My E-Flite Blanik Build

[Mark9]

Hello,
Just joined the group a few days back and started aero tow late last year. I wanted a big scale ship and since I had a history with the Blanik, see my intro thread in the “Welcome” forum, and I heard lots of good things about the E-Flite Blanik it became my choice. My transportation requirements and the street price also made it an attractive option. So, my search for a kit began. Unfortunately I found quickly that the kit had been discontinued. However, I did find one kit at an American supplier and placed an order.

When I received the kit about a week later upon inspection I found that UPS had not treated her well. However, the price was so good and I have repaired other of my gliders that had much worse damage, although they were much smaller competition sailplanes. In this thread I plan to post some of the pictures of my repairs and solutions to the challenges of putting together a first time ¼ scale sailplane and making the needed repairs. I’m a newbie at scale and don’t plan to show the ship; just have a presentable, good, sturdy flier.

I am a slow builder, a neophyte at ¼ scale and my main focus in the hobby is TD flying, so progress has been slow on the Blanik. Plus, I hate to “redo” things that I have already done. As a result please bear with me since my additions to this thread may be sporadic. Also, sometimes I forget to stop and take photos if I get focused on finishing a particular task. So, on with the first segment.

When received the bulkhead at the TE of the wing was floating in the fuse in pieces. The first shot is the pieces glued together and the lite-ply replacement I fabricated. The next two shots show the set up I developed to hold the fuselage as I glued it in place with West Systems. I have short arms so it required some “constructive” tool design to prep the joint area, install and glue it in place.

The next two shots shows some of the skin damage that occurred when she was abused. The one that has two bare areas is what let me know about UPS on initial receipt. It had glass fibers breaking free from the top coat finish. During inspection it was not hard to see the skin damage inside the fuselage of the other area on the opposite side that required reinforcement. Both areas received additional glass on the inside and externally.

Mark

[ARUP]

Looks like you are on your way! Awesome! If you haven't already then check the threads for 'improving the breed'.

[lenb]

Welcome again Mark and thanks for posting along your progress. The repair seem to be coming along well, just think, when its all patched up will look even MORE scale.
I had to replace the same former in mine. Lots of fun.

Len

[Mark9]

Installment #2:

I’ve read on another forum on the Blanik of issues with the tow release. These photos show my solution, at least I hope they are a solution! I fabricated a different tow pin from .092” piano wire and it then runs through a K&S brass housing. This was constructed of two thicknesses of tubing, cross drilled and glued into the original recess. I then set the bottom of the skin in that area “level to the world”, taped over the outside of the exit area, mixed up some West Systems, injected it in the nose under the tow release top plate and walked away for the night. What appears to be gaps are actually filled with cured West Systems. Hopefully this will cure some of the skin crushing and pin bending issues. The inside of the tube is radiused to have a smooth exit interface for the tow loop.

[Mark9]

My transportation requires that I have at least a removable rudder, the fuse assembly won’t fit under the truck bed lid otherwise. I have seen other approaches to the same ends and decided I liked using the stock hinge pins with a single rod to join the two surfaces best. An added benefit is that the rudder can go in it’s separate padded bag for storage and transport. A piece of tape holds the short “L” leg in the trough while assembled for flight. The first shot is of the rod partially inserted and the second is it fully inserted with a piece of masking tape used for proof of concept. I will probably harden the trough with some thin CA, which will water proof it some as well. Should be easy to assemble and disassemble at the field. Now, I just need to glue the hinges, spar tubes, control horn and install the vertical on the fuselage. Another design/modification hurdle completed!

[lenb]

Slick setup Mark.

[Mark9]

As I said earlier I’m a slow builder, but some progress has been made. The vertical and rudder sub assembly is complete except for gluing in the support pins. Over the last few days I started the horizontal sub assemblies. They will be as designed, even using the recommended servos. Their control horns and hinge points are installed.

Last night I fitted the servos and began to set up the servos. Frustration set in when I could not determine how to set up a dual servo elevator in my SD-10G using the glider template, never needed it before. I could find no way to have full independent adjustment and control of each servo with a single trim for elevator. Searched the net and saw postings to use the aero template. That solved the adjustment and control aspect, but then having the flaps on the left stick became an issue…lots of programming?

Then I remembered when I bought the kit I was thinking of maybe adding the optional spoilers and I had purchased a Smart-Fly Equalizer II at the same time, just in case. So, I dug into the parts box and plugged it into my mock-up. Presto, in a few minutes I had full functionality of both servos. Just need to finalize the actual control settings after I complete the installation of the servos with the push rods and two more sub assemblies will be complete. No pictures this time, nothing other than a “stock” assembly.

[Mark9]

Had a setback in my assembly schedule late last night. Did the final install, or so I thought, on the elevator servo in the left horizontal. When I went to hook up the push rod I discovered the elevator horn was not in line with the servo horn and the slot for it was only not in line, but off angle as well. Sure wished I had notice it before I glued the horn in. The servo was not happy even on center, I hate buzzing servos!

So, I just went to bed. This morning I played around with it some more and decided I needed to remove the horn, cut a new slot and fill the old slot to re position the horn. Strange the other horn was well with in position. I was not happy. Anyway, here are a few shots of what I did, sorry about the bad focus and lighting in a couple. The first shot is the pocket I created when removing the horn from the “factory position”. In the bottom of the pocket one can see some remaining epoxy from my original installation, which I didn't removve and the slot on the top is where the horn will go.

The next shot is of the block I made to fill the gap installed. It was glued using thin CA, then I trimmed it and sanded it slightly to fit reasonably well. After the CA was cured I then took some matching Ultracoat to cover the block. Lastly is the horn installed with epoxy and I’m now waiting for it to cure. Think I may have figured out how to get some better detail pictures in my shop in the last one too

Mark

[Mark9]

In another forum I read of weakness in the cockpit area and the wheel support. The two shots show the structural mods I have almost completed so far. I laid unidirectional carbon and heavy glass in the cockpit just under the combing from the nose to the former at the LE of the wing and across the mid-strut of the former. I also now have a new found admiration for those who work laying up composites. It is very difficult to align reinforcements accurately in a layup schedule while the working time clock is ticking. Once that uni hits the resin you are committed!

Poplar struts from the joiner tube to the aft former of the wheel box were added. This should help carry the load and impact of landing from the wings to the wheel assembly. Which should ease the stresses on the fuselage skins under the wing. When the carbon joiner tube is in place the fiberglass housing should not deflect substantially.

On investigation I realized the grain of the lite ply on the top of the wheel box runs longitudinally. When looking at the wheel support structure the lite ply is being stressed in the weakest direction on impact. So, birch aircraft plywood was laid with the grain running crosswise on top of the lite ply gear box plate, forward and aft of the LE former. Both front and back were then covered with heavy glass cloth.

To the front of the box I’ve also added birch aircraft plywood webs to the front of the wheel box to distribute the load from impact in the forward area. I have yet to finish the installation of the webs, since I plan to add epoxy and colloidal silica fillets to both sides to finish them out. At this point I have only added the fillets to the front side.

[Mark9]

It's been a while since my last update. Life and other RC flying has caused a delay in work on the Blanik.

However, this segment shows what I think/hope is my most complicated addition. A soaring friend of mine suggested I check into some batteries he has been using, Cyclon sealed lead acid spiral wound AGM cells. Read that they are quite sturdy and can even be TC’d by the FAA for use in human carrying aircraft. An added plus is AGM technology is well proven and easy to take care of. So, why not use them in an RC glider? They are 5 amp hour and since the Blanik, I’ve also read, requires quite some weight to balance I went for it.

The mount system for the battery posed some challenging issues. First a mounting base was attached to the tow release plate and a Velcro strap system was then developed to hold the battery in the tray. This then lead to making the forward instrument binnacle removable to improve access to the battery installation. Balsa cross braces with blind “T” nuts were glued into the instrument binnacle. Then nylon thumb screws are used to hold the binnacle in place on the cross braces in the fuselage. Slowly getting closer to finishing the fuselage and get started on the wings.

[ARUP]

Glad to see you back! One thing about this hobby... boo boos will be made, found and rectified! I've seen somewhere else on the forums about those batteries. Nice app... getting power and needed nose weight!

[Mark9]

Well it’s been awhile again, my TD/F3J focus which I consider to be TD in a world format got in the way. But, just finished another mod recently to the Blanik. Since I have transportation and storage concerns with this big guy I needed the rudder at minimum to be removable. Before I glued the vertical fin in place, Stephane, showed me how he made it removable on one of his Blaniks. By extending the fin carbon spars one can fill in the base of the tube and thread it for a screw through the bottom skin of the fuselage. It’s a really a slick way to attach the fin and very rigid once complete.

Drilling the holes through the fuselage was kind of scary. Also, a little fiddley to set up for, but will be handy if ever needed (only one chance to do it). I then rigged the pull-pull rudder system. Cool now another control system installed. Next is wiring in the fuselage, which will get the fuselage finished except for paint on the skin repairs is next. She (he?) is progressing slowly and cosmetics are secondary.

BTW, this year is an F3B Worlds year. One of the guys on our team is from our club here. I met all the guys on the team near the end of last year when he ran a distance practice weekend. All are well known names in our soaring hobby and I had a lot of fun trying an aspect of RC gliders that I had never tried before. Shameless plug to follow…if you feel of a mind they need help to get over to compete, so donate to the team if you like. You can use the link below.

http://www.teamusaf3b.com/store

Mark

[Mark9]

Well, since the last time I’ve completed the fuselage except for paint and CG ballasting. Nothing exciting except my custom wiring harness. The receiver buss provides power and elevator signal to only the Smart-Fly Equalizer II and it provides signals only to the dual elevator servos. In addition the receiver provides signal only to all of the other servos. I could not find a way I was happy with to program the dual elevator with my radio, so I used the EQ II which I had on hand. Very neat little add in, allows me full control of both servos individually (with end point adjustments) and a single trim function for both while in the air.

All servos are powered directly from the power on point, which at the moment is an EC3 connector. I’m using 18 AWG silicone insulated wire to all branches of the harness for the servos. The connectors to the wings are DB series ‘’power” connectors. They have the same form factor as an “E” shell DB-11, but only 7 pins. Two pins are 20 AMP (power + and -) and five are signal. At the moment I am only using two of the signal pins, aileron and flap, per wing panel.

Been working feverishly this week to get her ready for a maiden flight this next Monday. Still have much to do. Will post some more details when I can.

[Mark9]

Don't know if anybody is still following this or if I'm flogging a dead equine, but I've have read quite a few build threads where I've learned many new ideas and tricks. So, I will continue this through the maiden.

UPS also damaged the ailerons at the trailing edge roots, a simple fix. I only took a picture of one of them prepped for the repair. I scabbed on some hard balsa and a little spruce at the root to keep a sharp root tip. Once the Titebond was dry I shaped, sanded and covered the repair with Ultracote.

After the repair not much exciting. Except I did add an extra basswood triangle brace to all the servo blocks and a small wood screw from the underside through the plywood into the servo block. Included in this post are all the servos and the wiring ready to install in the wings. Attached a better shot of the connector configuration since the previous shot was so bad.

Spent most of yesterday (Friday) building a Vanessa Rig and gluing in the incidence pins. Still need to sand some more on the joiner tube, it keeps binding. And that’s here in the house, could be even tighter after sitting in the hot sun all day! Only have to CG it, decide how to add the weight and finish programming my radio. Looks like I can be ready by Monday, the WX is still looking good. Time to go for a club fun fly, winds about five out of the north, temps in the 70’s and we don’t have to launch into the sun. COOL!

[ARUP]

Mark, keep posting! I have a Blanik that needs building so all ideas will be useful!