The features involved in high-end manufacturing often require tight tolerances to achieve proper fitment and performance of the top-level unit. Understanding how critical features must be achieved drives the methods chosen to produce such complicated assemblies.
PEKO’s in-house machinery manufacturing processes give us a unique look at the techniques used to manufacture precision fabrications. Nearly every machine or hardware unit that leaves our docks has some metal frame, sub-assembly, or mechanism integration that needs to be fabricated with high precision.
In this article, we will explore the machinery used when processing precision fabrication jobs in the factory. The key equipment mentioned here is all part of a sophisticated system of manufacturing methods that can achieve tight tolerance assemblies and fabrications.
Horizontal Boring Mills and Vertical Gantry Mills
Horizontal boring mills are large machine tools that have the ability to drill holes in a horizontal direction. They typically have wide open tables and remarkably high positional accuracy. Typically, the spindle speeds are in the low range, around 3000 RPMs. The cost range for a horizontal boring mill can be hundreds of thousands or even more.
Here at PEKO, we have a handful of horizontal boring mills made by Mighty Viper corporation, like the Bridge Mill PMC 4127, and a single PBR. Their generous size and wide-open tables enable the frame or weldment to be staged for milling — even if it has a bizarre shape. These machines have been perfect for optimizing large precision fabrications with tightly tolerances holes, surfaces, and other features. Large fixtures can be created to ensure repeatability and accuracy.
Sometimes when performing milling of this nature, extended spindles over long distances can lose accuracy or introduce machining chatter. It is something of an art to getting everything dialed in, so choosing a competent contract manufacturer is just as important as the machinery type.
Portable Coordinate Measuring Machines (CMM)
Portable coordinate measuring machines are devices, shaped much like an arm, which can span many feet to measure common machining tolerance types.
The great part about portable CMMs versus a normal CMM is that you can take the arm into the manufacturing environment. Typically, a part must be brought to a traditional CMM in a Quality lab for inspection, but with a portable CMM, the device can be taken to the part itself, even if it is still staged on a machine. This is an ideal situation for measuring precision fabrications as features are being machined into them.
Another great benefit is that the portable CMM arm can reach around the precision fabrication itself, for instance, if you are trying to measure relational features that are opposite sides of a large, welded frame.
Portable CMMs are a must-have for any fabricator looking to add high precision to their arsenal. Here at PEKO, we’ve come to really love and embrace our portable CMMs. We use both FARO and ROMER by Hexagon portable measuring arms.
Modular Welding Tables
If you liked Legos as a kid, you’ll love modular welding tables. Modular welding tables are a great fit for precision fabrication manufacturing because they are easier to set up and tear down than the traditional method of building custom fixturing.
The idea with modular welding tables is that there are dozens, if not hundreds, of standard tooling jigs that can be assembled to create staging and fixturing methods for each weldment. Once you get it perfected, the welder can document the process for another day or operator. The setup will provide the same accuracy as the traditional methods, but with significantly reduced setup time.
On low volumes, these are an ideal time and cost-saving option. The modular weld table is becoming more and more popular with welding companies. Some popular types of tables that we have experience with here at PEKO are Bluco and Siegmund. There is some investment in the tooling that must be made, but with good management, the tool can easily pay for itself in recaptured wages and time savings.
Precision fabrications are such a huge part of machinery and assembly manufacturing; we would be remiss not to spread the word on innovative techniques. For more information about sheet metal and welded assemblies, download our guide on selecting the right precision sheet metal fabricator.
