tag:blogger.com,1999:blog-6940163880772720830.post1686980366150346839..comments2024-03-16T10:11:19.302-07:00Comments on Cold Thistle: Ice screw technology?Danehttp://www.blogger.com/profile/08300760603627210620noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-6940163880772720830.post-62988931472170325102013-12-18T19:51:59.102-08:002013-12-18T19:51:59.102-08:00More durable steel, higher quality finish and coat...More durable steel, higher quality finish and coatings all keep the teeth staying sharp longer. Danehttps://www.blogger.com/profile/08300760603627210620noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-83288953986726042032013-11-16T21:24:38.871-08:002013-11-16T21:24:38.871-08:00Was reading this study that concluded reverse thre...Was reading this study that concluded reverse thread ice screws weren't any stronger tonight:<br /><br />http://hmga.gr/storehouse/word-acrobat/Ice%20Climbing%20Anchor%20Strength%20-%20MRA%202009%20-%20Marc%20Beverly.pdfMichael Fingerhttps://www.blogger.com/profile/07576490613438647850noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-69295084941479423552013-11-12T21:50:08.186-08:002013-11-12T21:50:08.186-08:00Very useful topic.
Apart from how fast they go in,...Very useful topic.<br />Apart from how fast they go in, I wonder if the higher stress concentration shown with BD vs Grivel screws has anything to do with how quickly they get dull? Over 1 year of extensive abuse in the Canadian rockies and in Valdez, AK, my BD Express's had to be sharpened twice while Grivel remained untouched. Is that due to the composition of steel alloys being used for each? mitochondria100https://www.blogger.com/profile/07694238291066598923noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-39146617853888706332013-11-08T11:27:58.369-08:002013-11-08T11:27:58.369-08:00Dane,
Nice post. I'd really like to see a sim...Dane, <br />Nice post. I'd really like to see a similar test done with the CAMP screws. IMO they seem to be faster placing than BD or Grivel and have a more neutral thread angle than either. ExtraBluehttps://www.blogger.com/profile/13848504229954509398noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-55559122002411866652013-11-06T12:39:42.684-08:002013-11-06T12:39:42.684-08:00Dane, I wonder how many of your anonymous commente...Dane, I wonder how many of your anonymous commenters actually climb real ice on a regular basis or are just your run-of-the-mill loser internet know-it-alls from a site you unfortunately frequent. keep it up!snicenoreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-40259023783133215102013-11-04T10:38:16.815-08:002013-11-04T10:38:16.815-08:00all other things being equal, this result makes se...all other things being equal, this result makes sense to me. <br />the orientation of the BD thread creates a higher stress concentration in the surrounding matrix under pullout load. there would also be a higher stress concentration at the root of the thread as well. <br />you don't see that sort of thread profile in machine design, probably for that reason. Matthttps://www.blogger.com/profile/02179403544495148083noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-83395075817634948392013-11-04T00:36:32.570-08:002013-11-04T00:36:32.570-08:00Here are some experimental evidence and some more ...Here are some experimental evidence and some more data... unfortunately the report is in Italian.....<br />http://www.cnsasa.it/storage/wcms_f/alleg/LPV_documenti/Articolo%20Viti%20Ghiaccio.pdfMiles-Ghttps://www.blogger.com/profile/03505973086758798131noreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-53930051686934175042013-11-03T21:19:53.179-08:002013-11-03T21:19:53.179-08:00Additional questions come to mind. If you are int...Additional questions come to mind. If you are interested in "non-ideal" conditions, when the pull angle is not perpendicular to the surface, is the failure mode the same?<br /><br />Did these testers pull at an angle other than 90 (defined as the angle between the pull and the surface)? If so, what are the results? Again, same questions about number of samples, mean, standard deviation, and correlation with failure modes.<br /><br />Is there any reason to believe that the interaction of the threads with the material stays the same as the pull angle changes? The failure mode of objects is usually significantly different based on the angle (and location) of applied force.<br /><br />Did the testers have a hypothesis for the different thread types for variable angle pulls? If so, what was it and how did they test it?<br /><br />Also important for variable angle pulls, how would one account for the difference in material properties between concrete and ice? If the failure mode of screws is significantly different in these pulls, then the material properties are going to play a large role in this.<br /><br />It seems making any correlation between failure modes of the different thread types in ideal and non-ideal pulls would be very difficult using concrete.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-69546798903082725532013-11-03T20:17:57.063-08:002013-11-03T20:17:57.063-08:00Without numbers it's impossible to interpret t...Without numbers it's impossible to interpret these tests. Some questions that immediately come to mind:<br /><br />If the testers had a hypothesis about failure modes for different thread types: A) what was it and b) did they attempt to address that by changing the material properties of the concrete?<br /><br />Did the testers pour and set the concrete around the screws or somehow drill the screws into the concrete? If the latter, how did they ensure no damage to the threads?<br /><br />How many tests were run for each type of screw? What was the mean and standard deviation of the pull-out strength? Do those numbers correlate with failure mode? Related to the above question, did they start with a new screw every time or attempt to re-use the same screw?<br /><br />So many more questions come to mind for this to actually be a scientific study, but those are just the beginning. Without some sort of quantitative data, any conclusions drawn from these images are purely speculative.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-62102463515087048302013-11-03T19:53:23.959-08:002013-11-03T19:53:23.959-08:00Bill: "It depends on how good you are with a ...Bill: "It depends on how good you are with a file. When the screw is fresh, its like a brand new drill bit… Its like guys doing the same thing with disposable razors. You have five or six in a drawer and you just keep grabbing them and trying them and you aren’t quite willing to throw them out so you just keep cycling through them a few times until you finally get around to getting rid of them. Ice screws are the same way."<br />Chicks with picks, please get rid your old dull ice screws by sending them to me care of Dane at CT, many thanks.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6940163880772720830.post-71847457610839405382013-11-03T08:16:40.605-08:002013-11-03T08:16:40.605-08:00Hey Dane,
Perhaps I missed it, but any text/numbe...Hey Dane,<br /><br />Perhaps I missed it, but any text/numbers associated with the ice screws in concrete test?<br /><br />And for what it is worth, I picked up my first Grivel screw for last season and it was incredibly more easy/faster to place than BD screws.<br /><br />thanks,<br /><br />kevinokevinohttps://www.blogger.com/profile/04246003951750179402noreply@blogger.com