Cutty Shark I

[LeeWay]

Okay Guys. Its time to get busy. Since I first knew that I had to have a CNC router just a mere few weeks ago (Thanks CNC Zone) I have gobbled up as many different designs as I possibly could from here and elsewhere on the web.
I also took note of the items that I have on hand and developed a design that I want to use for my initial setup. Design has changed several times even after buying some of the materials that won't be needed now. I can see that it might pay to get the design down on paper first.
I make blade guards for tablesaws. The guards are called Shark Guards. Ergo the play on words with the name of this machine.
Anyway, the Cutty Shark I will mainly be for cutting polycarbonate and thin aluminum sheet. I have the basic frame parts already, so these dimensions are what I am hoping for. X axis = approximately 36". Y- axis = approx. 20". Y axis = maybe 4" or 5".
I'll add more details a little later on. Here are a couple of images to get started with. Comments and suggestions are absolutely welcome and the sooner the better.

[joecnc2006]

Looking at your drawing, do you really need the two top interior bearings? I would think the on the top the upper vertical bearing and outer horizontal bearing will work to hold it from moving side to side then on the bottom the lower vertical bearing is the only one needed to keep the gantry from upper movement.

Joe

[LeeWay]

You are probably right. This is most likely too many bearings. It would actually be 10 bearings per side with this setup.

I wanted to make each side of the gantry sorta stand alone on its own without falling off if the gantry weren't there. My thinking is that this may actually reduce any chance of racking. Therefore, I think the top three are a must for starters.
The gantry will be pretty heavy itself. All the parts are some nice steel that I had on hand. The 2" x 2" x 44 7/8" tubing is nearly 3/16" thick and the flat bar is 3/16" x 4" x 44 7/8". The end angle iron is 3" x 3" x 1/4" x 24 5/8".
I was thinking because of this, there would be very little chance that the router would want to lift the gantry anyway, so I might get away with just some delrin. This could be mounted and adjusted a little easier than the bearings.
I bought 100 bearings on Ebay. I have about twenty peices of 3/4" x 3/4" x 4' aluminum square tube and some brass rod on hand already. This was another reason for overkill in the drawing.
I have a mini-mill, mini-lathe and 4"x6" bandsaw to make the build much easier.

Some other details of this build that I have bought are the Xylotex driver board. Three 270 oz. steppers from Home Shop CNC.
A 24 volt power supply, assorted bearings, shaft couplings, fan, bushings switches and what not from Surplus center.

I bought some 5/8" 8 acme rod and 6 square brass nuts from Mcmaster Carr.

I haven't yet bought the license to run Mach 2, but that should be the last thing major that I'll purchase. I managed to pick up a couple of double bearinged 12" long new THK rails on Ebay for the z axis.
The basic design is one that I should evenually be able to retrofit THK rails on for the other two axes if I am able to find any deals on them.
I'll be makin my own contoller box out of aluminum. I'll powder coat it when done. Any suggestions for initil switches lights bells and whistles for the box?
Thats it for now. More updates soon. More thoughts and suggestions are welcome.

[CNCadmin]

Here is my idea for ya-

[LeeWay]

Thanks for a peek at that bearing design. It looks good and simple. I like simple and good. I have had this 4" zinc plated flat bar laying around for a long time. At least I have managed to cut it into shorter pieces now. I wanted to see how straight I could get it mounted, so I put one side together last night. It came out great. Its as straight as my T-square in both directions. I will use it for starters. I should have the frame complete this evening and will add some more photo's then. It feels good to start building it already, rather than just spending money and amassing parts.
After lifting the frame and track assembly for just one side, I am starting to think that this thing may weigh nearly as much as some of these smaller MDF rigs.

MDF and I do NOT see eye to eye. If thats all there was to cut in the world, My tablesaw would be on the curb.

[LeeWay]

Here's the next installment. I was able to get all my holes drilled for the 5/16" carriage bolts that hold the frame together. They also hold the rails on. Everything came out as square as I can measure. I had it leveled up in the picure and the frame is dead level. The rails tightened up great as well too. I am a happy camper at this point.
I had originally intended for the machine to sit on this stationary table in the corner of my shop. Now I know that it has to be on casters. All sides of the machine will need to be accessible at times. Plus a steel framed base with casters will actually have less of a footprint.
I ordered 4 casters from the Surplus Center. They had what looks like a great deal on them.
Here are a couple of photo's so that ya'll know it did happen.

[LeeWay]

I have just a little more progress to report. I worked on my all in one control panel this afternoon. Got a good start on it. I'll get it all together soon. I have a micro motherboard that will go in here. The fan on the bottom of the power supply is nearly as big as the big fan in the photo. Don't think I'll need to move quite that much air. I have two smaller normal size fans that I'll stick in there somewhere.
I will need to put a filter on the outside somewhere as well. Perhaps on the back. I won't be cutting ANY MDF with this thing. No fine dust. I use a dust collector in my shop too, so that will help. I will be hooking up a dust port for the router as well.
The box is .063 aluminum and 3/4" square aluminum tubing. All drilled and tapped with 10-24 screws. Could have used rivets, but just wasn't that sure I wouldn't need to take it back apart. Thought about powder coating it, but now that its going together....
The dimensions are 18" wide x 15" tall and 12" deep. Should be plenty of space in there. Thats it for now.

[LeeWay]

Todays update is a little more done on the control panel.
I found out that when I sand blasted the front panel on one side only, that it cups the panel. Like the glass beads actually stretched that side. Wow! Learn something new every day.
I reckon I'll have to blast the inside of this panel too.

I found some hammertone paint in a charcoal color that looks nice. I think I'll use this on the whole machine. Control panel and all.

I never thought I was going to get the computer part to work. This is my fourth mother board. The others were just spares from older computers. I could not get the bios to load. Guess those are bad. I picked up this computer monitor at a repair shop. They normally throw these little things out. I think it will do for this.
I want to try out Turbo CNC first. Got it loaded and I'll run with that first. I think its capable of doing what I want done.

What type of controls, switches and leds would ya'll suggest for the control side of the panel. I have the 3 axis Xylotex board. I just have the normal stuff for the computer side. I want to wire the big power supply up using an old socket from another power supply. Then I'll have a detachable cable. Both power cables will then plug into a surge protector with a switch.

Thanks for looking and suggestions are always welcome.

[LeeWay]

Todays update is short, but a little progress. I have worked a little more refining the control panel. It will sit on a shelf about 8" higher than the bottom bracing on the cart in the pics. I may put the little monitor down there as well. It would be tilted to be seen from a standing position. Keyboard will be covered with a big ziplock bag or maybe some press and seal. That stuffs pretty neat.
Anyway, here's the pics of the cart after I got the bottom welded up. The legs are some sort of overhead door track that I picked up. The bottom frame is just part of an old bed frame. I got these nice casters from Surplus center for $4.95 each. These are very good casters with a 200 + weight limit each. Nice rubber tires. These are made in Australia.

[LeeWay]

Well, I didn't wait.
I have been working on the control panel and had some computer problems, switch failures, new power supply short on the computer, wire routing issues, designing on the fly setbacks.
All in all, just about what I expected.
Anyway, I could not resist the urge to test the motors. All was going wll and my son was repositioning the motor and touched one of the untapped center wires on the x axis to the controllers case. This must have knocked a smoke seal loose, because my Xylotex board spilled some out. He felt bad about it, but it wasn't his fault. I should have tapped up those wires anyway.
The good news is that everything else seemed to be working fine in Turbo CNCjog mode.
I have possed another question on the Gecko drive forum here. I will send this board back home for possible fixing, but I was wondering if I should buy a second board as backup.
My motors are rated at 2.8 am bipolar, so this is just a little high for the Xylotex anyway.
I'm not sure what all I need to go with the Gecko's instead.
Any input would be appeciated.

Thanks.

[ger21]

A Xylotex (and Geckos as well) will die instantly if a motor wire is disconnected with power applied, or from any short of the motor power wires. Jeff @ Xylotex will repair it for a reasonable price. If you're careful, you shouldn't need a spare. If you think you'll need a spare, is 1 spare enough?

[LeeWay]

I may just wait on an upgrade to the Gecko's. I'm sure I will want to go that route eventually.
I have contacted Jeff and am awaiting some info.
I think at the stage that I'm at, a second board would be the way to go.
If I screw up again, , time won't be a factor. When I upgrade, I'm sure there are many guys that would like to have the drivers at a reduced cost. Assuming I don't blow them again.
I went through all the research it took for a niovice to get this hooked up and running just to let a stupid mistake set me back. Well, I won't make the same mistake again.

GUYS, cover your unused wires! See, now I can finally contribute some useful information to the Forum.