NorthernRV4
Well Known Member
Since it's close to Halloween the topic of skeletons seems fitting. Specifically how to properly jig the horizontal stabilizer skeleton for skinning.
I am at the stage where I have completed the HS skeleton and need to jig it square and true to install the skins. I have not trimmed them from the state they were in when they left Vans. The skeleton is fastened in the jig as per the directions and I am a little worried about proper alignment before I think about a drill bit touching anything. I've read over the instructions multiple times and I understand it.
from the manual:
Reinstall the skeleton in the jig and carefully true it up. The skeleton should now be pinned firmly in place, the tip ribs centered on the upright line and perpendicular to the rear spar, the center of the front spar held on the spanwise centerline, and all the spars straight-no bows or twists.
My dilemna is how to ascertain that everything is centered on the upright centerline. Seems inaccurate to use a level since nothing can be used to hold it squarely against. I could draw vertical centerlines on the tip ribs but I can't say those would be entirely accurate either. What have other builders done? I've considered stringing a taught line above everything on the verticle centerline from which I could hang a plumb bob. I do have a self leveling laser but honestly I don't trust it much, seems off vertical to me. any suggestions folks?
How much chance of introducing twist (washout/in) is there? The skins seem like they align the ribs really. The threaded rod attaching them to the jig uprights holds them well at 90deg but not so well from twisting.
I am at the stage where I have completed the HS skeleton and need to jig it square and true to install the skins. I have not trimmed them from the state they were in when they left Vans. The skeleton is fastened in the jig as per the directions and I am a little worried about proper alignment before I think about a drill bit touching anything. I've read over the instructions multiple times and I understand it.
from the manual:
Reinstall the skeleton in the jig and carefully true it up. The skeleton should now be pinned firmly in place, the tip ribs centered on the upright line and perpendicular to the rear spar, the center of the front spar held on the spanwise centerline, and all the spars straight-no bows or twists.
My dilemna is how to ascertain that everything is centered on the upright centerline. Seems inaccurate to use a level since nothing can be used to hold it squarely against. I could draw vertical centerlines on the tip ribs but I can't say those would be entirely accurate either. What have other builders done? I've considered stringing a taught line above everything on the verticle centerline from which I could hang a plumb bob. I do have a self leveling laser but honestly I don't trust it much, seems off vertical to me. any suggestions folks?
How much chance of introducing twist (washout/in) is there? The skins seem like they align the ribs really. The threaded rod attaching them to the jig uprights holds them well at 90deg but not so well from twisting.