HS-307 note

Greetings,

Even as an experienced RV builder, I have to admit that I screwed up the HS-307's. I like to get my mistakes out of the way early

The only reason I mention this is because I still don't see anything in the plans that would stop anyone from making the same mistake. In fact, had I not built a few of these, I wouldn't have realized the mistake until much later.

The problem is drilling for rivets to attach the HS-307's to the rear spar. The plans and manual neglect to tell you not to drill for rivets in the area between the main ribs (center 5" of the rear spar). In this area, you will have 4 bolts drilled with the center bearing brackets, but the rest of the area between the brackets and the main ribs is left without holes to allow for mounting to the fuselage later. If you put rivets here, you'll find them in the way later, and worse than that, the holes may be in a bad location relative to where you need to drill for bolts during the fuselage assembly.

Cheers,
Rusty (can't wait to taper more spar strips...)

Me too.

I discovered this recently as well. I am hopeful that the holes will fall within edge distance requirements when I get to that point, or maybe get lucky. There is a lot of "meat" between the rivets as well on those spars so unless you get really unlucky, it should be workable.
Randy?

This is just one of a thousand things you'll encounter where having built an RV before and visualizing how things go together helps. At first you guys had me saying "huh?", then I remembered this area. Knowing in advance that this is the area where the HS mounts to the rear brackets I didn't drill any holes there. Still, even if you did drill #30 holes, there's a good chance they will be fine when you go to drill the AN3 attach holes. If not there are other ways to correct the situation.

As you read the manual and look at the plans you really need to adopt an attitude where you trust nothing and verify everything. Just have a talk with yourself before every set of holes or assembly... "now does this really make sense, and how did this go together on my RV-(X)?"

randylervold said:

Just have a talk with yourself before every set of holes or assembly... "now does this really make sense, and how did this go together on my RV-(X)?"

Click to expand...

I have been talking to myself all right, and some of it is not very pretty!
Thanks Randy. I will try to find the dimmension of the attach points and see where my #30 holes fall. I am sure I can work around it if they do not fall within the other holes, or if I have edge distance issues.

Rusty - very much appreciate your post even though it was a tad late for me.

randylervold said:

This is just one of a thousand things you'll encounter where having built an RV before and visualizing how things go together helps. At first you guys had me saying "huh?", then I remembered this area. Knowing in advance that this is the area where the HS mounts to the rear brackets I didn't drill any holes there. Still, even if you did drill #30 holes, there's a good chance they will be fine when you go to drill the AN3 attach holes. If not there are other ways to correct the situation.

As you read the manual and look at the plans you really need to adopt an attitude where you trust nothing and verify everything. Just have a talk with yourself before every set of holes or assembly... "now does this really make sense, and how did this go together on my RV-(X)?"

Click to expand...

Not to hijack this thread, but I think the same can be said about the -4, and it is rather silent there at the moment. For a first time builder as myself, some of the things are completely impossible to foresee. In hindsight I think that I "should" have thought about it, and with more experience I probably? would (even though it is not mentioned in the manual or anywhere else), but I also have to keep on building, or I will never be finished. I can't stop and think 10 steps ahead for every little thing I do.

What I find is lacking in the manual and drawings is a list of checkpoints before doing an (irreversible and possibly unrepearable) operation. Simple things like "If you mark the rivet holes on the HS-402/HS-410 according to plans and manual, then edge distance will be too little on HS-410". Just a very simple form of QA up front to minimize the amount of mistakes, and a short explanation to why. Has anyone made such lists? Would anyone, except me, be interested in lists like this? I have thought a bit about this, and they have to be simple and printable with reference to drawings and "procedures" in the manual.

Thank you

I've got my empennage kit and the fuselage is nearing shipment, however, I haven't started cutting any metal yet. I do want to extend my appreciation for such posts. They are a great help to a first time builder like myself.

I've been working on a CAD Model Based Definition (MBD) of the airframe, as a way to verify both the plans and the parts as I begin building. My hope is that the MBD along, with a posts such as this one will help me to avoid some of potential interferences. Should the MBD be of any benefit, I will certainly post any relevant information.

Thanks,

Bob

HS - Rear Spar Mount to Fuselage

Randy, while I intend to find the exact dimmensions off of the center flange bearing in the prints, would it be possible for you to measure yours? Not sure if you can get in and do that without removing the empenage fairing or not, so don't bother if it is a hassle.
I want to make sure I dont have a real problem. I would hate to abandon the HS Spar at this point as I have a lot of work already invested in it but I would hate even more to finish the thing and then have an insurmountable problem.
I am sure it will be fine, but as usual, I have not worried enough about it yet. So, need to worry a little more then all will be ok.

Randy. don't bother

JonJay said:

Randy, while I intend to find the exact dimmensions off of the center flange bearing in the prints, would it be possible for you to measure yours? .

Click to expand...

The dimmension from the center of the Flange Bearing to the edge of the first rib is 2 1/2". The flange bearing angle is 3/4" plus a little for the bearing. That leaves less than 1 3/4" space where the 1 1/4" x 3/16" stock goes to support the HS Rear Spar. If you drilled the holes in the rear spar like I did, centered between the first rib rivet line and the center of the Flange Bearing bolt holes, there is no way those holes will not work for the HS Rear Spar attach bolts.

Rusty - dont trash your HS Rear Spar until you check this out for yourself and verify.

Building happily along now.....

I made the same mistake. Fortunately I got lucky and was able to replace the rivets with bolts. These little omissions seem to be never ending...I guess it will make the finished product that much more rewarding.

Wow, a lot of great comments.

Jon, Nice picture. I have to believe those holes will work fine, but for anyone who hasn't drilled theirs yet, don't drill those 4 holes shown between the center bearing and the main rib flanges.

In my case, I ended up with two holes in that space, rather than one. That's good, because it leaves the center of the bar open for a bolt hole, and bad because I have eight rivets that would be in the way. Mine are only drilled 3/32" in the 307 so far, and I'll just leave those #3 size, and make them flush rivets on the front side of the spar. Problem solved

There's also the matter of the 7/16" trim cable hole that can't possibly fit between the two 307 bars I had the same problem on my other RV-3 project, but just figured the original builder screwed up the spacing. Now I know he did it just like he was supposed to. FWIW, I used a different type of cable from Spruce. It's a smaller diameter, bowden type cable, but has a vernier knob on the end. It wasn't as precise as the heavier 3/8" cable Van's typically uses though.

It's too bad we don't have a more organized place for plans corrections and warnings online. I wonder if Van's would make the corrections if we took the time to email them? I'm guessing they would, but it would be a pretty low priority project.

Cheers,
Rusty (waaaaaay overdue for a web page...)

I have been watching and reading everyones posts about problems with building the RV3 and it makes me wonder about myself.

My father and I built one of the very first RV4's (s/n 37) and we had a lot of the very same problems that everyone, including myself, is experiencing with constructing the RV3. I have been re-living many of the problems we had with the RV4 over again in building my RV3B.

I think a solution for the problem of every new builder learning on their own and falling into the same "trap" could be handled without Van, that is most likely what he would rather see anyway since he has never taken this up.

Someone, not me, could post an EXCEL document where all of us could put in a line of information on what we found. There could be no "back-and-forth" about the information and it could not be authorized in any way other than something to read. If anyone of us felt differently we could make our own post. All we need is to be alerted, we can find our way after that.

This would be VERY similar to the Thorp T18 newsletters, (yes, I built a Thorp). Those Thorp newsletters were very helpfull to me in getting really ready for the areas that had been commented on.
I did not call or write anyone because in most cases you could figure it out on your own, all you need is a "heads up".

Another Newbie-same mistake

I drilled the holes too but they are also near center. My plan is to wait until I can fit the stab to the fuse and there may be some room to adjust the 11/4" x 3/16"bars before attaching them to the F-310 Bulkhead.
A few more FYI's
1)The spacing for the AN-3 bolts in the lower angle of VS-309 is hard to find until you discover the tailwheel bkt. bolts thru them.
2) My VS-307 spar doubler needed major trimming, I suspect its a -4 part
3) The rudder lower FRP tip mounting is unclear. I added a 1/2" flange,sandwiched btwn the lower rib and skin to attach it.
4) I would have pulled my Stab and Fin skins aft a little more to give tighter hinge gaps. I think the root and tip chord distances vary...probably explains the poor fit of the tips.
I keep telling myself the upside is there won't be two hundred -3s at OSH when I get mine there
Thanks to all that post and especially Randy and Rob H for their websites.
I have the tail finished, the QB Wing and Fuse kit shipped today.
Mike

Hi Alex,

Looks like you have an older kit. My old (#751) project had the same "angle" that bolted to the rear spar of the HS. The newer kits have 1.25" wide flat bar stock, which probably gives a larger target to shoot for. I'm not sure when they introduced that change though. It almost seems like angle would be better, but Van's uses flat stock on all the other models I believe.

Cheers,
Rusty

Alex,

There should be a plans serial number on it somewhere. You'll have to find that if you expect true historical authentication

The project I finished previously included a couple hand written tech support letters. I guess even fax wasn't common at the time, so tech support that required drawings was via letter. Van had drawn sketches in his letters showing how things should fit. Very cool, and I wish I had kept them

That must have been in the days where 6-8 weeks for delivery was considered normal

Cheers,
Rusty