If so, how? Did you wear it out by turning it on/off too many times, by breaking the lockout/rotary stop at 0 and 12, or by some other method?
Does anyone know how an Aimpoint Micro rotary switch/rheostat works mechanically? What actually clicks, provides the resistance, and holds the dial in place as you change settings? What mechanism causes it to stop at 0 and 12?
Curiosity has me hunting for an answer to all of these. Any help would be awesome. 
I broke one a few years ago on an Aimpoint 1000 that had been on a large hunting pistol since about 1988.
Would you be able to elaborate on how you broke it and what happened to the Aimpoint?
50 rounds/ year of 240 grain SJHP .44 Mag ammo and general rough handling x 21 years, 357 battery changes as needed, and one day the knob just came off.
Sold to a guy that uses and refits Aimpoint 1000s exclusively at that point.
Not much of a round count but respectablelif/use out of an 80s early generation RDS.
In all fairness, comparing that to a modern Aimpoint for durability and performance is like comparing an '85 LB9 Camaro to a 2010 LS3 Camaro.
Aimpoint H1 - At the end of a three day class, it would only work on the highest settings. Sent in to Aimpoint. They repaired the rheostat.
Aimpoint R1 - The rifle it was on fell down right on the rheostat, causing it to separate from the body. Sent to Aimpoint. They replaced it with H1.
Sorry to hear about the broken R1. When it came apart, were you able to see how the mechanism worked on the insides? Was it a detent-like system that would click with every turn? And were you able to see what mechanism physically stopped the rheostat from turning once it hit 0 or 12?
ETA: or whatever the max/min settings are on an R1.
Sorry, the rheostat only came out about 1/8th of an inch, and I didn’t bother looking inside.
Understood! Thanks for the help anyway.
Unfortunately, I can explain this to you. The rheostat, or rotary switch/selector more accurately, is approximately the size of the battery. It has a hollow threaded cylinder attached to it that points backwards. There is a “set nut” and a washer that locks everything in position on the outside. Finally, there is an o-ring and threaded cap that seals everything up. The knob itself has a detent that inserts through the hollow threaded piece and mates with the switch. I’m actually perplexed right now what holds the knob in unless that hollow part is tapered and contracts with the nut… :no:
My rifle was dropped on concrete right on the knob. Aimpoints are tough, but not THAT tough. It snapped the hollow threaded piece. I’m going to attempt a fix with a dab of JB Weld. From whay I can tell, the knob is free-spinning because the lock nut is not holding the switch in place when I push in the knob and turn. If I can get the thing on and the knob won’t stay in, I will put it on a decent setting for early morning/late afternoon and plug up the hole. A couple of spare batteries will keep the thing running until I’m long gone.
I’ll try to follow up with results and pics.
My grenadier’s CompM4 rheostat spins freely and randomly adjusts brightness. No clicks to anticipate, it just randomly adjusts brightness. We keep it turned on all of the time so it’s really not an issue, but as has been mentioned, they can and do break. I remember when I was a new Private, my Comp M2 didn’t even have the knob on it because it had broken off.
We did maintenance today. I’ll check the 2404’s and see what count I can come up with. We have quite a few broken Aimpoints for everything from failure to retain zero, failure to make zeroing adjustments, broken rheostats, won’t turn on, etc.
I had something similar happen: One day my oldest T1 would only work on settings 10 and above and even those were dimmer than the same settings on my other T1. No particularly rough handling, just 20-something thousand rounds over a few years.
OP,
I apologize for my off topic reply. The internet here is very slow and all I read was “Broken Aimpoint rheostat”, not specifically the part where you’re asking about Micros.
I’ve never seen one break, but I’ve only ever had two. Both were never adjusted after being turned on. I’m sure one of the instructors who frequent this site or a LEO armorer who issues the Micro would be a reliable source of info for this question.
Once again, sorry for the off topic reply.