Machine frame and base: making the right choices for your custom machine
It’s the starting point of each of our designs and the first thing our technicians put together. We are talking about the machine frame and base. These two have a big impact on how your machine will perform. Choosing the right material is key. Let us have a closer look at all the factors we consider for your base and framework.
Steel, aluminum or stainless steel.
Those three materials make up the structures of nearly all the machines we design and build. And each of those materials has its advantages and disadvantages.
The right choice for your project? That depends on four machine characteristics.
- Precision
- Adaptability
- Loading capacity
- Cleanability
Let us talk through each of these in more detail. And have a look at how theory translates into practice.
1. Precision
Most machines require precision. Some projects even demand pinpoint accuracy, to a tenth of a millimeter. Even the slightest vibration would cause trouble.
Vibrations, however, are inevitable in fast-moving applications. Start, accelerate, stop. Start, accelerate, stop.
The machine base and frame must be able to absorb these forces and dampen the vibrations. To do so, we need to create mass. The machine structure must be robust enough to deal with these forces.
Steel offers rigidity that standard aluminum bases and frameworks cannot match. Their welded, stiff connections ensure the frame stays perfectly still.
Two cases that put this theory into practice.
- This assembly machine for PCB’s. Everything in this machine we designed to reach precision, down to the fixtures we custom made. We constructured the shielding framework on top out of aluminum. For the machine base, however, we opted for steel to create a counterweight for the two rapidly moving robotic arms on top.
- Case number two: this syringe transport system. We were contacted by this pharmaceutical company because they were facing issues with their previous transport system. Among other design faults, the framework was part of the problem. We made the base and framework for their new machine extra robust and solved several previous problems just by creating extra mass.
2. Adaptability
Steel equals mass. Mass equals robustness. Robustness guarantees accuracy, especially in high-speed applications.
But what if, next to precision, adaptability is a prerequisite? What if it is to be expected that some machine modules will be modified over the coming years? Or the machine itself must be mobile?
Then the modularity and lighter weight of aluminum has the advantage over steel.
Modularity
Bases for mobile and versatile machines can add much more utility if they are fully adjustable. Only aluminum machine framing systems offer this modularity. This material makes adaptations possible without having to take apart the whole machine.
Lighter weight
A very heavy framework makes it difficult for your operators to move the machine around. On top of that, the heavier the machine, the more safety measurements you must put in order.
The lighter the machine, the easier it gets. Aluminum extrusion framing systems are nearly three times lighter than steel alternatives.
3. Load capacity
If your processes need pure power, and weight is not a concern, we will opt for a steel frame base and framework.
That said, aluminum extrusion can hold more weight than you might think. Pound for pound, it owns a higher strength-weight ratio than steel.
Aluminum is interesting because it
- lowers material cost,
- improves sight lines,
- and reduces weight.
Best of both worlds
For some projects, a combination of both steel and aluminum is the best option. Like this custom stacking machine for vinyl tiles we designed and built. We chose steel for the machine framework as it guarantees the stability we need.
For the custom gripper we opted for aluminum, because vinyl sheets are lightweight. An aluminum gripper more than suffices. This also enabled us to integrate a lighter servo motor. Together with the lower material cost, this reduced the price of the machine.
4. Cleanability
When cleanability is a priority, stainless steel comes to the foreground for the machine framework and base. It is the go-to material for machines for pharma and food processing companies.
Stainless steel does not degrade under standard operating conditions and therefore does not put flakes into the air.
A seamless, sealed stainless steel structure can withstand cleaning and disinfection with even the most biting agents. Like the machine base and frame we built for this aseptic filling machine, for which the sanitary design and the degree of finishing had to meet the highest standards.
Conclusion?
Designing a machine all comes down to making the right choices in the context of your business case.
In this article we have highlighted four key aspects that play a role in our decision making for the machine frame and base. But of course, there are a lot of other factors to consider, ensuring your machine is up to its task. Want to put our more than 35 years of experience to work? Contact us.