Workpiece loading or pallet loading?

Detlef Scholz is the Sales Manager at RoboJob in the DACH region (Germany, Austria and Switzerland). He works mainly in southern Germany, but is also active in Switzerland and parts of Austria. "A lot of machining is done in this region, especially milling," says Scholz. "After all, this is where the heart of the German automotive industry is located, as well as precision mechanics and tool mechanics (ed. Hainbuch, Schunk, EWS, Eppinger, Heimatec). Machine manufacturers such as Hermle, Mazak, Hurco and DMG sell hundreds of milling machines here every year to customers who are also in the process of automating."

Why do many companies still clamp pallets manually?

Many customers have been working in the same way for years and are happy to stick with it.

An operator will often want to manually clamp a workpiece into a pallet and start machining it. After all, this is the way it has always been done: the operator has confidence in this way of working and, at first glance, this is also the most economical way to do it. There are also solutions available, of course, that allow you to clamp two or three workpieces in a single clamping unit. You can also choose from clamping pyramids, a pallet with four workpieces or a clamping bridge with six workpieces. There are even pallet changing systems that can accommodate up to two times twelve workpieces!

What are the disadvantages of pallet loading?

That is all great, but this way of working also has some major disadvantages:

1. Time: manually clamping the workpieces in the pallet and exchanging the workpieces in the pallets takes a lot of time. When you have a shortage of personnel, that becomes a major problem.
2. Space: I don't know many customers who don't have a lack of space on the shop floor. This way of working also requires extra space.
3. Money: every pallet costs money. The more you want to put in, the more expensive it gets. If you think you can work more efficiently with multiple pallets, you will of course spend even more money.

Why is workpiece loading often more efficient than pallet loading?

Workpiece loading can be considerably more interesting than pallet loading. Let me give you two concrete examples:

Example 1: pallet loading

I have a batch of 60 pieces with an individual cycle time of 2 minutes. Suppose I have a warehouse with 60 pallets: I can run my machine autonomously for 120 minutes. First I have to manually clamp 60 times, and after 2 hours I have to take all 60 pieces out of the pallets again. This means that for 2 hours of autonomous machining, at least 1 hour of manual work is required.

Example 2: workpiece loading

Now I take the same batch of 60 pieces with an individual cycle time of 2 minutes, but this time I place them on my Mill-Assist, from where the robot loads them into the machine one by one. Configuring the table and placing the workpieces takes me a maximum of 10 minutes. Clearing the table might take another 5 minutes. This means that for 2 hours of autonomous machining, I only need to do 15 minutes of manual work. Moreover, I don't need to buy 60 pallets.

Which loading method is best for your batch production?

When you want to automate, it is important to challenge your current way of working and examine your processes with an open mind.

"After all, when you want to automate, the idea is to make your production more efficient, right? Taking repetitive, boring work out of the hands of your operator should allow them to be more creative. Well, in my experience, for this type of batch work you should always be able to rely on a robot that loads and unloads the individual workpieces. This improves efficiency, is reliable, faster and cheaper."

Not sure which automation solution suits your milling machine and workpieces? Answer a few questions and we'll help you choose.