Author Topic: Speeds & Feeds Explorer  (Read 277 times)

Offline GeoffreyGRoy

  • Storm Trooper
  • ***
  • Posts: 177
    • View Profile
Speeds & Feeds Explorer
« on: March 27, 2020, 05:47:43 am »
I have gone out on a bit of a limb here, but I would like some feedback to see if it useful. 

I am attaching a first attempt at a "Speeds & Feeds Explorer".  It is a Speeds & Feeds Calculator but with some differences.  I would welcome comments and suggestions to see if it is worth taking any further.

For the moment the program is a stand alone windows application (keeps development time down), but if it is proven to be useful then  I would think I should be able to provide it as a CamBam plugin with some useful integrations.

Thoughts, ideas, criticisms, suggestions?

Geoff


Offline EddyCurrent

  • CNC Jedi
  • *****
  • Posts: 4248
    • View Profile
Re: Speeds & Feeds Explorer
« Reply #1 on: March 28, 2020, 16:47:47 pm »
Geoff,

I think it's necessary to show the units of each box on the form e.g. RPM, Kw, etc.
Made in England

Offline Bubba

  • CNC Jedi
  • *****
  • Posts: 2875
    • View Profile
Re: Speeds & Feeds Explorer
« Reply #2 on: March 28, 2020, 17:15:25 pm »
Tried today and not sure it works with inch units (at least I can't find it) so couldn't proceed.
My 2¢

Win 10 64 bit, CB [1.0} rc 1 64 bit, Mach3, ESS, G540

Offline EddyCurrent

  • CNC Jedi
  • *****
  • Posts: 4248
    • View Profile
Re: Speeds & Feeds Explorer
« Reply #3 on: March 28, 2020, 18:29:25 pm »
It's metric only at the moment, inches will follow later.
Made in England

Offline dh42

  • Administrator
  • CNC Jedi
  • *****
  • Posts: 5866
    • View Profile
    • Cambam French Doc
Re: Speeds & Feeds Explorer
« Reply #4 on: March 28, 2020, 20:23:48 pm »
Hello

I use an excel sheet that calculate almost the same things as your plugin, RPM, feedrate, Power ; in addition I've also the torque.

Because I want to enhance my excel sheet I explore the results that I obtain with HSM (free version) to try to retrieve what "formulas" they use to calculate the deflection depending of the tool length and flute lenght and what formulas are used to "slow" the RPM and reduce the toothload depending of the tool length/flute length .... but not easy !!

Do you have such formulas ?

http://micro100.hsmadvisor.com/?shell_id=247

In the doc, I found that a tooth load of 0.1mm/tooth is maybe too large for steel with 3mm tool ... (page 7)

maybe this document can be useful for very small tools (0.5 to 3mm - carbide)

http://www.sorotec.de/webshop/Datenblaetter/fraeser/schnittwerte_1_8_en.pdf

++
David
« Last Edit: March 28, 2020, 20:33:18 pm by dh42 »

Offline GeoffreyGRoy

  • Storm Trooper
  • ***
  • Posts: 177
    • View Profile
Re: Speeds & Feeds Explorer
« Reply #5 on: March 29, 2020, 06:13:34 am »
Dear David & Others

The units are only metric for the moment, until I can decide how much work needs to be done to make it useful and if there is enough interest by Forum members..  It would be helpful if I could be given some clues on what imperial units would be best to use (e.g. inches, feet, min, sec, HP, etc) for the various parameters.

I have not explored the more complex computations involving cutter deflections, so I don't have any formulae at hand, and I am not really sure of the complexities involved.  For example, whether the rotating cutter behaves differently from a static one (for which one might try to estimate defections using some simple elastic materials properties).

I have now taken a closer look at the HSM online calculator, and if I adjust the cutting speeds and chip loads to those included in the HSM, then I am quite sure that my SFE is giving close to the same results.  This may not mean that the results are optimal, however. 

It might be useful if you could try out some more cases from your own experience in both HSM and SFE (making certain that the same materials properties are used) to see if you can find any significant differences that might be explained by the more (apparently) complex machining model being used in HSM. 

The units used in HSM (after selecting "mm" units) are still a bit odd.  For example Surface Speed is given in m/sec, and power in HP!, Otherwise, it is not too difficult to compare results.

The Sorotec data sheet is useful, thanks for the reference.

Geoff


Offline dh42

  • Administrator
  • CNC Jedi
  • *****
  • Posts: 5866
    • View Profile
    • Cambam French Doc
Re: Speeds & Feeds Explorer
« Reply #6 on: March 29, 2020, 19:06:58 pm »
Hello

Quote
The units used in HSM (after selecting "mm" units) are still a bit odd.  For example Surface Speed is given in m/sec, and power in HP!, Otherwise, it is not too difficult to compare results.

For the surface speed, I get the value in m/min  ... (but of course both "Tool data" and "Result" section must be set to mm (it is strange to have the ability to mix in and mm in the calculation and it is easy to forgot to set the two units)

ex: for alu 2024 and "default" values for tool (Ø 12.7mm), I get 411m/min for a tool = 12.7mm of diameter and that match with the aprox formula (RPM = 318*Vc/D) > 318*411/12.7 = 10291 RPM

For the power, the soft said that HP is used for in and Kw for mm (move the mouse over the HP label), but on the display, the label stay to HP even when we select mm (but the result match for KW)

I also seen that (at least for alu) the APT (mm/tooth) never goes below 0.015mm/tooth, so it respects the minimum chip ..

But be careful it do not give any alert if we overload the tool !!! (if tool deflection > to max tool deflection)

++
David
« Last Edit: March 29, 2020, 19:14:03 pm by dh42 »

Offline GeoffreyGRoy

  • Storm Trooper
  • ***
  • Posts: 177
    • View Profile
Re: Speeds & Feeds Explorer
« Reply #7 on: April 04, 2020, 04:28:55 am »
Dear David

After some investigations I have found a simple formula for calculating tool deflections.  I am not sure this is really representative of the real machining operation, but it might be a start.  I have included it in  the attached Excel spread sheet. In this SS you can calculate the Force, then the deflection, by setting the other parameters.

 One thing it does not account for are the differences between Conventional and Climb cutting as we know Climb cutting placed less force on the cutter, but is possibly more demanding on the machine drives.

Geoff