Wing tips...who made theirs and how?

[DesertBearhawk]

Time to start thinking about wing tips.

Who has made them, how did you do it, what design did you use, do they sit flush with the skin or overlap, did you install a landing light in the tip, and if you had to do it again would you just buy them if available?

[Glenn Patterson]

I did a lot of research on Hoerner wingtips bought the fiberglass, epoxy, got dock Styrofoam SM given to us, routered a pair of wing patterns & parts to make a foam cutter. I just spent a lot of time building & glassing and perfecting a nose bowl. We can see the end of this project so we elected to buy a set to get it done. There still is work to fitting & finishing the trailing edge & installing bosses for the wingtip lights. The mounting along with the trailing edge & light bosses took 3 weeks to complete & perfect. I think in terms of scratch building it is best to stay focused & avoid extending the project with detours. Building wing tips will take some serious time. Hoerner wingtips may be a future project but priority one is now to get it done. 10 years is enough.

We slipped the wing tips over the wing & the fiberglass is less than 1/8" thick. It looks good & is not pronounced. A lot of airplanes have fences to redirect the air on the wing so we thought less than 1/8" would be okay. It saved a lot of time & effort to flush mount the tips and to make a perfect seam with aluminum butting to the fiberglass.

The purchased wingtips finished up nicely and will look good when painted. Add up the costs of the materials including forms etc. then the difference is labour. Spending a lot of effort to perhaps save $200 to build a pair means that a builder is working for about a dollar an hour if the initiative is to build wingtips similar to the ones that can be purchased. This may give some clarity if you are not going for Hoerner tips.

Glenn
BH727

[jaredyates]

If you can get the fiberglass under the aluminum it will make life easier, but it is probably too late to tell you to extend your wing skins out beyond the outermost rib.

[John Rheney]

I am attempting to make my own, and pretty much as Glenn has outlined. Hoerner style, fiberglass, plugs hot-wired from foam. I have the first one cut out to the airfoil shape and next step is to make the shaping cut. I'm using some instructions that were on the net for a while from a Thorpe builder showing the process. I posted them on the old Yahoo site. I can send them to you if you want to see the method. I did research the flush vs overlay mounting options and decided the overlay was easier, cheaper, and lighter. In particular, if you use hinge material like some of the RV guys do to mount the wingtips on a Bearhawk, you will add about 4# of additional weight and have to figure a more complicated hinge wire path than the RVers use. If you really want to flush mount I suggest you leave at least 1" of wing skin expending past the tip rib. Wish I could show you some pictures of completed tips, but life just keeps happening to slow me down!

John

[mswain]

Dave, I'm planning to make my own. Similar to what others mentioned, Hoerner style....with led lights in each. There are some videos on YouTube that show the Hotwire method of making them, so I thought I'd give it a try. I'm going to try to build a flange on them so they mount under the skin, I left about an inch overhang out on the tips.

Sounds like there is some interest in Hoerner tips, perhaps we should make molds instead of one offs? 😄

I'm scratch building to learn, so I'm not real concerned about trying to do everything in the fastest possible manner. As long as it remains fun, I'm pressing on .

[John Rheney]

Here is the article about making Hoerner tips (if I can get the attachment to work!)

Best,
John

[bestbearhawk1231]

Out of curiosity, what does a hoerner tip do and why is it better or worse than the standard rounded tip that I have seen? I could be wrong but I am thinking that is the type that is undercut on the bottom, right?

[alaskabearhawk]

This explains it pretty well. Look about a third of the way down: http://www.zenithair.com/stolch801/design/design.html

Some light reading: http://www.wfis.uni.lodz.pl/edu/Proposal.htm

[John Massaro]

I'd have to agree with Dave Patterson's post regarding whether or not it's really worth the effort when one can buy them already made for a few dollars more.
And sure, I can see MSwain's point about it being a part of the fun of building , and I totally get that the learning process is a part of the total experience and the enjoyment that comes from that pursuit.
For me personally, when the time comes, I for one will probably just bite the bullet and buy the prefabbed wing tips rather than invest more time, energy and $'s in learning a skill that I don't see much use for in any of my other worlds of interests.

[mswain]

Posting a couple of pictures of my completed Hoerner tips. I am happy how they turned out. Flush mounted with piano hinges. I did my best to write up the process in the 2016 Q1 Beartracks, will write up the lens process soon. It's formed from .09 Lexan.

2150 Lumen Baja Designs LED Landing Light and Whelen LED Strobe/Nav.
wingtip1.jpg 2016_06_14_Wingtip 006.JPG

[mswain]

Guest You are right on.

Just to clarify, the outboard row of rivets holds the piano hinge which connects to the wingtip.

[N3UW]

WOW..😳 Looks great. I am very impressed. So what took longer. Building the wing or the tips?

[Glenn Patterson]

Your wingtip is perfect. Thank you for sharing.
Glenn

[mswain]

N3UW Admittedly it's taken MUCH longer than I thought. I've never built anything from fiberglass nor thermoformed Lexan, so it was a lot of learning along the way. Throw in a 10 month old son and a daughter starting Kindergarten and a home purchase.......well you know how that life thing goes sometimes. Looking forwarding to beginning work on the fuselage.