No one wants to hear the words, “We have a system failure.” When you’re talking pallet flow racking, one component in particular that can cause the system to break down if it is not properly configured into the lane is the speed controller. Speed controllers are vital to the safe operation of the pallet flow lane and to ensure that everything keeps moving forward as intended. To that end, let’s review why pallet flow speed controllers can fail and, most importantly, how to prevent that from happening.
Common Reasons for Speed Controller Failure in a Pallet Flow Lane:
- Pallet loads are heavier than the system was designed to handle
- Pallets are launched, rather than placed into the pallet flow lane when loading
- Pallets are in poor condition and make insufficient contact with the speed controllers – i.e. pallet has fewer bottom boards than expected and/or the pallets have inconsistent bottom board thickness
Design for Pallet Load Weight
The first reason for failure is the most common and that is when the pallet flow lane is under-designed to handle the pallet load weight. As an example, let’s look specifically at drop-in speed controllers in a wheeled pallet flow system like the Magnum wheel pallet flow.
The placement of the speed controllers in the lane along with the pitch level will act together to control the speed of the pallet down the lane. If the pallet is allowed to gain too much speed, it will eventually strip the gears or the hex bolt/bracket connection of the speed controllers and cause them to fail. The hex connection can be repaired, but if the gears of the speed controller are stripped, the unit must be replaced. Instead of replacing and repairing… let’s get the design right the first time.
Typical Pallet Flow Lane Configuration:
- GMA-style pallets 40”w x 48”d with 5 bottom boards
- Speed controllers – 56” intervals
- Pallet load weight – <2500 lbs.
- Lane pitch – 7/16” per foot
This positioning allows the 48” pallet to have 4” of run space when leaving one speed controller and encountering the next. Quality pallets will ensure good contact of the bottom boards with the drop-in speed controllers slowing the pallet as it flows. When these conditions are met, we do not see system failures.
There is a situation where this configuration needs modification and that is where the pallet rack beam interferes with the first drop-in speed controller position. What often happens then is that the speed controller gets added further down the lane, typically around 60” in. However, this positioning has an increased potential for causing that first speed controller to ultimately fail from overuse. The Mallard team recommends instead to put the first drop-in speed controller in the load position when this situation occurs for all loads over 2500 lbs. Speed controllers can be added to existing systems that fall into this criteria.
Properly Load Pallet Flow System
While we are all about speed in your warehouse, tossing pallets into flow lanes instead of carefully placing them and letting gravity take over is going to cost you more in productivity losses than if your drivers simply loaded the pallets with some care.
Check out our videos for proper technique and training support:
Pallets must be loaded and unloaded with the forklift squared up to the face of the rack. Do not approach or withdraw at an angle.
- When loading a flow lane, the pallet must be level and two to three inches above the wheels or rollers, a true line by more than 1/16”.
- Position pallet into the lane and slowly lower and tilt the pallet down onto the wheels/rollers, ensuring the front of the pallet is flush with the front beam until contact is made.
- Position the second pallet by following the first procedure until the lane is fully loaded.
- When removing pallets from a lane, lift the pallet to a level position just high enough to clear the front beam and any ramp stops, if present. Withdraw at a slow constant speed.
- Make sure the following pallet comes to the front of the system. If for some reason the pallet is stuck and does not roll forward during the unloading, push the pallet back in then back out again (also known as “plugging”). If the pallet is still stuck, reload the lane and do not unload until the cause of the jam has been found and removed.
Design for Pallet Quality
This may seem less obvious than putting considerable effort into containing the pallet weight, but it is no less important. The speed controllers only work to slow the pallet when they can make contact. If the pallets have missing or weak boards, the pallet can either pick up too much speed or get stuck in the lane. There are a number of workarounds that the Mallard team has discussed over the years and you can find those ideas easily in the Blog Section of our website, but depending on the pallet challenge, the best option is always to use quality pallets for all-around warehouse safety and efficiency.
When in Doubt, Contact the Experts
Just like you wouldn’t stop a tractor-trailer with the same brakes designed for a sedan, you can’t stop a 2500# pallet with speed controllers positioned to handle <1500# pallet loads. The pallet load weight and condition must play a significant role in the lane development to ensure the productivity and function that is expected.
Can we help you find the best pallet flow rack configuration to meet your operational needs? Give the Mallard team a call today to speak with our gravity flow experts.