To enable further projects, I decided a while ago that building a CNC router would be a great idea. This would allow me to cut wooden bits for projects and engrave circuit boards. It also features metal pipes and skate bearings for the linear rails, which are simple and cheap but subject to slight flexing under load. Still, for a cheap home built machine, this is not too much of a problem. The other parts I needed were:. You are commenting using your WordPress.
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I have been looking at a bunch of web sites about CNC and its related functions. You can find the same plans and follow along with my build progress by going to CNC Zone and downloading them from the downloads section. If you need Acrobat Reader you can get it free from Adobe's Website.
You can also get the plans as zipped DXF files from there as well. The image you see to the left was obtained from Thunterman's website and shows what the finished machine should look like. I would encourage you to take a look at Thunterman's website, you can see pictures of his machine and video of it's first cut.
If you have downloaded and opened the plans you will see this is the first page. When I looked over the plans, I thought I would start with the router table the Y axis and work my way up, but after some reading on CNC Zone I decided it would be better to start with the Z Axis the part that will hold the router and work my way out. I decided to take this approach so that if there are any differences in measuring, I can adjust new parts to fit the ones I have already made.
To start out, I took some graph paper and went through the plans and laid out all the pieces I would need to build the router. If you are uncomfortable with this process, It has been done for you in a post on CNC Zone along with a piece of software that will help you with the process.
You can read about it by going to this thread on CNC Zone. Getting past First Cut Fever - When I bought plans to build a boat from Stevenson's Projects, I also decided to buy the video to help me decide if I was up to the task.
One thing they talk about is First Cut Fever. That is the feeling you experience right before you start the project, not wanting to mess it up you get a little apprehensive about making the first cut. And I expected to. I have never used MDF before but I have to admit, it is really easy stuff to work and that is saying something with my limited wood working ability. One thing I feel I should point out is that when you cut MDF the resulting dust is very fine and gets on everything.
I would cut outside if weather permits and make sure you use safety glasses and a dust mask. It is always better to be a little over safe than sorry! I think I will start with some simple pieces that will not affect other dimensions first. I decided I would start with the Y axis pipe rail supports first. Surprisingly they come out pretty good. This left me with a nasty ragged edge on the bottom of the block. The next one I ran the bit through just enough so the tip of the bit would poke through the other side, then flipped it over and finished up.
It is over sized by. After drilling a tapping the four outer holes I soaked the threads down with Super Glue to help strengthen them. The only difference is that they are a little smaller. Instead of being 2. I will do these next just to have them done.
I finished up the X and Z axis pipe rail support blocks. These were made just like the Y axis blocks above. I was surprised how long these took to complete, well at least until I thought about it a bit.
So I guess it should have taken a little while. I do want to mention something about the super glue. Super glue is a respiratory and eye irritant. Breathing the fumes can be rough on you.
I find it best to follow the recommendations someone made on cnczone, take them all outside, sit with a breeze to your side and glue them up. I done these blocks in my kitchen and by the time I was half done my eyes were starting to burn pretty good. Just something I wanted to pass along. Well I can think of nothing else to waste space by this picture so I will move on. Next I decided to work on the Z axis. My thoughts for doing this was that I would be working from the inside of the machine to the outside.
This way if there were any discrepancies between my z axis and JGRO's I could compensate by moving the holes a little bit in the x axis if need be. This picture is the front of the Z axis. Notice that the router clamp has not yet been fabricated. I cannot decide what I am going to use as a router for this machine.
I still have to get these parts. Finally here is a shot of the side of the Z axis assembly just for completeness. I will most likely be starting on the X axis parts tonight if I have time.
I am starting to get the bug to get this project rolling along a little faster than what it is. After looking at so many homemade machines across the Internet and at cnczone, I am itching to make my first cut. Thanks again Bob from Bob's Metal Casting for giving me some direction and some courage to start a project of this magnitude. Be sure to stop by once in a while to see where I am at on the project! Have fun. I did manage to find some skate bearings and attach them to the Z Axis bearing supports.
I thought I would include a picture so you can see them attached. I was surprised to discover just how smooth this arrangement slides. Getting the bearings has spurred me to do more tonight. I started on the X-Axis. I have the X axis platform and the X axis top plate finished. I am hoping that I can get a little more done tomorrow night. I think as long as I stick to my theory that a little work on the machine frequently will get more done than a lot of work infrequently will get me done with it sooner holds out I will be fine.
You know how it can go sometimes, You get engrossed in a project and then near the end life has a way of jumping in front of you and making you attend to it. I will try to post a picture as soon as I finish the X axis bottom plate. All of the X Axis parts have been cut out and any holes that needed threading have been threaded. I still need to super glue the threads and make the bearing slides for the X axis before this part will be done.
In all truthfulness, I probably should have been finished with this assembly by now but I got side tracked. More on that in a bit. For those of you following along with the plans in hand, you will notice that the bearing hole for the lead screw has been piloted and nothing else. If I make another machine I will go for better hardware for lead screws at that time. A lot of research time and energy went into deciding what to do about controlling stepper motors.
I played with a bunch of circuits ideas and even built a couple. But the more I learned about controlling steppers and the circuits that do that job, the more I moved away from building them myself. I need to confess a little too, Bob from Bob's Metal Casting told me right up front to just buy a controller and be done with it. I should have listened as it would have allowed me to be further along on the project than what I am now. Next time Bob, I will try to listen a little better! The next best thing to do is drive them with a circuit that senses current and will turn the voltage to the coils on and off to maintain a predefined current level through the coils known as a chopper circuit.
Then if you need more resolution you can microstep but that requires more circuitry. Well to make a long story short, I think you can buy a kit and build it cheaper than you can fetch the components and make the circuit board for yourself. Not to mention, de-bugging is simpler. There are quite a few kits available through the web to drive stepper motors. Some are better than others, some are capable of driving larger motors. I chose HobbyCNC's 4 axis controller board because it was affordable and met the requirements of the motors I had on hand to use.
I am not advocating them as the best controller available. I urge you to check around and get what suits your needs for your project. That aside, I soldered the board up Saturday. The instructions are clear and concise. Here is a picture of the completed board in it's temporary mounting. Now that the controller board was complete I needed a power supply that would be big enough to drive a couple of fans and 3 or 4 stepper motors.
I had a couple of options as far as power supplies go.
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