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-   -   RV-4 Spar Splice Plates (https://vansairforce.net/community/showthread.php?t=96428)

RFazio 02-13-2013 03:17 PM

RV-4 Spar Splice Plates
 
My friend steve, totally un-computer capable, purchased a partially completed 4 kit. He got it for a great price and has been working on it for about a year. He's to the point where he wanted to fit the wings, and finds out that he has two of the four spar splice plates. We called the original builder and he has no idea where they are, so we decided to get new ones. We ordered two plates from Vans and they came today without holes. I knew they were match drilled and kind of figured this was going to be the case. Has anyone gone through this? What is the procedure to get the two new plates drilled properly? We have the upper forward plate and lower rear plate drilled. I'm thinking of using the two drilled plates to match drill the new ones on a milling machine with turned bushings to start the first small hole. Then keep going up bushed for each size. All ideas welcome.

rocketbob 02-13-2013 03:39 PM

For my RV-6 rebuild I ordered a new center section from Phlogiston, which even though they were supposed to be drilled to exact dimensions I found them off. What I would do: take the two you have and duplicate the holes and not even do it on the mill. Just a drill press would be fine. Drilling with a twist drill is not exact so I would make up some bushings out of some fairly hard steel and pilot drill the holes, finish drill to a close size then ream using the old splice plates clamped to the new ones.

I think you'd find that your splice plates will bolt in either top or bottom on the spars and are probably an exact match. I think when they drilled them back then they drilled all four in a stack, then used those to drill the holes in the spar. And if thats the case then it should be just a matter of duplicating them exactly.

JonJay 02-13-2013 03:52 PM

Bob - did you talk to Wayne directly and did he know what you where trying to do? I know he has successfully done this for many who have lost thier plates or whatever. I am surprised it did not work out.
Anyway, I would call Phlogiston and speak with Wayne. He is a great guy and could at least guide you to the best way to accomplish this although what Bob suggests is exactly how I would envision doing it.
The beauty of the older designed spars is that you can do this in the field and the tolerances are not as tight like in the new spar design.

rocketbob 02-13-2013 04:07 PM

Quote:

Originally Posted by JonJay (Post 744039)
Bob - did you talk to Wayne directly and did he know what you where trying to do? I know he has successfully done this for many who have lost thier plates or whatever. I am surprised it did not work out.
Anyway, I would call Phlogiston and speak with Wayne. He is a great guy and could at least guide you to the best way to accomplish this although what Bob suggests is exactly how I would envision doing it.
The beauty of the older designed spars is that you can do this in the field and the tolerances are not as tight like in the new spar design.

Jon, only some of the holes were off in the new center section, not sure why. Some of them will have to be oblonged (is that a word??) which shouldn't be a problem. Not in the center splice plates parts but the AN3 bolt holes.

tturner 02-13-2013 09:35 PM

Richard

I bought a partially finished RV-6 and had the same problem. I have a vertical mill and made some custom drill bushings. I was able to match drill in a three step process, small drill bit, larger bit almost to final size and then reamer to finish. It worked out very well. I think I still have the bushings. Call me if you want more details. 770-639-6900

RFazio 02-14-2013 04:40 AM

Thanks for the responces
 
Thank so much guys for the responces. Tommy, we may call you. Did you use one plate as the template for the one you were drilling? That's what we figured we would do. We were going to assemble the wings and plates on saw horses with a bench top drill press setup between the wings. But if a single plate will give us the template that seems much easier. I'm thinking if we compare the two plates we have, and they match, we pretty sure the two new ones should also match.

az_gila 02-14-2013 08:57 AM

Quote:

Originally Posted by rocketbob (Post 744034)
......

I think you'd find that your splice plates will bolt in either top or bottom on the spars and are probably an exact match. I think when they drilled them back then they drilled all four in a stack, then used those to drill the holes in the spar. And if thats the case then it should be just a matter of duplicating them exactly.

Not according to my RV-6 plans...

The first hole is 3/4 inch from the centerline on the top plates, and 13/16 from the centerline on the bottom plates.

I imagine the -4 would be similar, but check your plans before you assume that all four plates are identical. Sort out top and bottom if applicable.

penguin 02-14-2013 01:12 PM

You will find that the steel part from a drill stop will be almost an exact fit in the larger holes in the splice plate. I had to re-make some of the spar booms on my 4 and used the originals as templates to allow everything to be clamped up and pilot drilled. I drilled 1/64" undersize and reamed to full size in assembly (although one hole must be reamed on the bench to hold everything together ...)

Pete

rocketbob 02-14-2013 01:17 PM

Quote:

Originally Posted by az_gila (Post 744215)
Not according to my RV-6 plans...

The first hole is 3/4 inch from the centerline on the top plates, and 13/16 from the centerline on the bottom plates.

I imagine the -4 would be similar, but check your plans before you assume that all four plates are identical. Sort out top and bottom if applicable.

Going off recent memory my F1 splice plates are all the same....all four. Really not sure what the reasoning is on the -6 to have them spaced different. Since the F1 is based off the -4 I would think the splice plate dimensions are the same.

az_gila 02-14-2013 01:40 PM

Quote:

Originally Posted by rocketbob (Post 744314)
Going off recent memory my F1 splice plates are all the same....all four. Really not sure what the reasoning is on the -6 to have them spaced different. Since the F1 is based off the -4 I would think the splice plate dimensions are the same.

It appears that extra 1/16 is caused by the dihedral. The bolt spacing differs (1.25 vs 1.125) for the first 4 bolts or so of the spar and the 1/16 extra is a "left over" dimension.

I'm betting the RV-4 is closer to the -6 than the F-1 on the bolt spacing.

Anyone got any -4 plans to check?

It does make a difference if you need to fabricate two extra splice plates - hopefully the OP has one upper and one lower...:)

rocketbob 02-14-2013 05:42 PM

Quote:

Originally Posted by az_gila (Post 744321)
It appears that extra 1/16 is caused by the dihedral. The bolt spacing differs (1.25 vs 1.125) for the first 4 bolts or so of the spar and the 1/16 extra is a "left over" dimension.

I'm betting the RV-4 is closer to the -6 than the F-1 on the bolt spacing.

Anyone got any -4 plans to check?

It does make a difference if you need to fabricate two extra splice plates - hopefully the OP has one upper and one lower...:)

According to the RV-4 plans all four splice plates are exactly the same and symmetrical. The different spacing applies to the top and bottom of the spar web holes but not the splice plates. Bottom left of pg 13 of the RV-4 plans.

Pg. 15 of the RV-6 plans show the same thing. In fact they look identical to the RV-4 parts.

So my earlier statement stands, you could use your existing plates to drill the others.

az_gila 02-14-2013 05:53 PM

Quote:

Originally Posted by rocketbob (Post 744385)
According to the RV-4 plans all four splice plates are exactly the same and symmetrical. The different spacing applies to the top and bottom of the spar web holes but not the splice plates. Bottom left of pg 13 of the RV-4 plans.

Pg. 15 of the RV-6 plans show the same thing. In fact they look identical to the RV-4 parts.

You are correct... the extra 1/16 is there because the plans don't reference the spar hole dimensions to the centerline of the spar holes...:rolleyes:

I could claim hard reading on the 11x17 preview plans, but I'll just send myself back to plans reading school....:)

More importantly, it does make it easier to duplicate the missing plates.

F1Boss 02-15-2013 08:29 AM

Old school talents required here
 
RocketBob sez: "According to the RV-4 plans all four splice plates are exactly the same and symmetrical."

Well, that would be nice. In the real world, it's not really probable that such would happen using any sort of hand drilling procedure. Some machining techniques can't get it right either! That's why oversize bolts are available.

BTW the F1 plates are NOT completely interchangeable; the lower plates are chamfered along their lower edges. Your plates may end up the same way for bulkhead flange clearance. After drilling, carefully mark the plates' positioning (top, lower, front, this side fwd, etc). All this in in the F1 manual, even tho the hole positioning on those parts is as close as possible using modern machining techniques. Once reamed to fit the spars per the manual, the parts are locked into that orientation; they do not interchange.

As usual, be careful what you read on the internet.

If you drill the plates to exactly match the current plates, which probably don't match each other to start with, you will re-order the parts and start over again, or go with the very expensive oversize bolts. Ugh.

So, you will likely drill the parts up using the early RV type setup where you set the spars up on sawhorses, with the drilled plates on top (pinned), and proceed to drill the clamped lower plates one hole at a time, using the drilled plates and the spars themselves as the drill template. Drill bushings will help greatly, but since the holes are not likely to be perfect 90 deg holes, simply setting things up and going after it with .374 & .249 drill bits would not be my recommendation.

If you need further info, send me a PM. Hole exact placement is less important than getting the holes round, and the correct size. Think 'tractor', not 'space shuttle'.

Carry on!
Mark


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