Money to burn. CNC Recommendations?

[miw]

This site is a real goldmine! I was hoping you guys might lend some advice in purchasing a CNC mill.

I've about £15k in a research grant to manufacture small (say 2"x2"x2") parts in plastic and non-ferrous metals. I was intially thinking of a small benchtop self-contained system of some sort.

I've no idea if this is realistic, and from my lurking I've a feeling this pricing drops between the 'buy secondhand and convert it yourself' and the 'meh, add two zeros to the pricetag' posse.

Help!

[Evodyne]

Hi MIW. Can you maybe elaborate on the parts you want to make? What are they to be used for? What environment will they need to "live" in? How many different types? How many of each? Let us know. Once you do I'm sure you will get a lot of good feedback.

Evodyne

[miw]

Let's elaborate away:

As things stand I see two types of component.

1) 1 inch cube of delrin with various holes, channels, etc. Potentially this could have quite a complex structure, the piece will probably need flipping over, calibrating, more holes etc.

2) Miscellaneous optical mounts, Aluminium construction. A good idea would be gained from going somewhere like www.thorlabs.com and thorlabs.com and machining your way through their catalogue.

Speed of manufacture isn't an issue here. It's more the ability to have an idea, whip up some CAD and have a new prototype without others having to suffer the worst excesses of my machine-shop bodgery.

I would be making maybe 2 or 3 identical items at most. Design iteration is the real reason for seeking out a CNC. The items would mostly be living in a lab bolted to an optical table.

Thanks for any words of wisdom - much appreciated!

[Geof]

Fifteen thousand pound sterling is about $US25,000 and in USA a Haas Toolroom mill base price is just under 20,000. Find out what they charge for this over there it would do want you want and more. Haas info is at www.haascnc.com with a link to their European site.

[Evodyne]

miw,

Thanks for the info.

Another question: Are you wanting to make some well-targeted purchases of CNC machinery and be up and running a.s.a.p, or is your goal to design/build your own machinery and then apply it to making these pieces whenever the machines are ready? What help do you specifically need-purchasing advice or design advice?

Lance

[ynneb]

Potentially this could have quite a complex structure

If I had that grant I would be looking more at building a rapid prototype machine than a old fashion cnc mill.

The advantges with RP is you make one and then make a mould to mass produce the parts. RP is much better for making complex parts.

I guess I dont exactly know your needs. Just spending your money, in my mind, for you

[wizard]

Try looking at WWW.CNCAUTO.COM or WWW.SOUTHWESTERNINDUSTRIES.COM for starters. Though both of these companies might have hardware bigger than you really need. considering the size and materials you might be able to get away with a TIAG or Sherline mill.

There are also, or where, companies that convert import mills of slightly larger sizes than the Sherline or TIAG. As far as the UK I'm not sure what is going on over there, I would have to imagine that there is atleast a company or two converting imports there. Do try looing in the local trades and model engineering magazines.

Dave

[miw]

Some good suggestions here - thanks guys!

Some replies:

- I'm interested in spending the money and getting up and running asap. I might *personally* be interested in building a computer controlled mill from scratch, but that's not for this project.

- I was considering a CNC mill rather than other rapid prototyping machines purely because from my limited investigations it appears milling will allow me to machine to higher tolerances, and make one-off parts out of aluminium or brass without having to go to the bother of creating a mould etc... Then again, my knowledge of rp is pretty close to nil, could anyone suggest a link to a machine and I'll have a look at its specs.

- I'm sure something 'big' from the likes of Haas or Fadal will probably do the trick (if I can get one cheap enough here in the UK), but I'd have to consider dedicating some serious floorspace to 'em. Anyone have any comments on smaller CNC mils available in the UK? Roland MDX-40, Charlyrobot or Datron M7?

I hope you're all enjoying spending my money for me! Very interesting to see what ppl are coming up with

[damae]

Anyone have any comments on smaller CNC mils available in the UK? Roland MDX-40, Charlyrobot or Datron M7?

My office just bought the MDX-500 from Roland and I'm impressed so far. The larger MDX-650 can be had for under $25k (from the conversion posted earlier this is aproximately the same as your 15k sterling).

These mills are fairly fast for a desktop and very acurate -- fine pitch ballscrews mated to AC servos. The gantry and table almost seem overbuilt, but the rigidity is very welocme; a nice package. Perhaps even better, the software is included, so you could convert CAD models to parts pretty fast. Here's a link to the specs:

http://www.rolanddga.com/products/3D...efault.asp?t=3

[ynneb]

Then again, my knowledge of rp is pretty close to nil, could anyone suggest a link to a machine and I'll have a look at its specs.

Rapid prototype CNC laser resin. (Stereolithography)

[ViperTX]

Personally RP is just for prototyping for proof of concept....I don't believe they have the accuracy required to make stuff for an optics lab. Rather then having an RP, it would be more feasible to farm-out the work.

[wizard]

I missed this item before but it is a serious component of any discussion. frankly machine shop equipment doesn't belong in an optical lab. That is what i'm assuming the fragment below refers to. This from a guy that works in the optics industry. Of course there is a huge differrence in what a lab is and does from place to place but if you are involved in optices I think you would want to reconsider having a mill sit on an optics bench.

The problem you run into is the creation of airborne contamination, even if dry cutting. Frankly you can't gaurantee dry cutting, so the whole idea of having such hardware in the optics lab is bothersome. Maybe you could allocate part of that grant for a partition to close off a small machine shop.

Now we don't want to avoid spending your money on new toys, just pointing out the issues. Your list of manufactures are not all that familiar to me so I can't comment directly on them. Have had good feedback on Rolands second and third hand. I'm still of the opinion that you either go cheap and small (TIAG or Sherline or conversion) or go with a much more substantial mill. Cheap and small to accomplish what you describe today almost on a throwaway basis. A more substantial mill to cover any likely needs in the future.

In this country both SMITHY and Industrial Hobbies (IH) have mill that might do well and fit inbetween the extremes described above. The Smithy is apparrently purposefully designed as a CNC mill and the IH is a conversion.

Unfortunately niether of these machines is likely to meet European safety standards though you could certainly contact the manufactures for details. This will likely be a huge problem for you as many manufactures are not likely to want to get involved in compliancy. Frankly some of the ISO standards are a bit irrational.

Dave

Let's elaborate away:
The items would mostly be living in a lab bolted to an optical table.