Five Design Points for a Laser Marking Fixture for Cylindrical Workpieces

The book covers five key points of fixture design for laser marking on cylindrical workpieces, including how to optimize stability, how to locate workpieces quickly, and how to choose the right material. It helps solve practical problems such as misalignment and low efficiency, and improves the precision and efficiency of the laser marking process.

Why is fixture design so important in laser marking?

When we are marking a cylindrical object, the most troublesome thing is that the object may turn or vibrate, causing the mark to be off-center.A good fixture can act like an "invisible assistant" to hold the workpiece firmly and quickly feed in cylindrical objects of different sizes.The following five design tips are the hard-won experience of engineers who have learned through trial and error.

This ensures a stable grip.

The "three-point method" is the most reliable.

A V-groove and a spring-loaded clamping block hold the cylinder in place at three points, much like holding an egg with three fingers. This allows the cylinder to be held firmly without deforming it, and also prevents it from spinning in the groove.Remember to put a rubber pad on the working surface.

The center of gravity must be carefully calculated.

The weight of the fixture base should be at least 1.5 times that of the work piece, just as with a toy that will not fall over.One master craftsman encountered a problem where a piece of equipment would start to shake when it was turned on. He switched to a cast-iron base, and the problem was immediately solved.

Fast positioning design.

The combination of the scale and the stop.

A scale was added to the fixture's guide rails, and the fixture was equipped with a slidable positioning block. In this way, the fixture can be set for a new model in five seconds.The cleverest idea I have seen is the use of magnetic positioning blocks. The workpiece is simply "snapped" into place.

The spring-loaded pusher is preinstalled.

The design allows for a 70 % reduction in the time required to load the machine.I would remind everyone to use stainless steel for the top pin spring, otherwise the ordinary spring will rust and jam after three months.

Material selection is also important.

The main frame is made of aluminum.

It had to be light enough to be maneuverable, yet strong enough to withstand the stresses of operation.Aluminum 7075 is the first choice, as it is three times more resistant to deformation than ordinary aluminum.Don't use plastic, which will melt in the heat of the laser.

The contact area is made of heat-resistant material.

Polyimide or ceramic films are attached to the clamping area to effectively resist the heat of the laser beam.One factory didn't pay attention to this, and ended up with indentations in the contact surface of the fixture, which caused the batch of workpieces to tilt.

Designing for compatibility.

Modular design.

The clamping device is divided into a base and an adapter, like a cell phone case and a matching stand.The same fixture can be used for cylindrical parts with diameters of 30-80 mm, with only the nylon sleeve in the middle needing to be replaced.

The range of adjustability is left open.

When designing the products, the company leaves a 20 % margin for adjustment. For example, a clamp that is rated for 50 mm is actually designed to be able to accommodate 45-55 mm.Some clients have had to buy a new fixture every time they wanted to change the diameter of the workpiece by 0.5 mm.

Heat dissipation and protection are essential.

Honeycomb-shaped heat dissipation holes.

The designers cut hexagonal ventilation holes in the non-load-bearing areas, which not only guarantee structural strength but also promote air circulation.Experimental data shows that this design can lower the temperature of the fixture by more than 15 ° C.

Dust and splash-proof design.

Add bellows to the critical drive components, especially the linear guide rails.The last time I was there, I saw a workshop where they didn't have any protection, and metal dust got into the tracks, so when they were moving the tools it was like a rusty door hinge.