Saturday, October 22, 2011

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.

Sunday, October 9, 2011

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.

Saturday, October 8, 2011

X Rails and Ganty assembly

Its days like this that make me proud to be a DIYer. Drilling the holes for the rails was much simpler than I had anticipated! I also noticed that CNCRouterParts just put out a jig to help people do the drilling. My dad owns a lower end drill press from Harbor freight. It works pretty well but you can tell it has a noticeable amount of play in the chuck so every hole has a small amount of variation in it.

In order to avoid compounding the variability I took extra precautions to ensure each hole was as close as possible. It worked out really well this time and I saved a good amount of cash by drilling the holes myself rather than buying the rails pre-drilled from FLA (not to mention the time I would have spent waiting for them to be shipped and get here )

For those of you willing to take the venture into making your own rails heres what I did.

Set up a guide to make sure your at least the same distance from the edge each time. I used a small piece of aluminum angle I picked up from Lowes  Use a center bit or a counter bore bit to start a small pilot  hole. Use some cutting fluid with every hole you drill. It makes things go so much butter. lol not really but it did make a big difference. After you have each of the holes started, move up to a drill bit about half the size of the final 3/8 bit your going to use. Any thing will do, just make sure you use the cutting oil. With this bit you can either go all the way through or only partially. Both are good but we found that not going all the way through helped to hold the cutting fluid when you move up to the final 3/8 bit.

Here's a couple pictures of the setup I had going on the drill press. It worked really well.

Once all the holes are cut it all goes together like seen in the drawings. An interesting side note is that the assembly forum post that I mentioned

Yeah that one. It shows him placing the carriage bolts on the 8020 and then tring to get the rail to go on it. That seems really difficult so I just put a bolt and nut in each of the holes and slid the rail into place. It only took a couple minutes. One of the legs was a wee-bit (sp?) close but in the end it all worked out.

That's all I had planned on doing today but I finished pretty early in the day so I got to throw the gantry together. That was much more complicated. The 3030 extrusion is extremely hard to drill through in a straight line. Even when using a jig made from another piece of 8020 I was typically not perpendicular to the piece.

Getting to this point never loses its appeal. Being able to push the gantry along that x-rail is the first pay off you get in a CNC build like this. This time I plan on cutting something. The original machine I tried to construct out of MDF never made it past the gantry push stage.

This machine is without a doubt the most sturdy machine I've attempted to construct so far. I feel confident that it will withstand the abuse were going to put it through.

Ok so whats next? Next I need to drill the holes for the Y rail. Mount that and the associated bearings. Drill the Z axis rail and mount that plate.. Then comes the hard part.... Finishing. Ive got some power train parts I need to order but that going to wait until I get the table assembled.

Sunday, October 2, 2011

One step closer - Base Assembled

Here is a couple pictures of one of the more beautiful things I have made. Alright alright. I didn't really make that. I assembled it. A lot of work went into it to get it from the raw t-slot to its current state. Its incredible how many times you have to take that thing apart in order to fit everything and then you realize that something else needed to go on there so you have to take it all apart again
Extruded Aluminum CNC frame

Extruded Aluminum CNC frame
Next task is to drill the hole in the x-axis rails. That's going to be a long hard task to do in a steel rail.