DIY 2X4 CNC Version 1

I had been quite excited when I found out about CNC machines and did a lot of research on them.  After a while I started to look at the DIY reports about people making their own CNCs.  While not the best out there it seems like making a CNC for wood carving out of wood was possible.  I let the idea sit for quite a while but have finally bit the bullet and ordered parts for my first attempt.

The CNC has four main parts, the software, the frame, the electronics and the spindle.  For software I used LinuxCNC.  For my frame I used v bearings and steel L brackets supported by 2x4 lumber.  This was driver by 1/2" threaded rod.  For electronics I grabbed a 3 axis kit from ebay (link here).  For the spindle I used my Proxxon rotary tool with 1/8" end mills.

The cost ended up being around $600, with half of that being the electronics package.  The v bearings were also quite expensive but I knew I could use them on other things if the CNC did not work out.  After a few weeks of cutting and putting things together I had a working CNC.

Now I knew starting out that I would either improve on this CNC or build a new one after getting some experience so I was not expecting the greatest accuracy or performance.  And my expectations were right.  While the cnc was ok in accuracy my linear rail setup was not the best.  Part of this stemmed from only having a few basic power tools and not being able to grind the rails smooth.  So the cuts on it tended to wiggle a bit as the gantry moved.  My choice of threaded rod gave it a lot of moving power, but the trade off was the speed was quite slow, close to 5 in/min which is quite slow.  I had no trouble with a small end mill but a full size router would likely have burning issues. 

 While far from perfect this CNC allowed me to do a few engraving projects that were small and worked well, as well as get used to using a CNC.  So after a year of poking at it I decided it was worth it to start looking as building a new CNC.

Looking back there are a few things that I would have done differently, the first is get better tools.  I was extremely limited in what building tools I had, (hand drill/jig saw/hack saw) so the frame and linear rails are very roughly built.  Now that does prove you can create a CNC with basic tools but the quality will suffer.  Second is making my gantry smaller.  I had some dreams of grandeur thinking I could have a CNC and 3D printer in one.  This is a bad idea and it will not work as CNCs are too slow.  A CNC really needs to have a gantry height that will just fit what you are working on, the taller it is the less stiffness you will have, which was a problem in this one.  Finally I would go with better linear rails.  I liked the v bearing idea as it is easy to extend if you need longer rails, but it just is not accurate and stable enough the way I did it.  I am thinking square tube embedded in a v channel in the wood would be a better approach, however I think i will go with SBR rail on my next design as I just do not think the tensioning on bearings is easy to work around.

The best thing about this whole project is that I was able to find good uses for a CNC and learn the software side as I used LinuxCNC with CAD software as well as some straight Gcode designing.  if you think you may want a CNC I would highly suggest going for a simple DIY version first, looking back a simple drawer slide version would have been cheaper and just as accurate if not better, but as you can reuse the electronics and motors a simple CNC will get you started and from there you can figure out if it is worth investing in a better CNC after that.

Destruction of Wood Playgrounds

I remember the joy I had running climbing and of course falling all over the large wood playground at the first house that my family lived in as a child. It was a huge structure, covering easily a hundred square feet and must have reached thirty feet high at the tops of some of the spires. I loved the ability to explore and climb anywhere I could, and a game of tag was filled with intense ducking and running through holes or quickly climbing to the next platform to escape. Even the smaller simpler wood playground at the second house had plenty of potential with climbing and swinging. However if you look around, these places are vanishing at an alarming rate! Where are the colossal playgrounds of old, I can't even find a picture of the one I played on as a kid!





Now everywhere you look you have cheap tiny plastic structures! While kids will find way to play on anything, these lame (safe?) replacements lack the creativity and imagination of true wood playgrounds that pushed the imaginations of past generations. Look below vs. above and just try to argue otherwise!




I can understand the desire to protect kids now a days, however there is no reason to protect them to the point that there is almost nothing left. Kids need to play and fall and hurt them selves, it is called growing and learning. My parents did it, I did it and if I have kids some day I want them to have the same chance to grow and play. (Hm, could this a source of the obvious lack of common sense in this upcoming generation...) Still ignoring the danger of gravity you still get the whole arsenic levels in wood debate, though it is a naturally occurring substance. (Via Wikipedia)"In addition to the inorganic forms mentioned above, arsenic also occurs in various organic forms in the environment. [15]" However, what I can not understand is why completely destroy what could be considered national treasures, when they could easily plan to slowly replace the "supposedly dangerous" pressure treated wood materials with newer recycled alternatives. Lets face it, plastic is not all that healthy either, but that is a debate that is going to rage on for some time. So school and town administrators, instead lets agree to compromise, if you are planing on removing a playground for what ever reason, you better at least replace it with an equal or better structure! Otherwise you have officially neglected each and every kid that will play on it.

Custom Projector Mount

Continuing with my attempts to improve on our family home entrainment system, after getting a very nice and almost too big projector screen, I had to figure out a way to ceiling mount the projector. However it needed to be not permanent and easy to remove. So off to the drawing boards I went, and after brain storming and coming up with a few concept sketches I had my design all worked out. Luckily the living room has pseudo support beams, not my family's decision they where here when we bought the house. I could use the one that was near center with the screen as an anchor point, and then build a brace around it that would hold the projector up. Later I went back and added extra sheet metal for preventive safety measures. It works quite well, and even better, this means no more coffee table alignment every time we watch a movie!

iBook Photo Frame

After fixing an iBook, my next plan was to change it into a digital picture frame. This is something that many people have done with every old laptop you can imagine. So I took the stripped down iBook, and completely disassembled the lcd screen, down to just the panel, and took some measurements for a frame. The closest frame I could find to the screen size is a 8.5 x 11 inch with a nice looking border. The screen fit well in this, but it would need a bit more room to fit the rest of the iBook. So a box that fits inside the frame was made and attached with screws to the sides. Small wood dividers hold the lcd in place, while adding some space for air flow. I also cut out the holes for various connections, air vents and for the optical drive. It all just perfectly fits snugly inside. The back cover is attached to the sides of the box by small blocks of wood, and puts some pressure on everything below it with. All it needs a quick paint job, probably black to match, but that is for another weekend.

The end result looks amazing. Another successful project, completed!

DDR Pad Revision 4

I like playing stepmania which is DDR for the computer, however playing with your hands is just not the same as feet. So I set off to build a pad for the computer, and several revisions followed after getting the first one working. Now I finally had a chance to update the DDR pad at home to rev 4.

To sum up everything before this,

Rev 0: was two tin foil covered squares of cardboard with some foam between, it worked but not well. More for the proof of concept and to get a USB IC controller working .

Rev 1: was 9 pieces of colored acrylic sheet held up by rubber and screws on a 3x3 foot piece of particle board. Between them where strips of metal tape which acted as the conductor and switch. This actually worked extremely well, and lasted a full year, with a little maintenance here and there. I later added black tab to hide the gaps between squares.

Rev 2: was a solid piece of acrylic and a piece of plywood. The top contacts rested on metal foil contacts in the center so no wires where used to actually connect the top. Much more sturdy, and was easer to maintain because the whole top lifted off instead of having to remove 9 squared with 4 screws each. This also lasted a year, but tended to break more easily.

Rev 3: Took the same design to the next level and placed solid copper wire in a grid on the bottom, epoxy was used to hold the wires in place. Now the bottom contacts would not need replacing like metal foil tape did. Sadly it tore through the weak top foil in a matter of minutes during testing. Rendering the pad useless.

Rev: 4 fixes this by having solid aluminum sheets on the top under the acrylic. Also wired clips now connect the aluminum contacts, thus always giving a good connection, yet letting access and maintenance continue to be easy. The metal was adhered by a special "for plastics" silicon. So far after a good amount of play by my self and others it looks like this might be the best revision so far. Unless the plastic cracks or the metal contacts fall off it should be nearly indestructible! I should have gone with solid metal conductors from the beginning, but it was a learning experience.

Wood iPod Touch Case

My first iPod was a 500Mb shuffle, and after getting it I quickly went to work making a wood case, which was rather big but still worked out well. Now that I have a new iPod it was time to get to work on a new wood case.

I started off looking for two good pieces of wood that where about the right size. After selecting two pieces I had the dilemma of how I would carve them out to fit my touch inside. In a previous woodworking project I made a scabbard for a sword, the task was long and tedious in which I carved out an indent with a chisel. This was a little different because I was not working with hard woods and this had to be cut thin. I pondered this for a while until I remembered how my Dad had cut a grove out of plywood for me before. I could drill out the area I needed. Using a 25mm Forstner bit I very carefully remove from the two piece of wood the space that was required, and then drilled through the thinner of the two in a few places to make my window. Later I also removed the spaces for the charging cable and for some headphones.

Then all that was left was a lot of filing smoothing with sandpaper. The two pieces of wood where not the same size to start so I used a rasp and carefully brought the two pieces to the same dimensions. Then using a course sandpaper I smoothed out all of the differences in the edges. Finally finishing with a fine grit to smooth everything. Now that everything matched up I glued the two halves together and let it dry over night.

For finishing I used a rich early american stain. I wanted it to be dark to match the touch's black color. Then gave it three coats of finish to protect the wood from the handling it will be receiving. The last step was to glue to the insides a few thin strips of fabric. This is to protect the iPod Touch from ware when sliding in and out. The fabric also helps put a little pressure on everything so my iPod stays inside the case, even when pushing the headphone plug in.

The best part of this case is that it is thin, about the size of the touch itself not including the space in between. The big complaint that people had with my original wood case was that it was too thick. Now with this wood case that is not a problem, in fact the little extra width is better because it is easier to hold in my hand. All in all I am very happy with the outcome.