SV-11 electric build thread

[bob branch]

I have received on of the first Brodak SV-11 ARF's. I have had a few requests that I post a build thread on it so I'll go ahead and do that.

I am going to be using motor from Brodak, the Arrowind 2832-05 at 960 KV. Batteries will be Rhino 4S 3700 mah packs. This will be the first time since my first year in electric I have returned to a high kv motor. But I wanted to evaluate the lower pitch apc EP props and anticipate using a 12X6EP. Esc will be castle creations ice 50 lite and timer will be the Wil Hubin FM-9A. 

This is a picture of the first trail assembly. I have posted a complete set of pics at this stage in the ARF forum.

Weight of all components out of the box, ie everything but power system and spinner is 34.2 oz. I have added probably an ounce to that in the nose to deal with cowling reinforcement, cowl hatch attachment, and esc and timer mounting.  I'll start pics on those before I go further in the build. Right now the power system is completely installed and the cowl installation is completed. \

My decision to do the plane as an arf instead of an arc was to determine if I like it enough to do the arc. I am very pleased with my T-Rex since its recent repowering (see its build thread) with the power system I had in my electric strega (dualsky 4260CA5 on 5S but turning 12X6 APC EP. I will continue to retrim to that power system from this point out and will fly it in contests where BOM is applied. The SV will let me experiment with the higher kv approach and evaluate comparison of the two planes.  I'll get pics of the motor and cowl installations and begin them with the next post.

bob branch

[bob branch]

I am going to start with the nose of the airplane. I usually do this area first since for me the power system and cowl are the areas I most often have the greatest amount of modification to do. The first picture shows my basic nose layout. Things not yet included are the battery retention straps, the esc connectors to the motor wires (wrong size receivers in this pic), the wire routing guidance for the motor power wires, and the spinner. I'll address these one at a time as I go along.

The motor is bulkhead mounted with a Rick Sawicki type mount like I used in the T-Rex. The plywood bulkhead is retained by two ply strips one in front and one behind the mount. The mount can slide out the bottom and is retained by one or two screws thru the fuse side using the doublers as stops for the 1/2 inch #2 socket head screws I use so often (R&L fasteners... they are online and at Toledo. You will save mucho $ buy getting to know these folks. Really great prices). Nothing new there except because of geometry limits in this particular install I cannot make it slide out with the motor still attached as I usually can. It has to do with the balsa filler between the maple motor mount beams and the fact I am using a solid instead of a split nose ring. I could remove them further but I opted for another solution. I did not glue down the motor top block. Instead I recessed a 1/2 inch # 2 socket head screw into the nose ring and it goes into the nose block from the front. After threading the screw in I removed the bock and hardened the threads with thin CA glue dripped into the hole in the balsa top block. Same thing we do to harden servo screw holes in rc. Works well. I then placed a second 1/2 inch Number 2 screw thru the top of the top block and into the motor mount bulkhead which is 3/16 birch ply. To prevent this pulling thru the top block I secured a 4-40 blind nut with epoxy on the inside of the top block with its collar projecting upwards. It provides a vertical stop for the #2 screw head (which is only a 3/32 hole.) These two screws secure this top block. Should I need to remove the motor I just pull the spinner and the two screws and I have total access to the motor for removal. The motor is mounted with 4-40 bolts into blind nuts secured with epoxy. I have used standoffs on this installation because I want the options of different spinners and this was a way (in my mind's eye at least) to achieve this. Your mileage might definitely differ. But I also want the option of using both longer and shorter motors. The standoffs are nylons sleeves from the local hardware store and were ground on the disc sander to get the length I wanted. I used lock washers on the bolts at the motor end.

[William DeMauro]

Very nice !!!! Is the battery going to load and unload through the bottom?

[bob branch]

Next I will discuss the mounting for the speed control and timer. This a departure from what I have done before which as you see in the T-Rex thread is to mount the esc and speed control on vertical surfaces like the fuse side or a bulkhead. Being the totally shameless copy cat that I am when I see a good idea I went to a horizontal mounting plate like I saw on Rick Sawicki's new electric Legacy (btw, there is one sweet electric conversion with axi 2826/12, 3700 mah Rhino 4S, and apc12X6EP... a killer system and flier! Nice job Rick. For any of you who know Rick and the history of his planes going way back into the day... I'll let you guess at the color scheme.... no points if it takes 2 guesses). Anyway, Rick put his mount at the front of the battery compartment. Due to wing layout and geometry of the front end I had to put mine at the back.  What I wanted to gain with mine was to be able to connect the battery cables without removing the cowl and to be able to reprogram the Hubin FMA-9A timer without removing the cowl. This layout lets me achieve both. Its disadvantage over the front position is I have to deal with the motor lead wires interacting with the battery install. I'l overcome this with some retainers that the jet guys use to guide fuel and air lines. We'll see those in a later post. Not real evident in this picture is that the mounting pad (1/8" ply) is angled down at the back. That does four things for me in this install. Gives me better ingress path for the battery (rhino 4S 3700 mah... a fairly long pack), it places the timer pins at an angle that lets me connect without removing the cowl more easily, and it gives me room to locate the start switch behind the pad, and gives me room for the hatch magnet installation that we will get to in a bit. The front pic below shows the mounting pad with the esc and timer from the front, the other from the rear with the start button assembly visible.

EDIT!!!!: Having finished the plane now I found a problem with what I did here. If you decide to mount the esc and timer as I have do NOT install the platforms until you have installed the wing and the belly pan. Otherwise you run the risk of the forward lower fuse reinforcements that ahve been added to the brodak kits having to be modified or removing the platforms to install the reinforcements. Better to wait til later to place the platfoms. ... same with the timer start switch...bob

Btw, lets not deride our wet fuel brothers their pipe tunnels. They are really handy for installing stuff. Nice to have the extra space.

Opps, missed mentioning in the last post that I ground out the maple mounts to allow the mounting of the motor bulkhead and then for space for the motor can itself. That's a cut and fit deal. Yes, I could have removed the rest, but it makes a convenient platform for the battery and I like the stiffness in the nose. Again, your mileage may vary on this. Still got to mount the battery to something solid.

[bob branch]

William

Its going to go in thru the bottom. The entire cowling is a one piece carbon fiber piece. It has zero structural integrity and could not be given any. It is extremely flexible... but of course very light. As we will see this will cause me extra work further along. I wanted to do a top load but after looking at the structure doing so would have removed all structural rigidity from the front of the airframe. If I were doing a scratch build I would opt for putting the battery tray structure at the bottom of the fuse and then load thru the top. Working with an ARC/ARF successfully is a mater of figuring out what you have and how to deal with it in the best way to get to the end result you want. Sometimes you have to compromise something but that is ok. I had a full kit SV-11 for 2 years and sold it because I just did not want to build it even though it was a very nice kit. For me the ARF /ARC route is more enjoyable right now.

bob

[bob branch]

On to the cowl installation. As I said earlier I had a couple of goals in mind. I wanted to be able to connect the battery wires without pulling the cowl off. I also wanted to be able to attach the fm-9 programmer without removing the cowl as well as reconnect the esc lead to the timer. Also, and probably most complicating I did not want to be fiddling around with screws, nuts, and bolts to put the cowl on and off. I want to just as easily as I can slide it off and slide it back on. I have found rare earth magnets to do the job nicely. But as I related in the T-Rex thread, the cowl must be self aligning without regard to the magnets. The do not provide lateral positioning well. They provide retention well.

The SV-11 comes with an all bolt on system. 4 about 4-40 (metric equiv) bolts pass thru the sides of the cowl thru standing plywood struts and into blind nuts. The system is very similar to the Vector 40 only instead of 2 nuts there are 4. And it needs four. This is one very long cowling. It goes from the nose ring all the way to the wing. Attached as it is intended it works very well. However, the cowl is very flexible. I know when you think carbon fiber you think stiff. But like all materials that depends on the layup schedule. Carbon fiber is also very light. But you need adequate thickness to get stiffness. In the standard install method there is no need for the weight of stiffness. The four legs lock in the shape when the cowl is bolted to them. However with no bolts the sides are free to flex out into all manor of shapes and waves, and such and they do. It was apparent to me that to use the cowl without the bolts I would have to stiffen it. I could apply more cloth or a light frame. I opted for the light frame since I did not have a mold. I used a 3/8 inch contest balsa stringer on each side to make them become straight. I then notched them for the passage of the legs. The legs are laminated from 2 thickness of plywood. I did not need both and did not need the blind nuts. Keeping them full thickness would only compromise the rigidity of what I was try to achieve. So with a scalpel I popped off the inner laminate of the legs (the part with the blind nuts) and That left my frame work rigid enough. I had to do a little carving to clear the esc mount pad. When I positioned this I found the sides were still not a perfect match to the fuse width. So once I got the air openings cut in and the cowl attached at the front (see below) I attached another cross piece of balsa across the stiffeners so that the width was locked in the same as the fuse. A nice rigid cowl resulted. It is self guiding into position once the centering bolt is aligned in the front... see next post.

[bob branch]

As you can see in the previous picture, there is lots of hole space. Big holes. The exhaust to inlet area ratio is 2.5 to 1. Your aesthetics may differ. It works for me. I like big exhaust openings and lots of air movement internally. One nice thing most of us seem to be discovering is you can never have too much cooling in electrics.

The front of the cowling is indexed and held in position by a 2-56 bolt that is recessed into the plywood nose ring and then passes thru the front lip of the cowling. On the inside of this lip I placed a 2-56 washer epoxied to the inside of the cowl so that the load was not on the thin carbon fiber. Electrics may not vibrate much, but the prop wash airflow does. The bolt was cut off to a length that did the job but allowed the cowl to angle up enough to clear the guide legs. The cowl passes over the nose retaining bolt/pin first then guides over the front legs, then the rear legs.

[bob branch]

Finally to the magnetic hatch attachment. With the nose retention, and lateral guidances already handled now all that remains is to keep the back of the cowl from falling down. This I did with a pair of 1/2 inch rare earth magnets from Jo Ann Fabrics. I have used a bunch of these on the T-Rex. You can pick it up by the cowl and shake the entire airplane and not have them separate. I think that might be overkill. On my oriental I used one pair of 3/4 inch ones at the back and a nose pin at the front. Really have to get in there to pry it off. Fortunately I learned there to make the area accessable thru the air exhaust so you can do it. The half inch ones are still pretty tight but because I can get to the mount area thru the air exhaust with my fingers and pull directly down on it I can separate it. I've used 1/4 inch in RC and they suddenly are a lot weaker than the 1/2 inch ones. So a table for them in some ply and glue them in with thick CA so they are proud of the surface. Glue that onto a table cut to fit the width of the fuse (yea, I know, why not do it in one piece? I don't feel like working that hard #1 and #2 the second lets me position the manets more precisely). Glued the fuse one to place first against a small stinger used to set the fuse width in front of the wing in the kit and then a matching one whose mount plate was fit between the balsa cowl stringers. Assembled the hole thing with the magnets n contact and adjusted it al thru all the nice big holes (I love big air holes, did I say that before?) and applied some thin CA thru the air exhaust opening to position everything. Once set pulled apart the magnets ie, pulled the cowl off,  and thick CA'd all the joints. Cowl done.

Next time I'll start with something else. Like maybe the wing and control systems.  Please feel free to ask any questions or make any comments. LIke all things in our hobby, I believe there is more than one way to do everything. Probably no original ways, but certainly more than one. What I am showing is just the way my mind feels comfortable approaching the build. You may see other things, have other ways to do it or ways that you have used for years and are a lot more comfortable with than something I might do. Have at it and feel free to share it here. I will have no hurt feelings except if you deride me for not building a full build and paint job. Been there. Done that for year. I just do not enjoy it any more. I love to see you guys do it who do and in no way want to take anything away from your artistry. I'm the first to drool. But arf and arcs work better for me in my life these days. The hobby is big enough for all of us (I hope). (short editorial off)

bob branch

[bob branch]

Goals achieved for cowling:

[Rob Smith]

Bob thanks for taking the time to post all the photos and the written descriptions. I know first hand how much time that takes.

Rob

[bob branch]

Thanks Rob. Yea, it takes time, but I think it makes it more interesting for me too. Sometimes keeps me from rationalizing a decision.   But sometimes not... just human I guess.

bob

[bob branch]

For anyone wondering, (probably not many), progress has stopped on my SV-11. Our contest season here in the Detroit Area starts next weekend (yea really, first one of the year) and last week and this week I'm involved with preparing and practicing. I'll be back at it in another 2 weeks.

bob branch

[Rudy Taube]

Thanks for the update Bob. We all appreciate your good ideas and help. Good luck with your contest season this year. Seams a little short? Late Aug to Late Sept.? 

[Dennis Adamisin]

Thanks for the update Bob. We all appreciate your good ideas and help. Good luck with your contest season this year. Seams a little short? Late Aug to Late Sept.?  

I think this year it runs from Friday the 20th thru Sunday the 22nd....  

[bob branch]

Ok, I'm back to the project. Going to start with pushrods and ball links. We have all heard stories of ball link failures. I think most occur from failure of the ball link itself in the threaded area or in the attachment of the threaded end to the carbon fiber pushrod. I'll review how to keep both from becoming a failure looking for a place to happen.

First the threaded insert should fit passively into the carbon fiber tube. If it doesn't, don't mess around, buy another tube. If you force it you will cause mircro fractures and it it will sooner or later fail. You can if you want sand the insert down til it fits if you have a tight fit. Be my guest. I don't care to sand anything that hard, but then I hate sanding and I keep a supply of different sized carbon fiber tubes on hand so replacing the tube is easier for me. If you have a tight fit you will have a failure. 

Next you would like to anchor the components not just with adhesive, but mechanically as well. I showed this on the T-rex thread and will just touch on it lightly here. I do this buy drilling two 1/16 inch holes thru the tube at 90 degrees to each other. When the adhesive is placed into the tube and around the insert and the insert pushed into the tube you should see adhesive come out of the holes. Actually you should see the adhesive come out of the holes before you place the insert. Its how you know you have adhesive in the tube. The adhesive is placed on a pad after mixing and the tube scraped into it with the tube at about 45 degrees to the pad and pushing the open end of the tube into the adhesive while it scrapes over the pad. If you have never done this you will be surprised how far up the tube the adhesive will be forced. Also you want to coat the insert and its hollows with adhesive so the hollows are filled in. Then push the insert into the tube. This will result in lots of excess, wipe it off with a dry towel. Do not use acetone or any solvent, you will weaken the epoxy. While on the topic, two adhesives work. JB Weld is the most common used and best recommendation unless you have a lot of epoxy experience. A structural fillet blend done at lower viscosity than normal fillet blend will also work well. The metal should be cleaned with solvent like dope thinner, acetone, mineral spirits, etc and ditto the inside of the tube... not so easy to do. pipe cleaner will work.  You need to be thinking ahead so that can get a heat shrink over the end of the tube and insert as well. This is a fall back that aids in preventing a spintering failure of the tube. Not likely to happen if you have a passive fit to the insert, but its just a redundancy I like to have.

If the bonding is done this way you will have the entire space between the insert and the tube filled with no voids with  the adhesive and the adhesive will be locked mechanically and chemically to the tube. The first pic shows the hole, pins are thru them, and the second shows the end result after the heat shrink is shrunk. If you look carefully you can see where the adhesive extruded thru the tube by the bumps in the heat shrink. Also the heat shrink makes a smoother contour at the head of the insert so it does not catch of a bulkhead or something. I of couse would never build anything that had the senario but that jerk Murphy is always tampering and modifying things in the shop when I'm not there so I just try plant traps for him.

[bob branch]

The other area that causes ball joint failures is over threading the ball link. In other words, bottoming out the ball link fitting on the threaded insert and then continuing the thread it on further. This will crack the plastic fitting, usually not very visible and lead to catastrophic failure later on down the road. If you see a failure of the threaded area or just beyond that of the ball link fitting, this is the cause. To prevent this I am going to directly contradict the instructions with the sv-11 regarding this failure. John, please forgive me. The instructions with the sv-11 would have you put the threaded fitting in a vice then start the ball link fitting onto the threads and then take a lever like a screw driver or allen wrench or something and put it thru the ball and then start twisting till the thing is threaded on. Two things can happen here. The ball can be levered out of its receive. Not catastrophic, it will snap back in. But while it is easier to thread the ball link onto the insert, you cannot tell accurately when you have bottomed out. Half a turn too far and you will have created the beginnings of a fracture if not a frank fracture. Much better to turn it on by hand. If you cannot, then I think it is Dubro that makes a plastic tool that goes over the ball link and is a knurled or ribbed knob that gives you more leverage but still not so much that you cannot feel when it bottoms out. 

Get the thread started a turn or so then start counting the number of turns it takes to bottom out. When you first feel increased resistance you are there. It was 18 turns for the fittings in the sv-11 kit for me. I then get a thick sharpies marker and coat all the threads remaining beyond the fitting black so I can see where bottom is. I then back off half the total number of turns it took to reach bottom, in this case 9 turns. That will be my total range of adjustment. Of course with two ends that gives me a total of 18 turns of adjustment. The picture shows the fittings backed off the entire 9 turns. Notice, it is not much, only about 1/4 inch. So your work needs to be precise along the way. I will set each fitting half of these 9 turns or 4 1/2 turns from bottom as my construction setting and that will allow me to adjust each as I trail fit the control system and give me some adjustment when I am done for fine tuning if I need it in flying the plane and adjusting trim.

The pic shows the ball links with the 9 turns out from bottom. These appear to be metric threads and are quite fine.

[bob branch]

After trial fitting the wing halves I glued them together with 30 minutes epoxy. The alignment spars fit perfectly and the alignment was perfect. The wing came out perfectly straight. There was no need to use structural fillet material for the joining in my kit. I used adhesive tape to hold the halves drawn together til the epoxy set. Then after it was all dry I applied glass cloth across the center section and adhered it with thin CA. Be sure to have a fan blowing across the work if you do this. I learned the thin CA part from Windy and it works much better than epoxy. Very fast and wets out perfectly. On the top section of the wing there is not the normal Brodak ridge for wing positioning and bonding. Rather there are several cross members along the wing joint spanning the fuselage to bond to. The fit is so good I did not apply cloth over these areas. I'll bond directly to them with epoxy structural fillet when I join the wing.

Fist pic is the wing root rib with alignment spars at trail fit,... each was coated with 30 minutes epoxy for joining along with the root rib. Second is of glasses center section on bottom.

[bob branch]

Finally, thanks to Bob McDonald for machining me a prop nut that allows me to use a non plastic spinner for the first time in an electric stunter. I know its an extravigance and not what I need weight wise, but its really about what I like to look at so thanks Bob. I really like what this is starting to look like.

bob

[Rudy Taube]

Hi Bob,

Thanks again for all your great tips. Your spinner does look great. And it is in keeping with the long tradition of metal spinners in CLPA. :-)

The good news for us is that TruTurn makes beautiful Aluminum spinners for our electric powered models. They are much lighter than the standard ones. They come in three different shapes; standard, pointed like yours (they call it "Ultimate", made for the famous biplane of that name), and a P-51 shape. They come in many Diameters for us. They are not inexpensive and they do need the appropriate adaptor for our different motor shafts (they have a complete selection with chart), but they are worth every penny. I have been using them for >35 years in all sizes from small 2" to my larger 5 1/2" Dia. spinners. They are perfectly balanced and are works of art. I still have some of mine that are over 20 years old with over a 1,000 flights.

If you ever want to get one of yours to look like chrome, just go to their web site and find their FAQ page, go to bottom, and use their method. It works perfectly. If you are interested I can post my tips to make it a little easier to do. The 5" spinner on my EXTRA 300L looks as good now as it did 10 years ago. I even made my Aluminum LG look like chrome.  :-)

Here is the link to their Spinner that looks like yours:

      http://www.truturn.com/cgi-bin/store/agora.cgi?p_id=tte122052b:13&ppinc=spinners130&exact_match=on

Thanks again for all your great help.

Regards, 

[bob branch]

Rudy

They will also do custom slotting for those of us who use pusher props if you do not want to do it yourself or what a perfect fit.

Thanks for the link.

bob

[bob branch]

Hinging comes next. I am not going to do any pics here. We all know how to do this. I will comment though on the Brodak recommendation. Your milage may definitely differ here and if so please chime in. This is I think the only other place I am going to contradict the Brodak manual. they recommend Gorilla glue for the hinges. I tried this on several airplanes a few years ago. I found the following problems. 1) it stains your fingers for weeks. You must wear gloves. 2) If you get any excess on the airplane, even though you wipe it up and cannot see it, over time in the sun it will reappear as a dark brown stain. No getting it off from my experience. 3) No mater how well you wipe excess off because it expands on setting it is going to ooze out anyway. 4) I have had it fail on a model... a 3D rc profile. Landed with one aileron hanging from the airplane and the other loose and only holding on by 2 hinges. (was my first flat spin landing however... that was pretty cool!). As I said, you milage may differ. It does clean up fairly easily but if you use a grease on the hinge barrels (I use a white marine grease I got at the hobby shop... seems to work better than vaseline) epoxy comes off pretty easily.

I have not been able to keep CA from locking up the hinges. If someone knows the trick to this please post it as I would like to know. What viscosity CA do you use?

Anyway, that's my 10 cents worth on hinging. I'll be using epoxy just cause in my hands it works the best for me. As with so many things we all have a method that works best over time for us so by all means, use what works for you. Personally, if the knotches were not there for the barreled hinges I'd use CA hinges. They still give the most trouble free friction free hinges in my hands. But not using those wide heavy things you get with a Brodak ARF. But that is not part of this build as the slots for the barrels would reduce them to hideous here and inappropriate without filling in the notches.

[RandySmith]

CA is terrible for hinges  I use epoxy in the flaps and elevators first, allow that to dry, then use canopy/plastic wood glue to attach them to the wing and stab, This is also a great time to get the hinges perfectly 90 straight.
When I set the hinges in  I push them in almost all the way, then bend them all down in one direction, I then use a edge of my table or a 2x4 and push the hinges edge of the flaps and elevator against them, this pushes all of them into the surface at the same depth, you never wind up with one hinge in deeper or a shallow hinge.

Randy

[bob branch]

Randy

In my hands I could not agree more.I saw Windy using it on his Strega arf series. Tired it and had to cut em out. Just not in my hands.

I did come to a duh moment though in hinging the plane which others may well know about but which has always frustrated me, especially with Brodak arf's. I tried something and it worked for me so I'll share it. If you already know of it just ignore me. My grandma was slow but at least she was old. Anyway, it relates to hinges that have a click as you move them. It always seems to be in the range that the controls will move in. In fact usually somewhere around center. I usually scrap the hinges and go to Dubro's which seem to not have this problem. The Brodak hinges have been getting better. The T-Rex I built had no clicks at all and was the first kit I used the kit hinges on. This one was fine except for two. So do I change them all for just two? I put on magnifying loops to see if I could see the bind, a tab of excess molding material or something. Nothing showed. I was, however, able to see a very fine mold line right along the height of the barrel, ie right where the barrel faces the opposing hinge in neutral. I took a scalpel blade and just pulled it over this, not pushed in a cutting motion but pulled in a dragging motion the length of the hinge...click gone!!!!!!!!! A giant leap for me, a tiny foot shuffle for mankind. Hope it helps somebody else. If not.... well, grandma was slow....

bob

[bob branch]

The normal wing attach method of a brodak arf is a sheet of 3/16 to 1/8 inch glued to the top center of the wing that is the same width and shape as the internal opening of the fuse. This engages the side of the fuse when assembled and is very friendly to thin CA wicking in and creating the joint. Perfect alignment, rarely perfect fit though. Odd considering all the laser cutting, but really shitty fits in reality. Still works fine if followed by a thick CA or epoxy fillet to fill the usually 1/8 inch gaps. The belly pan is just window dressing. Totally non structural.

This plane does not have the sheet on the top at all. Just standard sheeted wing center section top and bottom.  The fit of the fuse to the wing is quite good too. There are 3 pieces of 1/8 inch balsa about 1/2 inch wide, like bulkheads, spanning the fuse at intervals at the top of the wing cutout. But unlike a bulkhead (sitting vertically) they are on their sides mounted tangentially to the wing so that their full half inch width is in contact with the wing. The wing is then glued to these. I certainly hope people use a structural filler as I would be surprised if epoxy will provide an adequate fit. The belly pan is locked structurally to the fuse with a 6 or 7 inch long by about 5/8 inch wind ply piece spanning the joint of the belly pan to the fuse on each side. This ties the belly pan to the fuse solidly and the belly pan is then also epoxied to the wing. Much stronger setup. Also should provide more rigidity with very little weight. I think the ply carry thrus should be attached with fillet material since there is no way to assure clamping pressure or attachment internally in assembly, thus the need for considerably gap filling capability with good strength. If building from a kit you would not have the belly pan bottom on and this would be simpler. Just an arf compromise that requires different material.

[bob branch]

Final assembly was pretty uneventful. The method for trimming the pushrods worked fine. Thanks Randy for enough room in the back for a ball link! Did have to notch the elevator rails in the fuse to clear the bolt and nut but only a small section for them to slide into. Getting the elevator insert into the pushrod required some work but just small adjustment trim and trying of the insert. You will find rotating the elevator assembly gets you some more clearance to get the insert in but it is doable.

The lower fuse reinforcements were another story. No problem to the glow fliers, and here is a help to the electric guys. If you elect to position the esc and timer at the back of the compartment as I did.... WAIT!!!!!... until you have joined the wing and the belly pan to do so. It will save you a bunch of work. I'll go back and edit the earlier post.  Be sure to go over the bulkeads with glue to make sure they are well secured. One of the belly pan ones came loose on assembly for me. In that this belly pan becomes structural you want all the structure solid.

Everything else is pure normal Brodak arf.... gear.... rudder..... a.... er.... hmmmm. Its all done!

Final weight less battery is 56 oz. My pack is 14.3 ox so 70.3 ounces with fuel. That would equate to a glow weight of 63 ounces if you allow for 7 oz of fuel so I think that should be in the ballpark.

Any questions feel free to ask. Nothings going to hurt my feelings if you want to do different from me. I'll get first flight in the morning.

bob branch
 

[Dennis Adamisin]

ANOTHER great job Bob.  Nicely done again, with lots of cool features like the magentic cowl frame and such.  Looks like ECL got bumped up another notch with this one!

[bob branch]

Thank you Dennis.

bob

[Rob Smith]

Looks good! Can't wait for the flight reports.

Rob

[bob branch]

First flight report:

I'll preface this by stating that the conditions were not very good. I as faced with a 15 to 18 mph wind over low trees that then crossed my club's rc field and then assended over a 100 ft tree line. Probably as turbulent a condition as I have ever flown in. My nice treeless field here on the island just a quarter mile from my house did not get mowed as scheduled this week and weed shoots rendered it non flyable this morning when we had nice conditions. I wanted to at least get the rpm worked out. But the weather provided good and bad. The bad is obvious. Turbulence made it not a precise test. The good was how very good it was. This as you would expect from Randy is one very capable airplane. He mentioned the tail moment is longer the the original. Had it not been for the wings being buffeted laterally up and down as the plane flew I would not have known it was turbulent. It tracks like it is on rails. Even in these conditions perfectly level flight was absolutely no problem at all. Zero! Balance wise I am pretty close as when engine quite glide was dead level. Takeoffs were beautiful, landings effortless even in the turbulence.

Flying on 63 foot (eye to eye) .018 lines with an apc 12X6EP prop the 4S (rhino 3700 mah, phoenix 45 system required 8800 rpm (tached) to get 5.3 sec laps. In any kind of normal wind this will be 5.2 or 5.1 sec. I really cannot begin relate the choppiness of the air accurately. My guess is the plane will wind up at 8600 rpm the same as all Rick Sawicki's (my flying partner)  and my planes in this size and weight that fly the same power system except the T-Rex which I am still flying at about 9000 rpm (primarily a fuse drag issue there and I'm working at trim changes to decrease it.) Line tension was very good. The wings flew level off the board rightside up and inverted as best as I could tell in the turbulence so I do not think there are any major inaccuracies in the wing's construction. I did some round inside loops, inside squares and inverted flight in the 3 two minute flights it took for me to get the rpm set. The rounds were very predictable. The squares were very interesting. They were very precise, and each corner exited dead flat with no wobble whatsoever despite the turbulence. The corners were crisp and there was no detectable sag in the maneuvers.  This is a very capable airplane and is easily handled by the power system I have utilized. Of course I knew that would be the case because between Rick Sawicki's Trigear, and Legacy and my T-Rex the power system has pretty well been proven out in this size airplane. Oh, there was zero windup in the maneuvers I performed, dispite the wind. This has also been what Rick has found n the Trigear and Legacy and my T-Rex with this system as well. 

Once I got the motor rpm set I decided to call it a night rather than risk anything more in the unpredictable winds. The multiple tree lines is the reason I rarely fly CL at my club's RC field. The Club is chagrined cause they would love to have a CL circle there. But the tree lines just make it futile. Too bad. Nice to see another RC club that wants to enjoy the hobby with Cl fliers. Rick's Midwest RC Club is another, they have a really nice circle and keep it trimmed to CL nervanna length for us.

Well, that's about all I have to say on the subject. I'll start serious trimming on it during the fall. It will be interesting to see which I wind up liking better the T-Rex or the SV-11. Both are extremely capable and I have so much trim flights on the T-Rex any comparison right now really is not worth anything. Both are certainly capable of winning at the level I fly (Advanced) and in experts hands most likely in that class as well.  If you build one I think you will enjoy it. I look for planes that I can practice with and allow me to get better rather than spend all my time fighting the airplane and solving problems. Looks like this is a good one for that.

bob branch

[Rudy Taube]

Hi Bob,

Thank you for another great build thread and flight report. I'm very glad it flew so well. Mine is still in the assembly stage, but it is nice to know what a great flying plane I have to look forward to. I have always admired Randy's designs.

I must have missed which motor you are using, is it the AXI 2610? I thought you once said that you had gone back to using 5S batteries in these size planes? Have you now gone back to 4S?

One more ? ....  Do you think there is enough ground clearance for a 13" prop on a medium rough ball field? Or will I need to make a longer LG?

As usual, you are an inspiration to all of us. 

[Dennis Adamisin]

Ya know after Bob built his ill-fated Olympic, he said he was going to lay back on the building till the winter.  Since the Oly he's built an Oriental, rebuilt the T-Rex, built a UHP Nobler, a profile P-40, and then snuck in the SV-11.  This on top of his RC-3D & combat jobs, and of course (since he lives on the island) refurbishing his sailboat.

Slacker!

[bob branch]

Rudy

My power system is the Axi 2826/12 on 4S. Yes I had gone to 5S and did so to try to get 3000 mah packs to work. But they did not retain enough volts at the end of the flight to sustain lap times, so not enough capacity. When I go to the 3700 mah 4s packs I do not have the problem and the weight is the same as the 5S 3000 mah packs. This was the cause of the failure of the 3000 mah turnigy packs I reported earlier in the season.  In my hands the apc 12X6EP seems to be the best prop in this size plane for me so I do not need 5S if I fly the 3700 mah packs. Its a system Rick Sawicki developed and I have been using for about 4 years now and has proven itself and it allows the motor to operate in an rpm range that allows it to prevent wind up without going to lower pitch props (which need more cells, higher kv, more amps, etc). Its a system that has worked for us. As we are all seeing, there are lots of ways to make this work. You just need to find what does well in your hands and gives you the consistency you want and then stay as close to it as you can. Sometimes little variations (like going to 3000 mah packs to save some weight in my case) can cause a plethora of issues. Your mileage may differ of course. But I think we are starting to see what we have learned in glow. There are lots of ways to get the job done. Some prefer a PA on a pipe, some a Ro-jett on a pipe, some a Super Tigre and no pipe... they will all do the job if the principals to their use are applied properly and you get to know the system. Look a the guy who won the World's this year with a ST .60! We are learning the principals that should be applied in electric more and more. The better we apply them the more consistent and reliable our results can become.

As to ground clearance Rudy, I fly with 3 inch wheels as my field is rough grass (well never pavement). The plane sits with about 1 1/2 inches of ground clearance with the stock gear, a 1/4 inch larger than stock tail wheel, and the 3 inch wheels. On the T-Rex I did bend longer. Will not need to for this one but I will not be flying a 13 inch prop. Think I would start to consider it. BUT there is no tendance for the plane to nose over with the stock gear so that helps too. Having recently fried an ICE 50 on a prop strike, I know from whence you come. Set that cutout sensitivity setting to the most sensitive setting gang!

bob branch

[bob branch]

Dennis

Just goes to show what you can do if you are not retired! I look at my retired friends.... man if I had to keep up with them I'd be in a box in a week! At least while I'm working I still get a few days a week off!  Besides, Rick has told me I do not posses the skill set to be retired. So guess I'll keep doing it as long as I am gifted with the physical abilities to keep treating folks. 

bob

[RandySmith]

First flight report:

I'll preface this by stating that the conditions were not very good. I as faced with a 15 to 18 mph wind over low trees that then crossed my club's rc field and then assended over a 100 ft tree line. Probably as turbulent a condition as I have ever flown in. My nice treeless field here on the island just a quarter mile from my house did not get mowed as scheduled this week and weed shoots rendered it non flyable this morning when we had nice conditions. I wanted to at least get the rpm worked out. But the weather provided good and bad. The bad is obvious. Turbulence made it not a precise test. The good was how very good it was. This as you would expect from Randy is one very capable airplane. He mentioned the tail moment is longer the the original. Had it not been for the wings being buffeted laterally up and down as the plane flew I would not have known it was turbulent. It tracks like it is on rails. Even in these conditions perfectly level flight was absolutely no problem at all. Zero! Balance wise I am pretty close as when engine quite glide was dead level. Takeoffs were beautiful, landings effortless even in the turbulence.

Flying on 63 foot (eye to eye) .018 lines with an apc 12X6EP prop the 4S (rhino 3700 mah, phoenix 45 system required 8800 rpm (tached) to get 5.3 sec laps. In any kind of normal wind this will be 5.2 or 5.1 sec. I really cannot begin relate the choppiness of the air accurately. My guess is the plane will wind up at 8600 rpm the same as all Rick Sawicki's (my flying partner)  and my planes in this size and weight that fly the same power system except the T-Rex which I am still flying at about 9000 rpm (primarily a fuse drag issue there and I'm working at trim changes to decrease it.) Line tension was very good. The wings flew level off the board rightside up and inverted as best as I could tell in the turbulence so I do not think there are any major inaccuracies in the wing's construction. I did some round inside loops, inside squares and inverted flight in the 3 two minute flights it took for me to get the rpm set. The rounds were very predictable. The squares were very interesting. They were very precise, and each corner exited dead flat with no wobble whatsoever despite the turbulence. The corners were crisp and there was no detectable sag in the maneuvers.  This is a very capable airplane and is easily handled by the power system I have utilized. Of course I knew that would be the case because between Rick Sawicki's Trigear, and Legacy and my T-Rex the power system has pretty well been proven out in this size airplane. Oh, there was zero windup in the maneuvers I performed, dispite the wind. This has also been what Rick has found n the Trigear and Legacy and my T-Rex with this system as well. 

Once I got the motor rpm set I decided to call it a night rather than risk anything more in the unpredictable winds. The multiple tree lines is the reason I rarely fly CL at my club's RC field. The Club is chagrined cause they would love to have a CL circle there. But the tree lines just make it futile. Too bad. Nice to see another RC club that wants to enjoy the hobby with Cl fliers. Rick's Midwest RC Club is another, they have a really nice circle and keep it trimmed to CL nervanna length for us.

Well, that's about all I have to say on the subject. I'll start serious trimming on it during the fall. It will be interesting to see which I wind up liking better the T-Rex or the SV-11. Both are extremely capable and I have so much trim flights on the T-Rex any comparison right now really is not worth anything. Both are certainly capable of winning at the level I fly (Advanced) and in experts hands most likely in that class as well.  If you build one I think you will enjoy it. I look for planes that I can practice with and allow me to get better rather than spend all my time fighting the airplane and solving problems. Looks like this is a good one for that.

bob branch

Hi Bob

Looks like you did a fantastic job and the Retro...fit, And looks like you have a winner there, I will look forward to seeing the upcoming post on how the SV and you are doing.  I am sure people are very glad to have people like you share the info on setting up planes like this
Regards
Randy

[Frank Imbriaco]

Bob,

Following this closely and wondering if you have any updates.
I'm  ready to make a Xmas list of what I need to equip my  e- powered SV-11  ARF , so anything more said ; particularly about  the performance of your motor choice , battery, and prop would be appreciated.

Thanks

[bob branch]

Hi Frank

The power train has worked out very well just as expected. I am flying at 9000 rpm on the Arrowind motor with the APC 12X6EP on 63 ft lines. Lap times are 5.35 sec and draw from the Rhino 3700 4S pack is about 2300 mah per 5 min 30 sec flight. Line tension is excellent in all parts of the flight. I normally fly at 5.2 sec laps but to be real truthful, just have not found a reason to do so with this plane. It flies very well at that pace. Does everything the way you would expect any of Randy's planes to do. Just a mater of fine tuning the cg to what you like, but right out of the box it was pretty nice.  I have elected to keep this motor in it and keep the axi 2826/12 in my T-Rex just because they both work very well in each. I could exchange them and would set the rpms the same as the other.

 
bob branch

[Frank Imbriaco]

Thanks !

[bob branch]

Repower report:

I have repowered the sv-11 to cut some weight off the nose. I did not feel the plane was turning as I would like it and I felt there was too much line tension. My flying partners aggreed so I went to my normal power system for this size plane. The repower was to remove the arrowind motor and replace it with an axi 2826/12. Also the drop dead gorgeous brodak needle nose spinner got replaced with a light transpanrent black great planes electric spinner. Net result was to remove 3.5 ounces out of the nose with no other changes. Rpm is 9213 programed rpm on Wil Hubin's programing box. This was the same rpm that final testing in reasonable air was resulting in a 5.65 sec lap. Prop remains apc 12X6EP on 63 ft lines. The lap time dropped to 5.35 seconds with leadouts the same location. Line tension is very nice now,  firm but not overpowering my wrist as before. Corners are hugely better. The plane still tracks well but is not yawed out as much (yaw angle is about 1/8th inch at the gear when viewed from center circle. Could not ask for a better flying plane now. I have not recharged yet to determine battery draw but the axi draws less than the arrowind. I feel this is a much better setup for the plane.

bob branch

[Vincent Judd]

I've used this build thread countless times in putting my SV-11 together.  Thanks for all the great tips.  I should have photos sometime soon.

[bob branch]

Vince
Glad you found it helpful. Wish I could take credit for originality of it but I just copied the things that have worked for those around me who have been flying electric for so long. Especial thanks to Rick Sawicki. His pioneering work in electric has gone on for many years in both RC and CL. He even let me fly some of his really old rc electrics so I could see how far electric has come. Answer? F A R!!!

bob branch

[Dennis Adamisin]

I have seen Bob's SV-11 several times and hereby pronounce it IS the real deal.  Bob did a great job with the install & build and since then has spent a lot of time tweaking & trimming and pulling out all the performance the SV has to give.  It is a formidable package.

As one of the PIONEERS in CLPA and ECL, Rick Sawicki has not received the recognition he has earned.  Time to fix that...

[Paul Eisner]

I would also like to thank and BOb and can also attest to using his excellent write up and pictures during the building of my SV11 here in the UK last Winter. This is my first electric powered CL model which I have now had over 40 flights from. I fly on 66ft staystrate 0.4mm diam wire - 5.3/5.4 secs per lap, 3700mah - 4 cell 20c battery and 12x6 old style APC E pusher prop. I use the ICE lite 50 amp ESC and Will Hubin timer and field box interface. the motor is an Axi  clone sold by 4max here in the UK.
Having also flown IC powered F2B models I cannot understand why electric is not the fiirst choice of everyone who is serious about this event.

Thanks again Bob.

Paul.

[bob branch]

Paul

Keep those volts flowin over on that side of the pond and thank you for the compliments. Just as a note to others, I have done several of these on these forums and others and find that it is very helpful to me during the builds. Whether a scratch plane or an arc or arf it helps me organize my thoughts and if I find I have done something half a** it forces me to correct it rather than put up and adapt to it since others will be looking at it for who knows how long. But you also have to be humble enough to admit to changes that are required as you go down the line and come back and add them as I did on both this one with the power system and the T-Rex with the power system and structural changes later on. Again, its a help to me because it forces me to organize my thoughts and my plan for the changes.

bob branch

[John Hammonds]

Hi Paul,
 Pictures?? You know we crave pictures. 

Will you (Have you) be flying the SV11 at any comps this year? It's been a very lonely existence flying electric for the last few years over here in the UK.  I was beginning to think I will never see any others.

I plan on trying to make Slip End this weekend for the Chiltern Cup dependent on the weather.

TTFN
John.

[James Mills]

Bob,

Sent you a pm.

Thanks,

James

[bob branch]

John

Sorry I missed your post earlier. I have not flown this year. My wife was ill in the late spring with what we thought was a drug resistant pneumonia. After several hospitalizaitons we found it was a very aggressive lymphoma cancer. Actually, that is a good thing because the more aggressive and rapidly growing a lymphoma is the more suseptable it is to treatment by chemotherapy. She is in chemo now so I have not flown this year and the year will be over by the time the treatments are done. She is haveing a couple of units of blood transfused as I write this right now. I competed with it last year once and took a 3rd in advanced stunt in a hurricane of wind. Plane flew well. Did not get a first because I was pulled out of my stance by the plane in the 3rd corner of the hour glass. Rick Sawicki took 2nd with his electric Legacy, also a wonderful flier. We both used the same axi 2826/12 4S power system.

bob branch

[John Cralley]

Wow Bob,

I'm really sorry to learn about your wife. This Summer has had to be terribly hard for both of you. I'm sure that your friends on Stunt Hanger are going to join me in praying for a full recovery for her and some quality flight time for you in the future.

[bob branch]

Thank you John.

bob

[john e. holliday]

As always Bob, family comes first before model planes.   Hope she gets well and both of you get out to fly.

[bob branch]

Thank you John.

bob