. It is actually easy to engrave 2D sketches by using the trace option, rather than the engrave option. Engrave option is good only if you need a bit of a depth.

My choice of material was aluminum, and yes, they are dog tags.

This slideshow requires JavaScript.

I had to trace twice on the othermill because of the uneven arrangement of the material, yet it still took only about 25 seconds for each trace, i.e. both the sides were engraved in less than 2 minutes!

No, I did not speed up the video.

CNC and Machining, Creative

Tree puns

When I milled the piece of plywood and the sheet of aluminum, it was all to make this. I call it ‘Symmetree’, mostly because I like puns. You can see it etched on both the wood and aluminum. Almost everything in this design has something to do with trees.

The outer edge is a piece of laser cut acrylic in which the design is tightly fit. The reason why it looks glossy is because it has a few coats of polyurethane.

This slideshow requires JavaScript.

CNC and Machining, Creative, Engineering

Aluminum Tree

As shown previously, Aluminum is a relatively soft metal, and it can be milled easily. This time, it is  a 4 in. x 4 in. sheet of aluminum. I simply used a previous dxf file created for milling plywood, and reused the same gcode.

The process took only about 30 minuted to mill, and the output was clean, even though I had used a 1/16 in. ball end mill tool. Had I used a smaller sized tool, it would have been much more precise, but it would have definitely taken hours to finish the job.

Here is the time lapse video of the process. There is a bit of engraving at the end, but it is not very satisfying. I will make another one showcasing the engraving soon.

CNC and Machining, Engineering

Circular Milling

Aluminium or Aluminum is a relatively soft metal. It is light, but also durable, making it an excellent material to create useful parts for things used in everyday life. It had been a while since I tried to test different kinds of milling using Autodesk Fusion 360.

Fusion 360 has a really good way to create GCODEs for circular objects. It is similar to contour milling or profiling, but specifically meant to create circular or cylindrical objects with minimal wastage of materials.

I decided to make a couple of aluminum rings. Since a metal was being used to mill another metal, it was very important that the distance between each subsequent each step over was very small. Unfortunately, this meant that the process would create aluminum powder instead of swarf, and I had to be very careful while cleaning the OtherMill once the machining was completed.

Regardless, the finishing was beautiful and it actually did not need any extra polishing.

 

CNC and Machining, Creative

Milling and surface finishing wood

Wood is a beautiful material for milling. It is possible to mill any type of wood because of its relative softness when compared with the milling tools.

This time, I tried working with plywood. The unfortunate thing about working with a desktop CNC machine is the size of the spoilboard. Because of the thickness of the material, it is not possible to mill without using brackets, and this reduces the size of spoilboard significantly.

After laser cutting a 1/4th of an inch thick plywood sheet to a size of 4″x4″, I placed it on the spoilboard with a bracket. However, I did not use any double sided tape to see if the bracket would hold. And yes, it did hold the material in its place without causing trouble. Another reason for not using tape is because I did not want any sticky residue on the wood, as I was planning to mill both sides.

By this time, it is obvious that I’m still continuing to use OtherMill and Autodesk Fusion 360. I decided to get a DXF image of a tree and created a GCODE. The primary difference is the the tool. For the first time, I decided to use a 1/16th of an inch ball end mill tool (I also tried the same with a 1/16th of an inch flat end mill).

The ball end mill gave a better finish than the flat end mill. I have some place plans for this piece of milled wood.

CNC and Machining, Engineering

Can you mill floor?

It depends on what you mean by floor. The floor at one’s home is made of a variety of things: tiles, concrete, granite, marble, limestone, wood,  cork etc. Most of these can actually be milled to create beautiful pieces of artwork. Some of them can also be milled to make useful things.

Take linoleum, for instance. It is made from substances. These generally include solidified linseed oil, solid pine resin, ground cork, finely pulverized wood, and limestone, usually on a  canvas backing. An excellent use of these is to make stamps.

I simply created an SVG file, imported it in Autodesk Fusion 360, and made a CAM gcode file for the OtherMill.

Well, milling is fun. However, milling linoleum is a special case. The dust created from the milling is very much like powder. So it is very difficult to clean the OtherMill after the milling process is complete. This is also the first time I used more than one bit to mill the material, as some of the parts needed a finer milling tool.

This slideshow requires JavaScript.

Of course, this stamp is for display purpose only. The actual stamps will always be mirrored so that the text can be read once a paper is stamped.