Inspection Hole

[skywshuo]

hi,here I have a question, in the SEF form we should give the area and moment of inertia, however in the rules there are no detail informations of the inspection hole, so I do not know how to calculate it ,can anyone help me, thank you.

[skywshuo]

hi,here I have a question, in the SEF form we should give the area and moment of inertia, however in the rules there are no detail informations of the inspection hole, so I do not know how to calculate it ,can anyone help me, thank you.

[moose]

If you read a bit farther into 3.3.1:

"Note 3: Except for inspection holes, any holes drilled in any regulated tubing require the submission
of an SEF."

In addition...

"B3.25.1 The Technical Inspectors may check the compliance of all tubes. This may be done by the use of ultra
sonic testing or by the drilling of inspection holes at the inspector’s request."

So you really don't need one to start with at this point.

BUT, I do believe 1/8" is about what you would need (so bring that size drill bit with you). Figure big enough to stick the back of a caliper into, but not much more. And please, if you drill it, don't put it somewhere stupid in the roll hoop.

[Michael Royce]

The diameter of the inspection hole needs to be 4.5 mm (3/16 inch) to get the tailstock of a Vernier caliper through. This used to be specified in the Rules until the Rules Committee decided to drop it for 2011. The "old" wording was:

B3.25 Inspection Holes
B3.25.1 To allow the verification of tubing wall thicknesses, 4.5 mm (0.18 inch) inspection holes must be drilled in a non-critical location of both the Main Hoop and the Front Hoop.

B3.25.2 In addition, the Technical Inspectors may check the compliance of other tubes that have minimum dimensions specified. This may be done by the use of ultra sonic testing or by the drilling of additional inspection holes at the inspector’s request.

B3.25.3 Inspection holes must be located so that the outside diameter can be measured ACROSS the inspection hole with a vernier caliper, i.e. there must be access for the vernier caliper to the inspection hole and to the outside of the tube one hundred eighty degrees (180°) from the inspection hole.

For location, in the Main Hoop, try to put the hole in the part of the hoop between the Upper Side Impact Tube and the Lower Side Impact Tube. This is the lease critical area.

If you have a monocoque, whether the inspectors use the ultra-sonic thickness tester or not, don't forget that you need to have a straight portion of the Front Hoop exposed so it can be measured, i.e. not wrapped in carbon fibre or other material! Other wise they will make you scrape away some material.

And if you are going to drill the inspection holes, don't forget B.3.25.3. Otherwise, if the ultra-sonic tester is not available or is not working, they will make you drill new holes!