If it's a Dyson model, then it's a well understood problem, with a trivial solution. A solution that should be apparent to anyone with any sort of engineering background who doesn't mind actually thinking about the problem, rather than, say, just complaining about it without applying any thinking. Just sayin', and it might well not apply in your case.
Background: The canister has two cyclone systems. The outer cyclone is a lower-speed system designed to separate lint and larger contaminants (think wood chips, seeds, grains of sand). The inner cyclone is designed to work with rather fine particulates and performs better than HEPA rating. Both of those systems are "exposed" to the bottom lid of the canister, since you need to dump stuff from both of them.
The seal that separates those systems, and seals against the bottom canister lid, was faulty in a few production runs, and invariably resulted in large particulates entering the HEPA cyclone, promptly clogging it. Since the HEPA cyclone now doesn't work, all of the HEPA filtering is done by the HEPA post-filter, all the while dirty air passes through the motor and wrecks it as well.
If you ever have that problem, you need to inspect the seal that seals the HEPA cyclone cylinder against the bottom dust can lid. The seal and/or the lid may need to be replaced.
Again, it's well understood, and it's a fixable problem. A properly operating Dyson won't ever clog the HEPA filter. If you have a clogging HEPA filter in a Dyson, you're also ruining your motor, and you must fix it or else there's simply no point in operating the machine any further.
