Hi Bjorn,
They're great. Do you have any specs or drawings you could share that I could send to my FIL?
Thanks.
Allen
I do not have the measurement or drawing and now they are sealed inside the tanks.... I did it more or less 'freehand' anyways using a cheapo Harbor Freight mini-lathe.
I did it this way as I didn't believe the plastic tubing used in the Van's version would hold up over the years, ending up with a short between the plate and rib. This solution use a solid block of delrin as isolation.
Here's how (from memory and pictures) I made to two parts ('Rib insert' in the middle, and the 'Donut' shown on the left in the first picture in my log).
Both used a 1" delrin rod as raw material.
The dimensions were selected so I could use the screw, washers and nutplates described in the OP07 (AN509-8R14, A3135-017-24A, K1000-08).
Rib insert:
- Cut a piece 5/8" or longer (it's easier to cut back/sand later...)
- Drill a hole all the way for a AN509-8R14 screw (using the lathe is easiest).
- Reduce the diameter of one end to about 1/2", keeping about 3/8" as 1"
(The reduced diameter is the one going into the rib, the 3/8" width of 1" diameter, represent the 3 stacked rings used in Van's kit)
Donut:
Take a piece of 1" drill a 1/2" (using the lathe) hole all the way through.
Cut it into 3/16" thick slices. Lathe is best but waste material, I has plenty so I didn't care.
Now use some scrap with the same thickness as rib.
Drill a 1/2 hole in the rib-scrap
Sand the 'Rib insert' slightly to fit into the 1/2 hole. Alternatively scrape off a few 1/1000 in the lathe.
Insert the ehhh.. the 'Insert'. The donut fits around the insert (1/2" end), grabbing the rib-scrap between them.
I found it best to have the donut flush with the insert. Too thick and the washer gets deformed when tightening the screw. If you lack grabbing power, sand some off the insert. Finally countersink for the washer/screw.