Making the stable connection

 Its like one of those movies that starts with the ending scene. I put together a "Shield" for the Boarduaino to connect the motor drivers. Now its one step further away from looking so ghetto. Unfortunately one of the shafts of the steppers is slightly bent. Its not something I've noticed before so I'm pretty bummed. Never the less I'm hoping that its not enough to matter with helical cut motor couplers. 

I'm weird about symmetry so three motor connectors just wouldn't work. Which is cool because I have four stepper drivers to. Maybe one day Ill incorporate a fourth axis. For now its just a spare connector on the proto board since there's no designated pin for a fourth axis in the GRBL config file.

 There are 4 pins required to run each of the stepper drivers. 2 ground pins, a STEP pin, and a DIR pin. Its complicated to route the wiring on the bottom of the proto board without making it look like a rats nest. A finger nail clipper makes a great wire cutter. Its easy to handle and if you have a hang nail its good for that too. :-)









Here's a picture of the final wiring on the underside of the proto board. It's all pretty close but there's no shorts. The wiring will be hidden in the end when the whole thing is mounted in the computer case.

Hopefully Ill get a chance to connect this all back to the table later this week. Ive got some finals and a proposal to give to the Biosystems Engineering Department. Here's a couple pictures for you interwebians.

Trying to revive the dead.

As an engineer and resident nerd, when a piece of electronics breaks the first thing that comes to mind is can I fix it? I've managed to bring a sound system back to life with a single capacitor. Actually I met a guy while working at Radio Shack that was buying LCDs on Craigslist and fixing them by replacing capacitors on the main board.

So when my router stopped working I decided to crack it open. Netgears routers are simple to take apart if you have a set of torrix bits. There are four screws under the feet. Typically these feet are glued in place but it seems that Netgear may reuse these shells or repair them often because the feet are hinged rather than stuck in place with an adhesive.

 Looking at the internals, its pretty easy to look around. There's no metal covers hiding anything. Everything is open for the pokin'....Sorry. Ill never say that again. Anyway upon inspection I saw that it indeed had a blown capacitor. The green one on the left had a bulge in the top of the canister.





This gave me an opportunity to play with the macro setting on my Nikon D3000.  Enjoy the eye candy. It hard to tell its blown without comparing it to the brown cap beside it so I took a picture with both of them in the frame.

 You can see how flat the one on the right is. Its almost convex compared the blown capacitor.
Radio Shack is way overpriced on parts but the convenience of being able to go down the road and pick it up the same day makes paying 1.49 for a single capacitor ok. Its slightly larger than the original cap due to the fact that it has a higher voltage. When dealing with capacitors you can substitute one with a higher voltage but its important to keep the farads the equivalent. They balance the impedance of the circuit as well as other fun stuff.

So after all this did it work? Sadly it did not this time but it did give me a good reason to upgrade to a N router. It also may provide some useful spare parts in the future. There's several SMD LEDs, resistors, and other junk that could be salvaged with the aid of my high tech solder reflow system (an electric skillet). For now I'm going to keep it intact just in case I come up with another idea to fix it. Drop me a line if you have any clues.

Placing Random QRcode on walls!

HEY! Thanks for scanning one of my secret QRcodes strategically placed around UT campus. You are now one of the elite few that will be counted in this social experiment. Years have been added to your life. I swear.

If your interested in electronics and CNC related projects feel free to check out the rest of my blog!

Hope you enjoyed the link! If you're interested in making your own QRcode you can visit some one else's website.


http://qrcode.kaywa.com/

Oh, and feel free to comment on where you found the QRcode placed. I gave several to friends and told them to spread the love.

Steve-O

Mechanical Portion....CHECK

The CNC has a method of travel now! I finished up adding the power-train components I picked up a couple of days back. I'm pretty excited about that. The X and Y axis are pretty smooth. The Z axis is slightly rough to turn but this may be to the weight of the carriages and router plate. I'm afraid that the motors that I have wont be able to work that axis. We'll see when we get there. For now, we celebrate the victory at hand.

Now I'm going to make you quit being lazy and read from the other side of the screen.

A small list of items that will need to be acquired is growing as we move forward in the project. First is a table surface. A simple half sheet of MDF should do the trick there. Next is a router mount. I haven't decided on what I'm going to use for a cutter but its going to start out small. I have available to me something about twice as large as a Dremel but half as big as a typical router.  Its my dad's. This will most likely be the starting implement due to it's weight.

The next chapter of the project begins today. The electronics section of the project will be executed mostly in my lab (AKA a small room of my house I clutter up with my junk) . I've dug out the hardware that I was preparing for the previous iterations of the CNC. It was like digging for fossils. I had to blow the saw dust and metal shavings off of it with compressed air. As I've mentioned previously the brains of the setup is a Boarduino with an Atmega328. That's now running the latest version of GRBL. Version 0.6. Fortunately flashing GRBL to the Arduino was much easier this time. Used to be you had to compile it from scratch and then run a string of commands to get it to flash onto the processor. Now you just load a hex file using the Hex Uploader found here. It seems that if I was booted into UBUNTU at the time I was doing this that it might still be as hard as it used to with the AVRDude commands and what not. If your forced to do that and get hung up I have instructions on my old blog at www.stevetotheo.weebly.com.  Things may have changed a bit over the past couple of years but the idea should be the same.

Where am I now? So far I have repaired one of the broken Reprap drivers that ended up with a damaged connector early in the process during my last attempt at a CNC. I built four because I fully expected one to not work since it was the first time I had ever ventured into the world of surface mount soldering. It turns out not to be as hard as people make it out to be. All four turned out great and working. Back on topic. I have a working boarduino loaded with the latest version of GRBL, four working v2.3 RepRap stepper drivers, and a modified computer power supply unit to run it all. Things I need. I need to run back and grab one of my stepper motors to test each of the driver boards and get the wiring to a more permanent stage. Then I need to mount it all up, find a test Gcode file,  and hope that the motors are beefy enough to do the job. So that's the plan. Ive got 47 days to finish this up and at this point I am on schedule to meet the goal! Tomorrow its back to the daily grind of school and end of the semester Senior projects. 

A home of its own.

Well, I finally got the spare cash flow to order the rest of the power train components for the CNC. I picked up the couplers, shafts, and collars from Ahren at CNCrouterParts. That dude is fast. I emailed him a question and within the hour he had replied. I ordered the gear from him and it was at my house 2 days later. He is legit and a great person to do business with. I also got some astounding service from McMaster. I ordered the ACME rods from them and they were on my door step the next day. Crazy stuff compared to some of the other troubles I've had in the past from other companies.







I went over to my Dads shop to get to work on the power train and ended up building a rolling cart from random scrap pieces of building materials he had laying around the shop! As you can see I've found out you can post pictures beside text. So enjoy this new feature! Any way. There it is. Its held together with what I would call sewing needles (air-gun "nails") and glue. ;-) Its on wheels so its easily movable and once I cut some slots out in the faces of the cart it will be able to hold the electronics pretty well. Unfortunately, building this also means that I didn't even touch the CNC other than to pick it up and put it on the cart.  With classes coming to an end I'm going to have to hit it hard to make some free time to finish this up.  As I sit here and type this post Ive got 52 days 10 hours 40 minutes and 5 seconds...4 seconds...3 seconds... Its coming up on the CNC deadline.

That brings me to my next point. What is finished? Where is the line? I'd like to define that. The end goal is to have a working CNC machine....and something cut from said machine. I want to start the 2012 with a working tool that can be used to take a drawing and translate it into a physical piece you can hold in your hand. With the current hardware I think I'm going to be limited to circuit boards and 2 dimensional objects  due to some of the limitations of my driver setup and the gcode interpreter. We'll have to start there.

What's my hardware setup? Fair question. I think I may have alluded to it in the past. Its another DIY project I did in the past. Its troublesome...its unreliable, Its even ugly but I built it. Its a trio of reprap driver boards that I learned to make using solder paste, surface mount components, and an electric skillet. Yeah it worked great. Really. Anyway the thing is that there's a bunch of wires coming and going from each of the drivers to a boarduino (also a DIY project. First thing I ever soldered). It needs to be cleaned up and wire managed. Currently its all mounted in an old PC case. It ran one of the previous CNC machines I attempted. When I say "ran" I mean that very...very...very loosely. I was able to feed the boarduino a single gcode command through a terminal and it would execute it. Above that things would go wrong instantly. There were timing issues, wiring issues, and above all the screws were just that. They were threaded rods from lowes. The would bind and get all kinds of messed up. Ill try to pull a picture of the one thing I cut with it. Its just a couple of lines in a piece of MDF. I use it as the picture for my Dad when he calls my phone. He takes time out of his life to help me with these projects so I figure he deserves that.

Moving on past that learning experience. This time I have real ACME rods and legit hardware. Things such as helical couplers and thrust bearings.  Things that I couldn't afford back in the first two iterations of this project. Ill end the post with this.

Precision isn't cheap and no amount of engineering and creativity can be substituted for a well designed part. Sometimes you have to bite the bullet and buy the $20 dollar couplers or the $30 dollar carriages rather than trying to engineer your own.

Steve-O

Ardunio GPS on the CHEAP

I'm still waiting on money to get straight before I go off and purchase anything else for the CNC. I've got about 300-400 more to go on the table and then Im going to have to figure out the electronics I've already got. I'm sure they are going to need repair and Ill have to navigate my way through the software. That's all for another day.

I get antsy when I've got nothing going on in the project realm so I went ahead and spent 20 bucks on a Pharos 500 GPS. Its one of those stamp sized units that came with Microsoft's streets and maps software...I think. Anyway I've got a couple Arduino Mega 2560 boards and since the 500 natively outputs in a serial fashion it was easy to communicate with..

I say easy but it took me some tinkering. The mega has several serial communication pins and if you hook the GPS up to the main one, it trips up the Arduino on start up. So you have to (well I did, I dont guess you have to) unplug the GPS and then plug it back in after you get booted up. The solution to this is to move to one of the other serial pins and just edit the code. Ill post a follow up with the modified code and a picture of the modified receiver.

Modified receiver? Yeah! That's how its done. Everything Kuztoms! No for real I had to break it open and solder pins to the board to make it bread boardable<-- Spell check says Im making that word up].

All in all the project has been a success. It was relatively cheap and  filled that whole in my boredom. So check it off the list. Where can I go from here? I'm thinking a reverse geo-caching project but that will have to be another day.

Competition motivates me!

I wasn't planning on working on the machine today but I was inspired by one of the other members on CNCzone. KriegKuts is in the process of building a FLA-100 as well. Dude's Build Thread can be found at the link provided! The rail system I set up to drill the holes for the X rail needed to be modified for the 6 inch Y rail. Basically instead of the small bolts and wing nuts I had to use a C clamp. Not as elegant but it worked. Today I didnt have the help of my dad so having a plethra (<---Nice word huh?) of C clamps of all shapes and sizes to hold the rail as I drilled it. I skipped the mid size bit this time and went straight from the center bit to the 3/8 bit.

 

I was going to stop here for the day but then I realized that the Z axis only needed 6 holes to be mounted. I didnt trim the rail or the supporting 8020 extrusion so pretend you don't see that. As for going straight to the 3/8 bit.

 

 

You can see it turned out fine. Im sure it shortened the life of the bit but after today Im done with it and its paid for itself. I bought 2 and only needed 1. That means Lowes gets to have one of their nice $11 kick ass bits back Im am so amazed that Im able to work with raw steel and get precise enough results to even slide the rail into the extrusion. 

Without adjustment of anything I checked the height of the bottom of the Z rail on both sides. Less than 1/16th of an inch different. Thats nuts. Now Im off to check my bank account and see what I need to do to pick up the power components.

$310 plus shipping. Ouch. But that's all that stands between me and moving on to the electronics....which Ill be salvaging from my last build. Arduino + DIY Reprap drivers + some creative thinking. Thats the teaser of the day.