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deuce4
Social climber
Pagosa Springs CO
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Topic Author's Original Post - Mar 17, 2005 - 04:56pm PT
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Anyone used Trango's new MaxCams? Curious as to how they feel in terms of holding power.
I just did a quick study of the cam angles, got 16.5 degrees on the big cam, and 40 degree cam angle (!) on the little narrow one, measuring on the screen and using this formula:
Those are big cam angles for a cam, generally you need a 14.5 degree cam angle, or less, for cams to hold in most rock (assuming a coefficient of friction of .25). Havn't done a force diagram--any other engineers out there have a look at these cams?
http://trango.com/prod.php?id=113
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deuce4
Social climber
Pagosa Springs CO
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Topic Author's Reply - Mar 17, 2005 - 05:17pm PT
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Clearly the effective cam angles will be improved with consideration of the multiple axles, but one would need to sketch up a force diagram, hard to do from just pics--I'd like to see one in person. What looks like will happen is the 40 degree cam will have a lower effective cam contact angle (angle between the rock contact and the center of force--the main axle), but the 16.5 degree cam will have a greater effective cam angle.
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Moof
Trad climber
A cube at my soul sucking job in Nor. CA
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Mar 17, 2005 - 05:17pm PT
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I think you are missing out on what the third axle does. In the case of the large cam, as you pull on the stem, the axle on the big cam moves vertically at a slower rate than the stem. The result is the actual camming angle (relates to ratio of force applied to the stem to the resulting force applied to the rock) is less than that of the cam lobe by itself.
The smaller cam is more complicated with two loaded axles, more than my burnt out brain can handle.
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WBraun
climber
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Mar 17, 2005 - 08:25pm PT
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Real good point John. There’s no mention of any real world experience using them. Just the usual advertising hype.
They are hyping these units as
” This cam is, far and away, the biggest improvement on climbing technology that I’ve seen…”
Gota get some and take some whippers to see.
And Melissa, please edit your post using Larry’s example, thanks
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Shack
Trad climber
So. Cal.
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Mar 17, 2005 - 09:26pm PT
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Deucey,
I think the idea, although I havent played with them yet,
is that the longer cams work more like an adjustable fulcrum point much like having an adjustable Tri-Cam(tm) where you could change the distance betweem the "cams" and the "pivot point".
I AM NOT AN ENGINEER so this may be all wrong!
(just the way it seems to me)
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imnotclever
climber
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Mar 18, 2005 - 08:45am PT
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Perfect sence blinny, I'm glad you posted it.
John, in your experience is the friction factor about .25 for aluminum in contact with rock? Did you test that? Or is that a design value that accounts for things like moist rock, or different types of rock?
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deuce4
Social climber
Pagosa Springs CO
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Topic Author's Reply - Mar 18, 2005 - 10:23am PT
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Mark-
That must be it, the leverage aspect--but only a force diagram will tell for sure.
It looks like a great innovation, simple enough, 2:1 range. Likely on the brilliant scale of things. Makes you wonder....
Surprised it wasn't the buzz a the last trade show, I saw those other funky triple hinged cams, which looked overly complex and prone to problems, but no one really mentioned these MaxCams. Must have been hanging with the wrong crowd.
Looking forward to trying one out sometime.
cheers
ps: imnotclever: the .25 value is a good general low estimate of the coeff. fric., some kinds of rock may be rather higher, easy to test really. The sine of 14.5 is .25:thus the cam angle--see my article on cams for more info http://bigwalls.net/climb/camf/index.html
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imnotclever
climber
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Mar 18, 2005 - 12:54pm PT
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Deuce,
Ive done some pile foundations on rock that have used the friction to resist sliding, granted it is steel to rock, but the values I've used were a little higher. So I'm always interested in what others know about it.
p.s. I've read your article many times and have your site bookmarked. Thanks for both. Some times the log spiral is used in soil engineering, for sliding resistance of retaining walls.
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TomMoulin
climber
Las Vegas
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Mar 18, 2005 - 01:16pm PT
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I too am interested in how these Max Cams feel on the rock.
Quick reference comparison with the C4's:
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Lambone
Ice climber
Ashland, Or
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Mar 18, 2005 - 01:23pm PT
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Does this mean we need new supertopo books with yet another cam range chart?
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mark miller
Social climber
Reno
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Mar 19, 2005 - 09:26pm PT
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Pipe dream ...but any chance the UIAA ( or any other group) could get manufactures of camming units to use the same color coding across a size range? Purple C-4's, Red aliens, orange TCU's and I can't even remeber wild countrys color for that size. Am I just to anal on this or does it make sense to anyone else?
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nature
climber
Flagstaff, AZ
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Mar 19, 2005 - 09:43pm PT
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Mark... if you are anal then so am I. I doubt the color coding thing will fly with the UIAA (I say that as a pure guess). I sent off many of my cams to Misty Mtn. and had them re-sewn with "proper" color coding. It's sorta odd having a blue sling on a green alien - least I'm use to it.
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Moof
Trad climber
A cube at my soul sucking job in Nor. CA
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Mar 19, 2005 - 10:05pm PT
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Them darn offset aliens ALL have grey slings. I wish they just went with the larger color or some such. I almost bought one of them snazzy new gray aliens for kicks, then thought of having an 8th grey sling adding to the alien cluster. I dread the day I have to drag along my gray camalots on something, that'll be 9 cams in similar range with the same damn color.
WC at least is using colors now. Their spectra slings just didn't stick out enough in a sea of rigid friends. Of course my hand crack size pieces now have both an older red/black friend and the new purple, and of course a couple yellow camalots. The combo clashes with my tie dye lycra when I'm dangling off double cross!
I wonder why no one has used brown for their 4+ inch pieces...
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nature
climber
Flagstaff, AZ
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Mar 19, 2005 - 10:33pm PT
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To not be totally off topic, I think I need a closer look at the MaxCam. There is an advertisement in the latest schlock and vice - maybe it's just great marketing but I like the concept of the "floating axle".
I wonder why no one has used brown for their 4+ inch pieces...
coz maybe it'd make it hard to differentiate between your shorts and the #4 on that sick lead?
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vegastradguy
Trad climber
Las Vegas, NV
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Mar 20, 2005 - 12:57am PT
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got to play with one today- although Malcolm wouldnt tell me exactly how the thing functioned from a physics standpoint- i can tell you this much- the cam angle is not determined from the axles. you have to hold it and actually pull the trigger and then you'll see how it works and go..'Oh!'
it feels and works just like a normal cam- with a mutant expansion range. i'm looking forward to their release.
the Metolius Supercam (which i also got to play with) is much weirder in function, and tough to describe. I do think, however, that Trango's design is superior and will perform better in the long run.
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WBraun
climber
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Mar 20, 2005 - 01:05am PT
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To Mr. MaxCam
If you read this post I would like to try your new cam. Would you be so kind to send me some demo to test. I will write some nice result review afterwards.
I will tell everyone I meet about it, unbiased!
Thank you for your time, Werner
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healyje
Trad climber
Portland, Oregon
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Mar 20, 2005 - 02:17am PT
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Having held a SuperCam I can say that I have complete faith in the engineering and design of the Metolius product. It is very much an extension of their existing bombproof cam line and is utterly solid.
I haven't held a MaxCam on the otherhand, and while I have a high regard for Malcolm and team at Trango, I still have significant reservations and questions about the efficacy of any cam-on-cam design, regardless of the manufacturer. I simply have doubts about the resilence of the cam-on-cam link both when subjected to out-of-plane loads and a couple of years of repeated falls and general wear and tear.
The Metolius SuperCam builds on a proven design where Trango's SuperCam design is a fairly radical departure and will need to be validated over time once we all can get our [grubby] hands on some and collectively give them a few thousand real-world flight tests.
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Moof
Trad climber
A cube at my soul sucking job in Nor. CA
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Mar 20, 2005 - 01:08pm PT
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"Having held a SuperCam I can say that I have complete faith in the engineering and design of the Metolius product. It is very much an extension of their existing bombproof cam line and is utterly solid."
Gag. Anyone else note the location...
"I still have significant reservations and questions about the efficacy of any cam-on-cam design"
Any cam on cam design? I was pretty sure there was only one "cam-on-cam design", isn't that the point of getting a patent?
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healyje
Trad climber
Portland, Oregon
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Mar 20, 2005 - 07:12pm PT
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Living in Oregon has nothing to do with my opinions on gear. I've been climbing for 31 years and no one gets a free pass relative to what I'll take a dive on. I have nothing but the highest regard for Malcolm and team at Trango. Ditto for Doug and the Metolius team. It isn't about the people - it's about the designs...
Possibly you simply missed OP's link cam... HOOAP.
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