Step 1.Draw Plant Layout
Step 2.Draw Path of Conveyor
Step 3.Select the Chain Attachment
Step 4.Design a Carrier
Step 5.Determine Track Elevations
Step 6.Select Vertical Curves
Step 7.Select Horizontal Curves
Step 8.Determine Guard Requirements
Step 9.Determine Required Carrier Per Minute
Step 10.Determine Carrier Spacing
Step 11.Determine Maximum Conveyor Speed
Step 12.Determine Conveyor Length
Step 13.Determine Number of Carriers
Step 14.Determine Number of Loaded and Unloaded Carriers
Step 15.Determine Live Load
Step 16.Determine Lift Load
Step 17.Determine Chain Pull
Step 18.Determine Drive Size and Location
Step 19.Suspension Methods
Step 20.Summary
Step 21.Typical Layout

The following step-by-step procedure will illustrate general principles used in designing a conveyor system.

Step 1. Draw Plant Layout

• Draw layout to largest possible scale, for example 1/4” = 1’-0”
• Make a plan view of plant area where conveyor is to be erected. Show dimensioned column lines
• Show and label all obstructions in the path of conveyor, such as columns, walls, machinery, work areas and aisles.
• Indicate “North” direction relative to building. Refer to typical layout for example.

Step 2. Draw Path of Conveyor

• On plant layout locate all loading and unloading areas, as well as any processing stations that will be served by the conveyor. Typical stations: dip tanks, paint booths, ovens, etc.
• Draw conveyor route so that it connects all areas in their proper work sequence. Keep parallel conveyor routes as closely spaced as possible. This will reduce the amount of supporting members and guards required.
• Be sure the path of conveyor does not interfere with any machine operations or other work areas.
• Indicate location of drives, vertical curves, horizontal curves, etc., relative to column lines. Refer to typical layout and conveyor symbols.

Step 3. Select the Chain Attachment

• Select the attachment to which the load or carrier can most easily be attached, keeping within the load ratings.
• Almost any type of attachment can be fabricated on special order to suit specialized applications.

Step 4. Design a Carrier

• Determine number of parts to be placed on each carrier. Loads must be balanced.
• Design carrier bracket to fit chain attachment.
• Design of carrier should permit easy loading and unloading of parts, yet hold product securely during transportation.

Step 5. Determine Track Elevations

• Elevations are measured from floor line to the top of track
• At loading and unloading areas, the conveyor height must permit a person to easily load and unload the carrier.
• Over work areas and aisles, an accepted clearance is 7’-0” from floor to bottom of guard. However, over aisles where industrial trucks, etc., are used, the conveyor height must allow traffic to pass freely.

Step 6. Select Vertical Curves

• Using the figure below, select a degree of incline for vertical curves that will provide a clearance between carriers when they are on incline/decline runs. Also, to assure clearance between carriers, dimension “A” must be greater than single carrier length.
• Select load spacing.
• Because carriers swing, clearance must be provided between top of carrier and track.
• Select vertical curves from vertical curve chart.
• Indicate on drawing the horizontal length of each vertical curve from tangent to tangent.

Step 7. Select Horizontal Curves

• Make a plan view layout of horizontal curves as shown in figure below. Clearance between adjacent carriers when they are negotiating curves will determine the minimum horizontal radius and carrier centers.
• For increased conveyor life, use the largest standard radius horizontal curve possible in your layout.

Step 8. Determine Guard Requirements

• All guards must meet OSHA and ANSI B20.1 specifications.
• Select type of conveyor guard best suited to your requirements.
• Be sure loaded carriers will clear all guards. It is especially important to check clearances on horizontal and vertical curves. Carrier templates can be used for this purpose.

Step 9. Determine Required Carriers Per Minute

• How many parts are to be handled per minute at maximum speed?
• You have designed a carrier that will carry a specific number of parts. The following typical example will best explain the proper procedure:
• Assume your production rate is 1000 pieces per hour.
• Assume each carrier holds two (2) parts.
• Required number of carriers per hour equals 1000/2 or 500 carriers per hour
• Required number of carriers per minute equals 500/60 or 8.33 carriers per minute

Step 10. Determine Carrier Spacing

• Carriers can be spaced on a minimum of 6” centers or a spacing of any multiple of 6”.
• Refer to “Step 5” or “Step 6”, and note the minimum carrier spacing determined for proper clearances.

Step 11. Determine Maximum Conveyor Speed

• Required conveyor speed in feet per minute is equal to the number of carriers per minute multiplied by carrier spacing in feet.
• To illustrate this formula:
  1. In “Step 9” we determined that 8.33 carriers per minute are required.
  2. Assume a carrier spacing of 3’-0”.
  3. 8.33 carriers per minute multiplied by carrier spacing of 3’-0” equals a conveyor speed of 25 FPM.
• To allow for variation in production requirements it is advisable to set a maximum speed of about two times the calculated, and use a variable speed drive with a speed range of about 3 to 1.
  1. A speed two times greater than the calculated 25 FPM is 50 FPM.
  2. Using a 3 to 1 ratio variable speed drive would give you a speed range of 16.7 FPM to 50 FPM.

Step 12. Determine Conveyor Length

• Obtain the sum of all straight track dimensions.
• Obtain the sum of all chain lengths in the horizontal and vertical curves.

Step 13. Select the Chain Attachment

• The required number of carriers is equal to the total conveyor length divided by the carrier spacing.
• For example, conveyor length 240’-0” divided by 3’-0” carrier spacing is equal to 80 carriers.

Step 14. Determine Number of Loaded and Unloaded Carriers

• Establish distance from load to unload points
• Divide this distance by carrier spacing.
• In our example:
  1. Assume distance from load to unload points is 144’-0” with 3’-0” carrier spacing
  2. Total number of loaded carriers is 144’-0” divided by 3’-0” carrier spacing which is equal to 48 loaded carriers.
  3. Total number of unloaded carriers is equal to 80 carriers total minus 48 loaded carriers which is equal to 32 unloaded carriers.

Step 15. Determine Live Load

• The live load on a conveyor is equal to the sum of the weights of the chain, attachments, carrier and product.
  1. Multiply weight of the chain (3.5 lbs.) by the number of feet of chain.
     In our example: 240’-0” X 3.5 lbs. = 840 lbs.
  2. Multiply weight of attachments by required number of carriers.
     In our example: 0.5 lbs. X 80 = 40 lbs.
  3. Multiply weight of empty carrier by required number of carriers.
     In our example: 9.5 lbs. X 80 = 760 lbs.
  4. Multiply weight of product only by number of required loads.
     In our example: 40 lbs. X 48 = 1,920 lbs.
  5. Totals of a, b, c, d = total live load on conveyor = 3,560 lbs.

Step 16. Determine Lift Load

• The lift load is the amount of force required to pull the live load upward along the vertical curves in the entire system.
• To calculate this force, determine the change in elevation of all the loaded vertical curves traveling upward in the system. This net vertical rise (feet) will be considered the total lifting height of the conveyor.
• The lift load for the elevation changes of the conveyor is equal to the total lift height (feet) multiplied by the individual load weight (pounds) then divided by the load spacing feet.
• Example:
  1. Per our sample layout there are three vertical curves traveling upward adding to a total rise height of 28’-0
  2. The load on each carrier is 40 lbs. and carriers are on 3’-0” centers.
  3. Lift Load = 28’-0” X 40 lbs. / 3’-0” = 374.3 lbs
• The chain, trolleys, and carriers are excluded from the calculations because they are balanced by the portion of the system that moved down the vertical curves.
• To pull a loaded moving conveyor up any incline requires a certain amount of continuous force or horsepower. This requirement, however, is frequently compensated by a loaded decline of the same length further along the conveyor and, therefore, can be ignored. Starting conditions, however, often impose an exception to this rule, since at the start of production when the conveyor is first loaded, inclines could by loaded without normally loaded balancing devices.

Step 17. Determine Chain Pull

• Chain pull is the effort necessary to maintain the normal operating speed of a conveyor under a rated capacity load. To arrive at this figure, it is necessary to add the lift load and the friction factors, expressed as a small percentage of the live load, which acts as resistance to the progress of the conveyor. The live load and the lift load were calculated in “Step 15” and “Step 16”.
• Frictional resistance is found in the bearings of the chain wheels, and the drive unit itself. This friction figure is represented as a small percentage. It should be noted that these percentages are for average conveyors that travel under normal conditions. When adverse environmental conditions exist or the conveyor is abnormally long or complex and exceeds the chain pull capacity of one drive, a progressive chain pull computation is necessary where the friction losses are progressively calculated and accumulated through the path along the conveyor. Contact McGinty Conveyors, Inc. for these conditions.
• Using a 2.5% friction factor will cover most normal conditions. A large number of horizontal and vertical curves will create slightly higher friction.
• To determine chain pull due to friction, multiply total moving load by selected friction factor. Using figures from previous examples, the following illustrates proper procedure.
  1. Total live load from “Step 15” = 3,560 lbs.
  2. Multiply by friction factor of 0.025
     Add lift load to friction chain pull to obtain total chain pull.
  3. Friction chain pull = 89 lbs.
  4. Lift load from “Step 16” = 374.3 lbs.
  5. Total chain pull = 463.3 lbs.

Step 18. Determine Drive Size and Location

• To determine drive horsepower, multiply total chain pull by the maximum conveyor speed and then divide by 33,000 ft.-lbs. per minute.
  1. In our example: (463.3 lbs. X 50 FPM) / 33,000 ft.-lbs. per minute = .77 horsepower
• McGinty Conveyors, Inc. would recommend that a 1 HP motor be used. It is always recommend to oversize the drive in order to overcome inefficiencies in the gear reducer as well as the static friction of the chain during startup.
• The drive must pull – not push – the load.
• Locate the drive so it will apply a pulling force on the most heavily loaded portion of the system.
• For best results, locate the drive at the highest level in the conveyor system and place the take-up just after the drive in the direction of travel, preferably at the lowest point.
• Show selected drive location on conveyor layout.
• Drives are available in 750 lb. chain pull capacities. For multiple drive systems, consult McGinty Conveyors, Inc.

Step 19. Suspension Methods

• Determine the method of attaching hangers to your building.
• Determine the number and type of support brackets, joint brackets and/or track yokes required to suspend the conveyor from your building steel.
• The track should be suspended at every splice when using a track yokes.
• When using welded-style splices, the track should be suspended at the horizontal curves, at the top and bottom of the vertical curves and at all four corners of the drive and take-up.
• If overhead suspension is impossible or impractical, floor supports can be furnished to suit individual needs.

Step 20. Summary

• For quick and easy reference, make a legend on the layout covering the following subjects:

1. Direction of travel
2. Speed of conveyor
3. Length of conveyor
4. Carrier spacing
5. Total number of carriers
6. Number of parts on each carrier
7. Weight of carrier
8. Weight of part/parts on carrier
9. Live load
10. Electrical specifications
11. Guard cross-section with dimensions
12. Chain pull

• Make a list of all components required to complete your conveyor system. The following is a suggested check list:

1. Straight track
2. Horizontal curves
3. Vertical curves
4. Inspection section
5. Expansion joints
6. Drive unit
7. Take-up
8. Lubricator
9. Chain length
10. Chain attachments
11. Carriers
12. Welding jigs
13. Yokes
14. Guard material
15. Header and hanger steel

• The design procedure outlined herein assumes the existence of certain environmental and other conditions. For example, the following conditions preclude effective use of the design procedure set forth above:
  1. Adverse atmospheric conditions such as alkali washes, bonderite, dust or grit.
  2. Oven temperatures above 450°F.
  3. Conveyor speed above 60 FPM.
  4. All vertical curves should be balanced.