Fareed Mohmed · Engineering
Stopper Cylinder Selector
Carrier weight · Conveyor speed · Side force · Part number
Choose a pneumatic stopper (Mindman, SMC, Festo or AirTAC) for a pallet or work carrier on a conveyor. A stopper is chosen by what it has to stop, not by force and stroke.
Mindman, SMC, Festo and AirTAC catalogue data (other makers are not loaded yet). Curves in the catalogue were read off its graphs, so allow about 5 %. Confirm every part against the maker’s catalogue before you order. See also the Pneumatic Component Selector for ordinary cylinders.
Start Here: The Selection Process
Seven steps from the carrier to the order. Read this once, then use sections 01 and 02. Steps with a button link to where you enter or read that step.
Know what the stopper does
A stopper cylinder stops a pallet or work carrier on a conveyor and holds it at a station, then lets it go. It is chosen by what it must stop, not by force and stroke like an ordinary cylinder.
Weigh the carrier
Take the carrier together with the load on it, in kg. If two stoppers share one carrier, each takes half.
Enter it in section 01 →Note the conveyor speed
The speed at which the carrier arrives at the stopper, in metres per minute. The faster it arrives, the less weight a stopper can stop, because the energy grows with the speed squared.
Check the weight against the speed chart
Each stopper has a chart of the weight it can stop against the speed. Your point must be under the upper curve, and over the lower curve where one is printed. Keep it under about 80 % of the limit.
See the result in section 02 →Check the side force
When the carrier hits the stopper and the conveyor keeps pushing, the rod takes a side force. The tool takes it as friction × weight. Each model has a side-load limit that rises with the air pressure.
Pick the stopper type
With a shock absorber (Mindman MSBE and MSBD, SMC RSH, RS1H and RS2H, the lever types of SMC RSQ and RSG, Festo DFST and the toggle-lever STAF-K, and AirTAC TWH, TWM and the K types of TWG and TWQ): they stop heavy or fast carriers gently. Roller or round-bar rod end (Mindman MSBR and MSAR, SMC RSQ and RSG, Festo DFSP and STAF, AirTAC TWG and TWQ rod or roller types): rubber cushioning, for lighter or slower carriers, up to about 20 m/min. Mindman MSBS is a direct stopper for a large side load on a slow conveyor, and MSL is a compact range for light carriers.
Order and check what the tool does not
- Options in the order code: spring or double acting, lever lock, roller material, thread
- Absorber grade for the MSBD 50 mm
- Sensor to confirm the stopper is up or down
- The exact part number from the maker’s catalogue
Common mistakes
Brands that make this product
Outlined gold: loaded with series and part numbers. Grey dashed: not loaded yet. Confirm every part against the maker’s catalogue before you order.
Mindmanpart numbers
SMCpart numbers
Festopart numbers
AirTACpart numbers
Parkernot yet
Camozzinot yet
Norgrennot yet
Aventicsnot yetBrand names and logos are trademarks of their owners and are shown only to identify catalogues.
Your Carrier
Stoppers That Pass
How It Is Calculated
Weight and speed
A model passes if your weight is under its upper curve (and over its lower curve where one is printed). AirTAC prints a maximum curve per bore, and for TWH also a minimum curve, which the tool treats as the lightest carrier the absorber can handle; for its lateral graph, like SMC, the pressure needed for a given side force. Festo prints one load-against-speed curve per type, with a 1 mm elastic buffer on the carrier (the DFST curves are for friction 0.1). SMC prints a curve for each friction value (0 and 0.1 for RSH, RS1H and the lever types, 0.1 and 0.2 for RS2H); the tool uses the curve for the friction you enter, or the next higher one. If your friction is above the highest curve, the result is marked as optimistic. The curves fall as speed rises. Where the catalogue gives only the flat part and the value at 40 m/min, the curve between is fitted as a power law, which is on the safe side.
Side force
Side force = friction × weight ÷ number of stoppers. The side-load limit of each model is read at your pressure.
Energy
Kinetic energy = ½ × mass × speed², shown for information. The catalogue prints no absorbed-energy rating, so it is not a pass or fail test.
Limits of this tool
The curves were read off the catalogue graphs, so allow about 5 %. SMC prints no allowable lateral load number; the side limit is the pressure needed for a given side force F = weight × friction, from its graph. The lever types of SMC RSQ and RSG have no lateral-load graph, so side force is not checked for them. SMC RSA is the older version of RS1H and is not listed separately. The MSBD with a 50 mm bore has three absorber grades (L, M, H) and no printed side-load curve for M and H, so side force is not checked for them. Festo DFSP curves: the flat part is read from the graph and the falling part is calculated from the printed impact force (force × 1 mm ÷ speed²), which matches the graph to about 5 %; its side-force line is a straight rise from 1 bar to the printed limit at 6 bar. All Festo DFSP data applies only to mounting on the bearing cap or the DAMF-F7 flange; other mountings give lower values. The DFSP-16 is checked from 2.8 bar because the spring versions need it (the double-acting version works from 1 bar). The 2004 STA and STAF sizes are marked in the result; they print no side-force limit, so side force is not checked for them, and they may no longer be sold. The Festo DFST 50 and 63 curves top out at 400 kg and about 490 kg, below the 800 kg in the catalogue headline for 50 to 80. AirTAC: the TWH load curves come from a second catalogue, because the two AirTAC catalogues disagree for bores 40 to 80 (the one used is the lower, so it is on the safe side). The catalogue prints no TWM load graph, so TWM uses the TWH 50 curves (marked in the result). TWG prints one load graph with no K curve, so it is used for both its rod and K types. The K types of TWG and TWQ have no lateral graph, so side force is not checked for them, and AirTAC prints no weight or energy rating. AirTAC part codes follow the headline layout of the catalogue (model, S for magnet, bore, stroke, stopper letter); the TWQ data sheet writes it in a different order, so check the code. Part numbers are built from the order code with default options; for Festo the type code shown is one orderable example, so change the rod, function and stroke letters as you need.