The text manual, rudder section, says “4. Bolt the rudder horn mount tube to the spar“. Since the holes in the spar are not sized for the bolts, it seems obvious they need to be drilled. However, there is a hold slightly higher up the spar and off-center that is the same size as the bolts, so I know the CNC machine can make a hole that size. Since the machine can make holes that size and did not do so for the rudder horn mount, and there is no mention of drilling these holes, I wanted to confirm that this is the process.
I assume there are probably lots of places that need drilled to size where that isn’t called out, but since I have seen it called out in a number of other places, the fact that drilling was not called out in or prior to step 4, I decided I better check since I am just getting started and don’t want to screw up at the outset. 😁
m.whititng,
You have assumed correctly. The holes are left undersized intentionally to allow for any slight deviation in the rudder where it is a welded part. You need to up size one hole to number 11, pin the rudder horn and then use the rudder horn as a drill guide to up size the second hole. Manuals will be updated soon to elaborate on this process. Thanks for bringing it to our attention. Hope this helps and happy building!
Thanks,
Ryan
Stewart Systems Ekoprime. I plan to use their products for the exterior so I decided I might as well get familiar with them now and get my paint spraying equipment set up and get some practice with it in a less critical way. And this way I know I will have compatibility should some of the exterior products get on the parts I primed during assembly.
Just out of curiosity, what are you priming with? I primed the rudder spars and ribs with some of the NAPA self-etching stuff that I see people talking about on the forums.
I ended up doing pretty much the same. I drilled the top hole first and then bolted the mount tube. I tried to clamp the bottom, but that powder coat is so slippery on the aluminum that it really didn’t stay in position well so my wife and I just held it as parallel to the spar as we could and drilled it. I used the #11 drill since that was in the table as you mentioned. I don’t think this is a critical part alignment-wise as it just holds the rudder horn and as long as it ends up close to horizontal I can’t see it being an issue.
Now that I think of it, I don’t recall the text manual saying to install the rudder horn, but I assume it is done now since it is called out in the parts diagram. I’m a little cautious just starting out and probably got spoiled by taking the Sportair Van’s builder workshop as the Van’s manual pretty much called out every single step so when I see something “missing“ now I tend to check and recheck. I’m sure this fades as familiarity with the RANS manual style increases.
I am complicating things by priming parts and that bit me yesterday when I was transferring drilling the ribs. The drill broke through a little faster than I expected and hit the cleco on the opposite side. This pushed the drill to the side and elongated the hole somewhat. It was the last hole at the rear edge of the rib so I don’t think it is of any structural consequence and it will be easily covered by the rivet. I will check AC 43.13, but I think it is fine to just rivet as is. Had the other side been riveted already, that would not have happened.
Yes, just starting out. Picked up the kit July 13th and had to build a work table and now waiting on spray gun and related parts. I broke my leg in May right as I was getting my shop finalized. I got my compressed air system installed right before my accident, but did not get my work table built, storage shelves build, etc. so that has slowed my start a little. And I will be a slow builder as I am a perfectionist by nature and that always slows things down. 😁
For what it's worth, here's what I did:
The manual has a "Typical hardware drill size table" that shows a #11 bit is used for an AN-3. I drilled the center (top) hole up to a #11 and then temporarily attached the part to the spar. From there, I could use a standard 3/16's bit through the rudder spar mount tube without contacting the powder coat or touching the mount tube hole bosses. I used this as a guide to enlarge the holes in the spar for the AN3's. Although a #11 is spec'd for the bolts, the 3/16's allowed them to fit fine after drilling and deburring.
Hopefully some of the Rans guys will jump back into the forum soon. Sounds like we are both just starting out - I'll be interested to keep up and see how yours is progressing!
Ryan