Free Art

I see a lot of people in forums asking where to find free art for CNC because they either don't have the resources or they don't have the time. I've already shared one source earlier but heres some other sources to look. One of the first places I've found some decent designs is Microsoft fonts. Their free font site isn't up any more but there are plenty other font sites. So far I've found ninjas, leafy dingbats, old English designs, zodiac signs and many more. Best of all there are some free programs out there that can generate g code from text. The first one I used was Desk Engrave. So try blowing it up and making some bookends or whatever.

Another low budget solution for anyone with software that supports 3d figures is an abundance of free download sites for graphics design. Most of them are insignificant items like couches and fountain drinks but there is a lot out there. Try searching for "3ds download" in Google.

The best source however is to join a group like cnczone or mechmate where there are plent of people who are more than willing to share some of their designs. But remember with all of these, that your using someone else's work, so please get permission for more than personal use. Ill post some stuff I made from fonts later this weekend.

Delays

It's been a few days since my last post but I got sidetracked. After making two signs in a row without trouble I've been unable to make anything else without missing steps. So after using most of my wood I decided to try to put my old 12v PSU in series with my new 24-28v PSU. Looks like I may get to increase my feedrate but not before doing one more sign. For anyone interested this is how you hook up two power supplies together without blowing them. My new power supply stayed the same and the second already modified ATX supply had it's ground isolated from its case with some cheap plastic hardware.


Don't forget to test it's independence from ground and hook it up to a cheaper supply first just in case. If you see smoke you screwed up and need two more supplies. Then I just fed the 24-28v to ground of the modified supply yielding 36 -40vdc on it's previously 12v output. Looks like I'll be back to business tomorrow where I promise another post. price of this modification was $2.50 for plastic hardware. Old pc supplies are easily found for free in many unwanted computers.

Signs

At work a few weeks ago we had to label our doors for emergency personnel and such. So the boss went out and printed some signs with word and taped them on each of the doors. Thats all fine and dandy for regulations but not very attractive so I made these:



Much better! I have to give credit to Switcher from cnczone because my signs are a modified version of one of his. You can check out his site here, and in my links section, where he posts a great variety of vector art free for download, and well worth a bookmark. I gotta respect the people out there willing to share what they know.

I started off with a side of a birch bed frame That was hanging around for some time. Then I pulled off the nails and the bed slat shelf. My uncle was kind enough to plane it down for me to reveal a nice piece of wood. I made the signs in CamBam+ which you could also get a free version of. I erased the text in the original sign and entered my own with the text tool. For machining, I used an 1/8in ball mill for the border and a 90deg V-bit for the text. Then the whole thing was cut out with another 1/8in mill. Then I finished it off with a nice walnut stain. Pretty simple. Total cost of this project was about $4.50, the price of some stain. So go out there and find a hidden project. Mine started off pretty ugly so don't discriminate. Next time we'll talk about some basic tooling stuff.

My Pendant

When I first built my machine one of the first problems I encountered was an inability to easily access both the machine and its controls simultaneously. Buying a pendant was out of the question and microcontrollers are a pain, but luckily I recalled hearing about people hacking their old keyboards for custom gaming controllers back in the 90's. At the time I thought it must of been hard but now that I know better I got that old dusty keyboard out of the closet(I know you have one too), rustled up some switches, a prototype board, and bought a suitable enclosure at radioshack. And here it is:
































It plugs right into the keyboard port. I use an old laptop so a full keyboard is also accessible. You could also use a cable splitter. This project can be hardwired to control any function on any program that utilizes keystrokes. Heres a quickie Tutorial to get you started on your own custom controller:

Materials:

• 1 old dusty keyboard (will be cannibalized)
• assorted switches, mostly N.O. momentary contact
• 1 enclosure (buy one or use your imagination)
• old floppy disk ribbon cable or other wire
• zip ties, 1 rubber grommet, standoffs or insulating paper for metal enclosures

Step 1: Preparation

Open up that keyboard and remove the circuit board inside and keep the cable for later. You can see mine in the top picture. It'll have two rows of contacts on it, one for rows and one for columns. connect any one row with one column and wallah a key press. I had to lightly sand off some carbon for soldering. Now strip out two lengths of ribbon cable for soldering to the contacts(4-5in). I had 8 rows and 18 columns. Don't forget to tin the other sides of the wires. This takes a bit of practice and patience, but it all pays off in the end.

Step 2: Discovery

Now get yourself a breadboard and connect the row and column wires so each wire has its own track. Here's what I did. I marked the first wire in each length with a permanent marker. Then I downloaded a keyboard test program and made a table of each row/column combination by connecting jumpers between them and observing the results on the program. Now decide which functions you want to use and consult your table. If I wanted to press f6 I would consult the table and connect row 3 and column 8 (yours will probably be different). You can connect multiple switches at once but some may have unexpected results. For more info look for keyboard ghosting in Google.

Step 3 :Ratsnest

Once testing all my switch combinations, I soldered up my mess of wires on a protoboard just like on the breadboard. Then I drilled some holes for switches and finished it with some fine steel wool and acrylic spray. Now wrap it up in your enclosure, and pretend the inside looks as good as the outside. If you ever need a new function added on, get some switches and drill a new hole. I need to add a feed override switch to mine.

Tips:

• Keep your table for future reference
• label your switches
• insulate the inside of metal enclosures
• I have one non-momentary switch and if its on when I start my computer the keyboard wont work until I turn it off.
• rubber grommets and zip ties make suitable strain reliefs

In the Beginning...

Welcome. This site chronicles my adventures into the fascinating world of CNC (Computer Numeric Control). If CNC is your hobby too, then hopefully you'll find something of interest. If anyone does make anything featured here then send a picture or a link and I'd be happy to post it.

Let me introduce you to my machine:


I call it my money pit. For those of you who know something about CNC, my machine is a simple 3 axis setup with unused provision for a 4th axis, and travels a leisurely 24ipm. So far Ive been able to mill plastics, printed circuit boards and soft woods without a problem. Hardwoods and aluminum are not out of reach but don't turn out very pretty yet. I have some ball nose end mills in the mail so I'll post some project pictures after they arrive.

Anyone out there use Turbocnc? I'll post some pictures of my homemade pendant pretty soon and if people are interested I might start a site with instructions.