I have a job that is a gearless 131 ht job with small car guide wheels and the rubber rollers compound is bad and the rollers kind of melt and this goo comes off on the rails. Ever seen this, the poly rollers seem to be ok but it sure makes a mess. Jim

-- Jim (elevator555@hotmail.com), January 30, 2004

Answers

You did not specify the roller dia. and car speed. It could be that your rollers are too small for your car speed. The smaller the roller the faster it will go. Since guide rollers are driven by frition, they could be getting hot and actually melting during a long hi speed run. Some rubber and polyurathene componds tend to seperate and not resilidify after heating in uncontrolled conditions.

-- Mike (mlardner@lardnerelevator.com), February 01, 2004.

try top floor roller and screw company topfloorelevator.com

-- jag (gipp01@yahoo.com), February 01, 2004.

I have seen this, and similar. The prime reasons I have found are:

1. Environmental contaminants. Is there any chemical used in the building (such as labs) which may affect the rubber. Is there any cleaner which has been or was used in the hatch which would cause this (1,1,1,-TCE, or similar compounds), or perhaps a rope lubricant which would have an unfavorable reaction with the roller material when it becomes airborne (yes, rope lube does become airborne, especially at high speeds).

2. The rollers are just plain old. Otis, to my knowledge, hasn't used an actual rubber compound, per se, for many years. During the early days of Poly (late 70's-early 80's), many different compounds and compositions were formulated by many different companies. Sometimes it didn't work as well as expected. Some were too soft, and melted, some were too hard and shattered into little chunks or rode like steel wheels.

My own Otis equipment experience near to this was in a hoistway where any poly that was red in the hoistway (circa '70's AUV) melted and dripped off, and the same residue was on the controller contacts. But it was only the poly that was red. Brown and black poly's didn't have a problem (but they were harder than the red).

Just make sure you clean the rails squeeky clean, otherwise you might end up with little sticky spider webs all over the place or worse.

S.

-- Steve (magnevator@verizon.net), February 02, 2004.

Hi Jim I've experienced the same sort of thing on a number of occasions over the past twenty years or so. On 131s and 155s doing about 3.5m/s. On one ocassion we put it down to lubricant from the bearing throwing out and, via the centrifugal force of the rotating motion, ending up on the rubber face of the roller. however, as Steve says there can be many reasons but my thoughts would be that, if the rollers have been on the car for a considerable time, then the rubber is just too old and starting to perish. This seems to happen for no obvious reason and may not effect all rollers. I'd suggest replacing them all and giving the rails a damn good clean. I know its not the cheapest option but the ride quality will eventually deteriorate and piss everyone off. Hope you find the answer. If I can be of any further help let me know. Chears, Tony.

-- Tony Skews (tony@ampco.co.nz), January 06, 2005.

Some Otis rollers of the past lasted forever. A few vintages did as you describe. Bad urethane or something, even worse on the limits.

Me

-- me (me@me.com), January 10, 2005.