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Test drive Totem Cam's
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By kayakscum1
Aug 18, 2010

mattm wrote:
So based on the chart, the Totems in the small sizes look pretty spot on for replacement of the green and yellow aliens. Can anyone do size comparisons of the head width and the area right below the head? I'm talking about the area where the Aliens trigger wires connected and on the totems where the wires run through the "stem plate" Curious how the totems "bulk" affects pin scar placements etc. Thanks! Looks like they're solid cams but initial impressions say they're not world changing (as expected). Gear Heads will be first adopters here for sure. Also, I wonder if the cam lobes are made out of the softer 6061 Alu like Wired Bliss and CCH use(d) rather than the harder 7075. Better grip but less durable.

I will get a hold of some aliens to do some side by side comparisons. Do you want pics?


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By mapeze
Aug 18, 2010

Hello to everybody,

I'm Mikel, designer of Totem Cam. Just to answer one question arose in the forum.
Cam lobes are 7075-T6 aluminum alloy.


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By Tyler King
From Salt Lake, UT
Aug 19, 2010
Touch Up

First off, thanks Mikel for providing the opportunity to give users an experience with the Totem cams. I am very interested to see how they do. I am also interested to see what you do with the feedback you are getting. Secondly thanks to Tyler for facilitating this! *Side note, maybe this was clarified, but the trigger wires are not what hold you in a fall. They do the opposite of expand the cam, they retract it! There is another set of cables that runs on the opposite side of the lobes that effectively aids in opening the cam under load. I'd like to see a force balance of these compared to traditions cams with stems...

Sunny-D and I took the Totems up the Coffin in LCC this morning. The coffin is a classic 5.9 finger-hand crack on less than vertical granite. Being a BD cam user I found the similar color coding very useful in getting the right piece. Although, I'm not sure why the small yellow is not also the BD grey. I also found the cams very ergonomic to hold while placing. I use BD cams for the because they feel the most secure in my hand while placing and/or cursing. The Totem cams were nearly as comfortable. They are just a slight bit thicker at the triggers. I like the thumb rest, and the triggers. I prefer to have the triggers on the outside of the 'stem' as opposed to having the stems on the outside of the trigger bar like my metolius TCUs. This way you can also pinch the 'stem' between 2 fingers to stabilize it.

The other thing I noticed right away was a little bit of friction when pulling the trigger, at least compared to BD. However, not any more that some of the other cams on the market. They just didn't have that snappy feeling of the BDs.

All of the placements were confidence inspiring. Due to the lower angle of the route and a fresh pair of underwear I didn't take whippers like jason and adam, who are real climbers. I did place a few less than ideal placements and fell with the cam a foot or two below my waist + some rope out. I watched the cams carefully and they didn't budge. They also didn't seem to want to walk around in the crack too easily, which is a good thing! Over all it was a good experience.

The only real negative in my book was that I noticed in certain placements where you would typically have one lobe that is extended more than the others, the lobe didn't open up to it's position unless you pulled on the sling to set it. See the pics below. This is from some minor binding (for lack of a better word) of the cables attached to the back side of the lobe. It appears to be inherent in the design, where the spring used to force the cam open is actually part of the 'stem'/cable, and the opposing lobes are somewhat integrated. Simply put, the opposing lobs tend to want to move as a pair, although with a load the lobes will open up all of the way.

Ok, I lied the only other negative thing is the price. $80 for a non-huge-ish cam is a bit pricey when there are many other options for less. If I was an aid climber I would probably cough up the dough for a set just for the 2 lobe loading feature, which is what attracted me to the design in the first place. Now if there was a way to use only 2 lobes to hold a fall...

Pros:
- 2 lobe placement for aid
- ergonomic
- secure placement, even in flared cracks
- Well built/High Quality

Cons:
- Pricey
- a bit bulkey and maybe a bit heavy (I'm too lazy to compare the actual weight specs)
- Single lobe bind.

If the price were more competitive I would consider these as a second or third set of cams. It's a delicate balance, especially as the new kid in town. Making margins, staying inexpensive enough so people will buy your gear over their life long favorite piece, yet not being too inexpensive so as to seem cheap. I hope to see Totem do well. It is thinking outside the box that keeps us going up!

First placement.

Purple Totem placement #1
Purple Totem placement #1


Purple Totem placement #2
Purple Totem placement #2


Somewhat flaring placement. no problem.
Red Totem flared placement #1
Red Totem flared placement #1


Red Totem flared placement #2
Red Totem flared placement #2


Notice how the lobe I am not holding stays in place.
Red Totem sticky lobe #1
Red Totem sticky lobe #1


Red Totem sticky lobe #2
Red Totem sticky lobe #2


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By kayakscum1
Aug 19, 2010

mattm wrote:
So based on the chart, the Totems in the small sizes look pretty spot on for replacement of the green and yellow aliens. Can anyone do size comparisons of the head width and the area right below the head? I'm talking about the area where the Aliens trigger wires connected and on the totems where the wires run through the "stem plate" Curious how the totems "bulk" affects pin scar placements etc. Thanks! Looks like they're solid cams but initial impressions say they're not world changing (as expected). Gear Heads will be first adopters here for sure. Also, I wonder if the cam lobes are made out of the softer 6061 Alu like Wired Bliss and CCH use(d) rather than the harder 7075. Better grip but less durable.


In response to the alien comparison. I didn't have the orange alien to compare with its comparable green Totem Cam, but the others ran in comparable sizes. I am guessing the green Totem will be slightly larger than the orange alien.

Blue totem vs green alien width comparison
Blue totem vs green alien width comparison



Yellow totem vs yellow alien width comparison
Yellow totem vs yellow alien width comparison



Purple totem vs red alien width comparison <br />
Purple totem vs red alien width comparison




Red totem vs purple alien width comparison.
Red totem vs purple alien width comparison.


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By bheller
From SL UT
Aug 20, 2010

Now drop them in sand below a tower and see how those wires behave- I have yet to encounter a climbing situation where this cam design would offer an advantage over cams that are currently on the market... with regards to this product, I can't help from asking why?


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By Jesse Davidson
From san diego, ca
Aug 20, 2010
n cascades <br />

wasnt the direct loading intended to allow a more aggressive cam angle and a larger range? is this true?


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By Ryan Williams
Administrator
From London (sort of)
Aug 20, 2010
El Chorro

I'm interested in why these cams (apparently) hold in downward flaring placements. My little bit of physics and engineering knowledge would lead me to believe that when engaged, the load bearing wires run over the top of the cam lobes, actually pulling the cam lobes from the top and forcing the lobes outwards? Sorry, I probably wrote that poorly but does anyone understand and am I correct?

This seems different than a regular cam...

OK now I'm confusing myself... someone who is smarter than me please explain exactly how these things work.


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By Tyler King
From Salt Lake, UT
Aug 24, 2010
Touch Up

It's actually the cam angle that dictates how well a cam will perform in a flared placement. If the walls of the crack are perfectly parallel the cam angle is X. However, if the walls of the crack have an Y degree downward flare (per side) the effective camming angle of the cam is now X - Y. The less the camming angle, the less force is applied on the walls of the crack. The normal force applied on the walls of the crack results in friction (the vertical holding force) which is what actaully holds the cam in a fall. The only drawback to increasing the camming angle is that this also increases the stress on the cam.

I suspect that the direct loading of the cams may result in less force on the axle. Thereby allowing a greater camming angle. However I am not entirely sure. I would need to do a force calculation. Here's my logic: Traditional cams load the lobes through the stem, which applies shear stress to the axle, the opposing force of the lobes also applies shear stress to the axle. The totem cams only have shear stress being applied to the axle by the opposition of the lobes, so there is potentially less stress on the axle. Although to really be sure one would have to do some calculations and I'm just a bit too lazy at the moment for that! Or Mikel could magically appear on this thread and comment...


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By mapeze
Aug 25, 2010

The maximum downward flaring angle for a cam is 2 x cam angle. For example, a cam with 14 degrees cam angle can theoretically hold in a downward flare up to 28 degrees. In a larger downward flaring angle, the cam lobes would walk over the rock faces as the cam lobes are forced to open. To understand this: imagine a cam with circle shaped cam lobes (no spiral lobes, just round like a wheel). This would be a 0 degrees cam angle (0 degrees logarithmic spiral is just a circle). If you perfectly fit this 0 degrees cam into a crack with parallel faces, the cam lobes would just rotate like the car wheels. In this case, it happens with 0 degrees cam in a 0 degrees downward flaring crack. Exactly the same would happen with 14 degrees cam into a 28 degrees downward flaring crack.
About holding power: the holding power (otherwise said, the minimum friction coefficient required to avoid slip) is not affected by a downward flare. In a downward flare, only the axle shear forces (and cam lobes over rock) are affected. Near the maximum downward flaring angle, the axle shear forces would be increased to the infinite. And when the maximum downward flare angle is reached the cam lobes rotate and do not work.
The Totem Cams performs better in downward flares because the cam angle is 20,35 degrees. The holding power of a Totem Cam, is like a SLCD with approximately 13 degrees cam angle.
I will show all this with drawings and mathematic demonstrations next week. This week I'm out of office.


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By DannyUncanny
From Vancouver
Aug 27, 2010

Tyler King wrote:
It's actually the cam angle that dictates how well a cam will perform in a flared placement. If the walls of the crack are perfectly parallel the cam angle is X. However, if the walls of the crack have an Y degree downward flare (per side) the effective camming angle of the cam is now X - Y. The less the camming angle, the less force is applied on the walls of the crack. The normal force applied on the walls of the crack results in friction (the vertical holding force) which is what actaully holds the cam in a fall.


This is not true. I think you just got it mixed up. Smaller cam angles apply greater compressive forces.

mapeze wrote:
About holding power: the holding power (otherwise said, the minimum friction coefficient required to avoid slip) is not affected by a downward flare. In a downward flare, only the axle shear forces (and cam lobes over rock) are affected.


This is only true for regular cams where there are no torques involved. The contact angle of a regular cam is always colinear to the force vector. Not so with Totem cams. As the flare angle increases, the contact angle remains constant (20 deg off of perpendicular), but the applied force vector angle does not remain at the intended 13.something degrees, it increases with flare.

Another way to describe coefficient of friction is the slipping angle. A coefficient of friction of 0.25 is about equal to a slipping angle of 14 degrees. If you rest a block of aluminum on a rock inclined at 14 degrees from horizontal and it slides off then the coefficient of friction was less than 0.25.

So to apply this to downward flares, if the coefficient of friction were 0.25 (this is a commonly used value for cams), the maximum flare angle that could possibly hold anything at all is 28 degrees. The reason is that for anything to stay in there, it has to push down on the walls, and to be pushing down, it must be pushing at an angle greater than 14 degrees. And if you push at an angle greater than 14 degrees you slide. This doesn't matter for traditional cams because they always push at the same angle and will just roll out when the flare exceeds that angle.

The reason that Totem cams can be seen to hold in flares greater than 28 degrees is because 0.25 is a conservative estimate for coefficient of friction. In most cases it will be greater. To actually hold in a 40 degree flare, a totem cam would require a slipping angle of 20 degrees or greater.


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By brenta
From Boulder, CO
Aug 27, 2010
Cima Margherita and Cima Tosa in the Dolomiti di Brenta.  October 1977.

Very good explanation. I'll only add a graph that shows how the effective cam angle of a Totem Cam-like cam increases with flare (phi is half the flare angle). The little surprise, when I derived this graph some time ago, was that for values of phi between 3.65 and 14 degrees, a traditional cam with cam angle of 14 degrees requires less friction to hold.



How to read the graph:

The x axis shows half the flare angle. The y axis measures friction coefficients, tangents of angles, and force ratios.

The blue line is the tangent of the effective angle of a Totem Cam-like cam. The effective angle is the arctangent of the ratio of the (magnitudes of the) forces along the face of the crack (F_l) and perpendicular to it (F_n). This angle starts at about 13 degrees and increases until, for phi=20.35 degrees, it equals 20.35 degrees. The blue line gives the minimum coefficient of friction as a function of (half) the flare angle.

The horizontal red line is for a conventional cam with a cam angle of 14 degrees. Its interpretation is otherwise just as for the blue line.

The green line is tan(phi). It intersects the red line for phi=14 degrees and the green line for phi=20.35 degrees. The intersections mark the angles for which the two cams pop off the flared crack even with very high friction.

The blue and green lines look straight, but that's only because the angles are relatively small. The red line is straight.


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By Tyler King
From Salt Lake, UT
Aug 31, 2010
Touch Up

DannyUncanny wrote:
This is not true. I think you just got it mixed up. Smaller cam angles apply greater compressive forces.


Good catch... Yes I meant it the other way around!

DannyUncanny wrote:
This is only true for regular cams where there are no torques involved. The contact angle of a regular cam is always colinear to the force vector. Not so with Totem cams. As the flare angle increases, the contact angle remains constant (20 deg off of perpendicular), but the applied force vector angle does not remain at the intended 13.something degrees, it increases with flare.


Explain this a bit more please? When you say torque, are you referring to the torque created by the load being applied on the back of the cam lobes? How does that torque bear any factor on the force vector? I don't see how these cams would have increased camming angles at higher flaring placements. Are the lobes not logarithmic? Am I missing some fundamental cam principal?


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By brenta
From Boulder, CO
Sep 1, 2010
Cima Margherita and Cima Tosa in the Dolomiti di Brenta.  October 1977.

Tyler King wrote:
When you say torque, are you referring to the torque created by the load being applied on the back of the cam lobes?

Yes.
Tyler King wrote:
How does that torque bear any factor on the force vector?

Consider a conventional cam and ignore springs. The reaction force applied by a crack face has to go through the axle because the load has a zero-length arm with respect to the axle. Hence, if said reaction didn't go through the axle, the lobe would not be in rotational equilibrium.

In the Totem Cam, the load is applied in a way that, if not opposed, would make the lobes rotate around the axle. Specifically, the left lobes would rotate clockwise. The reaction, then, has to balance that tendency, and can only do so by passing under the axle thus trying to rotate the lobe counterclockwise. This is equivalent to having a cam angle smaller than the spiral pitch.

Tyler King wrote:
I don't see how these cams would have increased camming angles at higher flaring placements. Are the lobes not logarithmic?

The spiral can still be logarithmic. However, as the flare increases, the friction force becomes less aligned with the load. Hence, more friction force is required to contrast the same load. This leads to a reaction of larger magnitude, which produces the same torque if the arm is made shorter. The latter is achieved by the force vector re-aligning itself with the direction that passes through the axle.

This is the qualitative explanation. It's correct, but I wouldn't trust it myself had I not actually written the equations from the free body diagram and solved them for F_l/F_n. Fortunately, it is not that difficult.


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By DannyUncanny
From Vancouver
Sep 1, 2010

Tyler King wrote:
Good catch... Yes I meant it the other way around! Explain this a bit more please? When you say torque, are you referring to the torque created by the load being applied on the back of the cam lobes? How does that torque bear any factor on the force vector? I don't see how these cams would have increased camming angles at higher flaring placements. Are the lobes not logarithmic? Am I missing some fundamental cam principal?


Here is a quick picture. It shows the applied downwards force, the horizontal force from the other cam through the axle, and the applied force from the wall. What should be apparent is that as you change the flare angle, the angle of that wall force will change. On a regular cam, that wall force would always be going towards the axle of the cam, and so it would always be the same no matter how you rotate things.


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By mapeze
Sep 1, 2010

I have uploaded on our web site a paper explaining how regular cams and Totem Cams work on parallel and flared cracks. I have also added a graph that shows the influence of lateral loads on Totem Cam.

www.totemcams.com/content/index.php?id=1&se=3&su=1242136075&>>>

DannyUncanny and Brenta's comments are correct and very well explained.


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By kayakscum1
Sep 1, 2010

Tyler King wrote:
Tyler, I'm really interested in trying them out as well. I'd like to try them out on a weekday. Maybe this week or the next. I'll call when I figure out what days... Thanks for the heads up!

When you want to take them out again?


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By Josh Higgins
Sep 6, 2010

I wrote up a review of the Totem Cams: pullharder.org/2010/09/05/totem-cam-review/

It took me many hours to complete the review, so I'm just linking to it instead of reposting and reformatting.

Josh


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By bobmirko
Nov 5, 2011

Sorry to revive this thread but... I will like to get an update on the durability of these cams in a long term point of view. (If possible...)


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By Evan Sanders
From Westminster, CO
Nov 6, 2011
Flaming Pumpkin

bobmirko wrote:
Sorry to revive this thread but... I will like to get an update on the durability of these cams in a long term point of view. (If possible...)


This is just my experience but I've had my Totems since probably March or early April. From March to July i used them 2-3 times a week, August to now maybe once every week or two. I've used them on quite a few C1 aid pitches and free pitches. So far the thing everyone has been afraid of, the load bearing wires, are holding up fine. There isn't much exposure of the load bearing wires, and the part of the wires that are exposed are nowhere near being in contact with anything (usually). They've been wearing down almost equivalently to the wire on a stopper. The lobes are wearing down just slightly faster than a camalot, but camalots are pretty durable so that's saying a lot. And then the webbing is, well, webbing. It wears down as expected. Overall I think it's WAY more durable than people thought it would be.


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By kayakscum1
Nov 6, 2011

Thanks for the reply. This is great info to have.


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