Like so many projects within a project during building, the innocent looking fuel line between the fuselage and fuel tank lives up to that reputation. There are two main issues- how to make a 90 degree bend near one end to start, the other being fitting the flare tool over a short length of the tubing.
The first step is to bend the S shape to serve as a template using a tube bender matching the drawing on page 41-09 of the KAI. Trim it to match the fittings between the two fittings on your plane. Forget the flange depth for now. Flare the end of a new 8 inch length of tubing, then slide the 819 fitting in place. Next, place the tubing in a bender with the 819 fitting almost riding on the curve of the bender. Use a C-clamp to hold the assembly in place on the bender since the end of the tube and 819 fitting are out from under the holding arm of the bender. Can now bend your desired curve which will be close enough to the tubing end- this is the tank fitting end.
The middle photo shows making the second bend. Since the second bend is close to the first bend, grind away a portion of the bender arm so the tubing can slide farther into the bender allowing for the short straight area of the final tube shape.
Use your template to mark where you will make the final cut- be sure to add 3/32” to account for the flare- best to overlay everything to keep track of the flanges. The final trick so the 819 can be slid out of the way of the flare tool is to trim about 1/8th inch of the 819 to shorten it. I was stumped, but this idea was from another thread- I would still be pulling my hair out and trying to glue it back in if not for this tip.
Pete
The first step is to bend the S shape to serve as a template using a tube bender matching the drawing on page 41-09 of the KAI. Trim it to match the fittings between the two fittings on your plane. Forget the flange depth for now. Flare the end of a new 8 inch length of tubing, then slide the 819 fitting in place. Next, place the tubing in a bender with the 819 fitting almost riding on the curve of the bender. Use a C-clamp to hold the assembly in place on the bender since the end of the tube and 819 fitting are out from under the holding arm of the bender. Can now bend your desired curve which will be close enough to the tubing end- this is the tank fitting end.
The middle photo shows making the second bend. Since the second bend is close to the first bend, grind away a portion of the bender arm so the tubing can slide farther into the bender allowing for the short straight area of the final tube shape.
Use your template to mark where you will make the final cut- be sure to add 3/32” to account for the flare- best to overlay everything to keep track of the flanges. The final trick so the 819 can be slid out of the way of the flare tool is to trim about 1/8th inch of the 819 to shorten it. I was stumped, but this idea was from another thread- I would still be pulling my hair out and trying to glue it back in if not for this tip.
Pete
