Entry level CNC mills?

>>1126240
Depends on the tolerances you need to hold. For wood projects, sure, basically any one will be good enough. If you need +-.001 or better then you need to spend a lot more.

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>>1126240
Hellooooo fellow ShumaTech user!

>>1126255
>pick a random google image
>some guy gets excited

Y-you too

>>1126264
well, then, shame on you!
FTR, mine was $199 from HF. Well, that was before all the DIY add-ons.

>>1126240
what's a good CNC to mill an ar15 lower?

>>1126310
As in from scratch? If you have to ask you don't have the skills to do it.

An 80%? You don't need a CNC, just a drill press and a dremel/files.

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>>1126240

You can get deals on older industrial shit from time to time if you keep an eye out for it.

http://www.ebay.com/itm/322409722064

http://www.ebay.com/itm/332084191110

http://www.ebay.com/itm/122340430845

I really like these old milltronics, they use PC based components and are easy to troubleshoot and fix. If you see something not running with a Fanuc controller run the other way, all the components are highly proprietary and cost an arm and a dick to swap out.

>>1126240
retard here - how much cost % of these be the XYZ controllers? and these are not easily replicable with PC / touchpanel+soft / w/e?

>>1126356
Motor drivers will cost a few to several hundred, the motors will be few more hundred depending on what you get.

>>1126341
Thank you CNCbro! I've repaired a variety of manual machine tools and done simple shit like converting floppies to USB flash for file transfer, but now I know to look for that brand when I add a CNC.

Any thoughts on the Ghost Gunner as a general purpose CNC?

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>>1126500
Too small, too specialized. Can work for some things but I suggest not making the standard hobbyist mistake of craving babby feeble apartment mills unless you live in an apartment.

Best for most users and beloved by pros and amateurs is the common knee mill. You can convert those for CNC or find an older one for reasonable money.

They aren't hard to move either. I post now and then with my examples.

A manual knee mill is better use of money than a Ghost Gunner.

A shipping container can make a convenient machine shop with little work involved. I use two welded together. You can make them blend in almost anywhere. Pic is my 20' standard for a camo example. Don't buy a 20 for a shop unless room is tight because 40s sell for the same money.

How are the Taig cnc mills? Start at $2300

>>1126264
pic looks like micro machine shop

guy is a wizzard with taig stuff

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Would a full size version of this be worth it?

Could it work well?

I'm planning a sailboat in my mind and space for a workshop is limited. Its just a dream boat to occupy my mind, so don't expect me to be realistic.

>>1126341
my old boss has an old milltronics mill but the software took a shit. alot of that uses a compact flash card and you're kinda fucked if you don't have the floppies to reinstall the software.
so what then? the manufacture isn't going to work with you without paying something...

>>1126739
I can tell you you won't like taking your tool apart and puting it back together all the time.
There is a reason people buy two lathes. One for the chuck and one for collets.

>>1126739
No, it couldn't possibly be rigid enough to produce anything useful.

Professional CNC fag here

1) Do not buy cheap chinese mills on ebay. I have a 6040 gantry mill and it's hot garbage. I removed the flimsy faggot aluminum extrusions they use for a bed and replaced them with a solid 1/2" thick aluminum tooling plate which I drilled and tapped in a 1"x1" grid on my bridgeport. I removed the shitty knob feet and bolted the mill into a 200 lb steel surface plate as a base. It's still not very rigid and useless for machining metal. It engraves aluminum ok which is what I use it for. For what I have in it you can get a much better mill, and getting the chinese to actually ship the product you paid for is a pain.

2) unless you are already a CNC technician or are willing to spend hundreds of hours learning, do not buy clapped out surplus machines. You will find yourself going over miles of unmarked wires searching for mystery 10v signals. God help you if it doesn't come with a manual. Old industrial machines break down constantly. They were sold as surplus because nobody can use them for anything worthwhile.

3) See above for converting a bridgeport. You will embark on a thousand-hour journey into the world of electromechanical technicians. If you have the time and money and know what you're in for, go ahead - but it's a serious project.

4) I second the recommendation to buy a manual bridgeport. They're cheap (usually less than $2k), can be had in good condition, and are legit machines that can make useful stuff. Loads of free resources out there on learning how to machine. Keep in mind you will also be spending thousands and thousands of dollars on tools.

>>1127238
con't

If you're just a dabbler and want to dabble with a hobby level desktop mill, the Taig micro mill is the top of the line. Look for seller Deepgroove1 on ebay, he makes a living converting them to CNC turnkey packages. A mate I went to school with has one and he successfully machines hard and stainless steels on it. Slowly, but with good results. It will cost you about two grand for the package but the tooling costs are affordable and you can make small widgits and learn a ton about machining and CNC.

>>1127238
>Keep in mind you will also be spending thousands and thousands of dollars on tools
Different professional fag here.
This This This This This This This This This
So many people I talk to think that the machine is the big expense when it's really tooling. The machine normally doesn't come with anything, you still need collets or collet holders and if it's the latter you need to buy both, plus the wrenches to change them, and all sorts of other shit. Vices, holders, tooling, it's all expensive as fuck for anything decent and you will spend at least as much as you did on the machine itself.

>>1127240
Is there any reason why the deepgroove1 mills are preferable to the CNC mills Taig sells on their site?

>>1127288
Deepgroove1's package includes the stepper motor controllers, from Gecko which is really the name in hobby level motion control. Either way you'll need your own PC. I assume you'll use Mach3 to control the mill, it will output signals through the parallel port. The stepper motor controllers take these low voltage signals and amplify them until they're capable of actually driving the motors. You can buy the gecko boards directly and fab it up yourself if you want.

Keep in mind that Mach3 does not have a parallel port driver for 64 bit operating systems. If you want to use the parallel port you must have a 32 bit operating system. This bit me on the ass with my chinese gantry mill, I ended up using a "smoothstepper" breakout box that connected to my computer via ethernet cable (which is supported in Mach3 for 64 bit) and then parallel port to the stepper controller. As a side benefit, it increases the signal quality and lets me rapid faster and make more precise arc movements.

My chinese mill was ~$1250, came with its own servo control box and a bootleg copy of Mach3. The tooling plate cost me $140, the surface plate cost me $150, the smoothstepper breakout box was $300. The manual was bad engrish and the pin diagram was wrong so I had to spend a lot of time fucking around with a logic probe to get the pinout right for mach3 settings. The steppers they used aren't quite standard so tuning was a real bitch. Meanwhile my buddy paid Deepgroove1, got a turnkey system that he plugged into his computer and it worked right off the bat. I'm not shilling, just letting you know that the china mills are shit and I've seen the Taig mill shine. The one thing mine has better is a variable speed spindle that's water cooled and maxes at 40k rpm, which is great for engraving.

>>1127319
Taig's microproto site also sells CNC packages. It's a bit more expensive but the 3000 claims to have servos and a closed loop control system that's better, is it actually the case?

In any case the basic Deepgroove1 has a nice price point to it, so does the higher end one with ballscrews.

>>1127324
a closed loop system (servos) will be better than an open loop system (steppers). The main difference is that the closed loop servo system has an encoder that rotates along with the motor and provides feedback to the controller how much the motor has actually rotated.

For instance, if the axis drive on a servo motor slips under heavy load, the encoder alerts the control and it compensates for the error to arrive at the right coordinate anyway. This helps eliminate backlash problems, also.

For hobby use there's no real benefit, for serious production servos are an absolute must. Just keep in mind that if you stall the spindle or crash you need to pick up your coordinates again.

>>1127334
>a closed loop system (servos) will be better than an open loop system (steppers).

Technically, that is true.

Practically, not always.

The main advantage of servos is speed, especially in rapids. You could easily make a system have such a high top speed that it doesn't actually have enough travel to get there. Having an error thrown when stalling is also a plus, but that simply shouldn't happen with properly-sized steppers.

They don't really help with lash, because, unlike a DRO reading from linear encoders, you're still only measuring the motor shaft position, not the actual position of the axis. At best, it eliminates the very slight deviation from the an idea step that steppers experience under load. But, even moving an entire half step on a typical 200step/rev stepper and a 10TPI lead screw will move the axis just 0.00025". In reality, it's not likely to deflect that much. And the error is naturally elastic, unlike actual slop. It's only potentially relevant under heavy roughing load, which needs a light clean-up pass, anyway.

Given the same machine at the same price, yes, servos every time. But (and this is ESPECIALLY true for hobby-level machines) the money is much, much better spent on making the machine itself more rigid. Rigidity is the absolute most important requirement for precision. You can easily swap out motors and screws, and scrape ways or upgrade the bearings in a pinch, but none of that matters if the machine itself bends too much to make use of them.

>>1126739
Only if all of your parts will be made from machinable wax and tolerances don't matter...

>>1127238
I want a CNC mill or a VMC for milling chromoly steel and aircraft aluminum. I have used retrofits before, and I have a certification in cad and cam software.

I've been looking into buying a machine from a liquidation auction. I've already got some tooling, but is there anything else I should have other than collets, and a good vise and endmills?

>>1127545
>is there anything else I should have other than collets, and a good vise and endmills?

No, those are the basics. Everything else gets a little application-specific, and you'll just pick it up as you go.

I assume you'll be making your own fly cutters if you aren't buying them. Might want some slitting saws, IDK. Also consider a 4th axis.

>>1127334
>>1127342
Why would you fit encoders to a machine but not absolute linear scales? Linear scales are by far the more accurate, account for any backlash and don't need to be homed like a rotary encoder. Ideally you use both and compare the semi-full error of the two to watch for slippage. If all you want to check is stall, look for overvoltage in the motors, you don't need an encoder to tell you that.

>>1127602
>I assume you'll be making your own fly cutters if you aren't buying them.
yeah, that's actually a good project to do now that you mention it. Id probably have to buy a slitting saw like you said because some of the things I intend to do require them, and a clamp kit...

how much should I spend on an older cnc mill or vmc? I was thinking around 10k but my boss said to just go to a auction or buy a industrial machine trader magazine.

>>1126240
good starts at like $10-15k, Have $20k cause you'll need tooling and vises and all the cool toys that go with it.

>>1127652
>Why would you fit encoders to a machine but not absolute linear scales?

Because they're either not fast enough, don't have sufficient resolution, or both.

If it were the case that linear encoders could compensate for any issues in the drive system, why would manufacturers of high-end equipment bother shelling out for extremely expensive C0 ballscrews when they could just use linear encoders and shit-tier China ones instead?

Rotary optical encoders mounted to the motor (or ballscrew) shaft have a number of advantages. Perhaps the most relevant one is resolution. The servo drivers HAS to have at least several counts of the encoder to work with, the more, the better. If you were to try to read from a linear encoder, the counts on the encoder translate directly to distance traveled. This is a huge problem, because then you're forced to make an encoder with resolution far above what the machine can physically manage, simply to make the servo controller work well. This would be phenomenally expensive.

Instead, it's preferable to utilize the fact that screws, by their nature, convert large motions into smaller ones. By attaching the encoder to that, you can use a much lower-resolution encoder and still achieve the linear resolutions necessary for the controller to maintain stability.

Consider a 10TPI ballscrew fitted with a 1000PPR encoder. Because of the way quadrature encoding works, that's 4000 counts/revolution. Then you get 10 revolutions per inch. Multiply those together and you get a whopping 40,000 counts per inch (0.000025"/count). 1000PPR isn't even that high, either. I've got a couple 2,000PPR encoders lying around for future projects.

>>1127730
get a used Akira Seiki JR/SR. they are the number one starter VMC in the country and its because they have toyota tier reliability .

>>1127796

(cont.)

The other issue is speed. Servo controllers will usually run their loop a few thousand times a second. Thus, they need the encoders themselves to respond quickly to changes in position. The only encoders that are practical are optical ones. This eliminates the slower, high-resolution linear encoders that MIGHT work, and, due to the aforementioned need for high resolution, it's difficult or impossible to make a linear optical encoder that a servo controller could use directly.

Additionally, lash would wreak havoc with the stability of the controller. The controller needs to know how fast the motor is moving relative to how much power it's giving it, and, due to lash/flex, a linear encoder will show no movement until the slop/flex is taken up, at which point the motor will be moving faster or slower than it should be. It's only momentary, but it could still potentially affect surface finish, or, at the minimum, put some slight additional load on the servos for no reason.

I'm not sure why you don't think linear encoders don't need homing. The vast majority of them are incremental encoders, since the cost for an absolute encoder goes way up for (in this case) no real benefit. The only tangible benefit would be knowing where the axis is after power-up. If you're losing counts on an incremental encoder, you have other problems, anyway.

I dont know why but i read it "entry level CNC milfs"

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I impulse bought a non functional CNC mill. It's a taiwanese bed mill with a dynapath delta 20 control on it. Powers up but goes into an unspecified error and e-stops.

I'm in way over my head but it was $300 if I took it away that day (was being replaced by a new milling machine)

Where do I go to learn how to fix this stuff? I wouldn't mind being a CNC repair tech but you can't just nip on down to the local community college and get into this.

>>1128714
I'm a computer tech. We were called in to help a company with a down CNC router because the controlling computer was fried. The vendor wouldn't touch it because it was 20 years old and they wanted to sell them a new one. It ran on a first gen Pentium, used a protection dongle that plugged into the parallel port, and ran on a custom program on top of DOS. Everything but the Mobo was fine. Finding a replacement mobo cost $450 just for the part. Installing it took over three hours in labor because it used a custom ISA daughter card with a half dozen identical cables plugged into it that were not labeled and only worked when they were connected a certain way. Getting the old mobo out of the custom cabinet required you to unplug all of the cables blind, so you couldn't see where they went. It took forever to get everything lined up and communicating again because the vendor wouldn't do shit to help. All in all, they were close to a grand in with parts, on-site labor, and time spent trying to get the vendor to provide any support at all for their shit. It was a bunch of money and frustration for something that they couldn't sell for half that when it was in running condition because it was so old.

TL:DR, the reason you got it so cheap was because they did a cost/benefit analysis and found that repairing the shit cost more than the thing was worth. So, the replaced it and sold it for scrap value. See if you can convert the thing to manual control or swap out the computer system entirely.

Depends on your work size, but yes.

Tormach makes interesting CNCs for the 10k range, and you can get a bridgeport retrofit with a millpwr g2 for about the same amount of money. Those are actually industrial capable machines though, and I'm not sure what the low-level hobby market includes, but my guess is nothing really work,

>>1128714
You're shit out of look prend.

Those old, large mills aren't easy to just strip to hardware and replace motors and computer systems. You should just eat the cost and tear it down for everyone to see.

>>1128714
>it was $300

Christ, I'm still waiting to run across a deal like that.

>>1128747
>Those old, large mills aren't easy to just strip to hardware and replace motors and computer systems

Personally, I never saw why this determined whether it was worth it. Yeah, it's not as easy as buying a part and swapping out the bad one, but, at the same time, I feel like it is, by far, easier to completely re-do the electronics than it is to correct some critical error in the construction of the machine itself, or structural damage that affects its use (like, say, someone dropped a 400lb chunk of steel on the ways and shattered a section of them).

That being said, I'm at least competent with electronics, and I don't have much in the way of "real" shop machinery. "When all you have is a hammer", etc.

>You should just eat the cost and tear it down for everyone to see.

Fuck that. If, by some fluke, you live near the LA/Orange area, I'd have to seriously talk myself out of just grabbing it off you for the same price you paid, if you were to offer. Assuming my truck could haul it, anyway.

Can any of the machinists in here recommend me something free for viewing g-code tool paths that wasn't written by an autist?

I'm learning to program a Haas mill and I want to be able to mess around with code. Specifically I need G70 Bolt Circle rendered.

Seems like everything I have tried just absolutely refuses to play ball with G70 on a mill.

>>1127499
Is there a programmable version of these that can transfer computer models to make wax models? Can this do that?

>>1128801
>Can any of the machinists in here recommend me something free for viewing g-code tool paths that wasn't written by an autist?

LinuxCNC shows a backplot for whatever file is currently loaded. I don't remember if you even need to actually set up a machine to get it to open files. Even if you do, you can just bullshit all the machine parameters and it'll work.

Small downside, obviously, is that it's Linux only (no shit). And there's no guarantee it'll be perfect, as gcode isn't completely standardized. Should work fine for any basic programs or CAM software that spits out nothing but G0/1/2/3 and the usual feed/speed parameters, though.

>>1128829

You'd want a 3D printer at that point, I think.

>>1126739
>Would a full size version of this be worth it?

Both the weight and cost to get such a modular machine to work comparably to even basic equipment would be enough to almost completely defeat the purpose of having a modular tool in the first place. Never mind all the wasted time tramming it every single time you swapped parts around.

> tfw just a programming autist with a hardon for DIY and tools
> Going to spend 200k + on a sick garage shop if I ever get succesful at contracting/running my business
> I dont even give a fuck if I use it once a month I just want to have it to print/cast/machine parts for classic cars or some shit

I cant be the only one.

>>1128857
I wouldn't think you'd be able to cast powder models from a printer but I dunno shit/

>>1128949
Buy machines at auction a piece at a time and it's affordable.

A forty-foot High Cube shipping container makes a surprisingly good shop. See commercial outfits like Sea Box for examples. Mine isn't pretty enough for the autists here but it's two High Cubes welded together. Not hard to do.

One new "one trip" HC with doors on both ends only ran me ~5500 delivered. Used door on one end HCs are about 2500. Lovely gasketed storage and easy for any metalworker to modify.

Have a trailer and study how to move machines without a rigger. It's easy and safe. I make outrigger dollies with industrial casters or pipe skid bases out of scrap for little money.

Collect heavy scrap beam, channel and pipe. It can sit outdoors for years. Watch auctions for very large industrial casters. Never pay retail. It's a sin.

>>1128723
I'm aware I bought a non-profitable project, would love to replace the control. Ajax CNC sells a DIY recontrol kit from Centroid that replaces all electronics, encoders, and servos for about $6k. I don't mind spending that money but I'm leery of doing so before I'm qualified to install it.

>>1128747
I ain't skeert. I'm not in it for an easy buck, but rather to develop a skill. I have a manual lathe and a bridgeport in my garage that I use for my firearms hobby so I can make mounting brackets for motors or whatever needs done.

>>1128761
unfortunately I'm on the other end of the country. Even if I wanted to offload it it'd cost more than the machine's worth to ship. I'm going to use it as a learning project and do a total restoration.

>>1128801
Mach3 is free to use in simulation mode and will preview toolpaths
http://www.machsupport.com/software/mach3/