DMM Pivot belay device issue

There are burrs forming on the bottom of the DMM Pivot belay device. Is this normal? I'm having to sand it off every now and then. Been doing mostly gym belaying with it. I'm thinking it's due to heat/friction of lowering.

Location: It's on the bottom of the rope slat ( if orientated while belaying. middle piece of metal that separates two ropes if doing a rap for example). And the burr faces the rope/has potential to scrape it.

This hasn’t happened with mine. Any chance you could post a picture? It doesn’t seem like a gym rope would have any embedded debris in the sheath that could cause something like this

I had this happen with my pivot almost immediately as well and it appears to be simply a result of the pressure on a small surface area of aluminum since the middle web is a fairly 'sharp' semicircular rounded profile that would meet up with the rounded exterior of a carabiner. The formation of burrs has largely diminished after the radius was worn down. A flatter web with smaller radii would therefore likely decrease the occurrence of burrs from the start.  Additionally other tube devices like the BD ATC have the carabiner rest primarily on the two outside edges when a large HMS is used which spreads the load out seemingly more effectively and on the inside edges meaning it causes the burrs to be a bit less obvious than centered the middle web of the pivot, though they are still present after extended use. 

Realistically I don't see these burrs meaningfully contacting rope given its at a pinch point between metal and the rope is guided around it by the carabiner, but ymmv, ygd, and all that good stuff.

LEFT: DMM Pivot w/ fairly minimal outdoor use for raps and a couple guide mode belays used with a DMM Phantom HMS, RIGHT: BD ATC with probably 1-2 years of consistent gym only use right courtesy of my partner used with a BD rocklock.

Yeah this happens to mine too. I just keep an eye on it, I think I might have filed off some once? But mostly it’s fine. 

All my Pivots have had that, I don’t file them as they don’t seem to be in a high risk spot. It’s just from the carabiner pressing against the bottom of the device. I’d be surprised if this doesn’t happen to all ATCs in one way or another after some period of use. 

No big deal.  File the burr off if you like, but it's not going to slice your rope or anything.  I've used mine for a couple hundred belays and raps on the same rope with no inordinate fuzzing effect on the rope.  The rope runs in the vicinity of that spot, but there's no real pressure between it and the rope.

I've had a couple different belay devices develop sharp edges on the bottom. I bought the pivot precisely because it has more metal at the trouble spots. But it wears just like all the other devices, and I have damaged, skinned a brand new rope from that razor sharp edge, especially in top roping. I'm mostly using the GriGri or Revo now, and they don't suffer from this problem. Bottom line is I now keep a little round jewelers file (rasp) in my kit and round off any sharp edges as they develop.