Premium Members Sandy Hays Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 Upon completing the third take of the day (a simple push in to a lock off) I was met with a resounding snap and disheartening shift in mass. The second AC and dolly grip thankfully took the sled form me. The camera (Arricam LT, zeiss lens, a couple of motors- nothing "heavy") did not crash to the ground, since the arm did not snap completely from the hinge. A quick call to GPI secured a new hinge and socket block shipped out ASAP. Jack at GPI informed me that about 6 arms in the past year have suffered a similar failure. All arms were either in a back mounted vest or vehicle mount (I have used a Klassen vest for 3 years, the arm is about 10 years old). I would love to know who else has experienced such a failure. Sandy Hays Quote Link to comment Share on other sites More sharing options...
Premium Members Erwin Landau Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 Hey Sandy, Wow... I think to remember that Guido Lux had a similar incident.... Check out that thread: http://www.steadicamforum.com/forums/index...=3112&st=30 I had not as big of a failure: http://www.steadicamforum.com/forums/index...?showtopic=1695 Later, Erwin Quote Link to comment Share on other sites More sharing options...
Moderators Alec Jarnagin SOC Posted April 9, 2008 Moderators Report Share Posted April 9, 2008 Sandy, About as subtle as a cement block!!!! Wow - glad you and everything else is OK. Something that should be noted is that several years back PRO switched to using a Steel socket block on the arm because of these breaks (again in vehicle mount & back mounted vests only). I believe Tiffen sells their rigs with a choice of materials for the same reasons????? What I find extraordinary about your break is that it is not where the Titanium is but rear of that which I assume is aluminum and very much the same as on the newer arms!! Any thoughts people? Quote Link to comment Share on other sites More sharing options...
Premium Members RobVanGelder Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 I don't know how these parts are made, but it looks to me they are cast aluminium and then machined on the outside. This part is hollow and so the full stress is on the outside of the structure. Personally I would like to see a massive block here as this is the part that will have the highest stress of all blocks, together with the socketblock. It is also under torsion stress, even more than the socket block in my opinion. I don't think that a massive part here would give major weight issues for any operator. (my socketblock and arm has now a massive connection, after that 435 and Cooke S4 crashed with my rig on concrete. not exactly the same kind of accident, but still....) Quote Link to comment Share on other sites More sharing options...
Premium Members Lawrence Karman Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 Holy crap! My titanium socket block split a few years back while on a vehicle mount and I've heard of others that had similar breaks, but I have never seen the arm break there. Going to take a close look at my arm tomorrow. Quote Link to comment Share on other sites More sharing options...
Premium Members Jerry Holway Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 FYI, the corresponding piece in Tiffen arms has been the same for years - at least since 1995, possibly back to 1978 (?), and is of a different construction. A pix of the G-70 (with the "drop-down-kick-back" link) is attached for comparison. Jerry Quote Link to comment Share on other sites More sharing options...
Moderators Alec Jarnagin SOC Posted April 9, 2008 Moderators Report Share Posted April 9, 2008 "the corresponding piece in Tiffen arms has been the same for years - at least since 1995, possibly back to 1978 (?), and is of a different construction." Like I said, this is an usual break - everyone I've heard off has been in a titanium male socket block or in the rod ends (hell, I had rod ends fail in my 3a arm with steel socket block and front mounted vest). It is for this reason GPI (starting three or so years ago) started to offer you the choice of titanium or steel socket blocks (now they only offer steel). I was under the impression Tiffen also offered socket blocks made from both materials for similar reasons, but again, I've never heard of ANY arm breaking this far back. Weird. I would still argue that both Tiffen and GPI arms are extremely well made, but that the arms were not originally designed to have the male socket blocks used at this angle. I had hoped that using Steel would end this issue - now let's hope Sandy's arm is a fluke! Quote Link to comment Share on other sites More sharing options...
Premium Members Erwin Landau Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 From the archives: Guido Lux May 19 2006, 10:29 AM Guys! Backup seems the way to go no matter which arm you use!Since there's no titanium springs on the PRO arm...here's what happened to a friend of mine....! Guido "stick with the backup theory" Lux -------------------- Guido Lux www.liquid-moves.tv Quote Link to comment Share on other sites More sharing options...
Premium Members Lawrence Karman Posted April 9, 2008 Premium Members Report Share Posted April 9, 2008 From the archives: Guido Lux May 19 2006, 10:29 AM Guys! Backup seems the way to go no matter which arm you use!Since there's no titanium springs on the PRO arm...here's what happened to a friend of mine....! Guido "stick with the backup theory" Lux -------------------- Guido Lux www.liquid-moves.tv Well done, Erwin. If this has happened at least 2 times that we know of a redesign is in order. Be prepared to shell out more hard earned $. Quote Link to comment Share on other sites More sharing options...
Moderators Alec Jarnagin SOC Posted April 10, 2008 Moderators Report Share Posted April 10, 2008 Okay, I'm wrong about that one (or is it I "misremembered" where the arms broke).!!! Doc, "If this has happened at least 2 times that we know of a redesign is in order. Be prepared to shell out more hard earned $." I thought that IS why PRO redesigned the socket block! But, like I said, I think they only changed the titanium to steel. We should ask George if he changed anything else (Sandy's was an older version too). Quote Link to comment Share on other sites More sharing options...
Premium Members Sandy Hays Posted April 10, 2008 Author Premium Members Report Share Posted April 10, 2008 Received new hinge with steel socket block today (previously had titanium). Hinge appears to be identical to the one that broke. Sandy Hays Quote Link to comment Share on other sites More sharing options...
Premium Members Jerry Holway Posted April 10, 2008 Premium Members Report Share Posted April 10, 2008 A problem for all arms with the back mounted vests is the added stress on these parts, due to the constantly extended nature of the load. Although the sled is typically in the same place relative to the body (so we don't feel anything new), the socket block is further away, and in a different orientation than the original design. It surely feels the stress. So if there's any part that's weak or being constantly stressed in a new direction, well, failures are inevitable. Both PRO and Tiffen changed the Titanium socket blocks to steel to accommodate the realities of the BMV's... now something else is feeling the new pressures. No arm is immune from this; I'm going to push Tiffen to re-do the stress analysis on the complementary part in question on their arms... Glad Sandy is back in business. Jerry Quote Link to comment Share on other sites More sharing options...
Premium Members Sandy Hays Posted April 24, 2008 Author Premium Members Report Share Posted April 24, 2008 Just an update. I received the invoice from Pro and the hinge was covered under warranty and my only cost was for the new steel socket block. More importantly, on closer inspection the new hinge APPEARS exactly the same BUT in fact the wall thickness is greater on the new hinge. The hinge has been re-made to deal with the added stress of back mounted vest. Sandy Hays Quote Link to comment Share on other sites More sharing options...
Premium Members Lawrence Karman Posted June 13, 2008 Premium Members Report Share Posted June 13, 2008 From the archives: Guido Lux May 19 2006, 10:29 AM Guys! Backup seems the way to go no matter which arm you use!Since there's no titanium springs on the PRO arm...here's what happened to a friend of mine....! Guido "stick with the backup theory" Lux -------------------- Guido Lux www.liquid-moves.tv Well done, Erwin. If this has happened at least 2 times that we know of a redesign is in order. Be prepared to shell out more hard earned $. I would like to recant my previous post with apologies to the good folks at PRO. In a recent review of the PRO web site I noticed that the PRO arm chassis is warranted for life. That is why there would be no charge for replacement. Quote Link to comment Share on other sites More sharing options...
Premium Members Brad Hruboska Posted June 13, 2008 Premium Members Report Share Posted June 13, 2008 For the unbelievers. Yup heres my busted titanium socket block from a few years ago. Probably got its start at a crack on a vehicle mount. I notice the steel ones dont have that curve shaped lightening cut out anymore. I sometimes show this block to producers when they are pitching a heavy camera.... Brad. Quote Link to comment Share on other sites More sharing options...
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