4*120 Build Thread
12-05-2015, 06:24 AM
#902
Hopefully they will help.
Here are a couple more. First is my elevator servo setup, the second are the golden rod for the throttle and choke. I drilled under the tank floor so its looking from the bottom up. The hatch is under the nose.
Here are a couple more. First is my elevator servo setup, the second are the golden rod for the throttle and choke. I drilled under the tank floor so its looking from the bottom up. The hatch is under the nose.
12-05-2015, 06:30 AM
#903
I was looking at this picture and forgot that I had reused parts from the ARF that this one replaced. The fiberglass tube and servo tray came from the ARF. I think it is in a different location that what the plans called for as well to make room for the tank.
12-14-2015, 04:34 PM
#904
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I finally got back to my Four Star build after over a week of no work. My wife has wanted me to make this fish for her so she could hang it on the kitchen wall, and she wanted it before Christmas. So the squeaky wheel got the grease.
I came up with a way to do the fuel tank hatch that I think came out fairly well. I'm attaching some photos.
Lamar
I came up with a way to do the fuel tank hatch that I think came out fairly well. I'm attaching some photos.
Lamar
12-16-2015, 01:43 PM
#906
When I'm happy the wife is happy.
not kidding either.
Now I have more planes than room to store them.
Thinking may not have been that great an idea after all. Then again, they are easier to store than a bunch of car parts from a disassembled Thunderbird. Easier on the back too.
not kidding either.
Now I have more planes than room to store them.
Thinking may not have been that great an idea after all. Then again, they are easier to store than a bunch of car parts from a disassembled Thunderbird. Easier on the back too.
12-17-2015, 06:34 AM
#907
Storage is my biggest problem and the root cause of all the new winter projects I now have. I store on a removable rack mounted to the ceiling of the garage made of schedule 40 PVC. My son came over and was helping me move a large table and we bumped the rack. Next thing you know I have 5 airplanes and 2 unfinished crashing to the floor! A glue joint popped and down they came. Rack is repaired and the wings have been moved to separate storage mounted under a catch all shelf over the work bench to lighten the load.
12-28-2015, 11:17 AM
#908
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Not too much left to do on the fuselage before covering. I have some duel switches and fuel dot on order that I will need to mount. Also the tail wheel bracket. I'm using a Sullivan, instead of the kit supplied. I'm not fond of mounting the tail wheel per the kit. I've used the Sullivan mount on several planes, and have been pleased. Just finished up my rear fairing. I'm not mounting my servos in perminant place until the plane is covered, so that I can be able to shift for balancing.
The next part I need to work on is attaching the ailerons. This is where I have a couple questions & would like some opinions. One aileron is warped length ways too bad so I won't be using it. I have the balsa stock for a new one, so it will be easy to make a new one. I'm using Robart hinges, and once the hinges are installed, I always use my router table with a 45 deg bit to put the front bevel on. I was considerating then tapering the ailerons from front to back, instead of just rounding the trailing edge as per plan. Is there any reason why I shouldn't do this? I don't consider this to be hard to do. I think the appearance would be better, plus making the ailerons a little lighter, although probably not much. Also, has anyone drilled holes in the ailerons for lightening them. They only weigh about 2 1/2 oz apiece now.
Lamar
The next part I need to work on is attaching the ailerons. This is where I have a couple questions & would like some opinions. One aileron is warped length ways too bad so I won't be using it. I have the balsa stock for a new one, so it will be easy to make a new one. I'm using Robart hinges, and once the hinges are installed, I always use my router table with a 45 deg bit to put the front bevel on. I was considerating then tapering the ailerons from front to back, instead of just rounding the trailing edge as per plan. Is there any reason why I shouldn't do this? I don't consider this to be hard to do. I think the appearance would be better, plus making the ailerons a little lighter, although probably not much. Also, has anyone drilled holes in the ailerons for lightening them. They only weigh about 2 1/2 oz apiece now.
Lamar
01-02-2016, 08:22 AM
#915
Just for the heck of it I went down and took a look at mine, and did not realize it, but they are tapered on both the kit built and the ARF that I have. So did I miss something, or are you replacing the kit ailerons as they should already have a taper?
If this one flies anything like mine, you are going to want as much drag on that huge wing as possible, as these things are floaters. Landing them on a short runway is a real bugger. I went so far as to put flaperons on it using an eight channel RX. It helped a little, but may switch it up to spoilerons. Switching out the prop to increase drag at idle only helped somewhat, but the reduction in overall performance was not worth it. I love low level, high speed passes with the 4*, those tail wires sing as it goes by. Then at the end of the funway*, snap the nose up to a 45* climb, kill the throttle, then snap the tail around, slam the throttle to the firewall and do it again in the other direction.
If I were to build another one, it would have to be much lighter, and all that weight in mine is in the fuse, lightening the ailerons would have very little reduction, The most mass in my wings are the tips, which are solid balsa blocks that I hand shaped into rounded tips. I would add lightening holes to the ribs though, that might help a little. The rounded tips are wing savers, for when the tips touches the runway, there is little chance of it catching and cartwheeling when landing wrong, or if a cross wind happens at the wrong moment. Saved the plane several times, don't know why, but we get a lot of southerly winds during the summer, and both places I fly are east-west runways.
When I build a plane, except for this last one, the Citabria, I weigh each rib, spar, and longeron, then match up the parts of each wing so they balance as close to each other as possible. When I build the wing, I put the heaviest ribs towards the center, lightest at the tips. When it comes time for lateral balancing, I rarely need to add anything to the wings, my 4* was no exception, it balanced without any additional weight on the wings, just a chunk in the nose to offset the rear elevator servo. Moving the servo to the tail reduced pushrod deflection so I can get full travel at high speeds. I also overbuilt the center section to take up the stress of high speed maneuvers, such as snap rolls, and pulling up from a steep dive. I am considering putting a DLE 30 on it for even more power, as right now it has limited vertical with the DLE20, where my Cub has unlimited vertical, it can climb until it is a speck in the sky and still be climbing. My Cub is extremely overpowered, has a Saito 100 on it when it really only needs a .60 on it.
I would have to look at the plans, as I dont remember what they called for, but on mine, I took 1/8" aircraft plywood and made joiners that went in 3 ribs on each wing, made 3 of them one on each side of the main spar, and one at the rear spar, reason is, I had the ARF and the wing broke apart in flight, right at the second rib. It was a design malfunction that was the root cause, the wing was designed as a two piece with an aluminum spar joiner that slid into a box, the problem was the bx was not complete, the sides only touched the spars on the inside, they did not go all the way to the outside edges. This caused them to flex, eventually shearing the joints and snapping the spars at the end of the joiner. The kit does not build the wings this way as they are a one piece design, but taking what happened with the ARF into account I made darn sure it would never happen with the kit. I abuse my planes, making them do things, they weren't really designed to do, so I build extra strength into key parts that would fail. My LT-40 had I not built the wing as a bolt on would be a scrap heap by now, I fling it around like an aerobatic high performance plane, and it is still solid as a rock, only thing that has happened are the hinges are starting to fail, already had the rudder break off, and now the ailerons are starting to separate, so it is getting larger ailerons with pin hinges, also increasing the elevator a tad, don't really need to, but the one that came in the kit is not straight, it has a warp in it so there is a larger gap at the ends than in the middle where it joins the stab. With more aileron, I expect some more wicked snaps, along with a better roll rate, the stock elevator already snaps this plane into a tight loop, if I had smoke on it, the loops would look like those ribbons for breast cancer. The rudder is also very sharp, I can roll the plane with just the rudder, and in fact I had a couple instances where the ailerons stopped working, I didn't tuck the servo lead in and the throttle servo pulled it out of the RX, but I was able to fly the plane using just the rudder, and made it look as if I was using all three controls.
If this one flies anything like mine, you are going to want as much drag on that huge wing as possible, as these things are floaters. Landing them on a short runway is a real bugger. I went so far as to put flaperons on it using an eight channel RX. It helped a little, but may switch it up to spoilerons. Switching out the prop to increase drag at idle only helped somewhat, but the reduction in overall performance was not worth it. I love low level, high speed passes with the 4*, those tail wires sing as it goes by. Then at the end of the funway*, snap the nose up to a 45* climb, kill the throttle, then snap the tail around, slam the throttle to the firewall and do it again in the other direction.
If I were to build another one, it would have to be much lighter, and all that weight in mine is in the fuse, lightening the ailerons would have very little reduction, The most mass in my wings are the tips, which are solid balsa blocks that I hand shaped into rounded tips. I would add lightening holes to the ribs though, that might help a little. The rounded tips are wing savers, for when the tips touches the runway, there is little chance of it catching and cartwheeling when landing wrong, or if a cross wind happens at the wrong moment. Saved the plane several times, don't know why, but we get a lot of southerly winds during the summer, and both places I fly are east-west runways.
When I build a plane, except for this last one, the Citabria, I weigh each rib, spar, and longeron, then match up the parts of each wing so they balance as close to each other as possible. When I build the wing, I put the heaviest ribs towards the center, lightest at the tips. When it comes time for lateral balancing, I rarely need to add anything to the wings, my 4* was no exception, it balanced without any additional weight on the wings, just a chunk in the nose to offset the rear elevator servo. Moving the servo to the tail reduced pushrod deflection so I can get full travel at high speeds. I also overbuilt the center section to take up the stress of high speed maneuvers, such as snap rolls, and pulling up from a steep dive. I am considering putting a DLE 30 on it for even more power, as right now it has limited vertical with the DLE20, where my Cub has unlimited vertical, it can climb until it is a speck in the sky and still be climbing. My Cub is extremely overpowered, has a Saito 100 on it when it really only needs a .60 on it.
I would have to look at the plans, as I dont remember what they called for, but on mine, I took 1/8" aircraft plywood and made joiners that went in 3 ribs on each wing, made 3 of them one on each side of the main spar, and one at the rear spar, reason is, I had the ARF and the wing broke apart in flight, right at the second rib. It was a design malfunction that was the root cause, the wing was designed as a two piece with an aluminum spar joiner that slid into a box, the problem was the bx was not complete, the sides only touched the spars on the inside, they did not go all the way to the outside edges. This caused them to flex, eventually shearing the joints and snapping the spars at the end of the joiner. The kit does not build the wings this way as they are a one piece design, but taking what happened with the ARF into account I made darn sure it would never happen with the kit. I abuse my planes, making them do things, they weren't really designed to do, so I build extra strength into key parts that would fail. My LT-40 had I not built the wing as a bolt on would be a scrap heap by now, I fling it around like an aerobatic high performance plane, and it is still solid as a rock, only thing that has happened are the hinges are starting to fail, already had the rudder break off, and now the ailerons are starting to separate, so it is getting larger ailerons with pin hinges, also increasing the elevator a tad, don't really need to, but the one that came in the kit is not straight, it has a warp in it so there is a larger gap at the ends than in the middle where it joins the stab. With more aileron, I expect some more wicked snaps, along with a better roll rate, the stock elevator already snaps this plane into a tight loop, if I had smoke on it, the loops would look like those ribbons for breast cancer. The rudder is also very sharp, I can roll the plane with just the rudder, and in fact I had a couple instances where the ailerons stopped working, I didn't tuck the servo lead in and the throttle servo pulled it out of the RX, but I was able to fly the plane using just the rudder, and made it look as if I was using all three controls.
01-02-2016, 09:20 AM
#916
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[QUOTE=acdii;12154334]Just for the heck of it I went down and took a look at mine, and did not realize it, but they are tapered on both the kit built and the ARF that I have. So did I miss something, or are you replacing the kit ailerons as they should already have a taper?
The kit I have may be an older Four Star 120 kit. I bought it on ebay. The ailerons that came with the kit are preshaped 3/8" flat stock. The manual with this kit just instructs to round the trailing edge.
With rounded wing tips, my 4* total WS is 72", which I'm hoping will reduce the floating.
Lamar
The kit I have may be an older Four Star 120 kit. I bought it on ebay. The ailerons that came with the kit are preshaped 3/8" flat stock. The manual with this kit just instructs to round the trailing edge.
With rounded wing tips, my 4* total WS is 72", which I'm hoping will reduce the floating.
Lamar
01-21-2016, 09:37 AM
#918
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It's been awhile since my last post, so I figure it's time to get a little update on my progress.
My last post, I was asking about tapering my ailerons. After replies back, I said I would taper. Well that changed once I did my hinge installation. I fitted my ailerons with Robart hinges. I've used them in the past and have been quite pleased with their quality and ease of installing. Once they were installed, I realized that due to the length the hinge extended into the aileron, that tapering would cut into the drilled hole for the hinge. I proceeded to then do the 45 deg bevel on the front and round over the rear per plan instructions, except I don't sand as plans mentions. I have always used a router for the bevel and round over, since it is so much easier, fast and precice. I don't recall using a router being mentioned in build threads before, but I'll post some pictures of my proceedure.
By the way, I think the ailerons still looked fairly good, even without taper. I can still use the provided aileron positioning guide to set the ailerons for final neutral adjustment.
I am now starting the covering, which will be a slow process. I am using Sig Koverall, MinWax polycrylic for attaching and filling weave, then final painting with Rustoleum rattle can spray.
Lamar
My last post, I was asking about tapering my ailerons. After replies back, I said I would taper. Well that changed once I did my hinge installation. I fitted my ailerons with Robart hinges. I've used them in the past and have been quite pleased with their quality and ease of installing. Once they were installed, I realized that due to the length the hinge extended into the aileron, that tapering would cut into the drilled hole for the hinge. I proceeded to then do the 45 deg bevel on the front and round over the rear per plan instructions, except I don't sand as plans mentions. I have always used a router for the bevel and round over, since it is so much easier, fast and precice. I don't recall using a router being mentioned in build threads before, but I'll post some pictures of my proceedure.
By the way, I think the ailerons still looked fairly good, even without taper. I can still use the provided aileron positioning guide to set the ailerons for final neutral adjustment.
I am now starting the covering, which will be a slow process. I am using Sig Koverall, MinWax polycrylic for attaching and filling weave, then final painting with Rustoleum rattle can spray.
Lamar
01-21-2016, 09:55 AM
#919
I think your ailerons look fantastic! I have been looking at the Dremel #231 Shaper/Router table and #692 Bit Set your ailerons may just make we pull the trigger on it. It would be handy to use for surface rounding and beveling. I already have the Drill stand and was surprised how often I use it. My plugging router would be a bit too much tool for balsa and I already have several Dremel tools I could leave mounted in it.
01-25-2016, 09:49 AM
#920
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I would like to get an opinion from others who have built and flown the Four Star 120, on weather I should install the tail brace wires or not. When I built the fin & stabilizer, I put in the 1/16" plywood pads per drawing, so they would be ready for the wires if needed. I am not eager to put them on if not really needed, since I don't want the extra tail weight. I'll be flying with a 20cc VVRC gas engine. The instruction manual makes this an option.
Lamar
Lamar
01-25-2016, 10:38 AM
#921
I would like to get an opinion from others who have built and flown the Four Star 120, on weather I should install the tail brace wires or not. When I built the fin & stabilizer, I put in the 1/16" plywood pads per drawing, so they would be ready for the wires if needed. I am not eager to put them on if not really needed, since I don't want the extra tail weight. I'll be flying with a 20cc VVRC gas engine. The instruction manual makes this an option.
Lamar
Lamar
That and I love the whistling sound they make at high speed.
02-05-2016, 10:46 AM
#922
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I've had mine framed up since about this time last year but it's just been sitting. I need to get it out and get her finished! All the hard work is done really, just need to buy another iron since mine took a dump and get to covering. Ahhh, I hate covering!!! Lol!
I really like the looks of the 4Star with the FS cowl.....I may have to get one of those at some point.
I really like the looks of the 4Star with the FS cowl.....I may have to get one of those at some point.
02-25-2016, 09:43 AM
#923
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It's time for me to do an update on my build progress, since it's been almost a month since my last post.
I have finally completed the covering, and final sealing of the Koverall with 3 coats of MinWax polycrylic thinned slightly with water and some baby powder added to help fill the weave. I did a final sanding with 320 grit paper. I had a couple set backs from the sanding. While trying to be as carefull as I could, I still cut clear through the Koverall in a couple places along rib edges while sanding. They were fairly simple fixes though, by just adding a patch of Koverall over the cut then a couple coats of Minwax on top, then carefully sanding.
I've been keeping track of the weight of the plane components as I progress, so I can see what adds a lot of weight to the build. Here is what I have so far.
Total weight of all combined components. (Tail feathers, main wing, ailerons, body) prior to covering. 74.5 ounces.
After covering and sealing with Minwax. 85.9 ounces
That's an increase of 11.4 ounces. I am just starting to paint now. I'll be using Rustoleum on the entire plane. I will post the added weight results when finished. It may take me a while to get to that point, since I am not very fast.
Would be interested to know anyone elses results on weight change of their build during their build process if they kept track.
Lamar
I have finally completed the covering, and final sealing of the Koverall with 3 coats of MinWax polycrylic thinned slightly with water and some baby powder added to help fill the weave. I did a final sanding with 320 grit paper. I had a couple set backs from the sanding. While trying to be as carefull as I could, I still cut clear through the Koverall in a couple places along rib edges while sanding. They were fairly simple fixes though, by just adding a patch of Koverall over the cut then a couple coats of Minwax on top, then carefully sanding.
I've been keeping track of the weight of the plane components as I progress, so I can see what adds a lot of weight to the build. Here is what I have so far.
Total weight of all combined components. (Tail feathers, main wing, ailerons, body) prior to covering. 74.5 ounces.
After covering and sealing with Minwax. 85.9 ounces
That's an increase of 11.4 ounces. I am just starting to paint now. I'll be using Rustoleum on the entire plane. I will post the added weight results when finished. It may take me a while to get to that point, since I am not very fast.
Would be interested to know anyone elses results on weight change of their build during their build process if they kept track.
Lamar
03-15-2016, 10:25 AM
#924
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Well, mine is now to the ARF stage. Finished covering it a couple weeks ago but set It back aside again while I finish another project. Ordered a pair of wheel pants to go along with it. IMO, this plane looks 1,000 x better with them than without!!!!