Pictures!!

Here's some pictures of what I have finished...

(Below) A closeup of the front bolt on rail holder. The pipes were threaded so I just screwed them in this end.

A closeup of the rear rail holder. I added some set screws on this end to hold the rails secure. Both the rail holders were carved on the first machine so their almost perfect.Linear slides I made from mdf(also cnc'd) and soaked in epoxy. They turned out pretty well but I might remake these out of oak when I'm done. While I got the first few oak pieces cnc'd I couldn't get these made quite right.
another shot of the assembly.
I have one more cross piece drying at the moment that connects the two slides and holds the nut for the leadscrew. Then the table top just bolts on top with some barrel nuts to hold it all square. I also plan on replacing the X-axis rods with black pipe. They bend way too much with any signifigant cuts which is why I've been having so much trouble making new parts. With any luck I'll be finished in a few weeks.

Chuck's CNC Rebuild: Part 2

So I haven't posted in a Loooooong time. Being busy with school and all I didn't do much lately accept start part two of my rebuild, the bottom half of my new machine. I have to admit, I have more fun working on it than using it. Doesn't that seem backwards?
I built this part mostly out of oak just like before with 1/2in. black pipe for my linear rails and a few temporary parts that will later be properly made when I get it all together. While I liked the adjustment blocks I used for the X-axis I'm trying something new for the Y-axis. Instead of holes or rail supports on the frame I just added some bolt holes and the actual support pieces were made on my machine and bolted on.
Since I'm having rigidity problems I made some of the smaller parts from MDF instead of oak and soaked them in some 2 part epoxy. Now they don't swell with the humidity and don't mushroom when I drop them. I'm going to remake these later after I fix the rigidity problems (reason for my rebuild). I'll have some pictures up hopefully tomorrow.

Chucks CNC Rebuild: Part 1

Well I finally have my machine rebuilt and I'm pretty happy with the results. So far I've replaced the MDF x-axis supports with oak and shortened the z-axis to hopefully help reduce some vibration problems(It was too tall anyways). I've also decided I like lovejoy couplings better than my direct coupling I used before. I'll have to do some research into power transmission and see if it really makes much difference. If anyone already knows then please leave a comment, I'd love to hear some opinions. I also added some aluminum adjustment blocks for the bearing slides. Using a cheap indicator dial I was able to adjust either end of the lead rod within 0.001in which was something I was previously unable to do. I was thrilled, then I remembered the bearing slides flex a little so I measured without changing my setup and you know what it was?.04in difference!! Keep in mind this is with respect to a level board clamped to my table which I'm fairly certain isn't 100% flat. Regardless that will have to go. I plan on changing my bearing slides from 1/2in to 3/4in. I'll do that next along with all new oak parts for the x and z carriages. Despite my disappointment This is a big improvement on the rigidity and adjustability front. I should be able to handle some higher cutting speeds. So whats next? I'm gonna make some stuff. Namely some new parts over the next who knows how long. I have a small laundry list of upgrades for the future:

1. A new QUIETER spindle that can hold 1/4in bits
2. emc2(I use TurboCNC now)
   
3. a vacuum setup instead of just blowing air
4. 3/4in x-axis bearing slides
5. oak z-axis parts(I already designed these in CAMBAM)
6. new, more rigid y-axis
   

Between Projects

I've decided to share some of my project files as I go. Here's the resulting file from last weeks chinese font experiment. I'm planning on cutting out some coasters from it tomorrow. Right now I'm in the process of replacing some of the MDF parts on my machine to red oak and adding some mechanical adjustments I skipped during Version 1. I'll post pictures when I'm finished. Might take me a while though. In the meantime I've ordered a copy of CorelDraw for my next project. My grandfather was a brilliant artist and carpenter. He kept detailed pictures and diagrams of everything, and when CorelDraw arrives I plan on scanning some for use in CNC. Results to follow either next week or week after depending on how fast it arrives. And please take the time to vote on my survey, only two days left and I know I have more than 3 readers, your feedback is much appreciated.

Back In Business

Well I finally got my machine running again which means more posts every Sunday for now on. Sorry to all for taking so long but I plan on making up for it. I've upgraded from mere threaded rod to stainless steel. I should have much better accuracy thanks to my cousin Matt and for under $100; Not too shabby. I should have some fun projects coming up including another go at box joints.
In the meantime, I've found a fun new resource, this time for machine designs that might as well be art. I was checking out The Steampunk Workshop which has some interesting stuff from a time when technology worked with a bit more style and sophistication. Thats when I noticed this. A site with tons of interesting mechanical devices some of which are accompanied by cad files (SolidWorks?) for creating your own. I just need to covert them to something I can use with CamBam and you'll see it here whether it works or not. Plan to make your own? Post a comment, I'd love to see it and so would plenty of others.
I'm back and I'll see you Sunday with a last minute and ill conceived plan to make something interesting and completely useless.

Update

Sorry, I haven't posted in a loooooong time. My free art bookend turned out OK, but I also experimented with box joints to join pieces which didn't work out so well. I'll try again later. Anyone have any suggestions? In the meantime my cousin is helping me out with upgrading my lead screws so my machine will be out of commission for a while. While that's being sorted out I've begun a new robotics project based around a linksys router but thats a subject for another time. I'll post a link when I get a site up.

In other news I'm considering making my updates more regular, maybe weekly and slightly longer. Not sure which day though. I'll revisit that later.

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.

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