post #41 of 41
You raise some interesting points but I think you missed a few when it comes to glue. Glue leads to a more robust, unitized and durable product. I suspect that this is Apples primary reason for the use of glue on many of its products. Beyond that screws have issues in automated assembly, they are harder to handle, strip or break on installation and require features in a structure to screw into. Further the use of screws leads to stress concentration. I wouldn't be surprised to see some of Apples products in the future go to fully potted designs that end up being one solid mass of electronics, glue ( potting compound ) and support hardware.
Originally Posted by mbmcavoy View Post

It depends on how manufacturing processes are factored into the design. Apple products can be difficut to repair because they are generally designed for ease of assembly. Other products can be difficut to build because they are designed to ensure disposability. These are very different things!
Having both isn't impossible. For example would it really have hurt Apple to provide an access door for the HD/SSD on the iMac. It is something that can be designed in.
For example, having non-replaceable RAM means that the memory is installed via automated pick-and-place machines at the same time as all of the other surface-mount components of the main board. This eliminates the SIMM connector part which is not likely compatible with a pick-and-place installation and requires a separate labor step, and installation of the SIMM module, which is a separate labor step, and the chip no longer needs to be separately installed onto the SIMM board. Much simpler to build, nearly impossible to fix.
That is one aspect but future systems will move to soldered in components because it will be required for the fast high performance circuits that will arrive in the future. One spec for high speed RAM already requires soldered in components.
From a manufacturing standoing, glue is also extremely simple. An automated robot can quickly and accurately apply a few dabs of glue to a chassis before a worker or another robot drops a battery into an approximate position; glue will dry as the build process continues. Using screws requires threaded holes in parts, take a lot more time and precision to install, and the screws themselves cost more than glue.
Also this isn't like walking down to your local hardware store to get a tube of glue. There is an extremely wide array of industrial glues and solvents out there. Some set very quickly and others have an uncared strength to hold the components together for the duration of the assembly. People need to realize that this isn't Elmer's School Glue.
Another viable approach is a snap-together fit. Parts can be assembled quickly and easily, but taking them apart may require special tools, patience, and may break one or more parts!

I would guess that replacing just a few screws with glue or snap fit could easily shave 30 seconds off an assembly task. That may seem trivial, but it adds up. if you build millions of units, this directly will eliminate multiple person/years of labor!

It is likely much more than 30 seconds. Think about it on many Apple products the case is CNC machined and as such the bosses for those screws have to be formed, drill and possibly tapped. Getting rid of those could easily add up to far more than 30 seconds, cut tooling costs and deliver speed ups down the line. While doing this Apple ends up with a more robust product. That is pretty hard to beat really.