Personal Journals about Hang Gliding

Easy Riser Repair #16

Postby jcoyier » Wed May 13, 2015 10:12 pm

Easy Repair #16
Post #16

Since no one offered use of their paint booth last October, I was forced to wait until spring. So, here we are, April 2015 and already plenty of days warm enough to paint, however.....I ran into trouble last fall. I shot the rudders with Polybrush right over the old dope finish and then Insignia white color base coat and proceeded to mask the accent stripes. After making a masking error requiring tape removal, I found the base coat peeled off with the tape right down to the old dope finish. No point in going further. Ripped off all the covering on both rudders and set about prep'ing the frames for recovering. This pretty much shot the idea of completing the painting last fall. I found that the left rudder had actually sustained some damage once I had the covering removed so I fixed that and beefed up the aluminum ribs which are definitely the weak link in the frame structure. Here's a shot of the rudder frame leading edge rib before.

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I cut out a piece of ½ inch foam from the damaged wing rib to fit inside the aluminum rudder rib. I glued it in place using Gorilla glue which is supposed to work well on this type of foam. The stiffening effect on the rib was amazing. If I build another ER, I'd use this on all the aluminum ribs in the rudders which would also allow one to rib stitch rather than rely on the dicey fabric to aluminum bond using fabric cement (without the foam insert, the rib would just collapse as you tightened the stitch knot).

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I recalled covering these rudders back when I first built this kit that they were very difficult to do without many wrinkles so both these rudders were ugly anyway. I decided to try a different method this time around and built a quick frame out of 1X2 fir and attached a piece of fabric to it using an office stapler.
I cleaned up the aluminum frame, coated it with Polytak fabric cement and then place the wooden frame over the rudder structure.

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A small slit for the rivnut to poke through allowed the fabric to lay down nicely onto the rudder structure. I then ran a very thin line of 50/50 cement/MEK around the entire perimeter of the rudder, rubbed it in and let it dry (std process).

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I then simply cut around the perimeter leaving enough fabric to do the wrap onto the aluminum structure and got an almost wrinkle-free main area. The hard part was doing the snips and cuts to get the fabric fitted around the ends, brackets and horn. Repeated the frame process for the other side and ended up with no wrinkles after doing the final shrinking at about 300 F. Wetted out the glue on the ribs to attach fabric then applied Poly-Brush (coat #1 brushed on, coat #2 & #3 sprayed on). Same pin hole bubble issue. Just have to re-brush back over what you've just applied as you go to knock down the bubbles before the P-Brush tacks up. What you don't get will be ironed out at 225F prior to spraying.

OK, on to painting. I've poly-brushed the rudders and shot the base coat of white. Two coats was sufficient. One thing I've found in getting an even coat aside from being very smooth and even on your gun passes (you need to always be aware of how far the nozzle is from the surface, what angle the spray fan is relative to your gun pass direction and how fast you move the gun along the surface). It's a tough job and was hard for me to do. I would finish a panel and then go back and look for uneveness. I would then spot spray the light areas until the whole thing looked relatively even. I tried to put on just enough color on the first coat so that the second coat was the final one. In the photo below, notice the different color masking paper on the leading edge at mid span. That stuff is the paper you use when you paint a room in your house. It's crap for this application. The pigment goes right through it and onto the surface under it.

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In this next photo, I've removed a piece from the other wing panel where I had used it right in the area I was painting. You can see what happened.....bleed through! So go find your local supplier for automotive painting and get your paper from them but I'd still test it first before you commit to use it to mask an entire wing....it took me a couple hours to finish one panel and that was after I got the hang of it.

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I used Reducer on a Q-tip in an attempt to mellow it out a bit with limited success. I went over the area with red but could not make it go away.

Here are some shots of the masking involved in creating a simple design scheme similar to the lines on the glider Brian Porter flew in the 1976 National meet.

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The blue tape in that shot is vinyl tape used in automotive trim masking. You can form it somewhat around curves. I could not do a real tight curve successfully and ended up cutting the curves for the rudders which were much smaller radii compared to the wing panel curves.

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Back in the converted RV shed with the drop-down lights for painting.

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Masking the rudders.

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The finished rudders ready for painting.

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This next photo shows my attempt at getting an even first coat of red on the rudders. I always shoot the edges first since this is where the risk of generating drips is greatest. Making a couple light passes worked best followed with filling in the rest of the surface.

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As a side note, it was 58F and raining when I shot these. I saw no problem with the paint nor did I note any difference in spraying under these cool conditions.
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Re: Easy Riser Repair #16

Postby Bob Kuczewski » Sun May 17, 2015 12:54 pm

jcoyier wrote:I recalled covering these rudders back when I first built this kit that they were very difficult to do without many wrinkles so both these rudders were ugly anyway. I decided to try a different method this time around and built a quick frame out of 1X2 fir and attached a piece of fabric to it using an office stapler.

I cleaned up the aluminum frame, coated it with Polytak fabric cement and then place the wooden frame over the rudder structure.

A small slit for the rivnut to poke through allowed the fabric to lay down nicely onto the rudder structure. I then ran a very thin line of 50/50 cement/MEK around the entire perimeter of the rudder, rubbed it in and let it dry (std process).

I then simply cut around the perimeter leaving enough fabric to do the wrap onto the aluminum structure and got an almost wrinkle-free main area.


That sounds like a great approach to recovering the rudders.   :thumbup:

I hope you'll be bringing the Easy Riser to the Dockweiler event next Saturday. It would be a treat to see the results of your long effort!!
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Easy Repair #17

Postby jcoyier » Sat Jul 25, 2015 1:10 am

Easy Repair #17
Saturday, July 25, 2015

Ready for rigging now I've moved the right wing panels onto the frame I had bolted to the floor when I completed the pre-rigging from sheet #3.

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As I put the struts in place, I recalled the problems I had noticed when learning to fly. I took great pains to patch all the tears and holes in the glider I inherited only to have the leading edge root strut bracket punch a hole right through the nice patch I had put over the previous hole. Here is a photo of that bracket “after” I drilled out the rivets, flipped it and re-installed the rivets.

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It turns out that there is plenty of clearance now on both sides of this bracket and I get no contact with either the fabric or the gusset with the bracket in this orientation. The strut fit is not changed. If you don't do this, expect to see a nasty hole punched through the fabric by the rivnut end as shown here on Darrel's upper wing panel trailing edge which I had just patched prior to realizing what was causing it.

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I found it far easier to do the tail swage first, fit the cable loop over the bracket bushing, snug up the main swage and then compress it. The plan sheet says to do the main swage first which I tried at first and right away switched to doing the tail first. Another thing I'd do different would be to thread on shrink tubing PRIOR to all swaging. When I got to the end and saw where the cable ends contact the fabric I found it necessary to tape over all the swaged cable ends. In the folded storage/transit position there was a fair amount of abrasion happening not to mention getting holes poked in my finger tips from the cable wire sticking out of the secondary swage during set-up & tear down.

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Moderator wrote:
Note from update in subsequent post (dated Oct 23, 2019 9:25 pm):

On October 23, 2019, jcoyier wrote:There is an error I made on this blog where I show the cable swaging process using two swages per connection. This is not necessary according to Nicopress and originates from their technical suggestions where you can use a second swage if you are concerned about your ability to make a good swage. If you do they suggest a MUCH smaller gap between each sleeve than what I show in that photo. My practice from here on will be to make sure my tool is set right and that I check each swage and go with a single swage on all the connections vs UFM plans that had you double swaging all the connections. I've monitored all my connections after each of my crashes (yes, I've had more) and have yet to see ANY slippage in any single swaged joint. When I re-rigged my trainer, I did it with single swages throughout.

Note:  This section is no longer recommended (see Oct 23, 2019 9:25 pm):

In original post, jcoyier wrote:I used a random piece of plastic channel I had laying around, cut off what I didn't need and used it as a spacer to set the position of the main swage right where I wanted it. If you look close you can see where I used a hot knife (soldering iron with a blade tip) to melt the clear vinyl coating in order to strip the cable prior to swaging).

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In this shot I am setting the final tension on this flying wire using two vise grips held with my left hand while tightening the wire clamp with my right hand. Otherwise I'd have needed to find someone to help. This worked fine.

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I made multiple trials to get the tension on all the cables just right and it took a fair amount of time to do a decent job of getting them all “just right”. My swage tool (I finally had to buy one) was a short handled Nicopress model 32 VC-VG which does both 3/32 and 1/16 swages. It required quite a bit of muscle for the 3/32 swages so I ended up cutting a pair of extension “handles” from 1 ½ inch PVC pipe. The other critical tool I was lucky enough to borrow from one of the EAA members was a Felco cable shears. This made all the cable cuts a piece of cake producing nice, clean ends.

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No photos of my trials locating the control cable inside the tip of the lower wing panel. Located a hole based on how Darrel's cable was deforming the fabric and hot knifed it free-hand. Turned out fairly crappy. Should have taped a nice circle template and cut to that instead. Since this was a re-build, the bushing was already swaged onto the cable end so I had to make the hole big enough to fit the entire thing through the fabric. Rather than do an actual fabric patch (would require me to do a spot re-paint) I just used adhesive-backed sailboat Dacron patch tape which worked OK.
Next I rigged the rudder return spring exactly like I re-configured Darrel's where I removed the bungee approach specified in the UFM plans (a poor solution I felt) and installed a nutsert (that's what the guy at True Value Hardware called it).

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I picked out a spring from the hardware store spring selection and attached it to the wing tip using two nylon washers and a small bolt. I also picked out a steel pin, drilled it to accept a safety pin and used this as a quick connect to attach the rudder control cable during assembly.

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The next step was to rig the control cable which involved wrapping it around the twist grips per the plan so that the rudders come back to neutral when released.

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I really liked the grip material Darrel had on his glider which was cloth handle bar tape for bicycles. I had a hard time getting anything close to long enough. The best I did was less than 10 ft so that's what I used. The underwrap was just electrical friction tape followed by the cable winding then covered by the bike tape and terminated with vinyl electrical tape on both ends.

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Now I am nearly done. I got worried about the paint sticking to itself in the folded storage and transit position so I decided to wax every surface except the bottom of the lower panels using the Poly Fiber recommendation of a non-silicon based Carnuba wax which took me a good part of a day to do but I'm glad I did as you will hear about in a minute. So here's the completed glider ready to pack up and take it's second flight (recall the first one ended in disaster over 30 years ago...hence this project).

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Here I am at the local test flight area the next day on the Oregon coast (Cape Kiwanda) in perfect conditions....low tide, dune to myself with a 9mph breeze right up the hill.

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Although you cannot tell from this photo, the glider is sitting on a tarp I staked down in the sand so that the glider never touched the sand. I just could not bring myself to allow that after putting all this effort into the build.
I weighed the finished glider just to have an idea how much over weight I was and it came out at 66 lbs which is about 16 lbs over. I can feel the difference just carrying the individual wing assemblies and knew I was going to have my hands full getting this thing up the dune. I was right, I made it up to about 2/3 of the way to the very top and just decided I'd be so wasted if I went any further that I'd be too exhausted to safely launch it. I was determined to not even allow it to touch the sand that when I got as far as I was going I basically took off in what felt like 10-11mph breeze. Launched fine, flew fine, rudder response was fine and the landing was easy. I could not even visualize making another climb up the dune so I packed it up and went home with a smile on my face. This makes 19 flights in an Easy Riser for me to date. I now need to find an inland site where I can get some altitude with a low risk launch and wide open landing area. I will consider this blog, which was intended to cover my experience in building the glider, completed. I may choose to add notes on things I plan to add or change in the future including how I fit a parachute to the glider, how I rig a comfortable harness and what I do about covering the gap on the upper wing, etc. so watch for those entries if you are interested. I'm also interested in putting handles on the twist grips as Brian Porter suggested I do.

I hope this helps anyone out there in building an Easy Riser as that was my original intent. If you are interested in my experience learning to fly, please visit my other blog dedicated to the learning aspect of the Easy Riser at

easyriser2.blogspot.com
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Re: Blog: Easy Riser repair project

Postby Rick Masters » Sat Jul 25, 2015 6:12 am

Beautiful!
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Re: Blog: Easy Riser repair project

Postby Bob Kuczewski » Wed Jul 29, 2015 12:29 am

RickMasters wrote:Beautiful!


Ditto!!!!!!

Your workmanship is outstanding John.    :thumbup:

I've been following this blog for a long long time, and it's really come together ... beautifully!!

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Re: Blog: Easy Riser repair project

Postby jcoyier » Thu Jul 30, 2015 1:49 pm

Rick and Bob,
Thanks for the compliments....much appreciated! The downside here parallels what Worthington discovered early-on flying the Mitchell Wing.....you just cannot allow the aircraft to be damaged. Repairs are unthinkable. Puts some very stiff constraints on where and when you allow yourself to fly.
John
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Re: Blog: Easy Riser repair project

Postby Bill Cummings » Thu Jul 30, 2015 6:12 pm

Overweight may be due to many small choices options.
One very small choice could have been Weed whacker plastic cord instead of cable for the handgrips.
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Re: Blog: Easy Riser repair project

Postby Frank Colver » Fri Jul 31, 2015 9:48 am

Just one tiny nick in weedwhacker plastic and it breaks. Multi strand is the only safe way to go.

FC
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Re: Blog: Easy Riser repair project

Postby jcoyier » Tue Jun 14, 2016 11:40 am

Bob K.,
I have added #18 and #19 to easyriser2.blogspot.com. They deal with design and construction of strut fairings and also adjustable rudder stops.
John
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Re: Blog: Easy Riser repair project

Postby jcoyier » Wed Oct 23, 2019 9:16 pm

Re: the suggestion to use weedwacker line for the grips was a misunderstanding of what the cable was in the photo?? That cable (1/16 inch stainless) is the rudder control cable that terminates as a wrap around the twist grip. Once wrapped, it is overwrapped with filament tape and then a final overwrap of cloth bike handlebar tape. I am going to try a lighter weight stainless with Nicopress swages on the next glider I build (as soon as I finish my new shop). This cable is spec'd at 200lbs breaking strength which I think is plenty.
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