[RVG8tor]

I need some advice. I am about to start to rivet the HS, everything is ready, but as I reviewing the DWG 3 for any gotchas and I found one. In the exploded view it says to "trim the lower flange of the rear spar" (shaded area), it does not say how much but referes you to DWG 78. In that DGW it just says you may have to trim the flange to allow the elevator the full design travel, but no dimensions are given.

I called Van's to find an answer, and I was told to wait until fitting the HS to fuselage and in the same conversation I was told I could trim it back to the start of the radius to see how that works when fitted to the fuselage.

Given that the flange would be easier to trim now vice after it is riveted together, I would like to cut now if required. However, if there is typically no trimming required or very little then I would wait. I do not want to trim away any more than required, and trimming back to the radius seems excessive. The note cautions not to remove any of the 609 reinforcing angle. Now when you think of how deep the spar flange is there is a large margin there, how can a matched hole design have this much of a possibility unknown? Maybe it is due to the tail working for several models. Any RV-8 (A) builder out there who can tell me how much they needed to trim, and is this no big deal to leave until the fitting to the fuselage. Or is there a way to check now if any will need to be trimmed back. Thanks I know this forum will not let me down.

Cheers

 

[RVG8tor]

Well I found my own answer to my question. Some 40+ persons have looked at this message but no replies. I realized that I had not read ahead in the plans and in the elevator section it mentions having to trim the HS rear spar flange. I have the QB fuselage here so I realized all I had to do was lay the spar in place and see how much interferes with the elevator control horn stop. Well it is a sizable amount, in my case I will cut about 3/8ths out. I figure it is easier to make this cut and deburr before riveting the HS together. I don't think it would be a big deal to wait, it just is easier to do it now.

I placed the spar centered on the fuselage and marked an outline where the control horn is located. Now I will just drill come relief hole and cut out the pieces and deburr and touch up with primer (part is already primed). I hope this helps others.

Cheers

 

[Transporter]

Spar Trim

I haven't trimmed mine yet (doing SB everything and waiting til later next year for fus. kit), but your post is consistant with what other local builders have advised.

One builder suggested using a hand nibbler (Adel or equivalent) to bite off small pieces at a time, then smooth with a file and deburr.

Regards,
Mike

 

[mikeangiulo]

just a small nick of the horizontal spar bars could mean a big repair. One thing I like to do is take a small strip of stainless steel and put it in front of the spar bars when filing away at the flange. this way even if my file goes crooked (which it does after too many hours of squinting) the spar is safe. A piece of wood like a tongue depressor also works.

It's not a hard area to work on even after everything is put together so don't stress on doing it now vs. later

 

[RVG8tor]

Nibbler idea

I haven't trimmed mine yet (doing SB everything and waiting til later next year for fus. kit), but your post is consistant with what other local builders have advised.

One builder suggested using a hand nibbler (Adel or equivalent) to bite off small pieces at a time, then smooth with a file and deburr.

Regards,
Mike

The nibbler is a great idea, I just bought one at HF tools, reg $27 I bought mine for $15! After placing the spar on the fuselage I know how much I need to trim off. The notch will be about 3/8" deep and the width of the elevator control horn movement area (approx 3"). I figure it is easier to remove while I can work with each side of the rear spar separately. Once I install the HS there should only be some fine tuning of the notch required if any at all. Thanks for the help.

Cheers

 

[Transporter]

Adel Nibbler

I noticed today that Avery has the genuine (made in the good ol' USA) Adel nibbler on sale now for $19.99; reg price is $25.

Think I'll pick one up for this task!

Regards,
Mike

 

[Pirkka]

I noticed today that Avery has the genuine (made in the good ol' USA) Adel nibbler on sale now for $19.99; reg price is $25.

During construction of my plane, I've drilled to my finger tip(s), filed my fingers but most damage I've caused myself with this tool. It's so non-ergonomic that after using it a while I took gloves and used both hands but before I had finished the holes in the inboard end of fuel tanks I had bad vesicle between thumb and forefinger. So if you ever do anything with this, make sure to make the "sticks" bigger so they don't scrub so easily. You should feel the pain between these fingers right from the beginning... Even the "damage" isn't bad itself, it takes couple days to heal and working with that hand may be difficult so make sure you have couple days away from the plane if you consider this.

Otherwise tool is just wonderful -- saved the fly-cutter for now.