How To Select A Power Moller

PM Selection Example

1 – Material: What is in contact with the Motorized Roller?

  •  Metal
  •  Plastic
  •  Wood
  •  Urethane
  •  Natural rubber
  •  Corrugated cardboard
  •  Other material

2 – Product weight: What will be the maximum weight?

3 – Available voltage: What voltage are you using?

  • 24VDC
  • 3 230VAC @ 60Hz
  • 1 115VAC @ 60Hz
  • Other Voltages

4 – Desired transportation speed: How fast do you want to move the article?

  • Feet/minute (FPM)

5 – Diameter of the roller: What diameter are you looking for?
Common Itoh Roller Diameters

  • 1.50” (38.0mm)
  • 1.68” (42.7mm)
  • 1.91” (48.6mm)
  • 2.25” (57.0mm)
  • 2.38” (60.5mm)
  • 2.50” (63.5mm)
  • 3.00” (76.3mm)

(Convert English units to Metric units, 1 inch=25.4 mm)

 

6 – Between frame dimension: What is your between frame dimension (BF)?

  • In determining the correct length of the Power Moller required, you should first obtain the between the frame width of the conveyor you will be mounting the Power Moller in.
    • All dimensions need to be converted to millimeters.
  • Take the between the frame width and subtract 15mm to account for bearing end caps and clearances to achieve proper tube length.
    • Subtract 21mm when using the “JQ” type shafts.
    • For the PM635FS the deduction will be 20mm
    • For PM763BS deduct 30mm
    • For IP-G and HP-G rollers, deduct 35mm.

PM SELECTION(length)

7 – Options: Does the application call for any special options?

  • Lagging (Natural Rubber, NBR, Neoprene, Urethane)
  • Dust-proof
  • Waterproof
  • Brake
  • Clutch
  • Other
  • KF – Brackets not ordered with roller

Important Formulas:
Tangential Force (TF)

  •  Tangential force is the force in lbs. that is needed to move the item on the conveyor.
    • The force tangent to the roller’s surface.
    • Tangential force F can be found by the following formula:

Formula 1
TF = µ X W
TF = Required tangential force
W= Weight of article to be transferred
µ = Coefficient of rolling friction in accordance with the material composition
of the bottom of the article to be transferred. (See Table I)

  • To determine the number of POWER MOLLER units required for transfer, compare required tangential force (F) and the tangential force of one POWER MOLLER unit (f)

Formula 2
Number of POWERMOLLERS required = F/f

PM Selection Rolling Friction Table

The above values are based on industry standards of products with a smooth, uniform bottom surface in contact with the roller.

Example

  • Material:      Cardboard
  • Weight:         25 lbs.
  • Voltage:       3Phase, 230VAC @ 60Hz
  • Speed:          85 FPM
  • Diameter:   2.25”
  • BF:                 24”
  • Options:      None

A – Tangential force required (Formula 1)

Given W = 25 lbs.
Cardboard coefficient  = 0.11
TF =  X W
TF = 0.11 X 25 lbs.

TF = 2.75 lbs. required to move the article
PM570AS-20 TF – 5.4 lbs. > 2.75 lbs. ((Refer to catalog page for chosen roller to obtain performance data)

B – Match/Best fit the diameter

  • Diameter given 2.25” (57.0 mm)
  • Model: PM570

C – Given AC motor type

  • Model number/motor type reflects AC or DC
  • PM570AS 

D – Select the best speed for the customer

  • Speed code is an approximate meter-per-minute figure
    • Varies by model
    • Reference FPM values
    • See speed table for PM570AS, (Refer to catalog page for chosen roller to obtain speed codes)
  • Given 85 FPM, Speed code -20 offers 89.6 FPM

Model number with speed code:    PM570AS-20

E – Maximum Load Limit

    • See maximum static load limit table, page 60
    • PM570 series
    • 500 – 600 mm tube length
    • Maximum load limit of 176 lbs. per roller
    • 25 lbs. load < 176 lbs. limit – Okay

F – Select the correct voltage
PM570AS is an AC motor type

  • Available voltage is 3 phase, 230VAC @ 60Hz
  • Model number with voltage – PM570AS-20-595-3-230 

G – Options

  • No options given

Final model number:    PM570AS-20-595-3-230

Description

    • 2.25” Diameter
    • Standard AC motor type
    • 90.1 FPM
    • 595 mm Tube Length
    • 3 230 VAC @ 60 Hz
    • No Options