Sand your cam lobes ???

rgold wrote:

Does anyone even think about retiring their cams when the anodizing wears off because the geometry may have been compromised? 

This being MP, I'm sure some do. Hell, there are people worrying about getting coffee on their rope, using a sport biner on a trad climb, and a thousand other what-ifs, maybe's and outright incorrect suppositions so why would this be any different? 

You have a point, Marc...

rgold wrote:

And then there is the significant demographic that has nothing to say at all and whose only contribution is to whine about people who do have something to say.

Rgold, no need to be defensive.  Own it!  There is a large demographic (mostly men) with sufficient free time to do such things, mostly due to the lack of female interaction.  We are all worthy and play an important role here on earth.

Rgold:

"If you do decide to remove the anodize with sandpaper - don't over do it." I think that's perfectly reasonable.

grog m aka Greg McKee wrote:

But having noobs sand down their cams? Come on...all it takes is one inexperienced person sanding too much and the cam function can be altered. 

Thinking about what might cause a person to alter the cam's geometry by sanding, I don't think it's climbing inexperience.  I'm thinking the Breaking Bad scene where they get a meth-head to dig a hole..   "Don't take meth before sanding cams" would be my advice.

Joe Prescott wrote:

I just sanded all of my cams flat for more contact with the rock.

Please let us all know if you die or not.

Kyle Tarry wrote:

Let's focus on the issue as it relates to cams, and not go down a rabbit hole of "my experience is better than yours."  In the context of cams, I would state that type II anodizing is not "just a color" and that it is a (thin) coating which effects the friction between the lobe and the rock.  As it is very unlikely that cam lobes are type III anodized (due to cost and the fact that it's not necessary in the application), and as multiple manufacturers have begun masking the lobes (of their likely type-II cams) to improve friction, it seems like you're on the wrong side of this argument.

Phrased differently: if type II is "just a color," then why are these manufacturers masking the contact surface to improve friction?

OK, Kyle, for the record:

I don't believe that sanding anodizing off cam lobes will adversely affect the cam function. I've stated that upthread.

I do believe that the "design intent" in anodizing cams was cosmetic and for color code identification, not to improve wear resistance. If that was the case, I think they would be hardcoated - which you agree they likely are not. And stoppers and carabiners are also anodized for color coding. It's possible that vendors mask the contact surfaces of the lobe because there is initially some slickness. Unintended consequences.

My comment to RGold about "just a color" was to contrast (did you see what I did there?) that there is a difference in the design intent between plain anodizing and hardcoat anodize. And I wrote: "Simple anodize adds some slickness over raw aluminum. And I can tell you that aluminum that is "hardcoated" is much slicker than aluminum that is simply anodized."  I can't empirically prove that but it feels that way to me. Side by side one feels rougher to me. Maybe we have a crappy vendor....

It's not a matter of "my experience is better than yours." I did not know if you had any experience at all or just wanted to argue. 

rgold wrote:

There's nothing the matter with issuing warnings, but reasonable?  A climbing cam isn't even close to the kind of "precision machined surface" you are speaking of.  Ordinary usage causes "defects" which are literally orders of magnitude greater than .005" with little or no effect on performance, so the analogy to "flight qual" parts has no relevance to this discussion.

Of course you don't want to sand so much you actually change the shape of the cam on a scale where such a change would matter---duh!.  Who here besides me has actually done this sanding, and does anyone have any idea how much sanding beyond the removal of all anodizing is required to produce a detectable change in cam geometry?  For that matter, does anyone know anything about the tolerances for cam geometry to perform acceptably in the field?  I'd be really surprised if they are measured in thousandths of an inch.  In fact, under heavy loading, the cams flatten out, in which case  surface variations in the original curve might be of no consequence.

Moreover, the changes one is going to make getting rid of anodizing are trivial compared to the expected wear and tear of ordinary usage, which, let's not forget, also removes the anodizing if the rock is rough.  Does anyone even think about retiring their cams when the anodizing wears off because the geometry may have been compromised? 

The only relevance to the conversation is the ability to mention JPL and flight qual parts in a post on the interwebs.  :)    I'm not an engineer and didn't sleep in a Holiday Inn Express last night but I can tell you that much. :D

In terms of process, I know that DMM (not sure about WC) machines the lobes a second time after anodizing rather than mask the contact surfaces. Not that it matters, but i just wanted to sound smart. 

The color of the anodization also matters.  Blue cams are stronger and pink cams are weaker.

Dave Kos wrote:

The color of the anodization also matters.  Blue cams are stronger and pink cams are weaker.

Thank you for adding a note of rationality!

Dave Kos wrote:

The color of the anodization also matters.  Blue cams are stronger and pink cams are weaker.

That's a total stereotype and smells of microaggression.

Dave Kos wrote:

The color of the anodization also matters.  Blue cams are stronger and pink cams are weaker.

Does this mean that pink dyneema tricams are weaker than the nylon ones?

Gavin W wrote:

Yes, and the difference in friction between those two cams in this instance (#4) is due to differences in spring tension as has been discussed in multiple other threads. 

i am curious about which thread you are talking about.  i generally don't associate walking with a lack of spring tension, but rather pivot/leverage dimensions, slinging, etc.

Serge Smirnov wrote:

Thinking about what might cause a person to alter the cam's geometry by sanding, I don't think it's climbing inexperience.  I'm thinking the Breaking Bad scene where they get a meth-head to dig a hole..   "Don't take meth before sanding cams" would be my advice.

"Don't take meth before..." can end with *literally anything* and it's still good advice.

slim wrote:

i am curious about which thread you are talking about.  i generally don't associate walking with a lack of spring tension, but rather pivot/leverage dimensions, slinging, etc.

I've seen a number of cam comparison threads where folks compared BD and WC cams walking in the larger cams (#4) and the general consensus has been that it's because of a stronger spring (which prevents the cam from pivoting as easily because it catches better on irregularities in the rock).

Nick Drake wrote:

Does this mean that pink dyneema tricams are weaker than the nylon ones?

Don't you dare try to bash the pink tricam.

Dave Kos wrote:

Don't you dare try to bash the pink tricam.

Don't sand it either !

Petsfed wrote:

"Don't take meth before..." can end with *literally anything* and it's still good advice.

I once inadvertently hired a meth head to demo a living room along side of a strong climber friend of mine - the skinny meth guy was so good and so fast my climbing partner had to snap out of it and pour on the gas to keep up. I gave the guy a bonus.

Chris Owen wrote:I agree - it's a reasonable warning. Here at NASA-JPL if I told a tech to sand off .005" from a precision machined surface of a flight qual part, I'd get into a world of hurt. So - if you do decide to remove the anodize with sandpaper - don't over do it.

Gotta agree with rgold cams are so far from a precision anything as to be laughable and in fact are explicitly designed as non-precision machinces. Again, anyone 'over-sanding' their cam lobes by any means and for any reason isn't going to have a long career in trad.

If you read my post you'd see I agree with RGold - but recommended caution when taking sandpaper to 7000 series aluminum alloy.