CNC-Fräse: Unterschied zwischen den Versionen
Reox (Diskussion | Beiträge) rename |
Ripper (Diskussion | Beiträge) →How to: FreeCAD-Infos ergänzt |
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| (6 dazwischenliegende Versionen von einem anderen Benutzer werden nicht angezeigt) | |||
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| <math>z</math> || Number of Teeth || Anzahl der Schneiden || | | <math>z</math> || Number of Teeth || Anzahl der Schneiden || | ||
|- | |- | ||
|rowspan="2"| '''material specific''' || <math>f_z</math> || Feed per | |rowspan="2"| '''material specific''' || <math>f_z</math> || Feed per Tooth / Chipload per Tooth || Vorschub pro Schneide || <math>\text{mm}</math> || | ||
|- | |- | ||
| <math>v_c</math> || Cutting Speed || Schnittgeschwindigkeit || <math>\frac{\text{m}}{\text{min}}</math> || | | <math>v_c</math> || (Surface) Cutting Speed || Schnittgeschwindigkeit || <math>\frac{\text{m}}{\text{min}}</math> || | ||
|- | |- | ||
|rowspan="2"| '''calculated''' || <math>v_f</math> || Feed Rate | |rowspan="2"| '''calculated''' || <math>v_f</math> || Feed Rate || Vorschub || <math>\frac{\text{mm}}{\text{min}}</math> || <math>v_f = n \cdot f_z \cdot z</math> | ||
|- | |- | ||
| <math>n</math> || | | <math>n</math> || revolutions per minute || Drehzahl || <math>\frac{\text{1}}{\text{min}}</math> || <math>n = \frac{v_c \cdot 1000}{\pi \cdot d} </math> | ||
|- | |- | ||
|rowspan="2"| '''defined by process and<br>maximum load of machine''' || <math>a_p</math> || Infeed || Tiefenzustellung || <math>\text{mm}</math> | |rowspan="2"| '''defined by process and<br>maximum load of machine''' || <math>a_p</math> || Infeed || Tiefenzustellung || <math>\text{mm}</math> | ||
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| '''for time considerations''' || <math>Q</math> || Material Removal Rate || Zeitspanvolumen || <math>\frac{\text{cm}^3}{\text{min}}</math> || <math>Q = a_e \cdot a_p \cdot v_f \cdot \frac{1}{1000}</math> | | '''for time considerations''' || <math>Q</math> || Material Removal Rate || Zeitspanvolumen || <math>\frac{\text{cm}^3}{\text{min}}</math> || <math>Q = a_e \cdot a_p \cdot v_f \cdot \frac{1}{1000}</math> | ||
|} | |} | ||
Note for the English terms: It looks like they are not as precise defined as in German. | |||
The German terms are explained in "Praxis der Zerspanungstechnik" by Jochen Dietrich (DOI: 10.1007/978-3-658-14053-3), but I could not find any English reference book on that topic yet --[[Benutzer:Reox|Reox]] ([[Benutzer Diskussion:Reox|Diskussion]]) 10:06, 4. Aug. 2018 (CEST) | |||
These values are connected to each other. There are two main formulars to calculate <math>n</math> and <math>v_f</math>. | These values are connected to each other. There are two main formulars to calculate <math>n</math> and <math>v_f</math>. | ||
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Typically you choose a specific milling cutter for the job and lookup the values for the material. The process parameter are bound by the maximum load the machine can handle (See for example [[CNC-Fräse/Technical#Und_warum_kann_man_jetzt_keinen_Stahl_bearbeiten.3F|Why can't I mill steel in the CNC?]]) and of course by the workpiece you want to produce. | Typically you choose a specific milling cutter for the job and lookup the values for the material. The process parameter are bound by the maximum load the machine can handle (See for example [[CNC-Fräse/Technical#Und_warum_kann_man_jetzt_keinen_Stahl_bearbeiten.3F|Why can't I mill steel in the CNC?]]) and of course by the workpiece you want to produce. | ||
The cutting speed in the datasheet of a cutter is often calculated for a service time ("Standzeit") of 1 hour | The cutting speed in the datasheet of a cutter is often calculated for a service time ("Standzeit") of 1 hour, sometimes only 15 minutes! That means if you mill with the exact parameters that are posted in the datasheet, the cutter will be unuseable after only a short amount of time. | ||
You really need to check for what service time, the datasheet is written. Often the manufacturer will not tell you, so assume the worst (which is 15min). | |||
=== Milling Strategy === | |||
Or: conventional milling vs climb milling. There are two ways of cutting material: either the spindle direction is the same as the feed or not. The first method is called climb milling or in German Gleichlauffräsen, where the latter one is called conventional milling or in German Gegenlauffräsen. | |||
As our feedspindles have some backlash, we can not really make use of climb milling on our machine! Of course, you can use climb milling for finnishing passes, if you remove very less material. In all other cases use conventional milling. | |||
If you mill with the full cutter diameter, there is no difference of the feed direction though, as half the cutter is in climb mode, the other half is in conventional mode. | |||
If you are milling outer contours you have to go counter-clockwise, on inner contours you need to go clockwise to use conventional milling. | |||
=How to= | =How to= | ||
===FreeCAD Path-Workbench=== | |||
Siehe [[CCCP|CNC-Workshop]] von [[User:ripper|ripper]], mehr Infos folgen. | |||
Ganz wichtig:<br> | |||
Post Processor für die CNC-Fräse von [https://github.com/Metalab/freecad-cnc-postprocessor Github] holen. Hat zB automatischen Drehzahlhochlauf inkludiert. | |||
===CamBam Mini HowTo === | ===CamBam Mini HowTo === | ||
[[Bild:CamBam_Howto.PNG|thumb|400px|Werte die man bei CamBam beim erstellen eines 2.5D oder Pocket Operation beachten muss]] | [[Bild:CamBam_Howto.PNG|thumb|400px|Werte die man bei CamBam beim erstellen eines 2.5D oder Pocket Operation beachten muss]] | ||
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* [http://www.carbide-tools.com/knowHow.htmld/ Was Sie über Werkzeuge wissen sollten] | * [http://www.carbide-tools.com/knowHow.htmld/ Was Sie über Werkzeuge wissen sollten] | ||
* [http://de.wikipedia.org/wiki/Schnittgeschwindigkeit Wikipedia] | * [http://de.wikipedia.org/wiki/Schnittgeschwindigkeit Wikipedia] | ||
* [http://www.pferd.com/at-de/101_DEA_HTML.htm Drehzahlrechner] | |||
* [http://www.pferd.com/at-de/101_DEA_HTML.htm | |||
= Technical Details = | = Technical Details = | ||