[davidmc]

Hello all, i have been looking at the many lathes and mills available on the market.
I have invented several machines I need to prototype, I would like to make these from brass, aluminium and stainess steel, these i have designed in (my head) and more reliably in Autocad Inventor 2009.
What I now need to do is get them from Autocad into real life and this is my question, what is the best machine for doing this?
Most parts I need to machine are small, 7" or less in diameter, but need to be acurate to 0001" i would think. For the larger parts I have access to a fantastic machine shop that knows what they are doing (unlike me) when it comes to lathes.
I have funds of up to 1500 dollars but would rather spend less that 1000, i guess this narrows the options.
Obviously cnc machines would make life easier but I would love to learn manual machining as well is there such a machine?
Also, most parts require turning but some require acurate patterned holes drilling, to me this sound like i need a machine center.
Thanks for all help in advance,
and it's great to be part of the cnczone community,
Davidmc.

[RotarySMP]

Holding .0001" tolerances in production requires a temperature control machine, a lot of experience, good measuring equipment, and grinding. If the feature is 7" in diameter, it is only going to be within .0001" at a very limited range of temperatures once completed.

Hitting .0001" tolerance on certain features of a prototype requires a lot of experience, good measuring equipment, and the time to slowly approach the tolerance band.

Their are no machines in you price class which will simply allow you to chuck up stock, and turn an OD or Bore to X.000" (+.0001 / -.0000).

Read 5bears.com excellent article (http://www.5bears.com/cnc16.htm) on turning a precision bearing journal. He is experienced with tight tolerance parts , his lathe is a Hardinge HLV-B, which is about a good as it gets (Price class $10-20K), and he seems confident to machine to X.0007", and after that manually sneaks up on the final tolerance.

You should probably contract the machine shop to make those parts ($$$), or better still, take some time to learn about tolerances, as most general engineering parts do not need anything like that level of precision, and even those that do, only need them for certain features such as precision bearing journals or bores.

[davidmc]

Hello RotarySMP, thanks for your quick reply, I see what you mean I just re-read my post it is supposed to read 0.001", i missed the decimal (not a good start, sorry).
Do you know of any mini lathes on the market that can be cnc modified allowing me the best of both worlds (manual and cnc) as I would like to use both.
Thanks again.

[RotarySMP]

You talk of parts up to 175mm dia (7"). How long are the parts you want to make? If you want to turn something 175mm Dia that is longer than about 50mm long, you will need a lathe that can swing this over its cross slide. For this you are looking at a 12xXX lathe like this:

http://cgi.ebay.at/Drehmaschine-Juni...item2c520c759c.

For €1000, you won't get a lathe capable of turning 7" parts, convert it to CNC and buy the tooling you need to use it.

Do you already have precision measuring equipment?