3M Die Grinder

I am a Professional cylinder head porter so i have used a fair range of die grinders in my life from the early morrisflex ones right through to the pro desoutter die grinders. When the 3m range appeared on the market promising high horse power with high speed i thought great i going to get one. Not cheap but i thought for that price it must be good and Ive used 3M products before and found them good in the past. It arrived so i got to work and i must say first impressions were very good. The grinder was extremely fast and there was no chance of stopping the grinder while my finger was on the trigger ( Hp Very Good). Cheap guns can be stopped very easily with very little pressure on the carbide burr. I thought great but after only 5-6 mths the speed disappeared to around half what it should be. I continued to work with the gun until eventually it went down to approx 1000 rpm with the horse power of an ant. When i had a look at the gun to see if i could fix the issue i noticed the trigger button underneath the trigger handle had become very short. I removed the trigger handle and replaced the trigger button with a slightly longer bottom (6mm bar) and hey presto it works at full speed again. I was very disappointed that just after the guarantee ran out there was a problem which i now know was there way before the guarantee ran out. It is very hard to guess the speed and power when you loose a couple of hundred rpm per week. I emailed 3M because i was unhappy about there product yet the said take it back to where you bought it from at they will repair it for a fee. Why would i spend more money on trying to fix junk?? I have now hung the gun up and gone back to a desoutter die grinder which i can rely on. Be warned the 3m die grinders are not for professional use but more for your DIY man. Although I dont think many people will pay nearly £500 for occasional use.

My air lines have all the water removed long before the air gets to the gun and the gun is drip fed oil constantley so they cannot say i have abused the gun.