×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

calculation cutting force to power and torque at the cutting tool_I don't understand it ??????

calculation cutting force to power and torque at the cutting tool_I don't understand it ??????

calculation cutting force to power and torque at the cutting tool_I don't understand it ??????

(OP)
I encountered a strange calculation problem that I can not explain:

I calculate the power torque of a disc milling cutter.

cutter diameter Dc= 63mm
quantity cutting teeth Z= 5
cutting speed vc= 140 m/min
feed fz=0,1 mm
specific cuttingforce for the material Kc1= 2000 N/mm^2
exponent value for specific cuttingforce change mc=0.25
depth of cut ae= 3,4 mm
width of cut ap= 8.53 mm
surface section full depth cut = 29 mm^2

This is my calculation:
average chiptickness hm=fz*SQRT(ae/Dc)= 0,1*SQRT(3,4/63) = 0,023 mm (simplified formula)
cuttingforce for this chiptickness Kc=kc1*(1/hm^mc) = 2000*(1/0,023^0,25)=5135 N/mm^2
cuttingforce Fc=surface cut x kc = 29 mm^2 x 5135 = 148915 N
Pc= Fc x vf= (148915 x 353,68)/60x10^6 = 0,8778 kW
Mc=(Pc x 30 x 10^3)/pi x n = 0,8778 x 3000/pi x 707 = 11,85 Nm

This has all been confirmed by several calculators and should be more or less correct BUT now my problem !!!!

If I calculate the moment of torque Mc out of the cutting force : Mc = Fc x Dc/2 (Nm) = 148915N x 0,0315m = 4691 Nm

????? What will be the torque that my tool will need ????

This 4691 Nm can not be correct that is far too much but still I calculate it from the same force that I use in the other forumula.
I am really confused here. Am I mixing up different forces ?



Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources

White Paper - Effects of AIA Quick Guide to UL 489 or UL 1077
The function of a circuit breaker is to provide overload (thermal) and short-circuit (magnetic) protection to a circuit and its downstream components. A circuit breaker functions like an airbag in a car, protecting circuit components and people by tripping the circuit to interrupt the current flow if it detects a fault condition in the control system. Download Now
White Paper - Guide to Integrate Large-Format Additive
As with any new technology, getting into large-format 3D printing begins with investigation. The first question may be a simple one: what does “large-format” mean? For 3D printers, “large” is a relative term. Many extrusion-based (FFF) 3D printers are referred to as desktop machines, because they fit on table space. Some of these have very respectable build volumes – but when it comes to “large-format,” the machines will need their own dedicated floor space. Large-format 3D printers have significant build volumes and are most often found in professional settings, like manufacturing facilities and R&D centers. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close