Question for the Ridge Runner bulders

[dholly 718]

I have a question or two related to Stace's tanks that didn't come up in the earlier thread (search 'plastic tanks').

Q.) Are these tanks manufactured with any amount of wing twist built in? The wingtanks.com plastic tanks sold by Airdale have a L/R version, but I don't know if it is because of filler neck position only or because they have built in twist as well. The large Airdale and Kitfox f/g wing tanks DO have twist built in... and it caused a bit of a problem when I used the KF tanks in my Avid Mk-IV wing, as the twist specs are different. Based on the comments and pics in the earlier thread, it would appear that the RR plastic tanks do not have any twist built in. If true, the tank coves should lay flat against the spars on either wing. With dual sumps and filler necks in the middle, it looks like they were designed to be used in either wing. Can anyone confirm?

Q.) It also would appear that the HH wing section is thick enough to conceal the sumps within the wing covering when the tank coves are sitting flush on the spars. Can anyone confirm? Obviously one can extend a quick drain or outlet fitting as needed, but I would prefer not to have the unused sumps hanging under wing or bumps in the fabric.

Q.) The wingtanks.com tanks have support tubing for the center of the tank running lengthwise from spar-to spar. The RR tanks have support tubing for the center of the tank running side-to-side from rib-to-rib. Both are for install in a new wing, as opposed to foaming into an old f/g wing tank with the top cut out. I'm assuming the supports are necessary because the tank otherwise sag when filled. If you see a benefit to one over the other, which support method do you feel is best?

Q.) What, if anything, comes with the RR tanks when purchased separately vs. with a kit? I.e., caps, support or vent tubing etc.?

Thanks for playing!

p.s. - Also, just curious, what the recommended wing twist for the RR is?

Edited 10 Jan 2012 by dholly

[kosseman 3]

i used the ridge runner tanks in my avid speed wing and they did not have any twist in them. I did have to build up the second rib top cap to clear them. They cleared the butt rib fine i assume it's the same profile on top as the stol wing because the transition to the fuselage

[Tree top pilot 13]

My tank has no twist....the washout is .500" as per manual. Keep in mind the spar legth is 144". The bottom of the tank conforms to rib profile...no sump. I did not get a cap or anything else for the tank...I do have the support tubes....375" x .035". They are to be installed onto the rib capstrips for support.

[dholly 718]

i used the ridge runner tanks in my avid speed wing and they did not have any twist in them. I did have to build up the second rib top cap to clear them. They cleared the butt rib fine i assume it's the same profile on top as the stol wing because the transition to the fuselage

Good info, thanks!

I built my Avid+ wings to HH specs using speed ribs. At the time, I was undecided which tanks to use so I stopped and moved on. You can see in the pic that the blue tape marks 12" o.c. rib positions, red marks 18" rib position. If I use (2) of the 6gal. RR or wingtanks.com tanks per wing, I'll just replace the #2 and 3 ribs with one between the tanks at 18". I was aware that the issue you described would occur because of the different ribs, so I had Brett make up (4) of the special transitional ribs. I'll use them at the root and the #4 rib position. I thought this would give me the most internal wing space which, of course, gives me the most options for sticking different tanks in there. And, I really liked the fact that I can use full long ribs at the flaperon hinge points rather than the short tails. Finishing the wings is my winter resolution and I'm leaning towards these RR tanks.

Edited 11 Jan 2012 by dholly

[dholly 718]

My tank has no twist....the washout is .500" as per manual. Keep in mind the spar legth is 144". The bottom of the tank conforms to rib profile...no sump. I did not get a cap or anything else for the tank...I do have the support tubes....375" x .035". They are to be installed onto the rib capstrips for support.

Are you saying the tank has no sumps molded in like the pics in the prior thread, or they just end up under cover? 1/2" of twist, eh? I used 1/2" less twist than the manual called for on both my Avids and, again, I wish I used even less.

[Bandit 286]

I installed Stace's wing tanks in my Bandit. The last picture is taken of my old rotten fiberglass tanks that never had a drop of ethanol put in them.

Edited 11 Jan 2012 by Bandit

[Torch 18]

Bandit, does your aircraft have a longer than stock landing gear? Sorry for drifting off topic here and my apologies to the search police.

[Bandit 286]

I installed Stace's wing tanks in my Bandit. The last picture is taken of my old rotten fiberglass tanks that never had a drop of ethanol put in them.

Yes, it is Brett's new spring gear. It is 2.5" taller and 11" wider. It makes a complete different airplane out of it. Check out my taxi test video on U-tube.