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View Full Version : [Contest Entry] Summer of Projects: Project #3, DIY CNC



Connor
08-19-2010, 11:25 AM
This was my third project of the summer, I'm not done with this one yet. I decided I wanted to build a CNC. The idea is to make it have interchangeable heads.. I.E. a Plastic Extruder, Router, Vinyl Knife, etc etc. It's built out of MDF, the rails and Screws were are from China. The rails are 12mm, the X and Y screws are 1610, and the Z is 1605. It will be enclosed in a box with a Plexiglas door.

Thanks, Connor

Stobs
09-14-2010, 11:18 PM
As a CNC router, wouldn't you need to implement a method for traversing the y-axis (presuming the x-axis is left/right movement, as the pictures are viewed)?

Connor
09-14-2010, 11:56 PM
As a CNC router, wouldn't you need to implement a method for traversing the y-axis (presuming the x-axis is left/right movement, as the pictures are viewed)?

This is a gantry style CNC. The Gantry moves back and forth, which is the X axis. It has 12" of travel.

The Y Axis is the left-to-right movement, it has 18" of travel.

The Z Axis is up and down, it has around 4.5" of travel (instead of 6" which is what I was going for, I forgot to take into count the hight of the ball nut on the screw, and the bolts which hold it on. Lost around 1.5")

Mitch
09-15-2010, 01:39 PM
As a CNC router, wouldn't you need to implement a method for traversing the y-axis (presuming the x-axis is left/right movement, as the pictures are viewed)?

I see a bearing at the very bottom of it :) I'm gonna go ahead and assume theres another leadscrew underneath the work surface :)

Very cool Connor :) - what was your total project cost (outside of electronics) ?

Connor
09-15-2010, 02:24 PM
I see a bearing at the very bottom of it :) I'm gonna go ahead and assume theres another leadscrew underneath the work surface :)

Very cool Connor :) - what was your total project cost (outside of electronics) ?

What your actually seeing is the coupler for the X axis.. however, I've moved that to the back of the unit. Yes, there is another lead screw under the work surface.

As for cost.. I have NO clue at this point.. because.. I've been buying stuff here and there over time.. I know that I probably could have purchased a Fireball 90 for less or equal to what I have in it so far.. Here are the major expenses..

Rails and Screws
Lead Ball Screws with Ball Nuts X3, 6 12mm rails, 12 x linear bearing blocks, 3 x fixed bearing blocks, 3 x floating bearing blocks, 3 x couplers = $467.00 (included in that is shipping)

Had a slight issue with the screws, I didn't know I had to request they come already machined for the bearing blocks etc..: Replacement $190.00 (was cheaper than having the machined because they were hardened. Would have costed $300.00)

Motors and Electronics
2 X Nema 23 354Oz-In Stepper Motors, 1 Nema 23 287 Oz-In Stepper Motor, 1 Nema 17 68oz Stepper motor (for extruder), 1 X 200W-24v Power Supply, 1 x Parallel Interface Card with Printer Cable: $287.50 (shipping included)

10 x Opto Switches, and spare optocouplers: $40.68
E-Stop switch + 4 Conductor wire for Stepper Motors: $40.94

Computer
1 x Intel D510 Dual Core Atom MiniITX (with processor): $74.99
1 x Dual Port PCI Parallel Port: $11.99
1 x Kingston Dual 2Gb Memory (4 Gb total) $82.99
1 x SSD 32Gb Corsair Hard Drive: $79.99
1 x MiniITX case: 38.99
Shipping: 14.49

Hardware
McMaster: Cross Dowel Nuts, Metric Bolts and #6 and #8 screws and nuts: $74.46
HomeDepot/Lowes: MDF 4 Qtr Sheets of 3/4" MDF, 2 Qtr Sheets of 1/2" Sheets MDF, 1 Qtr sheet 1/4 MDF and a bunch of of sizes of 1/4-20 Bolts etc.. $???

CNC Machine Cost: (Without Router and Computer) $1100.58, not counting added trips to HomeDepot and Lowes for extra parts.. I hope to recover $190.00 for those unused Ball Screws.

Bosch Router: $99.58 + tax

Computer Cost: $303.44

The cost of the computer isn't bad.. it's really nice little machine. The machine is about 80% built now.. I have it in it's enclosure, I need to finish it up.. and get the Y and Z axis working. (motors mounted and finial adjustments made). I've not included any costs for tools purchased to make this machine.. They'll be some more hardware purchase (2 gas springs for the plexi lid)..

Not your super cheap DIY CNC, I went a little overboard using the higher end screws and linear rails.. But, I feel it'll be a better machine in the long run.

Thanks, Connor

aggrav8d
09-16-2010, 12:39 AM
I hope this helps you with your project:

http://www.instructables.com/id/How-to-wire-an-arduino-based-3-axis-CNC-machine/

I've been solving the same challenge from the other direction. I'm looking for linear rails, bearings, and screw thread. I'm thinking of using a rigid plastic like high density polyethelyne which (i am told) is stiffer than wood and cheaper than plastic.

sorry, i got off on a tangent. your work is inspiring and phenomenal and I look forward to reading more about it!

Connor
01-03-2011, 05:32 AM
Some pictures I took a while back since I've added the enclosure and router mount. More to come. At this stage of the build. The machine has been cutting it's own parts.. I've even printed a few times.. Still working on the printing, and tuning up the machine. I had some backlash due to the cheap chines bearing blocks, and had some issues with the Jam nuts on the screws rubbing up against the face for the blocks also. That's now been resolved. EMC2 works great with this machine, and I can get it up to around 50-60 mm per second (that's around 140 IPM). I'm not 100% sure I'm getting full power out of the stepper motors.. and I do know that the screws are a little harder to turn than I think they should be.

Thanks, Connor