[Pyronaught]

I'm looking for a small mill that will initially be used to trim excess carbon fiber from compression molded parts, which is a pretty light-weight task that could even be done with a CNC router. I have a $6K budget to play with though and was thinking it would be a good idea to get more machine that I currently need for this job in order to gain the ability to mill aluminum or even steel in the future. I've built CNC machines from scratch but really don't have the time to do that for this particular job so I'm looking for something turnkey (no conversions). From what I've read here, low-end mills like the Chinese 3040 are garbage (as usual) and I'm sure there are a bunch of other ones in that same class to be avoided. The fixturing for the carbon fiber trimming can be quite tall at around 7" to 8", so I'd need to be able to clear that on the Z axis. A probotix router with the tandem lead screws off on the sides would work since that type of design keeps the center clear and allows lowering the work surface down into the frame to gain more Z height, but it seems a mill is really better suited for this task than a router (and routers are pretty limited for cutting metal). I do need at least six inches of travel on the Y axis though, which eliminates a lot of the smaller mills.

Any recommendations of a decent cnc mill with min 6" Y travel and an adjustment range in Z height of at least 12" from spindle to base that could be used for both aluminum and steel in a prototyping environment for $6K or less? Or stated another way, what machine would get me the most capability in that price range without running into issues with the usual Chinese hit and miss workmanship and associated difficulties in returning/replacing broken garbage? It would be nice to be able to physically lift the machine onto a table, but I realize anything capable of milling metal will likely be much too heavy for that. A lot of these mills look like you need to rent a fork lift on the day the delivery truck arrives.

[Pyronaught]

It looks like the G0704 is extremely popular with a lot of people here and meets my working area criteria. If one of those conversion kits could be installed over a weekend then I'd be up for that, I just didn't want to have to source parts and design a conversion from scratch. I see Automation Technologies has a complete conversion kit for $1700, which is where I've been buying my CNC parts in the past. Maybe this is the way to go-- get a usable mill that doesn't require a forklift for around $3K and have money leftover for buying all the other tooling and mods that go along with these things.

[TitaniumProcess]

I have also heard good things about the G0704. My guess is the conversion kit time to install depends on how familiar you are with machinery. If you need to hire help, at least you'll have money left over in your budget?

[Pyronaught]

I designed and built a large format CNC fabric cutter from the ground up without any sort of plans, so I think I can handle it. I've already got Mach3 setup on a laptop connected to a smooth stepper board over ethernet, so if I put a smooth stepper on the converted mill I should be able to move the laptop between both machines and not have to get anther PC and Mach3 license to run the mill. Another thing I like is that so many people have converted these G0704 mills to CNC that there is a ton of discussion about every possible problem or related modifications online already.

[G59]

Ever think of buying used??
Check this mill out. Comes complete with all tool holders a vice and many other things that make life easier.

http://www.cnczone.com/forums/novako...ml#post1928274

[jdclark]

A mill than can cut aluminum and steel with a Z axis working height of 12" for 6K will be a Chinese machine with all the things that are characteristic of that type. If you are dreaming of an American made unit, your budget is not even close. You might get by with a used unit, but used machines are usually sold because they are mechanically worn out and/or the CNC technology is out of date.

[G59]

but used machines are usually sold because they are mechanically worn out and/or the CNC technology is out of date.

True but I don't think the machine I linked to is worn out. Read the description.
CNC technology continuously evolves and what's new this year is obsolete the next. Always stronger, faster and smarter, but for what the OP is planning to do, this used NM200 is a bargain.

Besides, if your looking for new with relatively new software and mechanicals, the G0704 seems cheap at first until you consider installing the upgrades and the time needed to do them, plus the cost of all the tooling needed, including work holding, probes etc...and you know that sooner or later you'll get tired of tracking swarf throughout the shop, so next on the list, you'll want an enclosure and yadi yadi yada..........$10k later and it's still not performing like an Speedio.

You have to be realistic when setting a budget. $6K will only gets you started, unless if you purchase a ready to go package as linked.

A lot of these mills look like you need to rent a fork lift on the day the delivery truck arrives.

That's just the reality when wishing for a decent work envelope and at the same time, wanting the ability to cut steel.

[Pyronaught]

Ever think of buying used??
Check this mill out. Comes complete with all tool holders a vice and many other things that make life easier.

http://www.cnczone.com/forums/novako...ml#post1928274

The problem with buying used is that the weight of the machines require that you pick them up in person. I live in Florida, so I'm pretty far away from damn near everywhere. It's a 5 hour drive just to get out of my own state.

[Pyronaught]

A mill than can cut aluminum and steel with a Z axis working height of 12" for 6K will be a Chinese machine with all the things that are characteristic of that type. If you are dreaming of an American made unit, your budget is not even close. You might get by with a used unit, but used machines are usually sold because they are mechanically worn out and/or the CNC technology is out of date.

I don't need 12" of travel on the Z axis, I just need to be able to raise the head enough to fit an 8" tall fixture under it. If the actual Z travel is only 2" then that is fine. I really don't have an immediate need to cut steel either, I was just going to see if I could get enough machine to do it with the given budget, but if I can't then I can't. The machine is being bought specifically for cutting carbon fiber that is about 3mm thick, which could even be done with a router but it would be nice to gain the ability to mill aluminum so that's why I'm looking at mills. The mills also seem to be cheaper than routers for some reason, even though they have considerably more materials into building them. They also look like they have more clearance between the spindle and bed compared to most routers, so it seems ideal for what I'm trying to do.

Here's an example of a probotix router doing the same type of thing with a bulky fixture like what I need to do:
https://www.youtube.com/watch?v=KAtt5BnOohU

If I go that route, I spend the same amount of money as converting a G0704, but then can't mill aluminum (but on the plus side, I'd be able to mill larger sheets of non metallic stuff). I'm being given the money to buy whatever tool is necessary to do this one specific job, I'm just trying to get as much mileage out of whatever machine I wind up buying. If the G0704 can get the intended job done and then also help get my feet wet as an entry level machine for CNC milling then that's good enough for me.

[hanermo]

Upgrade your budget by 100%.

Do you have any idea of CNC mill tooling ?
Minimal stuff is 2-4k$.
Toolholder, tool, inserts, import stuff (lowest cost) == 130-150€, each.
x 20 == 3000€.

Add metrology, threading, taps, drills, 2-3000€.

NOT saying You need it all to start.
AM saying You do need to get the tools and tooolhoders, as the nr 1 reason for CNC is not manually stopping to change a single tool.
And the converted mill G0704 - no toolchanger.

Cheapest solution, new, Tormach.
Used Tormach might be best-bet.

[Pyronaught]

Oh I'm sure the tooling is a never ending money pit, just like lathe tooling. It might even be fair to call the mill itself a "bankruptcy starter kit."

The Tormach does look nice. What do they mean by "knock down design?" One of their features states "Unique Knock-down Design allows for installation in basement or other restricted spaces." Do they just mean that it comes apart into more managable size pieces instead of just one big heavy thing?

[arizonavideo]

Skip the tooling question for now. Many jobs require a vice and two cutters. I'm guessing you can handle that.

You might want to first define how heavy the mill can be. They start at about 300 pounds and go to 1000 for the China import bench top mills. The Novakon in the link looks like a fine little machine that will do lots of little jobs just fine.

The next question is spindle speed. You really might want 4 or 5 K to get a good finish and perform the op in a timely manor. The 704 and most others are around 2K unless you change stuff.

Most any mill will be over 80 pounds so will need a truck to get it to your place any how.

I make kits for the PM-25 and 704 and people are happy with them. You might look at the PM-25 which has a fairly easy to speed up spindle.

Your 6k can get you a nice little mill and everything you need but for the end product to be what you want its hard to say with out more info.

[MikeC8]

In that price range today, I would be looking at a tormach 440.

[Pyronaught]

Any opinions on running a Tormach with PathPilot VS Mach3? I really like the look of PathPilot better, I've never been a fan of the cartoonish Mach3 interface or its quirks. The fact that Tormach makes PathPilot, pre-configures it on a controller and their support guys are going to know that system inside and out looks like it pretty much makes the choice a no-brainer.

[pippin88]

Pathpilot, there are reasons Tormach switched LinuxCNC based system.

[109jb]

I don't use PathPilot, but I do use LinuxCNC that is at its core and can say that LinuxCNC has never done anything unexpected.

[Pyronaught]

I thought PathPilot looked just like LinuxCNC. I've never used LinuxCNC myself but have seen screen shots of it. I use Mach3 on my fabric cutter and can say that it does unexpected things on a regular basis! Especially when using the tangential mode. Mach4 hasn't implemented tangential cutting mode yet so I'm stuck with Mach3. Does LinuxCNC have a tangential cutter mode for blades that have to be kept tangent to the direction of travel?

[Pyronaught]

The Tormach 440 is on back order and I think the 770 is just going to be too expensive to justify to the boss. As much as I like the Tormach, both the machine and their company/support and online videos, I think the small working envelope of the 440 isn't going to work for my primary application and cost on the 770 is a show stopper. So I guess I'm stuck with the G0704 for now, as it has a big enough range of motion to do the job and I've already got the green light for that price point. The main thing I want to use the mill for when it is not trimming carbon fiber parts is to make aluminum parts for making other CNC machines. I'd eventually like to make a small dedicated CNC router similar to the Probotix units just for doing the carbon fiber trimming, then I could send those units to the final production facility (I'm just R&D doing limited production in my garage). I'll just have to teach myself CNC milling on the G0704 and then wait for the right project to come along to justify a Tormach 770 later on.

I was wondering why the G0705 does not seem to be a popular mill for CNC conversion. Is it the round column that causes problems?

[arizonavideo]

Correct.

You have to power the quill so you only get about 5" of Z and the more it sticks out the more flex and many of the quills have too much slop.

The 704 is good but may have a bit slow of a spindle for some jobs.

They do sell a belt drive for it.

[kawazuki]

Interesting conversation. You note that you don't want / need big work envelopes but then you add in 8" high fixturing and i'm guessing there could be similar X and Y limits so add in a collet system and a tool and you'll NEED 12" to obtain maybe 2" of clear machinable space - tool changes would obviously have to be carried out away from the fixture so adding a bit more travel requirement. With milling machines, it would seem that the machine is expected to hold its tolerance within its work envelope, the bigger that gets (whether you are using all of it) the costs escalate!
Regarding the Novakon S/Hand machine - its a chunk of change you are spending so would expect anyone to at least look at it in the 'flesh' - a flight and hire car is cheap enough then if its for you there are shippers who'll move it for you - yes its a cost but you can offset it against the tooling you wouldn't be buying?