[dlavery]

Originally Posted by sanddrag

I just found this http://www.homier.com/default.asp?dp...tail&sku=03989 It is probably really junky and it has no z axis fine feed but at $199 it does seem to be a very good price.

It all depends on what you want to do with it. If you are just going to knock out a few small pieces, and aren't really worried about precision or any workpieces larger than 2"x3"x6" then this might be OK. But if you are going to do anything involving multiple copies of the same part, quality finishes, tolerances closer than 15 mils, or ever working with plastics or other non-ferrous materials, then run away from this thing as fast as you can.

Here is a clue: if the vendor (Homier) doesn't even bother to proof-read their advertisements and make sure there are no spelling mistakes, just how much care do you think they put into their products?

Originally Posted by roboguy #1

Well the mill we have is very nice its full cnc. I have a question if you cant run data from a comp. how can you cut round holes for bearings. Especially if you are using over 1" I believe we have 4 2" on our robot this year. But all in all digital cnc screen mpg all the goody's.

For small round holes, multi-drill to 3-5 mils under size, then use a reamer. Do not just use a drill - a standard twist drill will give you a triangular hole (there is a good, concise discussion of this here). For larger holes, cut out the bulk of the material with a hole saw or mill, then finish with a boring head to get a hole that is truly round.

Machinists were making large round holes in workpieces for decades before anyone ever thought about how to control a cutting head with a computer. All you need is the right tooling, the right experience, and the right amount of patience. Machinists and toolmakers in the late 1800's were able to produce parts that were accurate to within a millionth of an inch when necessary, all by hand. Machinists - it is almost more accurate to call them artisans - could hand scrape a surface plate to a level of precision that would easily rival a Grade AA/Laboratory plate manufactured today. When computer control was added into the mix, it didn't really improve the precision or accuracy of the manufacturing process. The ability to produce a part to a certain tolerance was always there. But it did radically improve the speed of production for a given part (and particularly, multiples of parts).

Originally Posted by KTorak

See if you can find a "table top" bridgeport...our bridgeport floor models in our machine shop are very nice machines, with Digital Readouts for precision, and they are great to use as a drill press too.

As far as I know, Bridgeport never made a benchtop/table top milling machine. I believe that all of their models were floor-standing (this is certainly the case for all their Series-1 and J-head models). If you are talking about the mill/drill machines and smaller "laboratory mills" or "mini-mills" then you might want to check out the first part of this very thread, which already has a discussion on the topic.

-dave