Chip load and Surface feeds

How do you know what Surface feed to start a Calculation with. Do you start at 100 and go from there. I never could figure that step out. Thanks for the help?


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Willy,
I hear you, there are several things I do to get speeds, feeds, sfm, etc.
Get chart, call your tooling rep. or through some mud against the wall and see what sticks. I work 99% with cast iron so I am pretty familiar with settings.
Use the numbers from the chart or rep as a starting point, I always start conservatively and work from there. Familiarize your self with tool geometry, positive neg, neutral rake nose radius etc. It takes time but you will be able to obtain how cutting is going by sound, feel (placing your finger on tool holder; sensing for vibrations, sound as well.
In closing IMHO it is a mix of art, science, and your senses. Keep your setup as rigid as possible. I keep a note book of different speeds and feeds for turning and milling what works what does not. When milling large 200#+ pieces I brace with wood sometimes to mitigate chatter. Also don't be afraid to fine tune using your spd feed overrides. Each piece has it own natural resonance, at which it will shake rattle and roll and chatter itself to pieces just a little tweak on the over rides will get you into that sweet spot. Just the way I approach "dialing in".

Sure there are other folks here that have MORE knowledge that I will chime in with better ideas for you.


Doug

If I understand your question, you would like to know where to find (or what to use to find) the suggested SFM of a given tool & material combination.

If so, may I recommend a (really inexpensive) program called MEPro,
It will "get you on paper" in terms of good (albeit: conservative) SFM recc's for a wide range of tools and materials.
PS, it is sold by M Rainy (spelling?) on this forum.

Beyond that:
1) Tool manufactures will specify SFM's and feed for their tools.
2) The Web
3) Here
4) The Machinery's Handbook
5) There are quite a few apps for your phone as well.

If I missed your question entirely, sorry. It's been a hell of a day!

Doug.

The old fashioned paper nomogram / nomograph where you lay a ruler across a bunch of printed scales and see what values make sense with the particular material, cutter et al combination is still the best way to get a general feel for whats going on. Unfortunately I don't know of any that are remotely modern in content.

Calculators are great for specific values but, as the OP says, you need to have some idea where to start. With nomogram you can fix a point on one scale and swing the ruler about to see what other values go with it.

Always felt you could do some very interesting things with a touch screen tablet display using data from a modern calculator. Maybe someone computer savvy could take shot at it.

Clive

Take a look at HSMAdvisor or similar. Helical Milling Advisor works good for their tools. Machinery's Handbook is always an option too.

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