Best Cnc for small 6061 alum. part.

Hey everyone,
I'm new at cnc and need help finding the best machine for job at hand. I will be milling 1 part made of 6061 about 3" x 4". The machine will need to be able to run at least 8 hrs. a day continuous except to change out part. From all those that I have spoke with lead me to the Tormach or Industrial Hobbies.
Which both seem to be very reputable. I've recently been turned on to the enclosed 2008 cnc machining center Mikini 1610L. All these machines are in my price range & I really like the enclosed part of the Mikini. Anyone with Mikini info besides Mikini reps.Truthfully I was sold on Ind. Hob. until now. Any advice will be appreciated. Also, if anyone has other machines in mind in this price range all options are still open. Would really like auto tool change but have not found in my price range.
Thanks,
Duane

Hi duaneblk

I not sure what you are looking for or at but the Mikini is night & day different from the other 2

The machines that you have picked out the best of the 3 is the Mikini by the spec that is on there site next would be the Tormach & then the Ind. Hob.

There's not many (if any) machines with toolchangers for ~$10K (I'm guessing that's your budget), but if you think you're going to need a tool changer now, get it. It may take a while for it to pay for itself, but it will, and when you need it, it will be worth it.

The tool changer will let the machine run truly unattended (freeing you up to make money elsewhere), prevent operator fatigue (6 tools per part x 1000 parts gets tiring pretty fast), and prevent operator error (try hitting "cycle start" with a (long) drill in the spindle when the controller expects a (short) end mill - crash city).

Chris Kirchen

First of all, whats your price range?

There are alot of good used machines out there for that kind of money.


If you can find one that was in a primarily aluminum shop, they could have many years of use left on them.

And the good side of a down economy is, if you do have money to spend, you can get some great deals!

Quote:

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Originally Posted by duaneblk@yahoo.

I will be milling 1 part made of 6061 about 3" x 4". The machine will need to be able to run at least 8 hrs. a day continuous except to change out part.

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Does that mean that you will be standing there, changing the parts for 8 hours a day? What about tool changes? Are there any drilled or threaded holes? How many of these do you need to make?

3x4 is not really a 'small' part. 8 hours per day is industrial duty. Keep in mind that a hobby mill is just going to destroy itself in that kind of environment.

I'd take a look at a really old, used Haas VF-1 or VF-2 before I'd buy a hobby mill for this application. I think hobby mills are good for custom jobs, one-offs or a few dozen parts. After that, you'll want an enclosure, flood coolant and a tool changer.

How many of these do you need? If the design is finalized, you might do better to just post the part in the RFQ portion of the site and see what it would take to get them made.

Trust me: if somebody with a real machining center can't make them for an attractive price, you won't be able to pay off a similar machine of your own, or make any money with a lesser machine.

I too have been eyeing the Mikinis that are on sale right now for all the same reasons Duane and Mactec give, but also would like to hear from someone other than a rep or press release about their experience with that machine.

I'm strictly a hobbyist, doing at most a few runs a day of prototype R&D type components out of my home shop (limited to 220/1/60 for power, which limits my options) for a performance parts business. Any feedback on these machines would be great!

Merry Christmas!

-R

Quote:

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Originally Posted by arpieb

I'm strictly a hobbyist, doing at most a few runs a day of prototype R&D type components out of my home shop (limited to 220/1/60 for power, which limits my options)

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I just looked at that Mikini. It's got R8 tooling which means difficult tool changes (more difficult than you'll do in the middle of a program). Yeah, you can buy specialized quick-change tool holders that adapt to the r8 spindle but then you're losing Z clearance and getting into specialized tooling that still needs to be manually changed.

The economy is in the tank. There are nice, used machining centers out there for $12-15K. A rotary phase converter is not that big of a deal (lots of guys in the Haas forum have done it--myself included).

For those interested, try this site:
http://www.craigshelper.com

It's a craigslist search engine that pings multiple sites, based on a radius from your location. I've seen the old fiberglass Haas VF-1s for under $15K.

I'm not bashing the hobby machines but I see lots of posts in these forums from guys wanting to do true production levels with machines just not designed for it. Be sure you know what you're getting into before taking the plunge on a machine that will drive you nuts after the fifth consecutive part.

Quote:

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Originally Posted by Donkey Hotey

The economy is in the tank. There are nice, used machining centers out there for $12-15K. A rotary phase converter is not that big of a deal (lots of guys in the Haas forum have done it--myself included).

...

I'm not bashing the hobby machines but I see lots of posts in these forums from guys wanting to do true production levels with machines just not designed for it. Be sure you know what you're getting into before taking the plunge on a machine that will drive you nuts after the fifth consecutive part.

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Sorry, I can't type your board name without laughing - I'll go with DH. :)

The thing is DH - the Mikini's are on sale for $8500, which is stilll a far cry from $12-15K. Financing on a new units is MUCH easier and cheaper than a used one. They are also under under warranty. If I bought a used VMC of late-90's vintage (which is the price point you are talking about) then I'm SOL if something breaks - and out a lot of money to repair it.

In addition - I'm not looking for production - strictly prototype work - which is a much lighter load, and not unattended/lights-out operations.

As for quick-changes - MicroKinetics (http://www.microkinetics.com) has a nice R8 quick change tooling system that I have seen in action that doesn't give up too much Z clearance - which the Mikini appears to have in spades for a perceived hobbyist machine.

Again, I'm more interested (as I'm sure Duane is as well) in hearing from someone who has actual experience with the Mikinis instead of assuming they are not in the same class as a 15-year-old Haas VF-1.

Not everyone has the room, resources, or finances to buy and maintain a large mill for home shop work... Please keep that in mind.

-R

I agree with all of your points--that's why you should look at the larger machines.

For example: you could spend a bunch on the R8 tool change-out systems. Tack that onto the cost of the machine, cuz you won't be using that if/when you upgrade to a Cat40 machine.

I also agree on the repair costs. That's one you'll have to sort for yourself. Haas is one of the cheaper brands to repair (from what I've read here). The real challenge is to buy a machine that is under power and can be inspected as running, then have it moved by an insured rigger and probably installed by your local Haas Factory Outlet (they can handle the minor stuff on startup and give it a clean bill of health).

Here's where I'm coming from (if you didn't see it in my sig line): I have two CNCs--a vertical maching center and a lathe.

Haas VF-2: fully automatic machining center with a 20-pocket tool changer. It's pricey but a pleasure to run. It's designed for production. I cannot imagine life without a toolchanger or trying to make even a basic part with a single tool.

Haas TL-2: tool room lathe, with a standard quick-change Dorian tool post. This is the lathe equivalent to the mills being suggested here. I have to do all the tool changes manually. It has coolant shields but it still makes a mess. Making a lot of parts on it can be a challenge. I have to be standing there to do every tool change. I get coolant all over my hands and often on my clothes. The tool post holds tolerance, as long as I make absolutely sure that there is no debris in the tool block when I change the tool.
http://www.haascnc.com/prod/CNC_large/61300_lg.jpg
Because of the manual tool changes on the lathe, I'd happily make a thousand parts on the mill before I'd make 100 parts on the lathe.

Again, the hobby machines have their place. They are great for what they're designed for (a hobby). We see people coming in here wanting to do more with them than they're designed to do.

When you start thinking about dozens of parts or more, I assume it's because you want to make money. You probably can't make any money doing production with a hobby machine (if you really factor in all of your time and expenses). I'm not knocking your decisions--just trying to get you to think through the whole problem before making a choice.

Thanks,
Maybe I should wait until I can get some quote's on someone else machining part.
I didn't realize there was so much involved. Which machine do think would be best to learn on.

I should have thrown two more options out there:

Haas introduced their Toolroom Mill back in 2003 (TM-1) and Fadal had the TRM-1 about the same time. Since they both came out at the $20K price point and they've had 5-6 years to depreciate, either model could be an alternative for about $10K (if you can find one).

I don't know about the Fadal but the Hass runs on single-phase power. Make sure you find one with a tool changer. One guy in the Haas forum traded up from a Fadal Toolroom mill to a Haas machining center because he was tired of manual toolchanges on his Fadal.

Also look for older Haas MiniMills; these came out in 2001. We have one dating from back then that has done many thousands of hours work with minimal maintenance.

I think the advice to consider getting your parts done outside is probably the best. Unless you are an experienced machinist it is a big challenge to design, prototype and then produce parts on your own machine; much better to farm it out to experienced people. Be upfront with anyone you deal with, explain your long term goal is to do your own in-house manufacturing and be willing to pay a sensible price for what you have done.

Hey DH,
I really appreciate all the advice. I think once I get to the point that I can disclose my product, I might see about getting some bids on someone else machining it. Then get a machine to do prototypes. I am going to start looking at machines with tool changer, definitely seems like that's the best move. Thanks.
Duane

Thought we would jump into this thread.

Great comments all the way around. We spend lots of time talking to people about applications, and what our machine (and others) are suited best to do. We want our customers to know fully what is out there, and what will work out best for them, be it our machine, or another solution.

We don't suggest that our machine is suited to full production work. It was designed for, and is great for short run, vertical integration and prototyping.

We're looking into a (likely) cat 30 based system with tool change for the end of 2009, and rigid tapping, but no promises, and not sure it makes sense from a demand standpoint.

We took a much different approach than most of the other mills of this class out there. We designed our product to be pretty squarely in between a small machining center, and substantially above anything on the hobby market. This is true for weight, tolerance, feature set, power, quality, etc. We use precision linear rails, and exclusive G3000 low silicon castings. The machine and systems were designed with a 100% duty cycle, and it is designed and built to last in a commercial application.

We encourage customers to really think about manufacturing process control and refinement. There are some applications where having 4 machines setup 100% of the time, and running with a single tool each can be much faster than a single large machining center. Or, having a large machine and a small machine. It really gets down to the specifics of how many parts, and complexity of each part. Things to think about.

In some cases, it can make sense for a small business doing just a couple parts to run a machine without a tool changer, depending on the part, complexity, and volumes. For a job shop, it makes no sense as a primary machine.

A couple other things to think about:

1) Support and parts cost for older industrial machines. Price out a replacement ball screw, a replacement control board, and a replacement drive motor for any machine you are looking at. Make sure you can find them, and that you could afford them.

2) Power, transport, rigging and operation of the machine. Do you have access to 3 phase ? What will it cost to ship or move the machine ? How loud is the machine going to be ? how messy is it going to be ? How big is your door ? Can your floor handle the machine ? What's it going to take to move it to a new space if you move in the future ?

All machines out there (ok, most at least) have a place. But each has it's pro's and cons, and costs.

If we can help, let us know. [email protected]

Happy to talk too, give us a shout at 831.254.2012

We promise to build and support the best in class machines out there. We welcome feedback, and will try to remain as neutral as possible in all the forums, discussions and feedback we give.

Thanks for your time & Happy Holidays

For what it's worth and despite the certain chance of sounding patronizing, I think the post from Mikini Mech is very sensible. And if anyone gets offended at being patronized I remind them it is an old farts privilege :).

The suggestion about having one machine per tool is unconventional but can be sensible; it depends largely on how sophisticated the fixturing is to allow the parts to be tranferred quickly and precisely between machines. Back in the dark ages this is how my company did production on multiple manual machines.

However, I strongly urge Mikini to go toward a toolchanger with all haste; most of the people buying these machines will not have the experience and skills to create the necessary fixturing for multi-machine operation.

I also think Rigid Tapping is almost essential and I also think it is not a case of worrying about demand; do it and then extol its virtues in product literature. I have never considered demand for any products my company makes because I think the money that would need to be spent to get an estimate of demand is better spent on developing the feature/product.

I think another important aspect for these less-than-large-scale-production machines is to have the full range of G-codes offered with helical interpolation, drilling on bolt circles/arcs and all the canned cycles imaginable. Reading threads and post here on CNCzone I have come to the conclusion that many of the smaller machines have a limited feature set. And make sure the product literature describes these features and their applications; I also read posts here that indicate people often do no know the full capabilities of their machine because the descriptions are buried in 'manualese' somewhere obscurely in the machine manual. We manufacture our own product and know how difficult it is to get the detailed information into users or potential users' hands. A lot of people even ignore the; 'when all else fails read the manual' aphorism.

Now I will stop pontificating and go off and watch the snow fall; it is not a common experience here and considering we have about 15 inches on the ground and our city is not equipped to cope with it it is starting to get a bit of a nuisance.

Merry Christmas to all.

Duane,

I was in the same boat as you as far as deciding on a machine. I'm a plastics engineer and I build prototype injection molds on the side. I picked up a used Haas mini mill and couldn't be happier. I used to have a retrofit knee mill. The tool changer is a must. While I'm working at my regular job my mini mill is cranking away on a mold. I looked at all the machines your talking about, but now I'm so glad i got the Haas. BTW I run it on the single phase power which was real easy to change over on the haas (5 minutes)

Those are some realistic points that yuo made Donkey Hotey .
I am in the same boat - Someone wants me to machine small runs of parts
( 15 at a time ) I have looked at the hobby machines and I just can't
see them doing it without problems . No tool changer is the big one .

I've done both now- ran an open cnc, no tool changer- stepped up to a VMC...

Unless this is a hobby only, save up and step up to a VMC. After a few hundred tool changes and a few ponds of coolant on your floor you'll be sick of that open mill.

I just ran a part on my old machine the other day and was reminded how spoiled i've already gotten. It's nice not getting wet!