Two factors need to be determined to make the decision on which benchtop pneumatic press is the best- Force and Application. If you know how much force (in force-pounds or tonnage) is required to complete a work cycle, then that will help to determine if a pneumatic press will fulfill those requirements. Additionally, the Application will help to determine which type of pneumatic benchtop press is best suited for the work being done, as well as the physical configuration.
Pneumatic (air) presses are economical and simple machines to set up and run with minimal expense. Unlike hydraulic presses, pneumatic presses do not require pumps, motors, tanks, heat exchangers, or hydraulic oil reservoirs. Most pneumatic presses simply require a connection to shop air, and in some instances a 110V power source for accessories. In the case of Joraco Press Company’s benchtop pneumatic presses, the standard models only require a ½” line air connection at 100PSI.
FORCE
Pneumatic presses, and pneumatic machines in general, are best suited for applications requiring less than 40 Tons of total Force, although there is no actual limit to the amount of force air can generate. The force requirement can be deceiving based on the application, part material, surface area, tool design, and much more, but in general, after 40 tons of required force, the physical size of the press and the volume of air required becomes cumbersome for most needs.
Once you know that a pneumatic press will fit your needs, then further narrowing down the required force will help find which style of pneumatic press will be best for you. The great thing about pneumatic benchtop presses is that the force can easily be controlled or “throttled” down from the max capacity simply by adjusting the air pressure to the press. There are some limitations, so it is best to narrow down your needs and choose a press rated within 5 Tons of your target force.
The simplest pneumatic presses are straight cylinder presses that use piston surface area to control the force capabilities of the press ram, and further control of the force can be adjusted using air pressure. Another attribute, cylinder length, controls the stroke of the press, but that requirement falls under Application. Generally speaking, straight cylinder presses are great for applications requiring forces up to 5 Tons. This puts them in the range of manual hand presses like an arbor press plus a little more. Some straight cylinder presses will only exert 50-100LBS of force, which is far less than what can be done manually, but there may be other application requirements that require pneumatic control.
From 5 Tons to 40 Tons, the best pneumatic press gets more complicated, or at least there are more variables to take into consideration. To make a pneumatic cylinder efficient at higher forces, additional mechanisms are required. One of the most efficient mechanisms is a toggle. A toggle press uses the advantage of levers to increase the force output of a pneumatic cylinder. In the case of a Joraco Press Company TOGGLE-AIRE® Series press, the force output of a cylinder can be increased up to 10x. However, the additional force is achieved at the expense of force throughout the entire stroke and available stroke length. A toggle press produces the 10x force on a curve up to its max force as the ram actuates, whereas the cylinder alone would produce the base force throughout the entire stroke.
A second mechanism for generating more force from an air cylinder is to add a closed loop hydraulic stage to the cylinder(s) so that the air cylinder acts as an intensifier. The air cylinder also provides an initial ram stroke at a baseline force before valving sequences to a hydraulic “power” stage to provide greater force. The air “charges the system,” rather than a traditional hydraulic press that requires pumps, tanks, and motors, while still benefiting from the power of non-compressible hydraulic fluid. These presses are also called hydro-pneumatic or air-over-oil presses.
APPLICATION
The Application that the pneumatic press will need to perform is by far the most important factor in knowing which benchtop pneumatic press is the best. In a way, every Application is unique, but there are some common factors to consider in every Application. Rather than discuss each Press Application independently, it makes more sense to discuss the common factors and requirements to keep in mind when choosing a press.
Applications that require force less than 10,000LBS are almost always good candidates for straight cylinder, direct-acting air presses because of their economy, simplicity, and configurability. Hard stops, force limiters, and stroke adjustments are all options that will help this style press perform as needed for a variety of light-duty applications like Assembly, Press-Fit, and Heat Stamping.
Other Applications like Crimping, Staking, and Swaging that require more force, but also higher precision and depth control will benefit from a pneumatic press that uses toggles. A toggle press will always actuate to a fixed dimension that can be adjusted with the shut height. This gives the operator superior control over precision and repeatability as long as the press fully actuates. The toggle press, much like a pair of vice grips, will self-compensate for the required force of the Application by generating an equal and opposite reaction force against the work it is engaging until the toggle fully locks.
Additionally, Applications like Piercing, Punching, Cutting, and Shearing often need high force, fast cycle times, and variable strokes. These Applications are unique in that they are often very simple but will cause the most uncertainty when selecting the best benchtop pneumatic press for the job. This is because all types of presses with simple tooling will handle these Applications under most circumstances, so more investigation into the other factors and requirements of the work need to be considered. Will the work have to be duplicated quickly and over tens of thousands of cycles? Then you will have to consider a toggle style press that uses less air consumption to get higher forces allowing the press to cycle very fast. Because a toggle press will have a shorter stroke than a straight cylinder or air over oil style press, this will also give it an advantage with speed. Will the work be consistent in size and tolerances, or will it vary? Then you may consider an air over oil press that can vary the advance of the ram before it turns to a power stroke. A toggle press will also tolerate mismatched part sizing by always actuating to a fixed dimension.
For some Applications, like these few examples, several mitigating factors will need to be considered before selecting a press based on Force or Application alone. All benchtop pneumatic presses will provide force, but the best benchtop pneumatic press will be the one that fits the parameters of a specific Application.
The last consideration regarding the Application is the physical configuration of the press. Straight cylinder presses and hydro-pneumatic presses can come in both C-Frame and H-Frame mounting configurations. Die to the nature of the toggle mechanisms, generally toggle presses will only come mounted in C-Frames. The most common benchtop pneumatic press style is a C-Frame press because they are compact and allow for many types of work holding, fixturing, and tool holding devices, particularly 2 and 4 post die sets that have been in use for over a century. Many larger presses, as well as smaller shop presses will come in H-Frames because they can accommodate very large work pieces and can maintain rigidity in large sizes much easier. Ultimately, the best benchtop pneumatic press for you will have a configuration that matches your work.
Joraco Press Company Benchtop Pneumatic Presses
Joraco Press Company manufactures pneumatic presses in many forces and are well suited for many applications. We have four press families that cover the gamut of press needs: TOGGLE-AIRE® Series, DIRECT-AIRE® Series, HYDRO-AIRE™ Series, and the INDEX-AIRE™ Series.
TOGGLE-AIRE® Series: Benchtop Pneumatic Toggle Press in C-Frame configuration, with forces ranging from 3 Tons to 30 Tons. Well suited for applications needing high precision, pressing to a dimension, fast cycle times, low air consumption, and die set tool holding.
DIRECT-AIRE® Series: Benchtop Pneumatic Straight Cylinder Press in C-Frame or H-Frame configuration, with forces ranging from 200LBS to 5 Tons. Well suited for applications needing force throughout the entire stroke, configurability for multiple uses, and lower volume ouput.
HYDRO-AIRE™ Series: Benchtop Hydro-Pneumatic Cylinder Press in C-Frame or H-Frame configurations, with forces ranging from 4 tons to 30+ Tons. Well suited for applications that need high force, variable work heights, short power strokes, and simple set up.
INDEX-AIRE™ Series: Benchtop Pneumatic Rotary Indexing Press in multiple forces and configurations. Combine any C-Frame press with a rotary indexer to increase output.