Different circumstances but did the same here. I only had to change one.
Phil
I only needed to change one but I ordered all four because I don’t want another one to break during flight. @Voltair, Don’t you also have a batch 2?
I do. Pretty happy with it overall, besides the fact that I am sand blasting my lower blade like its going out of style😆 They erode faster than the Long Island North Shore🤣
Was it you who made a locking system to keep the upper and lower sections of the frame at the same place - if I remember, it was made out of Lexan or something like it. I would like to do it to because it is a bit of a pain trying to keep the while thing straight when installing the batteries, especially on shifting sand at the beach.
I did designed a hinge stop. It works great. Once the bottom tubes are connected it doesn’t shift at all. You should try them.
What was your reason for replacing a prop standoff?
It was a weird one,… I had forgotten to bring the hoops stiffeners I had made with me that day ( they work great and I think your brackets would make things even better). So, I took off with an angled cage because overtime, the connections at the ends of the tubes had loosened quite a bit. I inflated the wing, an accelerated. I remember hearing a weird noise and almost aborted the takeoff but went for it anyway. The noise did not last more than a few seconds while I was running. 40mn later with a bit of help from the ridge lift, I landed, and when placed the PPG on the beach, I walked behind it and my lower jaw just dropped… I realized I had flown 40 minutes with only 3 propellers 
In retrospect, I remember my right turns being sluggish:crazy_face: The bottom prop was gone and the shaft, just like your busted clean. The bottom left section of the hoop came loose during the run and must have hit the prop, creating enough force to snap the shaft. Interestingly enough, after retracing my steps on the beach, I first found the piece of tubing and it was completely intact ( I can’t figure this one out). I kept zigzagging slowly on the beach and sure enough, found my prop, with the rest of the shaft and the bolt. That was the flight THE ELECTRIC BUZZARD 6 - YouTube
If you look carefully, you will notice that there is no orange/beige colors at the bottom left (the blur made by the props😏
Dang, that’s crazy! So it happened on takeoff and you didn’t notice the thrust difference during climb? Do you think the hoop came off first and hit the prop? Or did the prop come off and hit the tube? On mine the prop came off during flight and could have hit the batteries! That’s why I’m replacing all four with the new one piece design.
Difference during the climb: not really because I was relatively close to the ridge and there was a bit of lift.
Take a look at those pix 
Notice the left tube section disconnected from the arm…
Locating the lower left tube
Locating the prop which landed further down the beach
Notice one of the blade is missing the tip and the entire leading edge
The batteries were fine and so was the tubing. I don’t really understand all of it. No one will resolve this one😆
All I am sure of is that the bottom left connection came loose during the run; the rest is a mystery.
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That makes perfect sense. Based on where you found the parts, the tube came off first and then the prop hit and broke off.
About a month ago I forgot to tighten my net. The prop struck it after I hit full throttle. I bet that damaged my standoff because 3 weeks later the standoff on that same motor broke during flight. The other standoffs are probably fine but since I couldn’t tell the damaged one was about to break I’m happy to be getting the one piece versions for all 4.
I may get 3 more standoffs. Lesson learned. All is back on track now.
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23nm is just about 17ft lbs. I have a two foot torque wrench. Grabbed the motor braced my arm against the propeller and swung the wrench until the needle approached 20. Repeated for the other three. We’ll see how things hold up.
Thanks for sharing this. What is your rationale for using 22x13 (as opposed to 22x12 or 22x14) props and where did you get them?
Also in need of a spare prop standoff. Did somebody find the 3D-drawing of this part so I can duplicate the part locally? Am not getting reply through email for ordering the part directly with openppg…
Thanks for any assistance getting me airborn again any time soon!
Never had the problem. The imprint works good enough. I changed quite a few props over time (mostly because the sand blasts the leading edge) and no slipping issue so far. I do not hold the propeller in place by hand when tightening the nut. I use a fat adjustable wrench and lock it on the shaft, hold it an take care of the nut. I usually tighten the nut a bit more a short while later, that’s all.
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My prop 10mm nylon lock nut is seized! (X4) any suggestions to release it?
I’ve tried heating the bolt with a soldering iron but no luck yet. It’s rock solid.
The stud on that standoff is aluminum. If you force it off it will probably sheer the stud. That might be the only way to remove it though and then replace the whole standoff.
Thanks Paul. I’ve done that & it did shear the stud. So I’ve ordered another 2 standoffs. Fingers crossed they will not take too long to get here to the UK. The nut was completely “welded on” so I think you’re right that was the only option. Funny because the other 3 are perfectly fine. I think I’ve been unlucky with this machine but I love the design and I am determined to get it back in the air.
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Unfortunately Paul & Zach say they don’t have any prop standoffs in stock. They said to contact MAD motors but I haven’t heard back from them yet. I wonder if there is any other way of obtaining this part. for instance if it could be manufactured using a CAD file?