Hobby CNC, the rotor way

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Hobby CNC, the rotor way

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

and by 'the rotor way' i of course mean 'cheap and halfassed.'

A while ago - maybe a year or so - I started getting interested in machining metals. My dad was a machinist, his dad was a machinst, and before that I dont think there were machines so great-granddad was a stonemason. Anyway, I sort of felt a genetic obligation at some point to make things from metal. At first it started out with the idea of making little aluminum replacements for lego parts like this guy and then I found this page and then the obsession really went into high gear from there.

I really had no idea where to start, but this page really lays it out nicely. More than anything else, that dude set me on the path to setting up my stuff. Most of it's geared towards milling molds for plastic parts, but the intro part is solid gold.

So after like 8 months of hemming and hawing I took the plunge on my birthday and ordered a taig micro mill set up for CNC, a gecko g540 to control the motors (along with 3 280oz motors to control) and a power supply to drive the whole thing. I dug up an old thinkpad and dock that had a parallel port, put linuxcnc on it and BAM, that was about it.

all told, this came to around ~1500 and after a couple hiccups and after a household emergency put a stop to all fun for about a month or two, it was all assembled and functional.

Here's a picture of it before it was all wired up:

So far i've done mostly manual milling using an old game controller and this, which is sort of hilarious but works ok when you're just eyeballin stuff. I've made a few basic actual CNC'd parts and have done a lot of engraving using simple v-bits and some some free software. For instance, here's 'yospos' engraved into some scrap wood. You can do the same with aluminum, you just have to go slower:
https://www.youtube.com/watch?v=4QKl0TAULT8
WARNING: VIDEO IS LITERALLY FIVE AND A HALF MINUTES OF A NOISY MACHINE AND lovely CAMERAWORK

Anyhow, there's that. I'll try to update the thread now and again with stuff i've discovered or made or whatever, but i'm super lazy so i probably wont. I mostly made this thread because I think people have the idea that CNC is hard or new-car kind of expensive. It really ain't.

# ¿ Jul 4, 2013 07:32

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# ¿ May 2, 2024 06:14

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

UberVexer posted:

That's a pretty neat machine, do you have a rotary indexer for it?

no, the 4th axis was like ... $600 or something, and a simple rotary indexer wasnt that much less.

quote:

You could machine some neat rounded parts, like bats and whatnot using it.

you mean bats like baseball bats? that's a lathe thing.

# ¿ Jul 8, 2013 03:34

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Spring St posted:

What kind of CAD/CAM software are you using? There's no such thing as a freeware Mastercam is there?

this is really the weak point and I wish I had a better answer. I'm super lovely with CAD so I haven't made anything in CAD myself yet. As for CAM, I halfassedly tried to pirate rhinocam but gave up after a minute or two and used Cambam: http://www.cambam.info/ it does some pretty adequate things like drill holes here here and here, mill a pocket there, stuff like that. That's really where the learning curve is for me - drawing that stuff is hard, and figuring out what proper speeds are so simple parts don't take an hour while it moves around at an inch a minute because I punted and played it super safe or whatever.

# ¿ Jul 9, 2013 04:38

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

pycam is alright i guess sorta but it expects a dxf or stl or whatever. the nice thing about cambam is it can do stupid things like bolt hole layout and slotting and simple poo poo like that on its own.

last I checked rhinocam was $1k+, which counts as hideously expensive to me. if you know somewhere to get it cheaper, make with the links.

# ¿ Jul 9, 2013 06:27

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Sagebrush posted:

It is pretty weird that there's no good free 3-axis CAM software available, though...maybe with all the 3D printing someone will get around to writing something?

its like the only thing i've been even a little bit interested in trying to write in my spare time for like 5 years.

# ¿ Jul 9, 2013 06:28

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

cant say enough good things about linuxcnc tho, poo poo owns.

# ¿ Jul 9, 2013 06:29

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

mafoose posted:

Cool setup! I have a Sherline 2000 with IMService servo setup. I got it none running on craigslist for $900. I've got it running but the lead screws need replacing as the PPO did circuit boards with it. Luckily it's not very expensive.

sweet. post some pix bro.

# ¿ Jul 12, 2013 06:20

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

V-Carving is super cool. I was really surprised by how crisp the corners got. Here's how to use FEngrave with a random SVG file.

https://www.youtube.com/watch?v=Mhc_1kfS3ck

# ¿ Jul 19, 2013 06:16

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

AbsentMindedWelder posted:

rotor,

It's time for you to start cutting foam, build a foundry, and start doing lost-foam casting! Or, you could get yourself some machinable wax...

lol

i think so far on my TODO list is:

1) clean up all this loving wiring and get some kind of halfassed enclosure so the chips dont end up 12 feet away
2) mill up some workholding clamps like so: http://www.cad2gcode.com/cncprojects/id14.html because my current solution sucks
3) make some wood planes
4) make a decent enclosure for the power supply and controller

# ¿ Jul 25, 2013 07:37

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

this dude pisses me off so bad.

look at this loving immaculate workshop:

look at all these loving vises:

that's like 10% of his vises and they're not even the nice ones

look at this loving bandsaw just lopping off a bigass hunk of 5" steel round, you know, no big deal, whatever:

just look at this poo poo http://www.micro-machine-shop.com/Micro-Machine-Shop_Photo_Gallery.htm

i need to be retired like loving asap

# ¿ Jul 26, 2013 06:10

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Tres Burritos posted:

Speaking of assholes with super nice shops, I really enjoyed reading this guys:

http://lcamtuf.coredump.cx/gcnc/

stuff.

i linked that page in the OP. More than anywhere else its the page that set me down the road with this stuff. I didn't see any photos of the dudes shop tho - where they at?

# ¿ Jul 26, 2013 06:54

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

rotor posted:

this dude pisses me off so bad.

look at this loving immaculate workshop:

look at all these loving vises:

that's like 10% of his vises and they're not even the nice ones

look at this loving bandsaw just lopping off a bigass hunk of 5" steel round, you know, no big deal, whatever:

just look at this poo poo http://www.micro-machine-shop.com/Micro-Machine-Shop_Photo_Gallery.htm

i need to be retired like loving asap

as far as i can tell this fuckhead has like SIX rotary tables

dude's all "sure, rotary tables are nice, but what's really nice is mounting a rotary table onto another rotary table" :smug:

# ¿ Jul 26, 2013 07:39

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

yeah, i'm finding materials to be the hardest thing. I've got some stuff off amazon but OOF like $40 or something for 2x2x12 aluminum bar. I've turned into some sort of weird hobo constantly going over trash piles looking for any metal over 1/8" thick and destroying old printers for the sweet, sweet steel rods and gears contained within.

I dont know if anyone else here has a taig lathe or mill but here's a cool guy with both:

http://toolingaround.ca/

# ¿ Jul 29, 2013 06:10

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

maybe. i'm in a dense urban environment tho. I have a garage, and i do have a tiny, postage-stamp sized yard, but I think my neighbors would finally revolt if I started an aluminum forge in my back yard.

# ¿ Jul 29, 2013 06:54

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

speaking of pcb, here's a taig modified to be a pick & place machine. the motors sounds all weird but iunno

https://www.youtube.com/watch?v=__dEMKzkLYc

# ¿ Sep 10, 2013 04:43

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Martytoof posted:

Sounds like some weird resonance in one of the axes but nothing terrible. The vacuum pump is much more annoying

Neat idea in theory, but too slow to be really useful IMHO. I can place parts by hand a little* faster than that.

* a lot

yeah im not sure why its running so slow, my taig'll go way faster on rapids

# ¿ Sep 11, 2013 05:11

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

got some time on the mill for the first time in months, tried the svg v-carve thing i posted about earlier. came out pretty well in aluminum, just used a regular 1/4" router bit

# ¿ Oct 21, 2013 03:26

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

echinopsis posted:

nice! what kind of alu is it and are you using a lube?

whatever home depot had in the big rack of sheet aluminum. i used aluminum tap magic and i hate it because it stinks of cinnamon.

# ¿ Oct 21, 2013 04:09

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

echinopsis posted:

we used to find that there was a world of difference between like 8001 and 8005 Ali [or whatever it was], the cheaper stuff that was great for folding bending etc was substantially worse for machining.. maybe it doesn't matter but I guess it's worth knowing that the marine grade was so much easier to cut so if you are having trouble with it cutting clean just something to be aware of. maybe preaching to the choir but I'm risking it

i didnt know

i mean, i knew some aluminums are better than others but given the source material i have (whatever crap I can scavenge from whereever) i just live with it.

I keep trying to find a machine shop that will let me dig through their scraps but this is SF and apparently there are no machine shops?!?

# ¿ Oct 22, 2013 01:59

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Sneaking Mission posted:

What Is The Best Metal?

steel because of that thing in conan

# ¿ Oct 22, 2013 02:00

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

i think you underestimate the sizes that would be useful to me, but yeah you're probably right about the last part.

metal is so expensive gosh

# ¿ Oct 22, 2013 02:56

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

i live in sf and have a tiny postage stamp sized back yard and some kind, long-suffering neighbors. I am not about to start a backyard smelter.

# ¿ Oct 22, 2013 03:47

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

oxbrain posted:

Don't waste time with machine shops, call metal recyclers and ask them if you can buy scrap metal. It'll be way cheaper than buying new, but you won't know what alloy you're getting if that matters.

gently caress any aluminum that isn't 6000 or 7000 series.

i have but they dont want to sell me ingots, they want to sell me bundles of crushed trash and cars and stuff

# ¿ Oct 24, 2013 03:27

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

mafoose posted:

You need to try different metal recyclers, like the ones that work with construction companies.
Worst case scenario, a metal supplier. There should be lots, and most sell remnants for $1-2/lb or so over scrap. Here I have Industrial Metal Supply. They have a whole room of aluminum remnants, that sell for like $2-3/lb.

Try this place perhaps?
http://www.bayshoremetals.com/aluminum.htm
(ugh flash + music)

If you plan on making parts, you need to know what aluminum alloy you'll be using. You don't want to be using scrap of unknown source.

Oversimplification:
5052 for parts that get bent, or don't require lots of rigidity (try to bend with the grain to avoid cracks). It's also pretty inexpensive.
6061 for a good mix of strength/lb that won't break the bank. Most "billet" parts are made with this. You can bend certain tempers (T0, T4) pretty easily, but unless it's a big radius, 6061-T6 will crack if you try to bend it.
7075 is the most common "super strong" alloy. It's pretty awesome, but it is aerospace ($$$) and unweldable.

Avoid cast aluminum for structural parts, as it is usually much weaker than 6061. Cast jig plate is nice and flat and good for making fixtures though.

Material comes in basic shapes:
Sheet (thin)
Plate (thicker than sheet, can't remember what the cutoff is, something like >3/8" or so)
Bar (best for smaller parts, this is usually what I buy, because I can easily cut it with a chop saw or band saw to load in my machine)
Rod (solid)
Tube (hollow)
Angle, Channel, Beam (usually for structural parts, I like using angle and channel for parts that require 90deg bends, you can usually get them with sharp or round corners)

You really shouldn't be using ingots, as they aren't very uniform and might be hard to hold down to.

Also, you want to invest in proper tooling. Router bits are not replacements for proper endmills. Avoid 4 flute endmills on aluminum. 3 fluters work amazing, but 2 flutes cutters are substantially cheaper, and work almost as good. High spindle speeds, low depths of cut and high IPM are your friends on these non-rigid machines.

Have fun making chips!

this is really super useful to me and that bayshore metals place is kinda sorta on my way home. Thanks a lot!

# ¿ Oct 28, 2013 06:55

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

i just set it for whatever and hope nothing breaks.

# ¿ Oct 29, 2013 03:53

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

so far lots of stuff has broken

# ¿ Oct 29, 2013 03:54

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

CarForumPoster posted:

I shall explain it then. 1% of cutter diameter per tooth is a good rule-of-thumb starting feed rate for milling aluminum.

Power consumption is essentially a function of MRR and the way to decrease your cutter load effectively is to use constant cutter engagement angles. You don't want to run the cutter on center line nor do you want to slot if you can avoid it so your "good" cutter step over ranges tend to be 10-35%, 65-85% with the ideal being 70%. With <50% you get chip thinning effects and should increase feed but on your baby mill at 1% cutter/tooth (e.g. a 1/4" cutter would be fed at .0025/tooth or for a 2 flute .005/rev) you'll be ok staying in the 10-30% step over range even if your effective cutting thickness isn't the full 1%.

for serious tho this is good advise, thanks

# ¿ Oct 29, 2013 05:26

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Sagebrush posted:

No, no, corner cutting depends on the tool radius.

it's a fine line between clever and stupid

# ¿ Nov 6, 2013 04:12

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Loving Africa Chaps posted:

I'd like to make a small cnc mill. The parts I'd be playing with would be small, like 100mm x 150mm x 40mm. Most of it would be plastics but I'd like to be able to some light brass and aluminium. Most of the designs I've seen have much bigger areas and it seems silly to sacrifice rigidity and accuracy for space I'd never use. Anyone got any links to any examples of small mills?

what's your budget?

# ¿ Nov 9, 2013 21:47

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

bung posted:

Just saw this today. A desktop 5-axis mill with a projected price of $3000.

sounds neat but I have no idea why they're trying to make it weigh less

also having a hard time imagining that it'll actually cut steel with any effectiveness.

regardless, sure hope it works. a 5 axis for 3k sounds sweet as hell.

# ¿ Nov 21, 2013 20:34

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

I'm not very clever though so it would suit my needs

# ¿ Nov 21, 2013 20:58

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Loving Africa Chaps posted:

I'm not sure why you'd need 5 axis unless you like impellers because thats all i've seen them make

honestly? because they look cool as hell when they're running.

# ¿ Nov 22, 2013 05:46

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

also I think you don't have to be as smart about how it's milled but idkwtf I'm just some dumbass

# ¿ Nov 22, 2013 05:47

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

I've gotten my taig mill + steppers + linuxcnc all hosed up.

I can't figure out how to zero it. Currently it thinks (0,0,0) is somewhere in the middle of the table about 2" up and it won't let me jog past it. This it putting a serious crimp in my abilities to machine things. he;lp

# ¿ Mar 3, 2014 06:28

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Sagebrush posted:

unless you have some bizarre firmware on the mill controller or something that's gonna be 100% a setting in linuxcnc. The mill doesn't know where its center is and the steppers just spin happily around as many times as you give them a pulse. you could just try resetting the software to default values.

also if you don't know how to zero your mill god drat old man, get with it

I'm not very good with this I just started, gosh

# ¿ Mar 3, 2014 17:25

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

do you usually have home set at 0,0,0 or does it not matter?

# ¿ Mar 3, 2014 17:26

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

machine zero

# ¿ Mar 3, 2014 21:51

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

i think??

# ¿ Mar 3, 2014 21:51

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

I've been rearranging and fixing up my garage/workshop so I haven't done much with the machine tools lately. But things have settled a little and the lathe & mill are now somewhere better lit and easier to clean up after (put some plastic sheeting under it so I dont have a wooden bench full of sharp chips that is impossible to clean).

I'd been using this http://wiki.linuxcnc.org/cgi-bin/wiki.pl?Simple_Remote_Pendant to run my cnc mill freehand. It's a bunch of bindings that let you use a cheapo gamepad as a mill controller.

It worked ok, but I've had a couple times where I wasn't paying enough attention and instead of running the mill up the X direction only, it would veer off on a curve and destroy the workpiece.

So I just used this this:

http://softsolder.com/2010/03/24/emc2-gamepad-pendant-joystick-axis-lockout/

which was more complex, but still lets you use the analog sticks as speed control, but locks out the other axis so you only cut in one direction. I had to do a little editing to define the right button names and remove the cruft from the A axis which I sadly don't have, but that only took an hour or so. Works pretty well.

# ¿ Apr 27, 2014 21:49

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# ¿ May 2, 2024 06:14

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

M1A1 posted:

Is it in any way feasible to set up something similar to the OP in an apartment? How much smoke/noise/vibration is generated when milling steel for example?

the lathe is super quiet and you can totally turn steel in an apartment

the mill can be loud, but no worse than ... oh, i dont know, say running the vaccuum?

if you're working wood or plastic yeah it's plenty quiet

# ¿ May 3, 2014 05:42

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