PACIFIC CONVEYORS LTD.
STANDARD PRODUCT CATALOGUE
engineered material
handling systems
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Technical Page 8  MISCELLANEOUS PRODUCT SELECTION
  The Basic Principles
SELECTING ROLLER CENTERS
for power and gravity roller conveyor
 
For Light Packages
Each package should be supported by three rollers.
Divide length of package by three to find roll centers.
Example 12" long package requires rolls on 4" centers
For Heavy Loads
Roller capacity should not be exceeded.
Divide weight of package by roll capacity.
Example    400 lb crate on 138G (50 lbs capacity rollers)
               should be supported on minimum of 8 rolls
               regardless of length of object.
Notes   Extra rollers cost more, but make for easier operation.
           Soft or irregular packages require more rollers
 

Lineshaft Conveyor
All the above guidelines apply to lineshaft conveyor, but there are also extra conditions.  Each small drive belt delivers only 0.75 lbs of belt pull.  This translates to a driving  capacity of about 15 lbs per roll, regardless of what the nominal capacity
of the roller may be.

In selecting lineshaft conveyor, do not exceed 15 lbs per roller for Model 196 or 10 lbs per roller for Model 138

GRAVITY ROLLERS  Decline grade suggestions
Object Weight GRADE Object Weight GRADE
Oiled brgs. Greased brgs. Oiled brgs. Greased brgs.
lumber std. board 1" in 24" 1" in 16" cartons 1-5 lbs 1" in 24"  
barrels empty 1" in 20" 1" in 18" 5-15 lbs 1" in 27"  
full 1" in 30" 1" in 24" 15 -50 lbs 1" in 30"  
milk cases empty 1" in 20" 1" in 12" crates 20-50 lbs 1" in 24" 1" in 16"
full 1" in 24" 1" in 20" 50-100 lbs 1" in 27" 1" in 18"
bricks   1" in 24" 1" in 16" 100-250 lbs 1" in 30" 1" in 20"
soft drink cases empty 1" in 20" 1" in 12" wood cases 20-50 lbs 1" in 24" 1" in 16"
full 1" in 24" 1" in 16" 50-100 lbs 1" in 27" 1" in 18"
milk cans empty 1" in 20" 1" in 12" 100-250 lbs 1" in 30" 1" in 20"
full 1" in 24" 1" in 20" tote pans 50-100 lbs 1" in 30" 1" in 18"
Gravity is tricky to control exactly. 100-250 lbs 1" in 35" 1" in 24"
250-500 lbs 1" in 40" 1" in 27"
The force required to start an object from rest is greater than that required to keep an object in motion.
Product, once in motion picks up speed.  Objects move most easily on close center rollers.
Objects following each other pick up speed as rolls gather angular momentum.
This chart will serve as a guideline, but be sure that the supports you purchase are adjustable.
And be prepared to experiment.
SELECTING CURVE WIDTH
Package Width 8" 12" 16" 20" 24" 28" 32" 36"  
Package Length Width (between frame rails) of curve  
8" 10" 14" 18" 22" 26" 30" 34" 38"  
12" 10" 14" 18" 22" 26" 30" 34" 38"  
16" 11" 15" 19" 22" 26" 30" 34" 38"  
20" 12" 15" 19" 23" 27" 30" 34" 38"  
24" 12" 16" 20" 23" 27" 31" 34" 38"  
28" 13" 17" 20" 24" 28" 31" 35" 39"  
32" 14" 18" 21" 25" 29" 31" 35" 39"  
36"           32" 36" 40"  
40"           32" 36" 40"  
44"           33" 37" 41"  
48"           33" 37" 41"  
INCLINE BELT CONVEYORS   recommended maximum slope

Pacific Conveyors incline belt conveyors are adjustable to 30 degrees of slope.  But in practice, increased use of slippery waxed, printed and shrink wrapped packaging has made slopes greater than 20 degrees problematic in some applications.  "Sticky" belt is available for steep inclines, but it is expensive and wears quickly.  Cleated belt is used for bulk products, but poses timing problems when used for packaged goods.
If, because of space restrictions your conveyor absolutely must be steeper than 20 degrees, call Pacific Conveyors.  We will test your package on different belts and inclines to find the best solution for you.

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