| Further to the adjustable tail incidence (post No. 79 above). Having had a few sessions with the Acrowot to get my thumbs up to speed again after the winter recess, I got the Elf out for it’s pre-flight checks.
Of course the Laser fired up “first flick” and ran faultlessly but when I checked the nut on the tail incidence adjuster it stripped the thread with only slight torque on the spanner. It was actually the rod that had stripped; it was one of the 2mm rods from the model shop with a thread at one end. I needed a short rod; about 50mm long, with a thread at both ends so I’d tapped the extra thread. When I investigated the problem I found that the rod as supplied has a “rolled” 2mm thread but the rod itself is only 1.7mm diameter. All had seemed OK when it was made but obviously with vibration from the engine and the load when elevator is used, the undersized thread wasn’t good enough for the job.
At least I found the problem before anything disastrous happened and it re-enforces the need for regular checks and especially before the first outing of the season. |