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Easy to Build Desk Top 3 Axis CNC Milling Machine

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Step 3: X it Stage right

Picture of X it Stage right
C:\Documents and Settings\Tom\Desktop\Pictures\Mill Blog\Bearing.JPG
C:\Documents and Settings\Tom\Desktop\Pictures\Mill Blog\LeadNut.JPG
C:\Documents and Settings\Tom\Desktop\Pictures\Mill Blog\Xstage.JPG
Take a piece of plastic(I used Plexiglas) or metal, something strong and flat and mount a piece of the U channel to it. Now the tricky part. The round thing is a bearing. You can get them out of motors or buy them at a hardware store. Mount it to a short piece of aluminum like so. Then take a 1/4 in. coupling nut(a long nut) and wrap it with aluminum like so(see pic.) The bearing will hold the X stage to the X rail and the coupling nut will allow the motor to run the satge back and forth. It wouldn't hurt to grease the skids a little and the nut too.
Here's a video on making the bearing fixture.

 
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I'm using nylon bearings such as the kind that keep a shower door running smoothly. 4 for 3 dollars. We'll see how it goes.
fgleich4 years ago
Here's a source for hobby RC cars, trucks, etc bearings. Try to buy one from Ace Hardware for less than 10 dollars per bearing......I'm NOT paying that amount when I can order a pack of ten for about 20 bucks. Anyway,
http://www.vxb.com/Merchant2/merchant.mvc

BTW, Lowes and Home Depot do NOT carry bearings any more
bluumax fgleich4 years ago
They're a great bearing for the price.
I bought 1000 for $270 for my machines.
You can get them by 10, 100, 1000.
10 for $4.95 + $4.95 S&H - 10 for $10.
They ship priority mail in the U.S.
http://www.vxb.com/page/bearings/PROD/608ZZ10
Item # 608ZZ
You can get the 10 bearings even cheaper from the same company by ordering them on Amazon ($1.64 in shipping charge as opposed to $4.95): http://www.amazon.com/Bearing-Shielded-Diameter-Miniature-Bearings/dp/B002BBICBK/ref=sr_1_1?ie=UTF8&qid=1313250027&sr=8-1
bluumax bluumax4 years ago
They come in plastic tubes too, not bags.
tjuxed5 years ago
Remember to cut away FROM your finger so you don't cut away the finger.
bobbval tjuxed4 years ago
I would take it a step further and suggest investing in a cheap vice so you can hold the tool with two hands and maintain proper control. rotary tools can "jump" from the part you are working on and cause some major damage to the hand which is holding the part (I say this from experience!)
Mastros bobbval2 years ago
Yes, I fully agree with that caution. When the screw starts turning inside the aluminium, it will also start forcing the aluminium to take a spin. If you are not holding it really strong, the aluminium piece will hit your fingers like the turning blade of a fan.
-.
chinda.raul3 years ago
you can get a pack of 8 bearings from a skate store ... high quality, high volume = good value.
iklln64 years ago
 tap the screw with a hammer before getting it with the screwdriver to keep it from sliding around.  tapping it will make a slight indentation that will hold the screw in place before the self-tapping edges catch and start digging through the aluminum 
dop36 years ago
hi great idea! :)
but will the driver work with MACH3 CNC CONTROLLER
????
http://www.machsupport.com/artsoft/index/index.htm

mfg dop3
zoot686 dop34 years ago
If you build Tom McWire's driver shown here it will, as his driver uses the step/direction schema, and Mach3 also uses the step/direction schema.
Both use two pins for each motor driver one pin for step and one for direction, and those can be mapped to specific pins in the mach3 setup/configuration.
Great Idea, would like to build, what is the software that drives the mill? Hopefully it's as cheap as the machine.
Hey what sized bearing are you using and what abec rating? i've got a load of old skateboard bearings that i could use for this ranging from some abec 1s to abec 7s. i'm mainly going to be using a mill like this for making some longboards since it will let me just slap down some wood when i leave the house and come back to a cut board.
HankMcSpank5 years ago
What are the dimensions of the bearings you nare using please? (ie inner hole diameter, overall bearing diameter & bearing width)....even better if you have them in metric!
Hank, I think the GREAT thing about this CNC mill as opposed to other designs on the net, including this site, is that it's freely adjustable in all terms. You can make the bearings what ever size you wish, from the 5mm OD ones to the 4 inch wide ones. So long as it all comes together nicely. You also can place 1 or 2 or 3 of them if you want. And you don't have to measure their positions accurately, just judge it by eye. The leadscrew does all the accuracy setting for you. I suggest though, you 2 coupling nuts for each threaded rod (leadscrew) one oneach end of the plexglass (or what ever you choose to use) stage. This way, you can get more stability. Even the placement of the rails isn't critical, as they're just guides. If you make the holes in the U channels a bit bigger than the screws that pass through them, you can adjust it if need be, then tighten them up for stability.
pressure applied to bearing.bmp
Dodgy5 years ago
What keeps constant pressure on the ball bearing race to press it against the rail ? I would use an adjusting screw thru the middle of a compression spring. How does that sound ? I've made a simple diagram to illustrate what I mean. But damn, it's wrong... incomplete and I'm not sure how to do it. I know that all the adjuster screw should do, is possibly keep the spring from bending outwards, but mainly it should increase or reduce the pressure on the spring, like squashing it harder or less.
pressure applied to bearing.bmp
Dodgy5 years ago
Can we see a side view (cross section) to see how the 2 rails (U channel) , plastic & ball bearing race all come together? Also, what stops the plastic nearest to the T piece from hitting the rail under it? Shouldn't there be a ball bearing race going downwards, not just horizontally ?
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