Calculate Tube Uncoiler Reel Acceleration | P-J

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Discussion Overview

The discussion revolves around calculating the acceleration of a tube at the reel of a tube uncoiler. Participants explore the dynamics involved in the uncoiling process, particularly during the acceleration phase, and seek to clarify the mechanics at play.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • P-J seeks assistance in determining the acceleration of the tube at the reel during the uncoiling process.
  • Some participants question the existence of acceleration in a steady state and request further clarification on the uncoiler's operation.
  • P-J clarifies that the uncoiler is not in steady state, as it accelerates due to a force (F1) pulling the tube, and mentions the movement of the dancerrol with acceleration a2.
  • Another participant notes the need for a mechanism to prevent the reel from spinning freely, suggesting factors like reel inertia, natural friction, or a braking system.
  • P-J confirms the use of a pneumatic brake but states it is not engaged during the acceleration phase, indicating that the force F1 is responsible for accelerating the combined inertia of the reel and dancerrol, assuming no friction.
  • A question is posed regarding the relationship between accelerations a1, a3, and a2, specifically whether a1 equals a3 plus a2.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the uncoiling process, with some asserting that acceleration may not occur in steady state, while others acknowledge the intermittent nature of the process. The discussion remains unresolved regarding the specific calculations and relationships between the different accelerations.

Contextual Notes

Participants have not fully defined the assumptions regarding the forces at play, the effects of inertia, and the role of the pneumatic brake during the acceleration phase. The mathematical relationships among the accelerations have not been established with clarity.

Pieter-Jan De Loore
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Hello,
I'm making a tube uncoiler and I'm trying to find the acceleration of the tube at the reel (a3) can someone help me with this.

acceleration.PNG

kind regards,
P-J
 
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Not immediately obvious why there would be any acceleration with the uncoiler running steady state .

You'll have to explain a bit more about how this uncoiler works so that we can understand more clearly what your problem is .
 
Nidum said:
Not immediately obvious why there would be any acceleration with the uncoiler running steady state .

You'll have to explain a bit more about how this uncoiler works so that we can understand more clearly what your problem is .
Hello Nidum,

Thank you for your response. Sorry for the bad explenation.

This uncoiler is not a steady state process. The uncoiler stands still and gets accelerated for a certain time because of F1 pulling the tube.
During this period, the dancerrol will move with acc. a2.
I'm trying to figure out what the acceleration of the reel is during the acceleration of the uncoiling process.
I hope this helps?
 
OK . It is an intermittent process . I've seen similar equipment in use .

There must be something that stops the reel from just spinning freely . Is this the reel inertia and natural friction or is there some positive retarding mechanism such as a friction brake or a brake motor ?
 
Nidum said:
OK . It is an intermittent process . I've seen similar equipment in use .

There must be something that stops the reel from just spinning freely . Is this the reel inertia and natural friction or is there some positive retarding mechanism such as a friction brake or a brake motor ?
yes I use a pneumatic brake, but during the acceleration time I don't use the brake. The force F1 is to accelerate the the inertia (reel+(dancerrol)?). You can assume there is no friction.
 
Is it correct to say that a1=a3+a2?
 
upload_2017-2-12_20-6-20.png

https://scontent-bru2-1.xx.fbcdn.net/v/t34.0-12/16730050_1445025058841271_1442485757_n.png?oh=2099815ac924837c5a74a25648495c00&oe=58A26271
 

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