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jimfun
02-26-2005, 04:05 AM
I'm sure you guys have heard this one a million and one times. I'm looking to purachace my first machine. I'm seriously considering the central machine 9x32 combo and the grizz 0516 combo. They both seem to offer the most bang for the buck. (Cost is a definate factor in this equation.) Good size and power plus it a combo. Yea Yea, I know a seperate mill and a lathe would be best. Ah, if I was only rich instead of good looking. Just kidding. Wholesale Tool has a lathe plus a milling machine deal but both machines are so small I doubt they would be usefull for anything besides very small work. Also if I could find a complete cnc system (software, controller and servos) I might be able to swing it if the price is right. Any and all advice is appreciated. Thanks,
Jim

hammerhead74000
02-26-2005, 05:37 AM
Ehhh... Depends on what you want to do with it. I might be a bit concerned about the rigidity of the milling setup: the mill head pivots about the base, which puts a large lever arm on the pivot; and for working on larger pieces, you might need to make a larger table, which, being cantilevered over the saddle, is likely to have rigidity issues also. If the mill head starts acting like it's bending about it's pivot, you could add bracing I suppose... And if your parts were not much larger than the saddle; I guess it would be OK.


As for CNC on the cheap, this is what I would do:

an old PC (say, 100 to 200mhz pentium)
TurboCNC from www.dakeng.com (http://www.dakeng.com)

For steppers, Xylotex drives: www.xylotex.com (http://www.xylotex.com)

For servos, SV-500 drives: www.imsrv.com (http://www.imsrv.com)

And then go hunt about in the various surplus stores for some cheap servo or stepper motors to match the drives.
If you need to replace/add an encoder to a servo, check out www.usdigital.com. (http://www.usdigital.com.)

So... PC - $20 (or maby free) TurboCNC v4 $60 (shareware reg) Drives $100-$200 (3 axis) Motors $20-$100 Power Supply $10-$30
Total $200-$400; depending on options and luck.


Disclamer: No, I don't work for, own stock in, or have any affiliation with any of the above mention sources, other then being a pleased customer of TurboCNC and Xylotex. Your Mileage May Vary. Objects in Mirror are closer than they appear. Do not eat this posting. And Stuff Like That. http://bbs.homeshopmachinist.net//eek.gif

JeffG
02-26-2005, 09:46 AM
I started out with separate machines (import knee mill similar to Grizzly G3102, and an Atlas 6" lathe). Have since upgraded the lathe to a 1950 South Bend 9". I'm glad I have the (separate) mill. By the time you throw a vise or rotary table on the mill, then a drill chuck and bit, there isn't much space left for the part on many of the small mills or combo machines. Also the small table limits the size of the workpiece that you can clamp down. Give some careful thought to what you will be using the machine for.

hoffman
02-26-2005, 06:21 PM
I'd check the specs on a 3 in 1 carefully before buying. A lot of them have limited speeds and the slowest is often really fast. Most don't have threading or power feed either. You could get a 9 x 20 lathe for pretty cheap and then add a mill/drill later. With a 920 lathe you could do some threading and a lot of guys hot-rod them.
Check this site out:
http://bedair.org/9x20.html
I've seen these machines go for around $500.
Good luck!
Also remember all the tooling, micrometers, indicators, etc. you're gonna need...

------------------
Hoffman in Warner Robins Ga

JCHannum
02-26-2005, 07:52 PM
Tony's Lathe site has some excellent advice on buying a lathe, particularly for the beginned. I recommend it to anyone contemplating the purchase of a first lathe.
http://www.lathes.co.uk/page2.html

jeastwood
02-28-2005, 07:39 PM
Do check the archives; there is a LOT of discussion and advice on this topic to be found there.