Tail Stinger Hole Enlargement

[spinningwrench]

I developed a precision jig and step by step method for enlarging the pilot hole in the stinger and tail of my Patrol kit to the final AN5 size. This is not a simple operation as an elongated or poor quality hole could easily result when drilling into the hardened stinger. Contact me if you would like to borrow the jig and instructions.

[Bdflies]

So, you milled the jig to fit over the welded structure and have removable drill bushings in the jig??
That's so cool!!
You guys in the build process really should take this gentleman up on his offer!

Bill

[H. Ivan Haecker]

The hole in my LSA was factory drilled to 1/4" at a slight angle causing the tailwheel to be cocked counterclockwise. Would your fixture allow the hole to be enlarged to 5?16" at the correct angle, i.e. 90 degrees?

Ivan Haecker

[spinningwrench]

It depends on how badly it is cocked. Your only enlarging the hole 1/16” The jig was designed to register off a properly drilled and level 1/4”hole but if your fuselage holes are crooked you could level the jig itself and hope the fuselage holes clean up when going to the final 5/16”. I don’t know if the tailpost design of the LSA is identical to the Patrol. I had to do a lot of work to get the jig to clear all the tubing on my Patrol. Your welcome to try it but possibly Bob can verify if the designs are identical in the tail.

[H. Ivan Haecker]

Visually, it appears that the hole should clean up when enlarging from 1/4 to 5/16. I will be going to Mark Goldberg's tomorrow and will look at both the LSA and Patrol and see if things are identical.

[S Lathrop]

You might take a chain saw file and work the hole a bit before you enlarge it to 5/16.

[spinningwrench]

You need to verify in the LSA that the horizontal tailpost piece with the crooked 1/4” hole measures 1.136” or slightly smaller as that is what the jig is designed for. Also verify that the vertical tube in that vicinity is the same in location. This might be a little difficult to do with a covered fuselage.

[H. Ivan Haecker]

Based on my observations, I think the Patrol and the LSA are similar at the tail post area. The problem is that I can't see both planes at the same time. Also, I like the idea of using a 1/4" chain saw file to get things moving in the right direction. Unfortunately for me, I won't be back to my LSA project until this Thursday afternoon and I will then be in the process of getting to Oshkosh. I'll make a final determination on how to proceed after the show is over.

[spinningwrench]

OK, I might see you there if your going to the dinner

[PaulSA]

Can anyone confirm that the holes attaching the wheel to the spring rod on the 4-place Bravo need to be enlarged to 5/16" and have AN5 bolts fitted? It would make sense to me because I had a lot of difficulty getting the 1/4" holes to line up and they have been "ovalled" slightly to get the AN4 bolt through.

[Mark Goldberg]

Paul - on drawing 21B you will see that Bob actually wants this one bolt to be a AN6 bolt on the 4 place Model B. The spring is 1" diameter compared to the Patrol's 7/8" diameter spring. Mark

[PaulSA]

Mark. I am talking about the other end - the 2 bolts that hold the wheel to the spring. The holes in the spring and the holes in the wheel tube didn't exactly line up and I had to "ease" them slightly to get an AN4 bolt through. I'm sure it will be fine as they are but if they were designed to be opened up to 5/16" then that would make sense.

[Steve W]

Hey thanks for the discussion on this topic. Made me think and recheck what I had done. All of my bolts were at 1/4". Will have to open up the fuselage bolt to 5/16". Always great to be bouncing things off one an other.