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Page 09-03 Step 3 Spar Box Assembly Problem

T

Tom Delaney

Well Known Member
Good Afternoon,

I hope everyone is having a great holiday weekend! I was looking forward to the time in the shop but immediately ran into a problem.

The difficulty is the HS-1202 forward spar inner dimension is too small to slip over the step 2 assembly of spacer caps, inspar ribs and spacers. The HS-1203 aft spar slips right over.

The fabrication of the step 2 assembly was double checked and was correct. Turning this assembly over produced the same results. Trying to use some slight force only led to the outward bulging of the HS-1202 flanges. I have read many times that if something doesn't fit in Van's kits' then stop and figure it out because you have probably done something wrong.

Measuring the inside dimension between the flanges of both spar shows the forward spar is approximately 0.075 inches smaller than the aft spar dimension. The step 2 assembly has nearly identical dimension throughout its length.

I am wondering if this has been seen before (search function was no help)?

Thanks,

Tom
 
Photos may help:

Aft spar fits easily:

HS1203AftSparFitsEasily.jpg


Forward Spar is too tight and the flanges bulge outward:

HS1202ForwardSparSmaller.jpg
 
Maybe

I'm working on same part at the moment and this does not look right. I do not have drawings here but I think the bit you show riveted should be done later on other side (outer side) of spar cap.
Jamesey
 
Tom,
It has been so long ago that I can not remember much. But here are some notes that I wrote on my plans:
Mark rib flanges forward and aft.
None of these parts are symmetrical.
Aft side of ribs have 1.25" hole spacing.
Mark the ends of long parts left or right.

So the only advice that I can give is to double check that all parts are oriented correctly. Use tooling holes as a reference to help orientate parts.
Joe Gores
 
I believe the inspar ribs are not oriented correctly. Note the small reference tooling hole in the corner and the other centered along the oppisite edge. The edge with the tooling hole in the corner goes aft. The edge with the tooling hole centered goes forward.

See figure 1 on page 9-03

As a general rule, if the parts don't fit, STOP, because the kit is telling you something is wrong.

Hope this helps. -Dave
 
Last edited:
i concur with the suggestion that you check the spar box rib orientation. They need to have the correct and identical orientation
 
Problem Solved

Thanks for all the help!

The problem of course lay with me and not Van's. The ribs were all oriented properly. What I didn't realize was that the step 2 assembly was wider on one side which will mate with the forward spar and smaller on the opposite side which mates with the aft spar. Makes perfect sense in that the stabilator tapers towards the aft. When I was testing fittings all the pieces together repeatedly I just kept missing the right combination. :eek:

I think I will take the battery out of the calipers so I will be reminded that if I start measuring to find the problem I need some rest and then the answer will magically appear.

Hopefully this will help future builders who may have a day where the mind just doesn't click.

Thanks again,

Tom
 
Hi to all builders:) I have finished this step this evening. All stuff fits perfectly to each other :) :) :)
 
I think we all have those moments. Often the solution is so simple we feel dumb, but the secret I think is to do what you did, put it on the forum. If you were to look back on my posts, you would see many of the same type, always someone had a solution, sometimes backing off just to put it on the computer gave me enough space to see the solution.

Tom Delaney said:
Thanks for all the help!

The problem of course lay with me and not Van's. The ribs were all oriented properly. What I didn't realize was that the step 2 assembly was wider on one side which will mate with the forward spar and smaller on the opposite side which mates with the aft spar. Makes perfect sense in that the stabilator tapers towards the aft. When I was testing fittings all the pieces together repeatedly I just kept missing the right combination. :eek:

I think I will take the battery out of the calipers so I will be reminded that if I start measuring to find the problem I need some rest and then the answer will magically appear.

Hopefully this will help future builders who may have a day where the mind just doesn't click.

Thanks again,

Tom
Click to expand...
 
Agreed, during the build we have all been in the same position. You just have to step back, re-read the plans a many of times and then, move forward. If it does not fit, something is wrong!! Keep on going.
 
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