Known building "Gotchas" for the Sling TSi

[PatrickC]

Another note on the vertical stabilizer riv-nuts: In addition to the issue already reported with the bottom two riv-nuts not allowing the doubler angle to sit flush against the rear spar, the clearance holes in the rear spar and the doubler angles for all the remaining riv-nuts were not large enough for an M4 screw.

I stepped up the hole size gradually while checking with a screw borrowed from the wing kit. I ended up with 3/16" holes to provide enough clearance for the screw to thread in cleanly. I did confirm with the factory that this is correct. Hopefully this has been obvious for everyone, but it did require another step that was not detailed in the instructions.

[ncs]

I'm not sure if this counts as as a "gotcha" or just a reminder to pay attention, but two of the nose ribs for the horizontal stabilizer that I got with my empennage kit had holes that were punched too large. It was pretty clear they were off in comparison with other pieces, but I'm not sure I would have noticed immediately without that comparison.

The factory is sending me new ones so it's not a big deal, but I would have been sad if I had spent any time cleaning them up before noticing.

[AaronG]

Wings - on revision 6.1 of the wing manual on sheet 4 it says to use 25x 993 (4.8x10mm) rivets on the rear spar double/triple plates. The rivets need to be 4.8x15mm - also got reply from factory support confirming. This became more clear in later steps when attaching ribs 1-5 to the rear spar where it calls for using 991 (4.8x15mm) and 994 (4.0x12mm) rivets.

[arjenv]

Flap ribs 2 and 3. One of the dimpled holes in rib 3 is being obstructed by flap control bracket 1. Even with shortened rivet, there does not seem to be enough space for the rivet to be pulled because the hole is dimpled. Sling advised to make a gradual cut out in the bracket as per drawing and shorten the rivet.


So with this gradual cut the rivet still needs to be shortened but it will be able to fit:

[ibgarrett]

thanks for sharing - I appreciate it!

[Edward_H]

Question on the flaps and ailerons - Evan’s “How to” videos show using countersunk rivets for the back of the flaps and the current build manual also shows countersunk rivets for the ailerons. Are they actually supposed to be countersunk per directions, or not countersunk per the notes in this thread?

[PhilipRueker]

Question on the flaps and ailerons - Evan’s “How to” videos show using countersunk rivets for the back of the flaps and the current build manual also shows countersunk rivets for the ailerons. Are they actually supposed to be countersunk per directions, or not countersunk per the notes in this thread?

I just checked the latest build manual online (rev 6.2, Sept 2021) and they list Dome Head rivets for Flaps and Ailerons.
Can you point where you found reference to countersunk rivets for them?

[Edward_H]

On Sheet 52 for the Ailerons and sheet 56 for the flaps, there are holes outlined that say to dimple. The parts lists for those components, however, do NOT call out countersunk rivets. I got an e-mail back from technical support in South Africa today that says “We have had a few cases in the past where the domed rivet heads of the flap and aileron touched the wing top skin and the rivets that protrude to the bottom. We decided to install countersunk rivets to avoid this completely. The flap touched more than the aileron.” And, Evan’s video (which is good but not gospel) says to countersink the flap rivets.

The build manual I am looking at online is Rev 6.2, dated September 2021, and has different dates for different pages. Page 52 for the Ailerons is dated August 17 2021 (as is the aileron page with the parts list), and page 56 for the flaps is dated January 14 2021 (as is the flaps page with the parts list).

[PhilipRueker]

Ah right, so yes, those rivets that are close in the movement zone with the wings have sometimes caused issues for some people touching the wing skin, so I guess they not suggest to countersink those to avoid it.

[Edward_H]

It does seem like they are suggesting to countersink and dimple to avoid the problem, but there are no c'snk rivets called out, so they are still not quite in sync with the countersink.