Finally

It’s been a while. The first unit of Virk I has been finally finished (more than a month ago, indeed). There’s a fourth working axis now and I’ve polished my modified Marlin version.  Currently, I’m working on a simple python program to implement some simple tasks using OpenCV. Here’s the video.

The python software runs on a computer with a webcam, and the perspective transform is used to convert camera coordinates to robot coordinates. This implies a previous calibration process using four points. Eventually all this stuff could be, as far as I know, run on a RPI, thus avoding a full computer on the chain.

I’ve been decided to postpone the Open Hardware thing, as there’s really no interest, probably because the trend today is to 3D print arms, and milling is too overkill for most people.

So what’s next? I’m not sure. Maybe I’ll finish the other units and just try to sell them. Or I could make something else with all those robots. To be honest I will love to open a place with robots and cnc machines, where people can interact with robots and see cnc machines in action. A place to learn and have fun. Or maybe I will start to make and sell just some simple crafts. Who knows.

Currently, I’m competing on several local entrepreneurship contests, searching for a business plan, talking with people to get feedback, etc. In a few words, I’m going outside the shop, into the real world. Any ideas about my new direction now?

 

 

 

Wood clamping

I’ve been making a lot of wood parts lately. Here, I show the three main ways I use to clamp the wood.

Long stick on vise

This is easy.

Pros: Low setup time, great for series.

Cons: Final cut-off should be carefully planned.

Disposable wood support

This is my favorite. You  just glue a piece of “decently” squared wood to the base of your blank, and use it to clamp to the vise. After machining the top and the sides, you cut away the base block and machine the underneath.

Pros: “Indexable”: you can use a vise stop so you can put your part on exactly the same position several times. So, if you have a lot of parts, you can make a round, use one tool on every part, and do another round with another tool. Of course this only have sense if you don’t have an automatic toolchanger.

Cons: Setup time: you need to cut a piece of wood squared enough, and glue to your wood. Also, if you make “rounds”, re-clamping can time consuming and, depending on your setup, prone to positioning errors.

Base block and screws

Here you machine a piece of wood and use some screws from below to secure the part. The block itself should be bolted to the tooling plate (or held on the vise). If your part has some straight holes you can look for a wood screw that thread on that hole without damaging it. I use this method for a second step on some parts clamped on previous ways (you can see the remaining of the disposable block on the back of the picture). This is the method I’ve used on my last video.

Pros: You can get a very precise positioning with the proper setup (e.g. using index pins). You can also clamp several parts at time.

Cons: Making the base block can be time-consuming. Also, you need holes where you screw can attach to, or you would need to make some holes on your part if you don’t have enough or appropriate ones.

As a final note: wood is a nice stuff to work with, but you should be careful and plan ahead your cuts to avoid tear out.