Irish John put a brilliant project on here last year where he mounted 2 vacs in a tool kit to add extra vacuum it was an inexpensive way of adding more grunt also it could be used as a back up all in all an excellent idea perhaps he may add to it and tell us of his ongoing experiences with it.
Shaun
Irish John definatly found his toolbox booster usefull .... but now he has scrapped it ...
To make way for toolbox booster mark II !
I have four 6.6 motors , two for the enforcer , two for the newer booster .
The new booster is sturdier , built in a larger toolbox with proper metal mountings , it will have soft start so i can use it with remote control like i do the Enforcer .
With the winter coming i def sometimes need the improved drying times it gives , and its great for speed in large functions rooms etc .
The original question ... all you have control over really is changing the brushes .
I dont know if you can predict how long motors last , pretty random , lots of variables .
http://www.brighthubengineering.com/commercial-electrical-applications/78579-determining-causes-for-electric-motor-failure/