[thurminator]

A lot of times feeds and speeds from the machinist handbook or other sources can't be achieved due to lack of Swiss machines horsepower or rigidity. Does anyone know of a reliable source for feeds and speeds designed for a Swiss?

[MCImes]

I don't know of a good resource for feeds. In terms of speed, that should be fairly universal, regardless of machine type, since speed is material dependent, not application dependent (within reason of course). This is because the cutting point temperature must remain below the oxidation temperature of carbide, as it breaks down quickly above that temp (I want to say its around 1900F, but I cant find the article in CTE to quote). Materials that have a melting point below that temp have an almost unlimited potential speed (like brass or aluminum) because the metal liquefies before the carbide reaches oxidation temp. In that case, you are more limited by machine horsepower and the actual strength of the tool.

I think that for a Swiss application, the 'recommended' speeds and feeds tend to be quite generous (high). I get most of my speed and feed info from the supplier itself. Most have spec sheets with recommended machining conditions that at least provide a baseline to start with.

As for feeds, I think its something that you just learn after a while. I know a lot of 'resources' recommend feeds .004+ IPR, which makes sense for larger parts or roughing in a conventional lathe, but due to our surface finish requirements and the generally small diameters we make, I rarely use feeds over .002, with .001 or .0005 being quite common regardless of material. In our case, whether its 304, 316, Ti6, or a nickel alloy, .0005-.001 is pretty much the standard. The only time I can think I used a feed over .004 was for 1 job where we were just ripping down some 4130 and cutting it off before it went to centerless grinding, so the finish and OD had very loose tolerances and it was a big 38mm machine with .625 stock we were ripping down to .505, so it had the required torque to drive the heavy feed.



So i know that didnt exactly answer your question, but that's my experience with Swiss speeds and feeds.

[lowjoe]

I agree with what MCI stated... Feeds in the .0005"-.002" range depending on the material. So if you start with the feed at a fixed .001" You can bump up speeds until you either start getting wear or your finish goes away then fine tune your speed. Your Chips will tell you alot. I have had better luck with the ground inserts. And love VCEX style insert in a -3 degree holder.