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Ever wonder what’s inside an Ultralight Camalot?


Former Climber · · PA · Joined Jun 2019 · Points: 2
Sam Skovgaard wrote:

So, the next obvious question is:  why did you need to know the pin diameter? Or the hardness of the lobes?  What sort of chicanery are you REALLY up to? 

Some people golf.  I design and manufacture climbing gear as a hobby.  

(Shrug)

Been at it 15 years, but winding down now since I have little time to climb anymore.  Finishing things I have interest in, passing along things I see as worthwhile, scrapping the rest.  In fact, this is the only reason I’m back on MP after a long hiatus.  Needed data for my current project, and to hand off other things. 

Will likely be making my cam calculator public this weekend (there’s a thread about it in For Sale, where I was looking for a web developer to convert the Mathematica code to something more web-friendly). https://www.mountainproject.com/forum/topic/117507346/admittedly-a-longshot-wtb-web-developer-to-convert-mathematica-slcd-calculator-i


A couple other things coming as well, but a lot of what I’ve worked on over the years is scattered between here, ST, RC, etc, if you go digging.  But really, aside from heretical thoughts on Double Axle cams and SRENE/EARNEST, I’ve got little to say anymore.

Anyway:

Pin diameter:  There is simply little public data out there for strength reduction of 12 strand when loaded over small diameters (I’ve spoken with several manufacturers of 12 strand about this, and it simply isn’t done in industry so they have no data).  

BD is fastidious about testing, so seeing what they do gives me a baseline to compare my results to (I’ve been using 12 strand for prototype slings for 15 years, and it directly applies to what I’m currently working on).

Hardness:  if /you/ had a bench mounted hardness tester, wouldn’t you also put everything you come across in it?  :)

Edit:  one of these days I’ll cut a hole in the top of the cabinet, and gain 6” more range.  But lose use of the top drawer.  Which means finding a new home for the microscope.  :(
Sam Skovgaard · · Tucson, AZ · Joined Oct 2017 · Points: 87
Former Climber wrote:

Some people golf.  I design and manufacture climbing gear as a hobby.  

(Shrug)

Been at it 15 years...


Rock on!  Don't hesitate to spray some pics of your creations on MP; plenty of us would love to nerd out on stuff like this. 

Chris K · · Clemson · Joined Oct 2017 · Points: 56

so if you're making your own stuff as a hobby, where are you obtaining dyneema? Straight from dyneema? have you bothered splicing any yourself? 

Long Ranger · · Boulder, CO · Joined Jan 2014 · Points: 316

I can't understand 99% of what you're talking about, but it's 110% interesting.

Matthew Campbell · · Redondo Beach, CA · Joined Feb 2019 · Points: 0
Chris K wrote: so if you're making your own stuff as a hobby, where are you obtaining dyneema? Straight from dyneema? have you bothered splicing any yourself? 

Samson Amsteel blue is a pretty common DIY dyneema line material, which you can get from any number of places. I picked some up for making lightweight, low-stretch hammock lines, and it is very easy to splice yourself.

Matthew Campbell · · Redondo Beach, CA · Joined Feb 2019 · Points: 0
Former Climber wrote: May as well throw this here as I can’t find my notebook at the moment.

Calibrated the hardness tester with a certified HRB96 sample, spot on.

Lobe from this cam tested HRB70-72 (3 tests).

Known piece of 6061T6511 came out HRB58, which is in the ballpark for 6061T6 (~HRB60).  Don’t happen to have any 7075T6 at the moment, but that should be ~HRB87 (hence calibrating with the HRB96 sample, as I thought they use 7075T6).

Not sure what to make of this.  I don’t recall anodizing throwing things off this far, but maybe it’s skewing 6061T6 high?  No time at the moment to skim it on the mill and recheck.

Anyone got an authoritative link for the material BD uses for the lobes?

Not sure how authoritative it is, but I found this article which says BD uses 7075 for their lobes, but doesn't mention the treatment or temper. I cannot for the life of my find a temper with a HRB in the low 70s, so my current theory is that they under-age the 7075 (relative to standard -T6) to give it a bit more bite on the rock, and maybe to prevent over-aging due to the repeated cyclic loading of the device over it's lifespan.

Former Climber · · PA · Joined Jun 2019 · Points: 2
Chris K wrote: so if you're making your own stuff as a hobby, where are you obtaining dyneema? Straight from dyneema? have you bothered splicing any yourself? 

Amsteel I tend to get through McMaster.  Other brands from West Marine and various other sailing suppliers.  Cheapest way to get it is spool remnants.


And yes, I do my own splicing.  Thought that was clear?

Edit since I’m out of posts:
2005-ish attempt at 12 strand sling using 3mm Amsteel threaded through what is likely sheath from 7 or 8mm accessory cord (pattern doesn’t match any of the double braid I have).  No idea the bury length, but lock stitched.  Broke at 21.82kN by way of the splice pulling out.  Before breaking, the sheath formed a nice thumb loop. No notes on the tag regarding diameter pins used on each end when breaking it.

8” 3mm Whoopie Sling, likely because I was bored watching the CNC mill make cam lobes (I can think of no reason to have an 8” Whoopie Sling, other than boredom).  Butt splice on free end, locked brummel loop.

Got a couple double braid rabbit runners around here somewhere.  Probably in the gear bin since I actually use them on occasion.  BTW, double braid is a PITA.
Former Climber · · PA · Joined Jun 2019 · Points: 2
  1. Matthew Campbell wrote:

Not sure how authoritative it is, but I found this article which says BD uses 7075 for their lobes, but doesn't mention the treatment or temper. I cannot for the life of my find a temper with a HRB in the low 70s, so my current theory is that they under-age the 7075 (relative to standard -T6) to give it a bit more bite on the rock, and maybe to prevent over-aging due to the repeated cyclic loading of the device over it's lifespan.

Yeah, no idea what the deal is.

FWIW, just tested a Blue pre-C4 and it came in at HRB50 (a bit surprised at this, but unfortunately I only have the one lobe from it anymore).  Red pre-C4 HRB60.  Purple C4 from 10-15 years back HRB75. Can’t figure a way to get an intact 2018 C4 on there, and would prefer not cutting up my other new cams.

Oh, calibration sample was dead on at HRB96 and known 6061T6511 came in at HRB60.

Edit: found another lobe from the blue Pre-C4.  Results below.
Matthew Campbell · · Redondo Beach, CA · Joined Feb 2019 · Points: 0
Former Climber wrote:

Yeah, no idea what the deal is.

FWIW, just tested a Blue pre-C4 and it came in at HRB50 (a bit surprised at this, but unfortunately I only have the one lobe from it anymore).  Red pre-C4 HRB60.  Purple C4 from 10-15 years back HRB75. Can’t figure a way to get an intact 2018 C4 on there, and would prefer not cutting up my other new cams.

Oh, calibration sample was dead on at HRB96 and known 6061T6511 came in at HRB60.

Oh, I did find that 2024-T4 is benchmarked at HRB 75, and that's converted from Brinell so you'd expect a little wiggle room. asm.matweb.com/search/Speci…;

So maybe it's a 2000-series alloy, but that seems unlikely. I think I've read that 2024 has corrosion problems and fatigue issues, which aren't what you want in outdoor gear that is loaded and unloaded frequently.

Edit because MP won't let me post again yet:
Yeah, I don't think 2000 series is very likely, I was just digging for anything that matches the HRB you found.

That dimple is a good find. Given BD's reputation for QC, it seems likely they are validating the temper on each batch before final assembly.
Former Climber · · PA · Joined Jun 2019 · Points: 2

Can’t say I’ve ever heard of anyone using 2000 series for cam lobes.  Doesn’t mean it hasn’t been tried though.

Loosely related, I noticed all five of the 2018 C4s I recently got have a dimple on the underside of the one interior lobe.  Always the same side of the stem, and only the one lobe.  Looks suspiciously like a HRB penetrator dimple to me, and likely done after assembly (since it would likely not always be in the same position if done pre-assembly).



Edit: the purple Ultralight in the OP has it too.  It has a 2016 tag, so whatever it is they’ve been doing it a while.

Edit x2:  looks like 2024T4 is available in rectangle bar, so it’s possible.  (Some materials are only available in round, which makes them ill-suited for cam lobes due to wasted material)
https://www.onlinemetals.com/en/buy/aluminum-rectangle-bar-2024

Edit x3:  I doubt they’ll answer, but I emailed BD anyway.

Edit x4:  Found another lobe from that Blue Pre-C4.  Also softer than expected.  Quite a few hardness test dimples in it, so it clearly struck me as odd when I first tested it.


Edit x5:  if you zoom in on the pic of the blue lobe, you’ll see 2 spots in the cut-out where the lobe is deformed.  That’s from the axles bending, and allowing the opposing axle to become load bearing.  Too bad I culled my video archive years ago, as I’m curious how this one failed.  All I likely have at this point is the log of applied force.  :(

Edit x6: Better pic, which also shows hardness testing dimples.  Might have been 3 separate tests...  50% expansion, 75% expansion, umbrella’d.  Smearing out due to axle deformation doesn’t leave individual indentations like that.  Will have to go digging to see if I have notes on it.
Chris K · · Clemson · Joined Oct 2017 · Points: 56
Former Climber wrote:

Amsteel I tend to get through McMaster.  Other brands from West Marine and various other sailing suppliers.  Cheapest way to get it is spool remnants.


And yes, I do my own splicing.  Thought that was clear?

Edit since I’m out of posts:
2005-ish attempt at 12 strand sling using 3mm Amsteel threaded through what is likely sheath from 7 or 8mm accessory cord (pattern doesn’t match any of the double braid I have).  No idea the bury length, but lock stitched.  Broke at 21.82kN by way of the splice pulling out.  Before breaking, the sheath formed a nice thumb loop. No notes on the tag regarding diameter pins used on each end when breaking it.

8” 3mm Whoopie Sling, likely because I was bored watching the CNC mill make cam lobes (I can think of no reason to have an 8” Whoopie Sling, other than boredom).  Butt splice on free end, locked brummel loop.

Got a couple double braid rabbit runners around here somewhere.  Probably in the gear bin since I actually use them on occasion.  BTW, double braid is a PITA.

Maybe I was just poking ya for some pictures. :) 


I wasn’t aware McMaster sold Amsteel but I shouldn’t be surprised that they do. 
Doing a little digging, 7075 can yield varying HRC bales from 30-75. Of course, as we know, it depends on the treatment. Have you looked mat properties for 7075-T651? Or T7351? I’ll do some searching later. Climbing to do and my own research. 
Former Climber · · PA · Joined Jun 2019 · Points: 2
Chris K wrote: 


I wasn’t aware McMaster sold Amsteel but I shouldn’t be surprised that they do. 
Doing a little digging, 7075 can yield varying HRC bales from 30-75. Of course, as we know, it depends on the treatment. Have you looked mat properties for 7075-T651? Or T7351? I’ll do some searching later. Climbing to do and my own research. 

Huh.  Seems McMaster doesn’t have Amsteel, only premade slings.  I wonder where I got it?  Was years and years ago.

7075 falls in HRB, not HRC.  And yes, it depends on heat treatment.  
7075T6/T651/T6511 should be ~HRB87.  IIRC, the difference between them is T6 is quenched and aged, T651 is T6 that had been stretched 1-3% to remove some internal stresses, T6511 is T651 that has been straightened in a press.   :)
Never looked at 7075T7351, and have never run across it.  Looks to be available in plate, round, and bar.  (Shrug)
Guideline #1: Don't be a jerk.

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