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Can somebody post the pic of keel under the topic of nyloc nuts on here,please . Maybe Paul can repost the original.[^] ( ? ). I am not a TA , however ,from what I can see in the pic , that arrangement is unsafe . Are there any TA's out there willing to comment ?
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quote:Originally posted by EchoCan somebody post the pic of keel under the topic of nyloc nuts on here,please . Maybe Paul can repost the original.[^] ( ? ). I am not a TA , however ,from what I can see in the pic , that arrangement is unsafe . Are there any TA's out there willing to comment ?Ok Eric, no problems. Oops, wrong pic. I will have to find the right one[:0] Got it!!!!Image Insert:
57.39 KBAussie Paul.[
]www.firebirdgyros.com
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One further question:Is the RHS shown 2.5 x 2" or 2 x 2"?Photos can be deceptive but it looks to be the latter.Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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quote:Originally posted by NiqueNaqueOne further question:Is the RHS shown 2.5 x 2" or 2 x 2"?Photos can be deceptive but it looks to be the latter.Nicholas TomlinNick. From what I saw it is the standard 63mm X 50MM Aussie Paul.[]www.firebirdgyros.com
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Paul, In relation to the bolt length , I wouldnt have a problem flying that machine . I have been riding motorbikes for 35 years & even done some racing on two strokes that would vibrate your fillings out , & have never had a nyloc with the similar amount of thread showing ( or any nyloc for that matter ) fail. However ASRA has standards we must adhere to & it is not my place to recomend anything else. My concern lays with the keel design , it doesnt appear to have more than one bolt passing through the ends of the RHS . Eric
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quote:Originally posted by EchoPaul, In relation to the bolt length , I wouldnt have a problem flying that machine . I have been riding motorbikes for 35 years & even done some racing on two strokes that would vibrate your fillings out , & have never had a nyloc with the similar amount of thread showing ( or any nyloc for that matter ) fail. However ASRA has standards we must adhere to & it is not my place to recomend anything else. My concern lays with the keel design , it doesnt appear to have more than one bolt passing through the ends of the RHS . EricMy thoughts exactly Eric. We need more info re how the vertical and horizontal RHS is joined. I will have a look at the pic of the whole machine and see if I can improve the knowledge.Aussie Paul.[]www.firebirdgyros.com
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Lets not get to carried away people.This is a case of a 2D pic taken from an obleque angle and portraying one thing when it is actualy another.The 2 keel sections are bolted using 3 bolts each and we must consider that one bolt which is out side the pic to the right is not visable. The vertical section is also bolted to the plated using 3 bolts.Image Insert:
19.69
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Ok people, I will post this better pic.Sam I think you are correct.[^]Aussie Paul.[]Image Insert:86.41 KBwww.firebirdgyros.com
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quote:Originally posted by Firebird PaulOk people, I will post this better pic.Sam I think you are correct.[^]Aussie Paul.[]www.firebirdgyros.comThat is what i was getting at before when i jumped on Nic, take all that into consideration, then add into that, there is the side presure friction of the plates being held to the RHS, the spread of the bolts, and Nic if there were that much corrosion, to cause the faulure, do you think the rest of the machine would be in perfect condition, and should be flying.The side pressure on the plates plays a huge part in the movement/grip control on material between them, when we used to design house footings, the size and depth of the footing was used in calculating the load factor, eg(from memory)on a 1 mtr dia hole, 1 mtr deep, the side carrying capabilities was 3 tonne, so if you had a hole that size with no bottom it could carry 3 tonne. All these things should be taken into consideration, before people start saying without any knowledge, that its unsafe..............A perfect example of this is the bracket around the mast for the trim spring, try to move that without loosening the bolts to near finger tight, that is pure sideways friction nothing else,and then there are places on the gyro where the brackets are only advised to be around the allu instead of through it, do they ever slip?? that was my point right from the start.That it for me....r0t0rcraft.com.au
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I think the some of us, me included, are too quick to jump in with "our ego" comments without enough data or info to make the correct rational decision based on corrct info. I now try harder not to do that.Aussie Paul.[]www.firebirdgyros.com
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Sam, I didnt read anywhere that people are getting carried away. I stated twice that it "appears" to only have one bolt passing thru each RHS . Your diagram has cleared that up , thankyou. Mark, as it was me who posted that arrangement LOOKED unsafe ( once again from one pic ) I guess your last sentence was directed at me. All I was trying to do was generate discussion & to get the facts not make up my own - sorry I made a mistake .
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A very worthwhile discussion in my book and congratulations to all the participants.PeteBairnsdale,Vic.
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Eric, actually no it wasnt directed at anyone in particular, rather a broad statement, along the same lines as what Paul said."All I was trying to do was generate discussion & to get the facts not make up my own - sorry I made a mistake ."Dont ever be sorry for trying to generate discussion, it is good and healthy.[
]Nic can you spel chec this for me 2 ??[:X]r0t0rcraft.com.au
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Mark,You aussie so funny.I mentioned nothing of 'corrosion', I said 'fatigue'.You make commentary about the friction on a house footing for a given depth and diameter, while what you say may well be true in a static situation, the picture changes completely with the addition of vibration.Gyros vibrate. Apply such vibration to the house footing and it will sink as this is one of the tools used in mining and drilling through rock and soil, though houses are not gyros the same principles apply.I usually discount the side pressure on a set of plates for the same reason that lock nuts are specified - why are they there? To stop the nuts falling off - why would they fall off? Because the nuts get loose - why do the nuts get loose? Vibration. When the nuts get loose what happens to the pressure? It is lost - what happens now - you are reliant on the shear strength of the bolts. A further note to make is the stain that is flowing down the side of the vertical leg, and, do you spray the machine with WD 40 or spill some two stroke or oil on it or anything similar, lovely capilliary action - where is your friction then? Remember what happened with the Larkin hub bar with WD 40 on it - bled out a black substance didn't it - did the pressure help? No, it didn't. Why? Because the hub bar has stresses that make it flex relative to the teeter block, will this happen with this connection? You bet it will.Nylocks will not stop a nut from unloading, they will merely hold it in position when the stress causing them to undo diminishes as a product of them being undone, you need lock tite in addition to a nylock if you just do not want it to come undone. I have had proof positive of this on my own machine. My controls felt loose and strange, clunky. It was not until I had assistance from two other blokes to look at it while we worked the controls that we did discover that the nylocks holding the rear yoke bearing block had come undone by 2 mm each were we able to fix the problem. The nylocks were greasy from residual engine oil and fuels that spilled onto the frame and from the bearing block lubrication.Vibration causes fatigue as components are worked backwards and forwards under loads that do not seem to distort the material. As I have posted before aluminium alloys have no lower fatigue stress limit. In review with a better photo the connection looks a little better than it initially did, the proportions of the top single bolts in the keel member are a good deal more healthy than I estimated, however, given the critical nature of the connection I am still not comfortable with the fact of a single bolt in the top of the member for the reasons outlined above, one of them is difficult to inspect - the one in the raked keel member. At least with four bolts you diminish the bearing pressure on the bolt holes by yet one third again, with an alloy member this can really add strength.Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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