# Gearing Diagram, Draft and Draft Constant of Comber Machine

Last Updated on 04/03/2021

Experiment name:
Gearing diagram and calculations of feed/nip, nips/min, brush speed, production, draft, draft constant of the comber machine.

Objectives:

1. To observe nipper movement.
2. To know about drafting system.
3. To know about speed of brush, cylinder, and lap feed roller, detaching roller.

Specification of the machine:

• Main motor RPM = 1395
• Diameter of main motor pulley= 167mm
• Brush motor RPM = 2860
• Diameter of brush motor pulley = 243mm
• Diameter of cylinder = 125mm
• Diameter of brush roller = 110mm
• Diameter of feed roller = 70mm
• Diameter of back roller = 30mm
• Diameter of middle roller =30mm
• Diameter of front roller = 40mm
• DCP = 78T

Gearing diagram of comber machine:

Calculation:

1. Brush speed = 2860 x (97/243) x (16/19) rpm = 961.38 rpm.

2. Nips/min = RPM of cylinder.
= 1395 x (167/219) x (29/143)
= 215.72 rpm.

3. Feed/nip = Amount of feed in one revolution of cylinder.
= 1 x (25/181) x (31/94) x (39/100) x (38/74) x π x 70
= 4.48 mm.

4. Break draft = 1 x (38/30) x {(π x 30)/(π x 30)}
= 1.27

5. Total draft = 1 x (46/16) x (32/32) x (70/75) x (78/57) x (28/28) x (24/31) x (46/16) x {(π x 40)/( π x 30)}
= 10.89

6. Draft constant = Draft x DCP
= 10.89 x 78
= 849.42

7. Production/machine/ shift in lbs
= (4.48 x 215.72 x 60 x 8 x 8 x 900 x 90)/(10 x 2.54 x 36 x 7000 x 100) x {(100-16)/100}
= 394.48 lbs.

Results:

1. Brush speed =961.38 rpm.
2. Nips/min= 215.72 rpm.
3. Feed/nip= 4.48 mm.
4. Break draft = 1.27
5. Total draft = 10.89
6. Draft constant = 849.42
7. Production/machine/ shift in lbs = 394.48 lbs.

Conclusions:
Comber machine is very important and necessary machine of producing combed sliver. This experiment is very helpful for us to learn about combing M/C. So, we should learn about this experiment very carefully. Especial thanks to our teacher and his assistant for helping us.

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