Portable, homemade CNC machine WIP

robm

Billy Mays
Staff member
I've been talking about doing this for a long time now, and I've decided to move forward with it.

For those who aren't familiar with what a CNC machine is, see this:
http://www.youtube.com/watch?v=eLU_bdf2PEw

There are plenty of plans strewn across the internet on how to make one yourself, ranging from bathroom builds made out of MDF to workshop units made out of plexiglass (that look very sexy.) The plans themselves range from nearly incomprehensible to easy enough to follow, if you're mechanically inclined enough.

Conceptually, the workings of a CNC machine aren't complicated. You have three axis: left/right, towards/back, and up/down (z, y, and z.) Those dimensions of movement are each controlled by a stepper motor. The rest of the hardware is the table and gantry setup. The gantry holds your cutting tool, in my case a Dremel.

This thread will detail my foray into the world of industrialized production.

Project details:
Portability. This means the unit could be easily thrown in the backseat of my car/SUV and taken somewhere. Not handheld.
Lightweight construction. The unit will be on the small side for a CNC machine, about 24" x 30" or so. Frame construction is 1/2" MDF.

I want this to be an open discussion. My progress so far has been to get the pieces cut for the table, assembly will happen either tomorrow night or Monday morning, depending on when I go buy the hardware.

On cost: your cost for this project will vary. Some of those who attempt these projects likely already have an assortment of shop tools, such as Dremel-like rotory tools, table saws, jigsaws, circular saws, etc. The major cost of this project will be the purchase of whatever tools you don't already have. The dremel is probably the most important, and possibly the most single expensive, tool required - it's the cutting head for your machine, and without it, you won't be doing any Dang thing once your machine's built. That said, once the machine is built, you will need some precision tools like a dial indicator to make adjustments for accurate machining. If you don't have ANY of these tools, expect to spend upwards of $500 for this project.

For myself, in combination with being part lucky and part already having ALL the tools required, my cost will be well under $200, if not just a tad under $100. I am at around $75 now, and at this point I could build the table and gantry assemblies, put them together, and only need to hook up the electronics required. I already have a power supply ready to go for the motors.

My best advice when building one of these is to read EVERYTHING you can find on homemade CNC machines on the net. At the end of this project, I will list the online resources that were the most help to me when building mine.

Edit: Will be updating this first post with required materials and tools as I go along, will post pictures of each as I go along.

Required materials:
1/4 threaded rods (3)
Long 1/4" nuts
1/2" MDF (2 panels)
1/2" metal wire conduit
1/2" metal wire conduit clamps
Angle brackets to attach MDF pieces
Various nuts and bolts

Required tools:
Drill
Dremel
Flathead/phillips screwdriver
Table saw (or hacksaw, but... meh.)
Dial indicator
 
I am looking at doing something like this myself, I look forward to hearing how this works out for you. What are you using for rails?
 
If I was gonna spend $1000 on a CNC machine Id go ahead and get a full sized one at an auction. (Seriously, industrial tool auctions, $1000 is quite common for 4x8' CNC mills) You would lose portability, but gain precision and work area.
 
βeta said:
samjc3 said:
$1000 is quite common for 4x8' CNC mills

I call flux.
Not flux. Quality is flux though. We are talking flax condition, no heads or anything, but still. And if I was gonna get any desktop CNC it would probably be a makerbot.
 
It always surprises me when people actually use the word filter.

Anyway, $1000 worth of broke-ass CNC is a lot of dollars away from actual functioning CNC. Makerbot doesn't have a big enough bed for my tastes.
 
I was originally planning on using aluminum L-channels for the rails, but I'm going to go with round tube stock instead (metal wire conduit) because 1/2" MDF isn't thick enough to bevel to properly mount the L-channel.
 
βeta said:
Makerbot doesn't have a big enough bed for my tastes.
Because the Makerbot is a CNC machine.

I've wanted to build a CNC machine for some time.
Something very hacky, so I could play with it.
Dremel! Power Drill! Pen! Marker! Plastic Extruder Head! Cheese Extruder Head! A Gun!
 
LOL, gun.

I want a laser head for it eventually. That would be pretty sweet.
 
robm said:
If you do find you want a laser, I have a Markem CO2 laser or two I could probably get you cheap. :awesome: (cheap here is relative; these things are like $10k new)
 
I would so make a laser head for it, would be sweet.

The "coolest" thing I can imagine doing?
Adding at least one robotic arm, attached to the print-bed, but capable of reaching anywhere within the print-bed. (Up to a certain height anyway..)
That, plus, I want a standard head and a simple, large, magnetic plug too.
That way, I could make it change heads on its own.

Block of wood on print-bed, hit "Go," go to bed.
Wake up, it's cut it into 4 blocks, and carved them individually into wooden cars, laser-etched flames and flax into them, cut wooden wheels and axles, installed them, as well as all the little wooden gears, in a little wooden gearbox, installed in the cars, along with the battery holders and electric motors, AND pulled some copper clad, from the copper clad bin of course, and etched the PCB for the simple power circuit for the car. (Mechanically etched, as in, with the dremel)

Ready for me to solder on some components and go.

That's my, like, dream.
I want a machine to do that.
On my desk.
 
Auto-tool changing setups are huge, and not nearly that modular. You generally only change from milling bit to milling bit, but I am sure you know this.

Mech-E Tech major signing out.
 
0.o @ Sam.

You have interesting parts just "laying around," madam. "Cheap" being relative, I'm sure a 10k part new would still be out of reach for me used. I'm a married man with three kids (soon to be four,) so my discretionary funds are somewhat limited.

A laser head really is something I would love to have. But, it's probably going to be something that would be more of an etching solution as opposed to cutting, sadly.

Alright, progress so far:
Stepper motors purchased, Sam is being kind enough to send me two, and I've got more coming that I ran across for stupid-cheap.
Table pieces are cut, getting ready to assemble those here in one hour, pics shall be posted later tonight.
Gantry rails are purchased, will also be securing those to the table tonight.

Also, will be updating first post with required materials for build as I go along.
 
Alright, table assembled and rails installed. Pics... NOW.

IMG_1758.jpg


IMG_1757.jpg


Yes, my garage is a mess. It'll be better soon.
 
Wait, pics? It's not tomorrow.

Also, don't worry, my garage is fifteen times worse. We're going to finish cleaning it out in a few paychecks so we can rent a UHAUL and go to the dump.

Edit: Oh, I dumb. I forgot to comment on how sexy this is turning out.
 
Ok, gantry slides cut and prepped for bearings, slide inserts are also cut. Need to obtain bearings from local skate shop tomorrow...
 
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