HS-00003 Doubler Edge Distance

Tried searching to no luck, seeing if anyone else has had this.

I have a new RV-8 Emp that I've started. The left HS-00003 had maybe a half of a degree when it was drilled to the HS-702, didn't even notice it until I clecoed the HS-810/814 to the doublers to check edge distance.

It's very, very close on the right HS-00003 doubler and on the left the last couple of holes on the HS-810 side are .195 to .200 (depending how my caliper feels), inside of the minimum edge distance of .219"

Emailed the mothership last week and haven't heard back, just wondering if others have seen this and be told it's okay.

By "Edge distance" are you referring to the edges of the HS-00003 being exactly in line with the edges of the underlying spar, or are you referring to distances from holes within the HS-00003 and holes on the spar?

Talking about the edge distance from the holes in the HS-00003 from being match drilled from the 810/814 to 702 to 00003 outboard of the 6 degree bend.

Edge distance

How are you measuring the edge distance?
A 1/8" hole needs 1/4" from center of the hole to edge of the part. If you're measuring the distance from the edge of the hole to edge of part, that's probably within allowable distance.
You are correct to question it. Always check before drilling.

wirejock said:

How are you measuring the edge distance?
A 1/8" hole needs 1/4" from center of the hole to edge of the part. If you're measuring the distance from the edge of the hole to edge of part, that's probably within allowable distance.
You are correct to question it. Always check before drilling.

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Nope, as measured from center. I clecoed the 810 directly to the HS-00003 to see where the center of the drill hole will be.

I had exactly the same problem on my 7 HS a week ago. I'm still not sure how it happened. I have decided to reorder parts, not just because of the edge distance issue, but also because an asymmetry between left and right of about 0.1" has been induced at the end of the front spar, and because the HS-710 would be a little proud of the skin unless I grind some off it. So I would advise you check these latter two issues before deciding what to do.
Best of luck.

Doublers

Is it possible the doublers are flipped L&R. As I recall they are not symmetrical top/bottom so if they are on the wrong side top or bottom holes might be close. Just a thought.
It's a cheap part. Place the order and ship USPS priority. Fairly cheap to ship.

In my case I checked that and it wasn't the reason. The best explanation I have come up with so far is that it is a combination of the accumulation of tolerances on the clecos, and possibly some binding of the inboard edges of the HS-702 forward spars.

wirejock said:

Is it possible the doublers are flipped L&R. As I recall they are not symmetrical top/bottom so if they are on the wrong side top or bottom holes might be close. Just a thought.
It's a cheap part. Place the order and ship USPS priority. Fairly cheap to ship.

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Parts were pre-bent and the instruction had directed that the staggered rivet side be along the top side of the spar. still awaiting word from the mothership...

Support

TechSupport said:

Parts were pre-bent and the instruction had directed that the staggered rivet side be along the top side of the spar. still awaiting word from the mothership...

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That's way too long. Send it again and call. They usually reply in two days max.

wirejock said:

That's way too long. Send it again and call. They usually reply in two days max.

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Tech, did you ever hear back from Van's? I'm having the same edge distance issue.

HueyEd said:

Tech, did you ever hear back from Van's? I'm having the same edge distance issue.

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" Minimum ED on an #30 hole is ~.257" from the center of the initial hole to the edge of the work or the next hole. If you have that dimension, then you are OK. I cannot tell from the pics as there is no scaling visible for me to measure it. On the the actual HS-00003 part, the holes are ~.365" near the center area for the HS-810/814 alignment. As you move out, the distance changes to ~.250. These should all be valid ED for the assembly.


It sounds like you have have got the HS-0003 off a little on initial alignment so the the hole dims are reduced as you move outboard. I would simply swap the part out for a new one. "

This is the reply I received. I don't know if it was a misspeak but his first sentence he says that the minimum edge distance is .257 which is greater than the last sentence in the first paragraph saying it changes to .250". Anyone who has clarification on that is appreciated but I assumed it was a mistake.


I just ordered a new doubler and the corresponding spar. I was much more careful to make sure there was no tilt along the main part of the doubler as that gets exaggerated the farther out you go, which by virtue of math has no tolerance.

Since I knew this was tight I gave the side of the doubler that is supposed to lay flat against the edge of the spar a few extra deburring passes to make sure I didn't miss it.

TechSupport

TechSupport said:

" Minimum ED on an #30 hole is ~.257" from the center of the initial hole to the edge of the work or the next hole. If you have that dimension, then you are OK. I cannot tell from the pics as there is no scaling visible for me to measure it. On the the actual HS-00003 part, the holes are ~.365" near the center area for the HS-810/814 alignment. As you move out, the distance changes to ~.250. These should all be valid ED for the assembly.


It sounds like you have have got the HS-0003 off a little on initial alignment so the the hole dims are reduced as you move outboard. I would simply swap the part out for a new one. "

This is the reply I received. I don't know if it was a misspeak but his first sentence he says that the minimum edge distance is .257 which is greater than the last sentence in the first paragraph saying it changes to .250". Anyone who has clarification on that is appreciated but I assumed it was a mistake.


I just ordered a new doubler and the corresponding spar. I was much more careful to make sure there was no tilt along the main part of the doubler as that gets exaggerated the farther out you go, which by virtue of math has no tolerance.

Since I knew this was tight I gave the side of the doubler that is supposed to lay flat against the edge of the spar a few extra deburring passes to make sure I didn't miss it.

TechSupport

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Thank you!

#30 diameter is actually 0.1285 nominal, so 2D for a #30 is 0.257 nominal. The corresponding rivet size is 0.125 nominal, so 2D for that is 0.250 nominal. Most people use these values interchangeably most of the time.

In fact, there are tolerances on all the values, which overlap each other. Also, I'd be very surprised if Vans is using tighter general design tolerances in this area than about 0.010.

Additionally, the RV construction manual references MIL-R-47196A for rivet installation, and this allows less than the 2D value for rivet edge distances (0.219 for a 1/8 rivet). So, the 0.250 / 0.257 difference is very unlikely to be critical.

Hi Tech. I?ve had the same problem as you, albeit on an RV7. You may be interested in this email exchange I had with Van?s builders support on the topic (see below). My experience (see link also below) suggests that it?s practically impossible to get these edge distances right unless you fabricate your own HS-00001/00003. You?ll note in the exchange below that Van?s declined to respond to my question about why the doubler couldn?t be made just that little bit bigger.
Cheers,
Warbo

To Van?s Builders Support
Thanks for your email. I spoke on the phone to one of the support people who suggested that I was in uncharted waters with my edge distance as no engineering studies had been done which would allow a reduced edge distance in this case. I went ahead and ordered new parts and re-did the fwd spar. Still had the same problem although the edge distance was a little better the second time. I documented my woes on the VAF forums here http://www.vansairforce.com/community/showthread.php?t=124814&page=2
If you read through my post you will see that it's almost impossible to get these edge distances right so I'm still wondering how you guys do it. Any advice would be appreciated.

From Van?s Builders Support
The engineers don't like the idea of short ED on this part. I have talked to a few people with this problem and the way they have moved on is to fabricate a larger doubler that will allow proper ED.
To Van?s Builders Support
Thanks, I figured the best way to guarantee ED here would be to fabricate a slightly larger doubler. Which begs the question, doesn't it? Why don't Van's make the doubler just that little bit bigger in the first place? I think it would save a lot of builders so much heartache.
I've been thinking of fabricating a new doubler as I'm still not completely happy with what I have at the moment. Could you tell me what the specs are for the material used in the doubler please.
From Van?s Builders Support
The material used is 2024T3 0.063 thick.

I have no idea why Vans wont simply supply a slight larger doubler and let builders trim as necessary. I am on my second doubler and spar set and having the exact same issues with edge distances particularly at the outboard ends of the doubler(approx .200" on both L and R outboard end holes). The top edges of the doubler were exactly flush with the 810 and 814 bars just as per the plans and doublers 1 7/8" exactly from inboard end of the 702 spar.
Very frustrating how much time I have spent here... I think I am done with this part and am going to fabricate a blank doubler to match drill with my spar. Additionally, be warned that if you make your 702 spar relief notches with a 1/4" step drill like the drawings show you will also likely get into edge distance issue. I would recommend being conservative and going in just a bit with a round file and/or waiting until the parts are completely drilled before making final relief notches. Oh and if you are usings Van's HS-00003 doubler dont do any edge finishing till the part is drilled. Zero wiggle room all around. Not sure if any of this applies to the RV-7 but for the new 8 tail kits its a issue!

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