Took my gear off again yesterday to make the repair. Got it back this afternoon. tHe patches aren't quite placed the way James Ball did it, but close enough.
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| Repair of cracked A frame landing gear http://thorp18.com/thorpforum/viewtopic.php?f=7&t=6752 |
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| Author: | dickwolff [ Sun Feb 07, 2016 5:16 pm ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
Took my gear off again yesterday to make the repair. Got it back this afternoon. tHe patches aren't quite placed the way James Ball did it, but close enough. |
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| Author: | dickwolff [ Tue Feb 09, 2016 4:11 pm ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
 Another picture. |
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| Author: | Bill Williams [ Wed Feb 10, 2016 5:47 am ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
Wait and see,but my guess it will still crack at the crotch |
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| Author: | dickwolff [ Fri Feb 12, 2016 7:26 am ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
I'm more optimistic, Bill. The way I see it is that the original weld design could have been better. The cracks initiate at the inboard end of the weld bead... a spot where the bead is spanning a relatively large gap between the round gear leg and the thin flat reinforcing plate. As has already been discussed, the bead is also across the line of stress. One a crack initiates, it will propagate easily. This patch design does three things: 1 It rounds out the inside corner, which is much more resistant to fatigue. 2 It adds a lot of material section to the problem area, which lowers stress, which is also better for fatigue. 3 It turns the transverse weld into a longitudinal weld, which is a better way to weld something under stress. Personally, I think if the reinforcement plate design had originally incorporated a shape like this, we wouldn't see gear cracks in the fleet. Time will tell. D |
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| Author: | James Grahn [ Fri Feb 12, 2016 11:04 am ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
Dick, You need to make sure that surface is flat enough to handle the accompanying hardware. Side loaded bolts in that area would not be a good idea. Cubes |
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| Author: | dickwolff [ Tue Feb 23, 2016 6:30 am ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
Not a factor, Jim. 
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| Author: | SHIPCHIEF [ Wed Jun 01, 2016 10:00 pm ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
I understand the doubler plate on the front, this area is under tension when landing etc. I don't understand the need for the plate on the back, this area is under compression and does not have a history of cracking? |
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| Author: | dickwolff [ Thu Jun 02, 2016 5:14 am ] |
| Post subject: | Re: Repair of cracked A frame landing gear |
Yeah, I thought the same thing, but trust me, they crack on the back too. It'd just a poor weld design. In theory, theory and practice are the same, but in practice they're not. DW |
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