Sand your cam lobes ???

grog m aka Greg McKee wrote:

Love how this is a hate on Greg thread. Anyways, there is nothing more poisonous to a community than an 'expert' 'ive seen it all' crusty old engineer set in their ways. You know the guy, shitty attitude, cant learn new tricks, 'back in my day...blah blah'. 

I agree removing the small anodized layer won't affect cam geometry...no shit!!! But some retard could sand the lobes beyond that and affect the cam function - this is the point im making. 

Patto, cams primary function is not based on friction coefficent between cam and rock. It is based the friction generated from the applied normal force.

If you guys want to suck off Rgold then go for it. But im not going to if it means I can't warn other of the dangers of sanding your cams. 

Dude,  first wind your neck in and drop the persecution complex. If you wanted to get your original point across without coming across the way you did,  you could have said this:

"While I understand the desire to remove the anodizing for a better 'grip' between cam lobe and rock surface, be careful if you sand them and do it very lightly just to the point of removing the anodizing, otherwise you might distort the geometry of the cam lobe which is critical for it to work properly"

Instead you were like "NO!!! don't listen rGold!!" 

Next, go do some remedial reading on friction. It's a function of both the normal force AND the coefficient of friction of the materials. The frictional force is by definition the coefficient x normal force. FFS, it's been 30 years since I had basic physics and I still remember that. The irony of you whining about "crusty old engineer set in their ways" while fucking up a basic physics concept that never changes, is LOL funny. Yes Greg, physics equations do tend to be "set in their ways". And sure, the coefficients themselves can get complex, kinetic vs static values are different, high velocities can alter kinetic values and other edge-case scenarios, and those values are not mathematically precise. But the basic concept of coefficient x normal force does not change. 

I'm not trying to attack you, but you're making it pretty much impossible not to. And as a side note, Goldstone in a university math professor IIRC, with many decades of experience (I think he's in his 70s) just so you understand who's credibility you're trying to question. 

Cam Sanding? Isn't he the lead singer for The Lobes? 

Were they on the Lollapalooza tour this year?

Gavin W wrote:

The difference is negligent in a real-world scenario (i.e. not a qc lab). Just use your cams and the anodizing will wear off from use soon enough. 

You're understanding of words is negligent!!!

highaltitudeflatulentexpulsion wrote:

You're understanding of words is negligent!!!

It was negligent of him not to use negligible.

I guess I always thought that sanding and grinding were two different things.

Anyone old enough to remember the original Friends? Size 1, 2, 3, and 4. If you ground the teeth off, you had your half sizes. Probably not by intent but it worked out that way.

I've had a few cams over the years that looked like the Euler's spiral had been destroyed. Usually on Aliens with soft metal but old Trango's and Salewa's had a crap angle from the factory. They all still held. Angles even change from one brand to the next. Maybe it doesn't take nano precision to get them to hold. RC.com held a cam building competition a few years ago, they tested a whole bunch of crazy garage made cams. Most of them held. Even Valley Giant holds and they look to be cut on a band saw. 

Grog, I'm sure you can do a nice big math problem as an engineer. I would be super scared to trust your intuition on design or repair of anything though.

Will S wrote:

....... And as a side note, Goldstone in a university math professor IIRC, with many decades of experience (I think he's in his 70s) just so you understand who's credibility you're trying to question. 

and I believe a certified rock guide 

grog m aka Greg McKee wrote:

Anyways, there is nothing more poisonous to a community than an 'expert' 'ive seen it all' crusty old engineer set in their ways. You know the guy, shitty attitude, cant learn new tricks, 'back in my day...blah blah'. 

Dude, nothing about cams rises much above the level of common sense let alone rocket science. As such, common sense alone should tell you no one is going to affect the geometry hand sanding the cam lobes. If someone took a power sander or grinder to their cams then it's kind of irrelevant because they're a) not the brightest bulb in the box, b) not going to be trad climbing very long, and c) more likely than not are an accident waiting to happen sooner than later in any kind of climbing.

And, because nothing fundamental or particularly significant has changed in climbing or climbing gear in decades, when guys like rgold bring their experience, knowledge and wisdom  to the table folks should consider it a gift in the spirit of paying it forward. 

highaltitudeflatulentexpulsion wrote:

... I've had a few cams over the years that looked like the Euler's spiral had been destroyed. Usually on Aliens with soft metal .....

ha ha, i still have that old blue alien that you mangled the lobes on.  the lobes are pretty much the same shape as hefner's dried out old kidneys.  use it all the time.  seems like it still works pretty well.

Enough already with the worshipping and credentialing.   In the climbing business, I think one should be very wary of authorities and any associated credentials that may or may not buttress their claim to expertise.  The "experts" are wrong at least some of the time.  People should back up their points with reasoning that others can evaluate, and having done so, can decide for themselves whether the opinion is appropriate in the context that applies to their experience and practice. In other words, don't rely on who the "expert" is or what they've done, look at the reasoning and/or evidence they supply.  Beware of anyone who supplies neither, and be especially wary of anyone who suggests that their "expertise" absolves them from explaining. 

Just so that rumors don't get out of hand, it is true that I was involved in the very beginnings of the AMGA a long time ago, but have had nothing to do with guiding for many years now, and although perhaps certifiable, am not certified.

As for the discussion, it is pretty much a matter of tone, isn't it?  We all agree a little light sanding isn't going to do anything to cam effectiveness, other than to possibly improve it marginally in certain unusual extreme cases.  I have no problem, as I've already tried to do humorously, with adding a proviso for the clueless that sanding beyond what is strictly needed to remove anodizing is not a good idea.

FE certified.  That came off my resume as soon as I got a job. Gave me a chuckle though

grog m aka Greg McKee wrote:

Look guys, I do not think it is smart to disseminate information that people should be sanding down their cams. If you have some trad experience and know what you are doing then by all means make your gear mods. 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. 

Totem is asking for trouble by advising people to do that.

And Kyle Tarry, I am a mechanical engineer from CSU, FE certified. Go Rams!

Congrats on having the fortitude to sit through an eight hour standardized test.  I went into mine, guessed on all the answers, and walked out because I had other things to do with my time than the FE.

Not once has FE/PE come up in my professional career.

jgfox wrote:

Congrats on having the fortitude to sit through an eight hour standardized test.  I went into mine, guessed on all the answers, and walked out because I had other things to do with my time than the FE.

Not once has FE/PE come up in my professional career.

I assume that certification is not mandatory to work as an engineer?

Off topic, I know...

Bowens wrote:

I assume that certification is not mandatory to work as an engineer?

Off topic, I know...

I'll only speak to my field, electrical engineering, which is a firm no.

The only part of electrical engineering where certification is required is when human safety is a big factor like building electricity/power, transmission lines, and power plants. 

I don't do any of that, in fact that is a minority in my field.

There are PE exams that cater the other parts like computer engineering, electronics design, and etc, but in my humble opinion those are just cash grabs for the accreditation boards.

highaltitudeflatulentexpulsion wrote:

I've had a few cams over the years that looked like the Euler's spiral had been destroyed. Usually on Aliens with soft metal but old Trango's and Salewa's had a crap angle from the factory. They all still held. Angles even change from one brand to the next. Maybe it doesn't take nano precision to get them to hold. RC.com held a cam building competition a few years ago, they tested a whole bunch of crazy garage made cams. Most of them held. Even Valley Giant holds and they look to be cut on a band saw. 

This is an interesting response. I wonder if they have any videos of that competition. Sounds like the Euler's spiral wasn't as important as I thought. 

FE certification - yeah not that important professionally. But still pretty cool. Basically if you can search through a PDF you can pass it. Not that many people have it and I think its something to be proud of. PE is important for Civil Engineers and any engineer that has to do public contracting. 

I respect a lot of people that have commented on this thread and can't believe my responses have garnered their attention. I apologize for offending/challenging the status quo. I'm young, and I have some hubris and much to learn. Everyone can use a bit of humility once in while, and you guys sufficiently reminded me how little I know. I won't delete any comments I have written unless requested. I could have written more controlled responses, but its MP and sometimes I just shoot from the hip.

Kyle, you seem to have a special distaste for me. If you have anything you want to talk about feel free to message me. 

Anyways, happy climbing. 

grog m aka Greg McKee wrote:

The shape of a cam lobe is not something that an average joe whipped up on his garage lathe. It is something that only a CNC machine can properly create. 

I have at least one rigid stem Friend I purchased from Ray Jardine at Jardine Enterprises that were likely whipped up in his garage. Did you see my comment upthread "Homemade cams made on a freaking bandsaw and hand filed have worked just fine."? 

Early Abalakov cams with a constant cam angle were rudamentary at best (they looked like someone machined them with a hammer and chisel) but they worked just fine.

Of interest:

grog m aka Greg McKee wrote:

I don't know what hubris means. Not going to look it up. 

Am I the only one that got a big laugh out of this?

grog m aka Greg McKee wrote:

FE certification - yeah not that important professionally. But still pretty cool. ... Not that many people have it and I think its something to be proud of. 

I'm going to have to call shenanigans on that. Be proud you passed it, but also know that taking a review class and actually sitting through the test is required for many colleges.  No idea how hard it is to fail, but no one has failed in the last 15 or so years at university of idaho in ME

rgold wrote:

...the AMGA...

Just a note that the AMGA is hardly any more a credible a source of expertise than any number of individual climbers out and about and really, the very notion of 'institutional expertise' in climbing should be considered suspect as far as I'm concerned due to typically broad and generalized nature of such proscriptions.

Ditto for the source producers or the video up thread.

Sure, take it all in, but it's you on the hook at the sharp end and so it's on you to sort the wheat the from the chaff.