Pat Donnelly Posted February 17, 2018 Report Share Posted February 17, 2018 (edited) Zoom in on the bolt depression created in the base plate on the right side. Looks like a stress riser to me or too long of a bolt? Edited February 17, 2018 by Pat Donnelly 2 Quote Link to comment Share on other sites More sharing options...
Lurch Posted February 17, 2018 Report Share Posted February 17, 2018 I'm backing crack propagation from the bail attach hole too Pat. Quite different to Barry's failure. Quote Link to comment Share on other sites More sharing options...
nitro Posted February 17, 2018 Report Share Posted February 17, 2018 Here is some close up shots .The inboard threads for the toe block may be the issue . Lowrider I think the same thing would happen to the heel piece if the base plate was rotated 180 degrees. I read this thread when it was first posted & inspected my base plates but found no visible fractures. 10 carving days later Im laying a heelside carve, got a knee wobble ,looked down, and my toe block flew off! Quote Link to comment Share on other sites More sharing options...
Beckmann AG Posted February 18, 2018 Report Share Posted February 18, 2018 Too much lever, not enough fulcrum. As Lowrider points out, might not have happened at a different baseplate/stance angle. This failure mode may be seen more frequently as the flex cycles add up over the entire production run. If you ride frequently, might be a good idea to get a cheap dye based crack detection kit. (not an endorsement) Quote Link to comment Share on other sites More sharing options...
Corey Posted February 18, 2018 Report Share Posted February 18, 2018 Nice pictures! Do you have a lot of runs/years on this set of bindings? I see heavy wear on the toe/heel blocks. Ok, I'm not a failure expert but I've been through many failure analysis reports in event reconstructions. Here's my best guess: The shiny top area with the beach marks show the crack progression from near the bolt hole and the little ridge from the end lug pocket. So there likely was a crack hiding there when you last inspected but it was really hard to see. Cue Mr. Beckmann's video above. The rough/dull/fuzzy area along the bottom was the rapid overload failure at the end of the whole process. It always amazes me how parts can have so much cracked material and appear intact, and then the crack progresses 0.001" more and it just opens like a zipper. You can see where the beach marks converge to the top of the bolt hole and the ridge. Which means those points were where the cracks started. I assume that the crack wouldn't start on the ridge in the larger section, as I can't imagine that being the highest-stress area. I think the crack started at both bolt holes and cracked through the smaller sections to the inner diameter. Then that raised the stresses in the larger section until cracks progressed through them too. So what does that mean? A visual inspection likely isn't enough. Crap. Sound like it's a good idea to do a yearly check of baseplates with a crack detection kit if you ride a lot on a set of bindings. I don't think this indicates that TD3 bindings are weak, just that they do have a finite life after all. If another set of bindings were on that board instead of TD3s, would they have lasted that long? I'd bet no. Quote Link to comment Share on other sites More sharing options...
Corey Posted February 18, 2018 Report Share Posted February 18, 2018 2 hours ago, Pat Donnelly said: Zoom in on the bolt depression created in the base plate on the right side. Looks like a stress riser to me or too long of a bolt? This is a good point! I'm picky (ok, anal) - I file down the bolts so they don't protrude through the baseplate where they could touch the cant ring. But, Nitro didn't use those holes. Maybe a previous owner or different binding setup? Quote Link to comment Share on other sites More sharing options...
SunSurfer Posted February 18, 2018 Report Share Posted February 18, 2018 Not just big riders. I have weighed 80-82 kilos throughout the time I rode my TD3s before the rear foot baseplate failed. I ride mondo 29 boots so have toe and heel pieces on the outermost screw holes. That would increase the leverage I'm able to generate against the inner ring held by the M8 screws. Quote Link to comment Share on other sites More sharing options...
Beckmann AG Posted February 18, 2018 Report Share Posted February 18, 2018 (edited) ^That 'bolt stamp' on the left side in the photo may be partly an illusion cause by the upper contour of the base ring. As the upper plate flexed, the edge of the bolt hole was hammering over the edge in that area. I'd suspect that if the toe/heel pad bolt holes were the size of those on the TD1, and the triangular lightening hole under the toe pad was eliminated, the issue might be mitigated. Edited February 18, 2018 by Beckmann AG Quote Link to comment Share on other sites More sharing options...
lowrider Posted February 18, 2018 Report Share Posted February 18, 2018 My suspicion is that two factors are the main culprits anodization of the aluminum .It creates a harder surface unlike heat treating of a steel it does not penetrate very far and a duty cycle of repetitive shock loading ( heavy rider ). A slight imperfection or scratch in the surface treatment could act like a scratch in glass that provides a starting point for failure. Quote Link to comment Share on other sites More sharing options...
nitro Posted February 18, 2018 Report Share Posted February 18, 2018 This is the 3rd season of hard riding with this set of td3s . close to 150 days on this set. 2 days prior to the above pics these binders were on top of my main whip , af plate /163 rev with bomber bp 3 degree cants . very rapid fire turning. what you see in pics is the second board kit that stays mounted on the 185, there has never been a screw in that hole , its just a smudge. We have a very high volcanic cinder dust content in the snow here at my local area it really degrades the td3 Bling. I have to say this is might be a "one size fits all " issue that affects the large footed rider.. Quote Link to comment Share on other sites More sharing options...
teach Posted February 18, 2018 Report Share Posted February 18, 2018 (edited) I looked at my TD3s and there seem to be variations in hole placement for the toe/heel blocks. One pair is like Nitro's, inboard holes very close to the curved slot for the M8 bolts holding the base plate to the cant ring. The other pair has more space, so that a line joining the holes lies (just) behind the slot. I've wondered for a while how much more it would cost to have the baseplate made out of some kind of alloy steel. Better failure mode, much longer time to fatigue. I also wonder if the bindings were ridden (by anyone) with the toe block mounted closer in, so that the inboard holes were lined up with the edge of the toe block and basically right on the crease where the assembly was forced to flex (where the cant ring surface stops supporting it). Edited February 18, 2018 by teach clarity Quote Link to comment Share on other sites More sharing options...
Corey Posted February 18, 2018 Report Share Posted February 18, 2018 1 hour ago, lowrider said: My suspicion is that two factors are the main culprits anodization of the aluminum . The original TD3 plates are nickel plated, not anodized. Quote Link to comment Share on other sites More sharing options...
lowrider Posted February 18, 2018 Report Share Posted February 18, 2018 (edited) Top outer edge of the bale cutaway right side looks like old oxidation . Cracking started there and worked in ? Would have felt like F2's part way through the day a little soft. Doubtful it was around the threads as one would have expected it to break at the thinnest point. Were these parts baked or dried after plating ? Are all these failures toes side ? Edited February 18, 2018 by lowrider Quote Link to comment Share on other sites More sharing options...
Beckmann AG Posted February 18, 2018 Report Share Posted February 18, 2018 1 hour ago, teach said: I've wondered for a while how much more it would cost to have the baseplate made out of some kind of alloy steel. Better failure mode, much longer time to fatigue. Easier to go with 5/16 alu plate and relocate some of the 'features'. If it doesn't flex, it won't crack. Besides, your tongue will stick to the steel in the cold. Quote Link to comment Share on other sites More sharing options...
SunSurfer Posted February 18, 2018 Report Share Posted February 18, 2018 21 minutes ago, lowrider said: Are all these failures toes side ? My baseplate ruptured at the rear foot heel. Quote Link to comment Share on other sites More sharing options...
Ladia Posted February 18, 2018 Report Share Posted February 18, 2018 From these pictures it looks like a typical fatigue crack starting from corner of that machined groove. Spare parts will be problem with Bombers in future. Quote Link to comment Share on other sites More sharing options...
michael.a Posted January 19, 2019 Report Share Posted January 19, 2019 Another failure, my first TD failure of any kind. BTW this is the front foot, 3 degree baseplate. Im sure my 100kg had something to do with it and that the bindings were 9 years old - used every season averaging 10 days. Quote Link to comment Share on other sites More sharing options...
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