I had this pic from the other night when I trimmed the hatch rib tails back to the new template configuration. The new trim router is working out great for little stuff like this. It is very easy to handle.
It seems that I am not being as diligent taking step by step pics lately. I seem to be forgetting, or maybe I’m just focusing on the work.
Even though I had culled out the two ribs that I thought looked best from the outsides of the hatch, I found that I had marked them differently earlier, so decided to double check them against each other.
I found that two of them were a little narrower near the top (a little less than the 3 inches planned), and the pairs didn’t quite match. I decided, even though I had already match drilled two of them to the hinge spar, that I would rather have the thicker ones inboard at the actuators; a little extra meat near the bracket mounting locations.
By clamping the tails and middles together I was able to align the differences in the upper profile together without too much force needed, so I am confident that it will all work out once everything has been screwed to the spars. You can see the middle pair is a little wider here.
Another thing that I noticed, but isn’t really a big deal (and may just be something that I have forgotten) is that on one of the ribs the miter sections/joints don’t line up with the others. I don’t know if this is just a mistake; maybe I had a knot that I was trying to avoid; or maybe I put the template on the blank backwards. Anyway, it won’t be something anyone is likely to notice. (Geez, I seem to be getting a lot of those piling up around me these days.)
Next I clamped the two center ribs together and laid out the bolt pattern for the upper hatch actuator brackets. I wrapped the pair with some chipboard so that we could clamp the ribs together in the milling machine and drill the holes. By doing it in the milling machine I can be sure that the holes in both ribs are exactly the same, and that the axes of the holes are absolutely perpendicular to the faces of the ribs. This way I can be sure that the three thru bolts and the double shear rod bolt will all align on both sides of both ribs. Here they are after the drilling was complete.
Here the red pencil represents the approximate location of the hinge centerline.
The inside of the rib profile will be exposed so I wanted to round over those edges. I decided to go with the 3/16 round over bit, but I wanted to make sure that I didn’t wrap the corners where the ribs glue to the spars, and I didn’t want to lose any material under the actuator bracket mounting points. To keep from wrapping the ends I knocked together a couple of run out waster blocks attached to a backer that would allow me to clamp them to the ribs without getting into the way of the router shoe. The tails.
The top before routing.
At the actuator mount location I found that if I just put one of the bar clamps on the centerline of the lower mounting hole, that would act as a good stop location. Here you can see one after a little sanding with 220 grit to blend the round over in a bit and knock the sharp edge off where the bracket goes.
So I rounded over all four ribs this way on their street side, and will have to flip-flop the stop blocks to the opposite hand to do all of the curb sides.
Train kept a rollin’.