Problem
Our customer was designing a new inkjet printer that used a new small ink cartridge. The printer design was lagging behind the ink cartridge design, which was just a modification of an existing product with a smaller plastic case. Our customer needed a way to install the small cartridges into existing printers that used the larger ink pens. This would allow development of software to proceed while the printer mechanism was still in the early design stages. We needed to finish the project in less than a month.
Solution
In principle the project was simple. Just combine the outer mechanical features of the larger pen with internal features in the adapter to hold the smaller cartridge in position to mate with the pen pocket electrical contacts.
Complications arose because no one at the customer's local plant could open the files from the developer in Elbonia who designed the smaller ink cartridge. The files would not open in the programs we use at AO either, but we did find a 3D CAD file viewer that would display the content. Unfortunately, it would not translate the files to a format we could use. The viewer would create slices through the design, however, and save these slices in DXF format files. So we made hundreds of slices and combined them in our CAD program to regenerate the 3D drawing. This took more than a week while the clock was running.
We combined the two 3D models of the ink cartridges and produced a design that placed the relevant features in the correct positions. Then we designed the latch mechanism to hold the small pen in the pen carrier. The files were sent to the machine shop while we experimented with spring forces for the latch mechanism.
Results
All of the pieces came together and ten of the test adapters were delivered to our customer on schedule. The next day the inexperienced engineer in Elbonia discovered that he had set an option in his program that encrypted the drawings so no one else would be able to edit them.