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Messages 261 - 280 of total 303 in this topic << First  |  < Previous  |  Show All  |  Next >  |  Last >>
Tom

Big Wall climber
San Luis Obispo CA
Jul 3, 2017 - 02:39am PT
Erick,

You are right on it.

That dog-bone that rides along the cam lobe, which will suppress outward lateral deflection of the lobes, is brilliant.

But, inward deflection needs to be addressed.

Test.


JUST DO IT.



Break one, in a wide testing frame, and see what happens. Don't use a webbing sling. JUST DO IT.


Load a Merlin cam until the lobes bend, buckle and fold sideways, and report the results.


And, then it will be easier for people to decide if they want a VG piece that can pull a truck out of the mud, or Merlin piece that is strong enough for a great rock climbing experience.

Matt's

climber
Jul 3, 2017 - 08:14am PT
And, then it will be easier for people to decide if they want a VG piece that can pull a truck out of the mud, or Merlin piece that is strong enough for a great rock climbing experience.

Tom, you really are backing yourself into a corner here!!
Late Starter

Social climber
NA
Jul 3, 2017 - 08:51am PT
Perception..I'm not seeing any corners. In fact, it seems pretty civil, and with good constructive banter/discussion.

MAYBE it's that YOU'D like to perceive there being an issue?
JoeSimo

Trad climber
Bay Area, CA
Jul 5, 2017 - 11:31am PT
Hi Tom. I've been reading through this post a bit and was a bit confused by some of your posts so I corrected them below to what you probably meant to say:

"Merlin is another large cam for those crazies that like to climb off-width. It has some really innovative ideas and I tip my hat to it's creator for his obvious engineering prowess. I think both VG and Merlin have their advantages and disadvantages but truth be told both cams are great and only add to the wonder of climbing. I know Erick and I don't do this for profit and only do it out of true love of the sport and to give something back to the climbing community. So in that spirit I say again good work brother! I am impressed"

There Ftfy
Alexey

climber
San Jose, CA
Jul 5, 2017 - 11:49am PT
nicely done JoeSimo!
Tom

Big Wall climber
San Luis Obispo CA
Jul 17, 2017 - 04:44pm PT
With all this conversation about the safety of self-made cams, I totally forgot to mention this story I heard in 1983:

Some guys from Australia made their own cams, but they used the wrong spiral profile. Instead of an exponential/logarithmic spiral, they used some other type of spiral, which did not have the equal-camming-angle property, which is unique to the Exp/Log spiral. Those Aussie cams would not hold properly, and the word got out, around the Valley, that they were unsafe.


That was the first time that I became aware that it was possible to make cams that would not be safe. Cams look simple enough, especially the small ones, but there are myriad details that have to be addressed and taken into account.

BD's recent/prior quality control problems with making cams in China is a testament to that statement.



As an aside, my AutoCAD program will not generate an Exp/Log spiral, only an Archimedes spiral. My Microstation CAD program will generate a proper Exp/Log spiral from its parameters.

My guess is the Australian guys in 1983 trusted their computer to get the spiral right, which is not usually a good idea.



thebravecowboy

climber
The Good Places
Jul 19, 2017 - 05:07pm PT
Credit: thebravecowboy
BLUEBLOCR

Social climber
joshua tree
Jul 20, 2017 - 09:44pm PT
Got mine today‼️Very prompt. Thank You Erick..and to your helpers?
I think it would pull my VW out of the mud! HaHaaaa.
But gosh dang it is soooooooo LIGHT😎

Levitation
Levitation
Credit: BLUEBLOCR

Cheers Merlinrockgear@gmail🐡
Largo

Sport climber
The Big Wide Open Face
Jul 21, 2017 - 08:28am PT
Makes my mouth water looking at these fantastic gadgets, and remembering back to my early days in the valley, when we had to work our way up the grades which involved a lot of trembling up the wide sections of climbs with little to no pro at all. Before tube chocks and long before cams, even citizen testpieces like Midterm, Vendetta, Twilight Zone, Right side of the Hourglass, left side of the Slack, Right side of Absolutely Free, Ahab, Center route of the Slack, The Cleft, LA Chimney, Crack of Doom, even Sacherer Cracker, all had wide stuff you basically had to run out. Easy stuff like Chingando was okay because, as we used to say, your knee was the protection, because a good knee lock was unlikely to just blow out. But those were exciting times.

After a few initial efforts of scaring myself stiff, I wouldn't go up on one of those hard wide routes unless I felt like I could solo it. Keeps your learning curve pretty flat.

These tools make it a much saner game, and probably saved more than a few lives. Strange and fantastic how a personal piece of gear, like a well-worn big cam, is a talisman to our past.
jerome.stmichel

Trad climber
Montreal, QC
Jul 31, 2017 - 09:47am PT
Hey guys,

I would be interested in getting a merlin 8.

Cheers,

Jérôme

j e r o m e . s t m i c h e l at m e . c o m
grover

climber
Castlegar BC
Aug 10, 2017 - 02:44pm PT
#0019
#0019
Credit: grover

What a piece!

Stoked to have it for another go at this.....

The gash
The gash
Credit: grover

And hopefully less of this!

Lame technique, I know.
Lame technique, I know.
Credit: grover

Thanks Erick.
Naitch

climber
Blue Ridge Mts, Shenandoah River
Aug 11, 2017 - 07:32am PT
Thanks Erick,

Got mine about a month ago.

Credit: Naitch

https://www.instagram.com/p/BWpv2cJlvLc/?taken-by=sicgrips
Gnome Ofthe Diabase

climber
Out Of Bed
Aug 11, 2017 - 01:24pm PT
Boo hoo, I still have big wide dreams!

all I got for fathers day was cheap glass from China
OlympicMtnBoy

climber
Seattle
Aug 11, 2017 - 02:44pm PT
Waiting to put mine to use too. Beautiful metalwork! The sling could be prettier though, what do you test those to Erick?
Jaybro

Social climber
Wolf City, Wyoming
Aug 11, 2017 - 02:58pm PT
Taking mine to Vedauwoo on Monday.!
Khoi

climber
Vancouver, BC
Aug 12, 2017 - 02:08am PT
Erick,

I'd like to buy an entire set once they are available. In the mean time, I guess it'll just be the 2 larger pieces.

That was the first time that I became aware that it was possible to make cams that would not be safe. Cams look simple enough, especially the small ones, but there are myriad details that have to be addressed and taken into account.

BD's recent/prior quality control problems with making cams in China is a testament to that statement.

Tom, that is incorrect.

In the roughly 10 years that BD operated that factory of theirs in China there were ZERO recalls.

It was after BD shut down that factory and moved production to a factory in Utah that we saw the flood of recalls, all of which came from their American factory - save for the recalled slings... I think those came from a factory in Mexico.

Matt's

climber
Aug 12, 2017 - 08:02am PT
. Beautiful metalwork! The sling could be prettier though, what do you test those to Erick

I had the same thought--the sewing of the sling is not super confidence inspiring- density of the bar tack seems low compared to other slings-- care to comment?

Credit: Matt's

Best
Matt
matty

Trad climber
under the sea
Aug 12, 2017 - 10:17am PT
After reading the above comments and seeing the last picture I re-examined my cam. Several of the stitches seemed "long" and somewhat loose in that they were not super tight against the webbing.

I ran my fingernail over some of these long loose stitches near the edge several times and to my surprise they easily started to unravel. Knot a good sign! This is unacceptable in my view and uneasily forces me to wonder about other aspects of the construction. Visually the density of stitching on the Merlin cam appears to be less than the other slings from my rack that I inspected.

Awaiting Ericks response...

Matt

Exterior of Merlin cam sling
Exterior of Merlin cam sling
Credit: matty

Blue = long semiloose stitch
Green = stitches near edge I was able to loosen easily with one fingernail.

Inside of Merlin cam sling
Inside of Merlin cam sling
Credit: matty
BLUEBLOCR

Social climber
joshua tree
Aug 12, 2017 - 11:37am PT
Well he obliviously hasn't a bar tacker,,,, but he's got a CNC! hehe.

i just cut that crap off, i always use an adjustable draw anyway.
edavidso

Trad climber
Oakland, CA
Aug 13, 2017 - 09:44pm PT
To address the sling issues, I just sewed a sling exactly as I've sewn all the others and tested in my pull tester to 16 kN. Those who've been following the thread might recall that I posted a video of a Merlin #8 pull test where the sling broke at 12 kN. I noted on that video that I had tested using a wider spaced stitch, which I have since narrowed.

Unfortunately, I do not own an industrial bar tacking machine and instead use a manual semi-industrial Sailrite machine. As a result, most of my sewing jobs are not very pretty. They are, however, still strong regardless of how ugly they look. Each sling consists of two seams across the width at the top and bottom, which are primarily used to just hold the overlap in place while I sew the vertical seams. The seams across the width are short, discontinuous and come apart rather easily at the beginning and end of the seam where the threads end as pointed out in Matty's handy photos with the green arrows. The vertical seams, however, are either one, two, or three continuous threads across the entire width and account for nearly the entire strength of the sling. The "long semiloose" stitch indicated with the blue arrow is where I transition from one vertical seam to the next and from a forward thread to a backward thread. It is usually loose due to the horizontal and reversing movement but still continuous. There are about 180 stitches give or take per sling and if you listen to the earlier posted video, a few stitches break first but then the remainder all break at exactly the same time. This indicates that they are all contributing equally to strength and it only matters that they are there. A few loose threads/stitches will not noticeably affect strength. Perhaps someday I'll be able to buy a bar tacking machine and my sewing job will be easier and prettier.

If any of you do not want a sling or plan to cut it off anyway, please tell me so that I do not have to go through the headache of sewing it on! For the rest of you who plan on using the sling, rest assured that if you are taking a 15 kN whipper, the sling on this cam is likely to be the least of your concerns.

Khoi and anyone else who wants a Merlin #8 and/or #10, please send me an email at merlinrockgear@gmail.com. I do not think ST messaging works.
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