Choosing a steelworker - is a single or twin cylinder model best for you?
- Peter Dawber
Multi station steelworkers - sometimes called ironworkers - are versatile machines which can benefit most fabrication workshops. They are typically available in either a single or a twin cylinder design, each having its own particular features. It is advisable to carefully review which design would work best for you; the single cylinder models are attractively priced, but there are some limitations which need to be considered.
Let’s take a look at the most important differences…..
How do they work?
Steelworkers or ironworkers are multi function machines which feature a number of workstations for punching, shearing, cropping and notching of steel or other metals. They work by means of a hydraulically powered arm fitted with the moving blades, which is housed within the machine body which holds the fixed blades. A punching or notching unit is normally fitted at either end of the machine.
How do the designs vary?
With a single cylinder design the moving arm has a pivot point towards the middle of the machine, with the punching station on one side of the pivot point and all other stations on the opposite side, with one set of limit switches to control the cylinder stroke. Twin cylinder models on the other hand have one dedicated cylinder for the punching station and another for everything else; the punching cylinder has a vertical action with the other cylinder powering the arm in a radial action similar to single cylinder models.
Potential limitations of a single cylinder design
No vertical cylinder at the punch station
With a single cylinder model the die height is fixed as the radial action of the punch needs to meet the die at its most vertical point. This design is workable when punching simple round, square or slotted holes, however with larger more complex tools it can start to create uneven forces on the tooling. With a vertical punching cylinder, die heights can be changed, special tools can be used and set to a tight tolerance, and more precise bending tools can be fitted.
Single point cylinder stroke adjustment
A major benefit of a separate punching station is seen when setting up the machine. With a single cylinder ironworker the settings will need to be changed from punching to shearing, cropping or notching, as when the punching station is at the top of its stroke, then the rest of the stations at the other side of the pivot point are at their bottom position. This means the cylinder stroke will need resetting each time you change the process. With a twin cylinder steelworker there are two separate sets of stroke limit switches which allows the punching station to be left set up while using the rest of the machine.
Punching thickness capacity
Normally a single cylinder steelworker would be limited to 15mm plate capacity due to the radial action of the punch stroke; while it isn't impossible to punch thicker material it won’t allow for tighter punch and die clearances and is also likely to prematurely wear the tooling. Therefore if you are looking for a higher capacity machine, for example to punch a 20mm plate thickness, then a twin cylinder model with a vertical punching action is normally required.
Our conclusion is that a single cylinder machine - such as the Morgan Rushworth HSW model - is ideal for jobbing applications where set up time is not critical and the job requirement is mainly simple hole punching, shearing and cropping. A steelworker is a major time saver over sawing and drilling and these entry level models get the job done.
If however production punching and shearing is needed or special tooling is to be used then we recommend the twin cylinder machines like the Morgan Rushworth HST range. The steelworker can be set up for a process such as shearing flat bar into squares for structural steel base plates, which can then be punched without resetting the machine. In many twin cylinder models both sides of the machine can even be used at the same time, although typically not too full capacity. This is really two machines in one!
Need help deciding?
There is nothing like seeing machines in action to make a final decision; contact us to arrange a visit to our showroom to see both models in action side by side. To find out more about some of the lesser known features of steelworkers, have a read of our article on Getting the most out of your steelworker. Or just give us a call on 01785 336732 with any questions.