[RVG8tor]

OK, I need a little help with reading a DWG. It is DWG 3 Sec D-D, of the empennage kit. This should be common to a lot of the kits. The HS-404 and HS-405 ribs are not pre-drilled. I am not sure why other than to give builders a chance to see how it was done in the old days. In the instructions (Pg 6-2, second step under “Drilling the Horizontal Stabilizer”) it tells you to mark then drill the holes in the 405 fwd side of fwd flange according to SEC D-D (pictured below). I just want to make sure I am reading this correctly, so I will describe in words what I think the DWG is trying to communicate.

1. Looks like there will be 4 holes total in the fwd flange of HS-404
2. First hole is ¼ in from the top of the flange with a note to make sure the edge distance is maintained. I guess this means shoot for ¼ inch but make sure minimum edge distance is maintained. This would be the top hole in the flange, also top hole shown in the DWG.
3. Next hole down is ¼ inch BELOW where the HS-810 angle ends.
4. Next hole down is ¼ inch ABOVE where the HS-814 angle starts.
5. The last hole is ½ inch below the hole made in my step 4 above.

So the critical step is #1, it shows ¼ inch but you must also account for edge distance from the top edge of the flange. The other holes should follow from the first hole (top hole). My concern is the edge distance on HS-404 (nose rib in front of 405) could be an issue since the rear flange on that part is trimmed down to clear the 810/814 angles and depending on how that part lays into the gap between the 810 and 814 angles, edge distance might be an issue since the second and third hole from the top match up to the trimmed flange on the aft of the 404 nose rib. The step for drilling the 405 holes does not address the effect on the 404 nose rib flange but it seems that this needs to be accounted for, before drilling the 405 as this becomes a guide later. I know I can call Van’s about this tomorrow; I just wanted to see what others have done.

Cheers

 

[rv8_builder]

DWG 3 Sec D-D

Mike,

I was also concerned about the edge distance on the HS-404 when I got to this stage but it all worked out fine.

You are reading the drawing correctly but you should also take into account the clearance between the HS-810 / 814 and the HS-404. This should theoretically be 1/32". The 1/4" in step 3 and 4 is measured from the end of the flange of HS-404 and not the HS-810 / 814 angle.

Hope this helps.

Andre Burger
South Africa
RV8-Tanks

 

[rvtach]

It's been a while...

It's been a while since I did this so I don't actually remember what I did which may be a good thing since I made a LOT of mistakes when I started. I built 2 HS's; got a real ugly one in the attic and a nice looking one on my plane. Looking at the DWG and your post here's some thoughts:

1. Looks like there will be 4 holes total in the fwd flange of HS-404

I'm not trying to be picky but just to make sure we're on the same page you're talking about the REAR flange of -404 and the front flange of -405

2. First hole is ? in from the top of the flange with a note to make sure the edge distance is maintained. I guess this means shoot for ? inch but make sure minimum edge distance is maintained. This would be the top hole in the flange, also top hole shown in the DWG.

It is always tricky drilling through multiple layer of material because it's easy to wind up drilling too close to the edge of an underlying part. Measure one side, mark it with the Extra Fine point sharpie then measure from the other side. In fact, I would probably drill the next hole down first. No edge distance problems, it's location is not dependent on any other holes (just measure from the bottom of the -810-1). This way you have a reference on both sides to measure from to see where the hole will come out edge-distance-wise

3. Next hole down is ? inch BELOW where the HS-810 angle ends.

Correct. As I mentioned above I would consider drilling this one first.

4. Next hole down is ? inch ABOVE where the HS-814 angle starts.

Correct again.

5. The last hole is ? inch below the hole made in my step 4 above.

Look again. This hole is 1/2 inch below the top of -814-1.

So the critical step is #1, it shows ? inch but you must also account for edge distance from the top edge of the flange. The other holes should follow from the first hole (top hole).

The other holes are not dependent on the location of any other holes... just on fixed points of the flange and the angles. Step #1 is the hardest to do and keep proper edge distance but not all that difficult.

Rivet on brother...

Jim McChesney
Tucson, AZ
-7A Finishing Kit

 

[RVG8tor]

Thanks for the help

Thanks to everyone who posted or will post, Jim your suggestion is right on with what I was concerned about. The instructions step has you just marking and drilling the 405 in this step but where the holes go have an impact on the 404. Not sure I will get to this today, but if I run into difficulty I know I can count on other builders on this site.

Cheers

 

[rv8_builder]

Look again

3. Next hole down is ? inch BELOW where the HS-810 angle ends.

The next hole down is 1/4 inch BELOW the upper edge of the rear HS-404 flange (After trimming)

4. Next hole down is ? inch ABOVE where the HS-814 angle starts.

The next hole down is 1/4 inch ABOVE the lower edge of the rear HS-404 flange (After trimming)

 

[Transporter]

HS-404 and HS-405

Just finished my HS last week and will add my two cents...

1. Trim the HS-404 carefully, using the full scale drawing at the bottom of the blueprint. Don't forget to make one left and one right version! You want a nice snug fit around the HS-810-1 and HS814-1 angles; not touching, but close. This will give you the max room to play with in terms of edge distance. I had plenty of room for the two holes in the HS-404 flange when it came time to mark and drill.

2. The rest of the directions worked fine for me with the exception of the recommendation to use an angle drill to do the final drilling (fourth box down, page 6-3). I had much better control using a long drill bit. I recommend pre-drilling with a #40 and then final drilling to #30. YMMV.

Regards,
Mike