T-jetracer59

This is my first attempt at a build thread, so hope I can figure it all out. I will be building a GreatPlanes RV-4 as an Electric 46. With flaps. It will be a stock build, except for making it electric. The kit was purchased from Tower Hobby, they had free shiping on this plane. It arrived well packed with no damage, the kit was packed well also, the quality of the kit was pretty good for a GreatPlanes kit.

T-jetracer59

I am building the plane on a2' X 4' acustic celing tile, using wax paper to protect the plans. I will be using Mercury Adhesives (CA) Thin, Medium and Thick viscositys, which I bought from RCfoam, which recently moved here to Colorado springs, about 7 miles from my house, they have a real nice warehouse. For sheeting I will use Titebond wood glue, a little old fasion, but I like to use it on sheeting specialy when it is dampend. The stab and elevator halfs went together smoothly, I built them as one piece not as seperate pieces as per instructions, then cut them apart when done, I find this makes things lineup better when putting it all together again. Thin CA was used on all of it. I have sanded all edges except where the hinges go, I am setting that asside for later, to do all hinges at the same time

T-jetracer59

The fin and rudder went together smoothly, made no deviations to the instructions. Used thin CA for all of it, like the stab & elevator have it all sanded now except where hinges go, saving for later.

T-jetracer59

Sorry about this, I had more pictures of the wing being built, but I messed up and deleted the pics, so will try my best with limited pics. I cut the wingtips out, leaving about 1/4" extra rather than cutting right on the line. Then I lined up W-5 rib where I wanted it, used a clamp on the trailing edge to hold it tight, and thin CA working it around keeping it tight as I went, then after it cured, I used Exacto knife to trim it flush with W-5, then light sanding to make it smooth and flush. I did this while the wing ribs where curing,

T-jetracer59

Building the ribs, spars and anything that had hard wood, I used thick CA.I soaked the 3/32" sheeting with a squirt bottle and used Titebond wood glue to get a good slow cure onall the sheeting, using pins and clamps to hold tight.I followed the instructions untill step 15, at that point I chose to do things out of order, that made more sence to me. I sheeted both top and bottom, then jumped to sheeting the outboard wingtip top and bottom, then bottom trailing edge, then the CA hinge blocks which needed a very slight bevel sanded top and bottom, making sure it fit properly use a straight edge to make sure it is correct. then the top trailing edge then the cap strips. It probably makes little difference, but it made more sence to build it in this order. Trimmed and sanded everything smooth.

T-jetracer59

when it came to the balsa block that fits between ribs W1 & W2 I did things different. I sanded the 1/8" bevel on the leading edge and sanded the side to fit nicely between the ribs as per plans, But then instead of trimming the WBS plywood plate, I used the makes as a refrence and glued WBS flush to the trailing edge of the block, then trimed it as per plans after it was glued to the balsa block, this made a very clean cut, I used my Exacto blade to trim away the 1/32" of plywood. Then I test fit it and marked where I needed to trim the block down to. Used a sharp knife to cut it down most of the way, then used a block sander to finish.

T-jetracer59

I chose to attach the ABS wingtips prior to covering, I felt it would make a cleaner final wing. I filled the joint with putty, sanded everything to a nice finish. I chose to build the flaps and ailerons seperatly, I sanded a slight bevel to the bottom of the sub leading edge to make a nice tight fit. I went ahead and installed the servo trays in the wings now, got everything sanded except the hinges, saving for later, have NOT joined wing halfs together yet. want to get started on the fuselage.

T-jetracer59

I went ahead and put the wheel pants together, I cut them out on the cut lines per plans, except I did cutout the opening for the wheel, I found it easyer to work with. I used medium CA and worked my way around until nice and tight. Then used putty to fill in seams. Sanded down smooth, ready for paint. This was made very easy, following the cut lines.

T-jetracer59

So far I have been working on this project for about 2 weeks now. I will try to keep current, as time permits, I prefer to build or fly,than spend time on the computer. The fuselage and Electric modifications are where things will get fun

T-jetracer59

I have the cowl cutout , glued, putty, sanded, ready for paint. I added 2 layers of reinforcement to the center of the cowl, made from left over ABS as plans suggested.

T-jetracer59

The fuselage is pretty straight forward, make sure to build a right and a left side I followed the instructions untill step 16. I chose NOT to preglue the Aft Fuselage Bottoms together, I wanted to wait to verify proper fit later. step 17 instalation of the wing saddle doublerwas also NOT done yet, again wanted to wait till later. The formers MUST be 90 deg. I have modified a cheap plastic triangle with the corner notched out to prevent it from being glued accidently and glued balsa square stock to the bottom so it sits on its own, this simple tool has been very helpfull in all my builds. I use colored plastic pins to hold things in place without putting holes in the wood whenever possible. After step 20 glueing the right and left sides together is done, now I added the wing saddle doubler in place to make sure it is exactly in the right place. also I had to do some sanding and reshaping of the aft fuselage bottom to get it to fit correctly

T-jetracer59

step 31 firewall.... This is where the fun starts, because of being electric not gas. I thought I had it figured out, and used the exact center of the engine mount holes as my center, drilled holes and installed my T nuts. Only to find out later that this was wrong. The highth was correct, but I needed to have moved everything to the left 3/8" to get the cowl to fit correctly. I forgot to take into account the 2 3/4" mount extentions. I did not want to take it apart at this point so I made a secondary mounting plate to correct the offset.

T-jetracer59

I needed tomove themotor mountabout 2 3/4" forward to get the correct motor placement. I used 1/2" dia. nylon bushings purchased at local Ace hardware. longest length was 1", so I used 30 min, epoxy to glue 2 together to make it 2". and 1/2" length between the firewall and extention plate I made, I used 8/32 (#8) screws. 2.5" and 1" long.

T-jetracer59

Because I made the battery access hatch between formers 2A & 3A I had to reinforce 2A with plywood, because it will stand alone now, also drilled some 1/4" air flow holes to aid in getting air to the Lipo.

T-jetracer59

I moved former 3A aft 1" to give me enough room for Lipo. I traced 3A & 2A formers to make formers for access hatch. I am using 1/4" Rare earth magnets to keep the hatch in place. I will be sliding the hatch to the left to remove it, rather than convetional straigh up. The magnets are very strong, it is easier to remove hatch this way, I think there will not be a problem of the hatch falling out. Time will tell on that one. I built the hatch in place to assure propper alignment, using wax paper inbetween to keep from sticking to plane. I added 1/8" plywood on the hatch sides to hold the magnets.

T-jetracer59

Time to sheet. I like to prefit everything, making sure it will fit correctly before I glue anything. On the fuselage I use thin CA. I glue one edge of the sheet first, let it cure, then get it wet with a water spray bottle, I get both sides wet, and alow time for the water to soak in all the way, about 5 min. then slowly form the sheet untill it is the shape I want, don't force it or it with crack, if it does not bent easily, soak it a little longer. I used #64 rubberbands to aid in this proccess.

T-jetracer59

The cockpit went smooth, except I completed the mid pannel before sheeting, so I could sand it all easier. I got my pilot from Hobbypartz.com. I cut out the clear canopy and test fit it, to find the right location for the pilot figure, then put the mid section where it looked best. The pilot is not glued yet, just there for the photo.

T-jetracer59

Finaly got to work on the plane some more, I glued the wing halfs together with 30 min. epoxy, not the 6 min. as the plans called for. Personel preferance, I like 30 min. epoxy anywhere there will be a lot of stress. I use clamps with a small bit of plywood to protect my leading edge to help hold everything in place, the 30 min. epoxy gives you plenty of time to get it exactly correct. I sheeted the center section and drilled 3/8" holes instead of 1/2" holes, there is plenty of room to get my (Y) connectors through.

T-jetracer59

Time tomount the wing to the fuselage. I secured a T pin to the rear of the fuselage at the center of the fuselage, using packing tape and 4 other smaller T pins to keep it in place. I use a string looped around the T pin to get the wing as close as I can, then confirm the alignment with a yard stick measurment. I found I had to use a 5/32" drill not the 9/64" wich was to small to get the 1/4-20tap started. I used a 1/4" drill not the 17/64" because I did not have one,didnot cause any problems. I used thin CA to harden the threads as per instructions, also used thin CA to harden all the holes I drilled in the wing, helps prevent cracking. I am using my GreatPlanes slot machine for the first time, it works very well. makes the CA hinges a lot easier to install. Got the flaps and ailrons installed all looks good.

T-jetracer59

I coverd the bottom of the wing with jet white monocote, using one piece to cover each half of the wing and the top and bottom of both the flap and the aileron. I like to run the monocote in one piece around the movable surfaces on the wing to get a nicer looking joint and improve the aerodynamics of the wing, fewer open places on the wing makes for better airfoil. I added the 4 servos, 3 Hitec HS-311 standard servos and 1 Futaba S-148, because the futaba operates opposite the hitec, and that allows me to be able to use a Y connection for the flap servos and have them work correctly. I just had to find the correct controll arms to use on each so they would have the same throw. I had to add 1/4 ounce of weight to the right wing to get proper wing balance. I glued it to the wing cord as far out as possible to keep the weight in front of the CG and outboard as possible. I used a 24"Y for the ailerons and a 12" Y for the flaps. I shrunk some 5/8" shink tube over the 4 connections that will be hidden idside the wing.

T-jetracer59

Sorry about so much time gone by, I moved out of state, but good news I have finished and flown the RV-4. it is a beautiful flying model with no bad traits. now for the details. The fuselage with the fin and stab attached ready for monocote. I made a light balsa plate to go behind the wing with 6 holes in it for air flow, very important for electrics to keep cool. Also made more holes up front for air to enter the fuselage. I found that the model was extreemly nose heavy so I removed a 1" spacer on the motor, and moved all my electronics to the rear of the fuselage bay. I used an Exceed 60 Amp ESC OPTO and a 3 Amp UBEC. I used a ZIPPY 5 cell, 3000mah. 20 C Lipo. positioned the Lipo to get the balance correct as per instructions, 95mm from leading edge. The slideing battery acces hatch worked out great. The Monster Exceed 46 turning a 12 x 6 APC prop is produceing 800 Watts @42 Amps. The flying weight of the plane is 6.9 LBS. all control surface throws where set per instructions.

T-jetracer59

For the maiden, I took of from a grass soccer field, gave it full throttle and she was in the air in 30 feet. the power is not lacking. only took a few clicks of down trim and was flying true at 1/2 throtle. I used high rates for everything, found it quite docile. loops are easy and smooth, the roll rate is good for a sport plane, inverted flight did require a bit of down elevater but nothing out of the ordinary. I tested the flaps at altitude and they are very effective, but have not tried them for landing yet. it floats very well on landing, with a 5 MPH head wind it settled in nice and easy.
My first 6 flights where textbook, I was getting 8 minutes of flying time with throttle management. on the 7th flight about 4 minutes in I gave it full throtle and heard a noise and the motor shut off, I thought I spun a prop. so I started to land. Then I saw a trail of smoke comeing out of the plane, so I landed ASAP and ran to the plane, It was on fire. I slid the battery acces hatch out and saw that the ESC was burning, I yanked the battery out and started to blow the flames. Fortuneatly only lost the ESC and some smoke damage and lite charing on the battery holder. So I won"t be useing any more Exceed ESC's, This is the second plane I had problems with useing Exceed ESC's, I am waiting for another 60 Amp ESC and a 5Amp UBEC from Heads Up RC, I have had great luck with their products. But all things concidered, the electric conversion was a great succes, and would recomend it to everyone. I should have it in the air again by the weekend if Heads Up RC order arives in time.

blvdbuzzard

Does the ESC get a lot of air for cooling? I have the same ESC running a Monster power 60 on 6s and knock on wood, I have not had a problem

This is a nice build. Planes very good.


Buzz.

T-jetracer59

I think there is enough air flow, but Where I had the ESC it might have been out of the air flow, because the battery was located abouve it. Now I have the new ESC mounted inside the cowl directly in front of the 4 large holes I made for air flow. I originaly planned on putting it here, but when the plane was nose heavy I moved everything back some. In hind sight I should probably have left the ESC where it is now. I will take my thermal senser with me this weekend and check the ESC temp after each flight, but I think this should do the trick. Yes I have been useing Exceed products for a while and think that this latest problem probably was either a fluke or was not getting enough air. It was pretty cool seing the smoke trail as I landed, now that I have checked it all out and only lost the ESC and UBEC.

blvdbuzzard

I have a 60 sized low wing plane, it looks like a Golberg Sky Tiger. I made a cradle to mount glider. I use it as a glider tug. I had my brother in law 2 meter glider mounted and ready to. We get it to launch altitude and let it go. It starts to balloon, he over corrects back and forth. I land, take his radio and try to fly it. Well it locks up and goes into a very slow spin. It is 200 feet up and we see it leaving a smoke trail. We could not figure it out. Well he used BB's to balance his plane and one had found its way onto the open slot of the Rx and shorted the battery out. The switch, battery melted and that is what caused the smoke trail It looked COOL, but we knew it was not a good thing!!

Glad the burned out ESC did not damage your plane.

Plane does look very good.



Buzz.