Any. opinions out there on Cub Crafter Gap Seals, Pro or con
Any. opinions out there on Cub Crafter Gap Seals, Pro or con
This year at Oshkosh Cub Crafters introduced their new Gap Seals for the elevator and rudder. They are still working on the STC so they are only available to the experimental crowd at this time. I had the opportunity to test them at New Holstein on several aircraft (many thanks to you guys for trusting me with your baby for a while) both before and after installation. They work very well improving the control effectiveness and also lightening up the control forces. I was quite impressed. I did suggest to Jim at CC that when he writes the STC paperwork to try to get approval to install them on the Rudder only, Elevator only, or both as the user desires. Thus if you wanted a gap seal on your elevator but not on the rudder you would have that option rather than having to do both because that is how the STC is worded. I guess we will see how it works out when they get the STC.
The gap seal is a plyable rubber that is extruded into a hourglass shape and is wedged/fits between the stabilizer and the elevator/rudder. It is held in place by fit and friction. I did not have any come loose at NH nor on my aircraft but you could put in a little adhesive if you wanted. It takes about 5 minutes to install these things and no tools at all. There is no detectcable friction or binding in the controls with the gap seals in.
This is a really slick idea that works. Increased elevator authority at high AOA (ie in the flare) is really nice. It definately makes it possible to get the tail down first on three point landings and you don't have that feeling that you are running out of elevator in the flare. I predict that you will see these on just about every cub when the STC is done. Here are a couple of photos.
This is how it comes to you. In a coil like a rubber hose.
A little blury as the camera had trouble focusing but you can see the shape.
What they look like installed.
Again a little blury but you can see a little how they fit.
Pitts guys have been using these for years. Very popular.
Go to cubcrafters website. They are now STC'd and you can read a few reviews.
I have had them for a few years on my Smith Cub. I have a fwd cg when solo and they give me additional elev during the flare at high AOA approaches. Rudder is also more responsive. Like having power steering.
Maybe I should call them. It appears only STC'd for PA18. What about J-3,PA11, PA12, PA14, PA15, PA16, PA17, PA20, PA22. Seems like a lot of missed opportunity.
Bill has it right, one of the best go-slow mods out there for a cub. Amazing elevator control at very very slow speeds.
If you're exp. there a couple of ways to make your own, when the race is over I'll get a pic. or two
Veeeeeeery spendy for extruded rubber , maybe Pitts sells it cheaper ?
Most folks I see are using a clear 3 M tape for a fraction of the cost .
those who hesitate shall inherit the earth.
Maybe I'm the strange one here, but I think it's funny/strange that anyone would be concerned about whether or not these things were STC'd. Seems hard to believe that with all CC has going on, that they would waste time and money to push something like this through the FAA. As far as Cub pilots are concerned - why do you care? It's a piece of closed cell foam that takes 5 minutes to install and even less time to remove. If you want them - put them on, we know they work. If you don't like them or somebody says something, take them off. About half of the Trooper cubs I see up here have gap seals and they use a more "permanent" version. Maybe it's just an Alaska thing, like rifles always tied to the strut.
I remember the ones I had on my Pitts were fairly hard rubber and not very expensive.(everything was cheaper in the '80's of course) I'm sure if CC has their name on it it comes at a price, a high one.
The Pitts seals are cheaper but are made for strap-type hinges with narrow gaps. Pin-hinged surfaces have too large a gap and the seals won't stay in without gluing. Tape makes an effective gap seal.
I did some testing when I first flew my plane. Before I installed the VG's under the tail they definately helped. I found that after I installed the VG's under the stabiliser they had only marginal effect that I could perceive. I removed mine and rely on the VG's only. Maybe I should revisit them now I have a few more hours under my belt.
Back Country O-375 wide body extended wing cub
This is leading edge tape for a Dash-8 prop. I put some on 10 years ago and after 6 or 7 years it gets discolored and brittle. This is new tape I put on a month ago. You can also get 1 inch foam, cut it in 1 inch strips ( with a table saw ) and burn groves in it. I used a 3/4 inch elbow clamped to a propane torch. If you like what you got, glue some fabric on the foam with Stewarts glue and paint it. It should stay in without anything but I sprayed some 3M fabric cement on the horizontal then put in in. Thought I had some foam left over but I couldn't find it.
... best effective modification with STC for a cub and all for $ 250,00. I am happy with them ...
I don't think Cub Crafter's will sell them with out the N number and aircraft type. FA not much help if you can't get the material. Maybe they will now they have an STC.
I ordered an experimental set today.
DW's been recommending them for a while now. I have vg's on my wings but I didn't put the vg's under the tail. I didn't want rocks knocking them off under there.
I kind of hope they don't work. That way, I have something to bitch at DW about every time I see him. Although, I have to admit, he did find a great camping spot on the Columbia river we can have tons of fun on.
You'll like them Dave they work at all air speeds
not just slow flight.
I have been using the tape and it works well except you need to replace every 6 months or so. I used the musicians gaffer's tape. I will probably have to get a set of these CC seals eventually. Reapplying the tape is a pain. Wish they were cheaper, $200 for a piece of foam seems excessive. I know...pay to play...
Lucky deal from Aircraft Spruce for Bearhawk drivers since the Bhawk uses the strap type hinges with a narrower gap.
I used the tape for years...messy...just bite the bullet buggs.
I tried them on my Bearhawk. They were great when loaded light. Loaded heavy it was very twitchy. Just breath on the stick and you were going up or down. Really easy to get pilot induce occillations. I took mine out. Don't be afraid to try them out. Just be prepared.
casting foam rubber....
simple to mold, couple pieces of pvc pipe, on flat surface with lid
Now I'm going to have to order the "Pipe Wrench" version of the gap seals.
geech... and I just ordered the other kind from Vera at CC.
Can't wait to see how the pipe wrench gap seals work..!
Yes, I'm an Oenophilia. And I VOTE...!!
So Mike do those custom gap seals keep your pipe wrench from cavitating when your working it?
"Illegitimis non carborundum"
..been talking about simple tape gap seals for years.
On a grey cub...grey duct tape....
...place elevators full down and apply a strip of tape to upper suface of stab and elevator.
Change at annual.
This simple method does not collect debris like the 'other' tape method. Is quicker. Takes less tape.
Do the foam ones for sure if yu have them and want super easy installation and removal.(I wonder how long they last..black...in uv light)
If yu have duct tape the color of your airplane. Try it! Yu dont need gorilla duct tape or gaffer tape or other heavyduty tape
...coming from an Alskan who applied cheap grey duct tape on a cold day and had it last over a year!
When I first tried it I used 3" wide awning tape.
Thanks for all the posts, Haven!t got mine from Vera yet. Since my my cub has to stay outside I will probably put some white latex on the top of the seals to provide some uv protection. Also I have a Lyc 205 hp up front when I pull on full flaps I run out of fwd trim maybe the seals will help?
Why buy these????
At lease CC went out and spent the time, energy and $ to get it certified. copy cat ways of doing this will limit the amount of time and energy they decide to spend trying to certify the next great thing... and it might not be so easy to copy.
We need folks innovation and certifying stuff. Anyone seen the cool Keller flaps? Will they ever be certified????
Not if we all just decide we will build them ourselves.
Ok, off rant. I know many have had tape for years, but the time to do the FAA stuff makes it hard to sell stuff for manufacture cost alone.
I don't know where you've been me lad, but I see you won first Prize!
someone had told me how they heard about 'sculpting' a bigger piece of foam with a hot object, to make this shape.... and I was like, no just cast it..... that's why I shared the video... PLEASE Copy my sh!t.. that why I post instructions and pictures of my stuff!!
foam rubber casting suppliers
hmm that sounds fun too..... http://foamlibrary.com/portal/defaul...e=DRS_MNC_HomeYou can even make custom made cushions !
Last edited by mike mcs repair; 02-24-2013 at 08:48 PM.
I looked into having them made. Believe me, Cub Crafters is doing us a favor.
I couldn't find a way to have the small amount needed to do one Cub, custom made, for just $250.00. Not to mention the FAA approval.
Last edited by Crash; 02-25-2013 at 09:06 AM.
"The fear of God is the beginning of wisdom". Psalm 111:10
The following AD for a Bellanca trim tab shows an alternative method of closing the stabilizer/elevator gap.
51-16-01 BELLANCA: Applies to All Models 14-13 and 14-13-2 Airplanes.
Compliance required within the next 25 hours of operation, but not later than August 1, 1951.
As a result of a recent failure of the elevator trim tab in flight, the modification of the trim tab attachment to the elevator as shown in Figure 1 should be made.
(Bellanca Service Bulletin No. 14, Models 14-13 and 14-13-2, covers this same subject.)
Gauranteed that I will never again waste my time with that scheme. ......and especially with a "doped-on" tape.
The previously-described simple method..... "elevators full down and apply tape on top of the stab bridging the hinge-line to the elevator" is much simpler, cheaper, faster, and you don't have to lay upside down. And it is done with regular duct tape, nothing special.
I'm happy with mine, may be a little cheaper if you don't need paperwork don't know doesn't hurt to ask.
It seems to me that the CC gap seals would trap sand, small stones, and other debris, too. And if debris did get between the seal and the tubing/fabric, wouldn't it act like sandpaper and wear out the finish, if not the fabric also, over time?
Even if no crap gets in there, doesn't it "chafe"?