Goto Chockstone Home

  Guide
  Gallery
  Tech Tips
  Articles
  Reviews
  Dictionary
  Links
  Forum
  Search
  About

      Sponsored By
      ROCK
   HARDWARE

  Shop

Black Diamond: "Neutrino" karabiner - 2016 model. (Gate opening 22mm) Gate opening = 22mm. - Assorted "Ano" colours... (Red shown) Email colour preference . (ALL colours except BLUE in stock!)  $9.00
25% Off

Chockstone Photography Australian Landscape Photography by Michael Boniwell
Australian Landscape Prints





Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

 Page 1 of 2. Messages 1 to 20 | 21 to 21
Author
How thick could a bolt plate be?
TimP
22-Oct-2016
10:31:08 PM
I'm working on a new bolt plate for Climb Design and was making it a thin as I could, but a friend said he'd never seen a carrot bolt head closer than 5mm to the rock face. I thought I'd seen a few closer ones but can't really recall.
What is the range in your experience? I'm talking about the gap between the back of the bolt head and the rock.
Cheers
Tim
patto
23-Oct-2016
5:47:33 AM
I would have thought that 5mm is a pretty significant clearance. I'd expect you'd find numerous bolts with less clearance than that.
mikllaw
23-Oct-2016
8:11:27 AM
Any bolt that the old 3 mm RP hangers couldn't fit on had generally been hit in with 1 blow, and came out as easily

timfreddo
23-Oct-2016
4:52:02 PM
I recon the thinner the better. The current offerings are by far strong enough for their purpose- and rated as strong as the quickdraw / Carabiner you're clipping into them...

Fatter bolt plates would be too heavy and bulky in your chalk bag.

I recon 8mm is the average protrusion for carrots. Theres a bunch out there with 5mm or less though..
mikllaw
24-Oct-2016
7:08:45 AM
On 23/10/2016 timfreddo wrote:
>I recon the thinner the better. The current offerings are by far strong
>enough for their purpose- and rated as strong as the quickdraw / Carabiner
>you're clipping into them...

They are if clipped between 2 biners. They smear off a bolt head at about 10kN, depending on how bendy the bolt is.
rightarmbad
24-Oct-2016
8:48:02 AM
Do they still do this with a single biner?
I was wondering if something similar to a rope worn biner would happen here, in that as the plate is stretched it would collapse in on the bolt shaft and that by putting two biners on you prevent that from happening and the head slips through the wider opening?

What is the failure mechanism with 90 deg plates?

Has anybody ever seen that sort of failure in the field?

Is this type of failure limited to softer rock that breaks away from around the bolt easier and does not support it enough to allow it to bend that much?
mikllaw
24-Oct-2016
10:46:10 AM
On 24/10/2016 rightarmbad wrote:
>Do they still do this with a single biner?
Yes
>I was wondering if something similar to a rope worn biner would happen
>here, in that as the plate is stretched it would collapse in on the bolt
>shaft and that by putting two biners on you prevent that from happening
>and the head slips through the wider opening?
No
>
>What is the failure mechanism with 90 deg plates?
Same
>
>Has anybody ever seen that sort of failure in the field?
No, because loads above 7 kN are vanishingly rare. But you need to treat boltplates as good trad gear and equalise them on a belay.
>
>Is this type of failure limited to softer rock that breaks away from around
>the bolt easier and does not support it enough to allow it to bend that
>much?
No, most bolts will bend
TimP
24-Oct-2016
12:03:52 PM
On 24/10/2016 mikllaw wrote:

>They are if clipped between 2 biners. They smear off a bolt head at about
>10kN, depending on how bendy the bolt is.

Hi Mike, saw your post about this on RopeLab Facebook which made me lower my target load for the new bolt plate. Very useful real-world data thank you. 20KN stamped on that plate! I can see the angle of the load in relation to the bolt axis would effect the failure mode.

So I'm going up from 3.2mm to 4mm in thickness, that should help make it stronger and fit onto any carrot 5mm off and over.

I was talking to an engineer who suggested casting in precipitation-hardened stainless steel to make it over 1000mpa tensile strength. With the design in sheet metal it's a play between tensile strength and bendability. I had found a good sheet stainless (7C) at 1600mpa but you can't bend it (will use this for the next version of LittleHammer though!).

It is surprisingly difficult to shift my design mindset for bolt plates from the traditional punched / laser cut & bent sheet, to casting. It may be more cost effective to go the sheet method but small production volume might make it close, I'll work up both designs to get the prices.

I'm pretty sure carrots are no longer installed and being only in Australia the market is small and closing. But if it doesn't cost too much I'd like to release the new plates just because they solve the jiggling-off problem. Yes, yes, designers and jiggling-off... and do we need more new gear... but I enjoy this process!

One more question. With an angled bolt plate do you prefer it angling from high on the right to low on the left or the other way?
mikllaw
24-Oct-2016
12:42:20 PM
I'd recommend against casting (too many defects) and higher strength stainless steels (SCC becomes a real issue). 4 mm 316 cold-worked plate should be more than 25% stronger than 3.2 mm (as bending will be better controlled) and a slightly wider head may help also. My test rig is now in Victoria if you want to use it.

PM me
One Day Hero
24-Oct-2016
5:22:33 PM
What's the advantage of more thickness? You reckon there's a market for extra heavy bolt plates?
TimP
24-Oct-2016
5:41:43 PM
Cheers Mike, your PM is full
TimP
24-Oct-2016
6:20:19 PM
On 24/10/2016 One Day Hero wrote:
>What's the advantage of more thickness? You reckon there's a market for
>extra heavy bolt plates?
It'll all make sense when you see the design. It'll weigh about the same as current plates but be secure with any carabiner. I'll publish when I'm confident it'll get to at least 10KN and I'm close to going to market / kickstarter.
One Day Hero
24-Oct-2016
7:17:37 PM
On 24/10/2016 TimP wrote:
>It'll weigh about the same
>as current plates but be secure with any carabiner.

Cool. Moving parts?
mikllaw
24-Oct-2016
8:58:06 PM
On 24/10/2016 TimP wrote:
>Cheers Mike, your PM is full

I didn't realise I had so many friends, AllDoneDotCom

JamesMc
24-Oct-2016
9:28:09 PM
It would be a good idea lo design it to comply with EN 959. 15 kN axial and 25 KN radial.
rightarmbad
24-Oct-2016
10:52:09 PM
There are plenty of bolts out there that only just get a standard plate on, thicker would just be a pain.
There is also considerable difference in the size of bolt heads and some with filed off as well.
I don't know how you can cure the jiggle off problem when the bolt heads are much bigger than the diameter of a biner, especially around the nose of modern lightweight keylock type.

gnaguts
26-Oct-2016
9:01:56 PM
On 24/10/2016 TimP wrote:
>Yes, yes, designers and jiggling-off... but I enjoy this process!

U an ed need to get a room.

>One more question. With an angled bolt plate do you prefer it angling from high on the right to low on the left or the other way?

Facing tha cliff or away?
Talk about diminshing an already depleted market. Ur neva goin 2 make Ur millions sellin bolt plates, unless those who used 2 have jobs like bus conductors still have any cash flow left.
Even if mikl buys some 4 testing to amuse hisself it'll still cost U more to produce than U'll recoup.
rightarmbad
27-Oct-2016
1:43:57 PM
Maybe a better design would be to make a carrot replacement and matching hanger that are guaranteed to work together for rebolting of areas where the invisibility of bolts is a major factor.

Still cannot see a design that will not allow the jiggle off from occurring on the variety of bolts and biners out there at the moment.
I envisage problems with biners getting jammed and loaded at funny angles with torqued of plates and broken biners.
rightarmbad
27-Oct-2016
1:45:38 PM
So how is it that bolt plates got a 22KN rating if none of them seem to achieve it?
How were they tested?
gfdonc
27-Oct-2016
1:49:46 PM
I assumed you all knew about these already?
http://heightechsafety.com.au/kong-701-500-wide-soleymieux-anchor-bolt-plate-hanger-wall-roof-rock-attachment-point-wire-gate-kon07015.html

Actually this is a better link:
http://www.kong.it/en/2-products/items/f17-anchorage/p128-wide-soleymieux

 Page 1 of 2. Messages 1 to 20 | 21 to 21
There are 21 messages in this topic.

 

Home | Guide | Gallery | Tech Tips | Articles | Reviews | Dictionary | Forum | Links | About | Search
Chockstone Photography | Landscape Photography Australia | Australian Landscape Photography | Landscape Photos Australia

Please read the full disclaimer before using any information contained on these pages.



Australian Panoramic | Australian Coast | Australian Mountains | Australian Countryside | Australian Waterfalls | Australian Lakes | Australian Cities | Australian Macro | Australian Wildlife
Landscape Photo | Landscape Photography | Landscape Photography Australia | Fine Art Photography | Wilderness Photography | Nature Photo | Australian Landscape Photo | Stock Photography Australia | Landscape Photos | Panoramic Photos | Panoramic Photography Australia | Australian Landscape Photography | High Country Mountain Huts | Mothers Day Gifts | Gifts for Mothers Day | Mothers Day Gift Ideas | Ideas for Mothers Day | Wedding Gift Ideas | Christmas Gift Ideas | Fathers Day Gifts | Gifts for Fathers Day | Fathers Day Gift Ideas | Ideas for Fathers Day | Landscape Prints | Landscape Poster | Limited Edition Prints | Panoramic Photo | Buy Posters | Poster Prints