This assembly fixture is one of the best examples of a project that pretty much encompasses all of my skill sets in one project.

The Concept, Engineering, CAD, CAM, and execution is all my work, no one else was involved in bringing this fixture to life.

The legs shown attached to the top surface are normally stored inside of the case and are used when the machine is being service and access to the components on the bottom side of the fixture is necessary.

In this shot of the 3d model, you can see there are 4 legs on the underside of the fixture as well so that when it has been removed from the enclosure it has legs to stand on. There are more shots of the leg implementation at the bottom of the page.

The heads are secured to the reader body using UV cured adhesive applied to the heads prior to the machine placing them in alignment. The software running the machines controls the UV light source turning it on at the appropriate time and duration to cure the adhesive.

The machine is controlled using the Mach 3 CNC control software and a Gecko G540 4 axis stepper motor controller to drive the linear stages. I created custom macros and did all of the G-code programming needed to control the machine.

Machine operation is started by depressing both green buttons simultaneously to start the alignment sequence.

Once the heads have had adhesive applied to them, they are placed in the head holders on the opposing head slides. The center slide moves to the measurement position then each head slide approaches the measurement plate. Once it completes the probing routine both heads are moved to the retract position so the center slide with the reader body attached can move to the assembly position. Once in the correct position, both heads are simultaneously moved into mounting position with the desired head gap between the crowns. The UV light sourced is energized for the proper amount of time to cure the adhesive. After curing, the heads are released from the head holders as they are now adhered to the reader body. Cycle start is once again initiated by pressing both green buttons and the head slides retract to the loading position and the center slide moves back to the load/ measure location. All of this is controlled by the parameters in the software which are easily changed if desired.

Emergency Stop switch should a cycle need to be stopped mid sequence!

Head Holder #1

Head Holder #2

Notice the cable management and the nicely machined parts. I take the time to program and machine chamfer all of the edges of my machined parts whenever possible, it makes for some very clean and professional looking parts.

More cable management!

Here you can see the 4 axis G504 Gecko stepper motor controller. I designed the sheet metal part in Solidworks using the sheet metal module. I then flattened it in Solidworks and then CNC machined the flat pattern. Once complete, I folded the sheet metal using the box and pan break. I machined up all of the spacers, hand built the power supply board, installed the power transformer, fan, and power inlet module.

I like to use these NEMA electrical boxes for enclosures and I try to just use them as a cover. I prefer to be able to completely remove my fixture from the box without components mounted to the box and to the fixture with cables in-between, I have found that this makes for a very clean and easily serviceable setup. And most importantly it prevents wires from being damaged in the service process.

A nice shot of the controller / power supply module and the nicely managed cables!

In this photo you can see the measurement plate mounted to its Delrin isolation block and the coiled cord used for the continuity probing circuit. While not present, you can see the pocket and blade that holds the reader body on the measurement plate.

Here you can see the power cable that is attached to the power inlet mounted to the enclosure itself but it is easily removed from the power inlet on the Controller chassis for service if necessary.

Enclosure mounted power inlet with power cable strain relief.

This is the bracket that attaches to one of the internal legs on the bottom side of the fixture. It is used to hold the 4 legs from the top of the fixture plate when the unit is not being serviced. This keeps them handy for service but neatly secured inside the enclosure.

Another shot of the leg storage clamp. Notice the socket head cap screw used to clamp the holder to the internal leg.

4 legs screwed into the mounting bracket

Here you can see the legs attached to the storage clamp. Of interest here is the O-rings used as rubber feet that are attached to the legs. The groove they reside in has an undercut circular groove which is easily created using the 3d printer.

And finally, you can see the legs in the storage position mounted to one of the internal legs.

Some machining on the ground flat aluminum stock used as the fixture base plate.

These are the head holders after the first cnc operation. Notice that all of the edges are chamfered and the vertical edges all have a small radius machined on them!

These are the completed parts after 3 operations!

Notice that after the 3^rd and final operation even the bottom side has been machine chamfered!