I will be buidling this plane this week and posting as I go. Will include detailed pictures as work progresses.
First impressions of the F-18 pro design ARF are very good. Fiberglass work is nice and relatively light. Hardware supplied is of good quality and design.
The design of the plane is excellent which you will see as I post more pictures. Intake ducting is already there. Exhaust ducting come with it too. It is bi-furbicated and I am not sure if this will produce less thrust than a single exhaust but I plan on building it stock, take readings, fly it and then psoobily modify it for a single exhaust. If it flys well I might just leave it be. We will see.
All the formers are installed with exception of the taileron bulkheads which need to be assembled and installed. The formers are all well glued into the plane and are well designed. The plane comes setup for retracts but includes some additional wood pieces that can be screwed in so you can used the supplied fixed landing gear and still easily add the retracts later - Purely Brilliant!
Ok, enough of the nice talk lets build this bird.
First thing to assemble is the taileron bulkheads. You get all the pcs reuired to build them. First thing I did was to add some 100% silicone grease to the bearing sides to keep CA out of them when I install them in the black block. Used a small amount of thin CA with toothpick on the bearing block. This will keep you from loosing the tiny bearings as you do your assembly. I am now waiting on the epoxy to dry to finish the talerion bulkhead.
First impressions of the F-18 pro design ARF are very good. Fiberglass work is nice and relatively light. Hardware supplied is of good quality and design.
The design of the plane is excellent which you will see as I post more pictures. Intake ducting is already there. Exhaust ducting come with it too. It is bi-furbicated and I am not sure if this will produce less thrust than a single exhaust but I plan on building it stock, take readings, fly it and then psoobily modify it for a single exhaust. If it flys well I might just leave it be. We will see.
All the formers are installed with exception of the taileron bulkheads which need to be assembled and installed. The formers are all well glued into the plane and are well designed. The plane comes setup for retracts but includes some additional wood pieces that can be screwed in so you can used the supplied fixed landing gear and still easily add the retracts later - Purely Brilliant!
Ok, enough of the nice talk lets build this bird.
First thing to assemble is the taileron bulkheads. You get all the pcs reuired to build them. First thing I did was to add some 100% silicone grease to the bearing sides to keep CA out of them when I install them in the black block. Used a small amount of thin CA with toothpick on the bearing block. This will keep you from loosing the tiny bearings as you do your assembly. I am now waiting on the epoxy to dry to finish the talerion bulkhead.
Attached Thumbnails
Taileron parts26.7 KB · Views: 323
Start assembly of taileron blocks48.7 KB · Views: 260
While I am waiting for the epoxy to dry started to take a look at the wings.
They are short because a large portion of the wings are molded into the fuse. I plan on using HS81 servos as shown in the picture below. Instructions call for smaller 9gram servo but I am not comfortable with that since my setup will use the ailerons as flaps in addition to ailerons. So HS 81 it is.
Instruction say to glue to inside of pocket but i think I will add some blocks and screw them in. This is a 90mm size jet and desrves a little better.
They are short because a large portion of the wings are molded into the fuse. I plan on using HS81 servos as shown in the picture below. Instructions call for smaller 9gram servo but I am not comfortable with that since my setup will use the ailerons as flaps in addition to ailerons. So HS 81 it is.
Instruction say to glue to inside of pocket but i think I will add some blocks and screw them in. This is a 90mm size jet and desrves a little better.
Decided to go with some small bass wood block which will accept a piece of ply screwd down to lock the servo in place. Will then use some grey monokote squares to cover.
Added the last wood piece to the taileron bulkheads and waiting for epoxy to dry. Using 30 minute epoxy on everything.
Will start preping wings butt joint to fuse surfaces for epoxy tonight.
Matt
Added the last wood piece to the taileron bulkheads and waiting for epoxy to dry. Using 30 minute epoxy on everything.
Will start preping wings butt joint to fuse surfaces for epoxy tonight.
Matt
Well this is not going to be much of build thread and you guys arent going to get to participate much. Why? I am about 30% complete with the plane.
The tailerons bulkheads are complete. Make sure you build mirror images of the taileron bulkheads. I will let the bulkheads dry over night before I start putting them in the fuse. The taileron servo cutout is just the right size for a 9gram servo but too small for the HS 85BB's I am going to use. You can just see the outline where I have to open them up a bit.
You have to drill a large hole thru the fuse to line up with the servo thru hole in the wing. I sanded all the paint off the fuse wing joint. Sanded the wing rib that attaches to the fuse.
Wings were just epoxed on (not shown). So I am going to let everything sit until tomorrow.
The tailerons bulkheads are complete. Make sure you build mirror images of the taileron bulkheads. I will let the bulkheads dry over night before I start putting them in the fuse. The taileron servo cutout is just the right size for a 9gram servo but too small for the HS 85BB's I am going to use. You can just see the outline where I have to open them up a bit.
You have to drill a large hole thru the fuse to line up with the servo thru hole in the wing. I sanded all the paint off the fuse wing joint. Sanded the wing rib that attaches to the fuse.
Wings were just epoxed on (not shown). So I am going to let everything sit until tomorrow.
ere are misc pics for you huys to look at.
Each inlet is 2.75 in x 2.5in which gives a total area of 13.75 which is more than 100% FSA of Midi fan. So yes, there is will be some unnecessary drag caused by too large of intakes but I dont think it will be much. FSA for the Midi is about 8.2 sq inches if I calculated that right. Correct me if I am wrong.
Its hard to get a good picture of the inside of the ducting. I know what you are asking, but it is impossible for me to easily take the measurements to see if it has good "area rule" at different cross sections down the ducting. If I was to guess they did a pretty good job of creating a smooth "funnel" down to the fan. Could it be better? Probably but at what additional cost. I am not saying this to defend the designer just that I know in every design there are tradeoffs between, Perfection, Time, Effort and Price. I think they did a great job with the balance.
And Ed, I would expect yours to be better knowing you and your planes : ) My problem is I am a hack and ARF's are all I do.
Its hard to get a good picture of the inside of the ducting. I know what you are asking, but it is impossible for me to easily take the measurements to see if it has good "area rule" at different cross sections down the ducting. If I was to guess they did a pretty good job of creating a smooth "funnel" down to the fan. Could it be better? Probably but at what additional cost. I am not saying this to defend the designer just that I know in every design there are tradeoffs between, Perfection, Time, Effort and Price. I think they did a great job with the balance.
And Ed, I would expect yours to be better knowing you and your planes : ) My problem is I am a hack and ARF's are all I do.
Epoxied 1 of the taileron block/former into place. I am going to reinforce the areas circled in red with some addition wood stock and make two sets.
The way the taileron bulkead is now is pretty strong but I want to beef this area up a bit now that I see it installed.
Will complete more work tonight.
Matt
The way the taileron bulkead is now is pretty strong but I want to beef this area up a bit now that I see it installed.
Will complete more work tonight.
Matt
Received my new balalncer and what a difference in sensitivity. Fans that my old balancer showed balanced were not even close. I modified my new balancer to use the finger balancer as it was perfect size for fans. See pic
Add some triange stock and an additional back pc to the taileron bulkheads. The assemblies are sure to be up to the job now.
Matt
Add some triange stock and an additional back pc to the taileron bulkheads. The assemblies are sure to be up to the job now.
Matt
Waiting for all the epoxy to dry. It takes a long time in the winter. In the summer in AZ 30 minute epoxy is cured in 10 minutes. Now it seems like forever.
Added a plywood triangle to straigten out and stiffen up the cockpit. This will get a small latch in the back when installed.
Added a plywood triangle to straigten out and stiffen up the cockpit. This will get a small latch in the back when installed.
Fan is in. Retracts are in. Will bend new legs. Vert Stabs are temporary installed. Will start looking at where to put rx pack, rx, and 6S5000 battery to hit the specified CG. Hopefully it wont be long now.
Matt
Matt
Doing a little more work on the plane. Here are some shots of the retract install.
Not getting the time I thought to work on the plane.
Matt
Not getting the time I thought to work on the plane.
Matt
Ok, after the successful build and flights of the Mig 15 I am back on the F-18.
Redesigned the taileron linkage using ball joints and I am now very happy with the setup.
Also changed to a bigger servo and metal gears for the second time. There is no way a 9gram servo, as suggested is going to work those tailerons in a secure manner, so you will have to dremel out the 9gram openings to accept your servo of choice.
Looking at the other taileron Pro-desgn planes and holding the tailerons in my hand the F-18 has significantly larger moving surfaces in the rear than the F-22. The Mig-29 uses a slightly different setup where the tailerons are on bearings but it uses a control horn like a traditional setup so I am less concerned with those two.
Tonight, will finish the taileron servo install, will balance and assemble the fan and motor, finish retract install, and start looking at battery placement for the CG. Will give everyone a weight ready to fly tonight - well, thats the plan at least.
Matt
Redesigned the taileron linkage using ball joints and I am now very happy with the setup.
Also changed to a bigger servo and metal gears for the second time. There is no way a 9gram servo, as suggested is going to work those tailerons in a secure manner, so you will have to dremel out the 9gram openings to accept your servo of choice.
Looking at the other taileron Pro-desgn planes and holding the tailerons in my hand the F-18 has significantly larger moving surfaces in the rear than the F-22. The Mig-29 uses a slightly different setup where the tailerons are on bearings but it uses a control horn like a traditional setup so I am less concerned with those two.
Tonight, will finish the taileron servo install, will balance and assemble the fan and motor, finish retract install, and start looking at battery placement for the CG. Will give everyone a weight ready to fly tonight - well, thats the plan at least.
Matt
The airframe with everything except the motor batteries came in at 5lbs 1 oz, this includes the items yet to be installed. So I figure on 2lbs 4 oz of batteries and we will be at 7-1/2 lbs RTF. I placed my motor batteries 8S5000 in the plane behind the cockpit and she will balance without extra wieght at the reccomended CG. There is enough room for an 8S5000 to but you will need to use two batteries for anything over 6S as the cockpit opening is adequet but no huge. There is lots of room behind the cockpit area in the fuse.
My power system currently installed is the Het motor 600-37 with heat sink and paste installed. Getting about 2000 watts 80amps.
Have the ProEDF retracts installed and they seem kind of small for a 7.5lb airplane. Will find out shortly if they are up to the task.
My power system currently installed is the Het motor 600-37 with heat sink and paste installed. Getting about 2000 watts 80amps.
Have the ProEDF retracts installed and they seem kind of small for a 7.5lb airplane. Will find out shortly if they are up to the task.
Here are my specs and numbers
ProDesign 90mm fan with Het 600-37
7S5000 20-30c packs
CC Ice HV80
77 amps, 1900 watts, 175mph efflux speed out the exit.
Going to stick with the 7S setup, not going to 8S at this time. No sense stressing the components for the maiden. With all the rain we are having hopeful can get it in this weekend.
ProDesign 90mm fan with Het 600-37
7S5000 20-30c packs
CC Ice HV80
77 amps, 1900 watts, 175mph efflux speed out the exit.
Going to stick with the 7S setup, not going to 8S at this time. No sense stressing the components for the maiden. With all the rain we are having hopeful can get it in this weekend.
I am running 7S at 1900+ watts 175mph+ efflux. Motor and esc are capable of 8S but not going there until I get some flight behind her. I do not have a way to measure thrust right now. Might buy a fish scale in the future but what I have found is that efflux v is more important for my jets than static thrust. I don't plan on hoovering my F-18.
Will get some more picutes up soon. Maybe even a vid of my mixing to enable 2 flight modes. Its pretty cool
Flight mode 1 std elevator and ailerons
Flight mode 2 tailerons, ailerons, plus flaps for landing.
Will get some more picutes up soon. Maybe even a vid of my mixing to enable 2 flight modes. Its pretty cool
Flight mode 1 std elevator and ailerons
Flight mode 2 tailerons, ailerons, plus flaps for landing.
Here are some pics. She is ready to go.
few more
The Mains are located much to close to the CG.
Take a look at the Full-Scale Super Hornet pic below. Note that the Mains do extend from close to the front of the Intake, but angle back... then the knuckle-gear angle back even more to place the actual tire (point of rotation) alot farther back.
Now take a look at the build pic.
Based on a few of F/A-18 models I've had the pleasure of flying, CG should be right around the red hash-marks... and that's being conservatively nose-heavy. The black line represents how close the Mains (rotation point) are in relation to the CG.
As the model rotates for T/O, you're going to run the risk of the CG moving aft of the Mains even at low AoA, and a wicked tail strike for sure.
Everybody else building this bird, check your Main Gear legs' placement in relation to your CG... based on this picture, it appears that they should be at least a good 2" (if not more further aft) on the airframe.
Definitely report how it goes on the maiden though!
Take a look at the Full-Scale Super Hornet pic below. Note that the Mains do extend from close to the front of the Intake, but angle back... then the knuckle-gear angle back even more to place the actual tire (point of rotation) alot farther back.
Now take a look at the build pic.
Based on a few of F/A-18 models I've had the pleasure of flying, CG should be right around the red hash-marks... and that's being conservatively nose-heavy. The black line represents how close the Mains (rotation point) are in relation to the CG.
As the model rotates for T/O, you're going to run the risk of the CG moving aft of the Mains even at low AoA, and a wicked tail strike for sure.
Everybody else building this bird, check your Main Gear legs' placement in relation to your CG... based on this picture, it appears that they should be at least a good 2" (if not more further aft) on the airframe.
Definitely report how it goes on the maiden though!
Put a old set of batteries in her 7S (I hate lossing good batteries on a maiden)
Ran the throttle up. Sounded good but not as high reving as my newer batteries but still good enough thrust for a maiden. I would not be making any speed runs anyway.
Taxied her out about 2/3 the way down the 700 foot runway turned onto center started timer set for 3 minutes. Gave her full throttle. The nose on my plane sticks to the runway really well so I started easing back on the elevator, more and more elevator prepared to push her back down if she popped into the air. After a nice long run she lifted nicely into the air with an even climb-out and no "pop".
Flew her around a big wide circuit at half throttle about 6-7 times, I think. Everything was uneventful. Was concerned about some minor movement in the full flying stabs when on the ground but the plane flew smoothly. No aerobatics, no up on the retracts just a little down trim needed in the first circuit and I enjoyed the rest of the flight.
At the 2.5 minute buzzer I called landing and was on the back side when I started pulling back the power and she just kept flying level. In the final turn I was out pretty far and way up so I took the throttle to 0 and started to glide her in. I was still pretty high coming over the far edge of the runway but she was just "parachuting in" with a nice slightly nose high attitude. Real steep but slow glide now as she bled off speed. She touched down about 2/3rd down the runway at a walking speed and rolled to a stop just before the end. NICE
This plane flies even better at slow speeds than the Mig15 and weighs in at a full pund more. Those LEXs in front of the wing really make this plane a joy to land.
The CG from the manual is spot on, dont go further back or I could see a balloning stall on a cool landing approach like I had.
Speed. Dont know as I only wanted to maiden it and get used to its slow flight character. I put 1700 mah back into the 5000 7S battery for a 3 minute flight but I was putzing arounf the sky. I will download the data from the ICE controller later and post the results.
Only minuses is it is hard to see with that military grey compared to the Migs Big Fat Red Fuse. I do like the military scheme just be careful when she get out there.
Someone mentioned about the position of the landing geat being too far forward, I think. I would not change it a bit. It has solid taxi, take-off and landing character on the ground.
Next week I plan on having some video. I just dont like the stress on the maiden. There were many witnesses to the maiden as everyone has seen this plane out at the field but not fly
Enjoy your F-18's
Ran the throttle up. Sounded good but not as high reving as my newer batteries but still good enough thrust for a maiden. I would not be making any speed runs anyway.
Taxied her out about 2/3 the way down the 700 foot runway turned onto center started timer set for 3 minutes. Gave her full throttle. The nose on my plane sticks to the runway really well so I started easing back on the elevator, more and more elevator prepared to push her back down if she popped into the air. After a nice long run she lifted nicely into the air with an even climb-out and no "pop".
Flew her around a big wide circuit at half throttle about 6-7 times, I think. Everything was uneventful. Was concerned about some minor movement in the full flying stabs when on the ground but the plane flew smoothly. No aerobatics, no up on the retracts just a little down trim needed in the first circuit and I enjoyed the rest of the flight.
At the 2.5 minute buzzer I called landing and was on the back side when I started pulling back the power and she just kept flying level. In the final turn I was out pretty far and way up so I took the throttle to 0 and started to glide her in. I was still pretty high coming over the far edge of the runway but she was just "parachuting in" with a nice slightly nose high attitude. Real steep but slow glide now as she bled off speed. She touched down about 2/3rd down the runway at a walking speed and rolled to a stop just before the end. NICE
This plane flies even better at slow speeds than the Mig15 and weighs in at a full pund more. Those LEXs in front of the wing really make this plane a joy to land.
The CG from the manual is spot on, dont go further back or I could see a balloning stall on a cool landing approach like I had.
Speed. Dont know as I only wanted to maiden it and get used to its slow flight character. I put 1700 mah back into the 5000 7S battery for a 3 minute flight but I was putzing arounf the sky. I will download the data from the ICE controller later and post the results.
Only minuses is it is hard to see with that military grey compared to the Migs Big Fat Red Fuse. I do like the military scheme just be careful when she get out there.
Someone mentioned about the position of the landing geat being too far forward, I think. I would not change it a bit. It has solid taxi, take-off and landing character on the ground.
Next week I plan on having some video. I just dont like the stress on the maiden. There were many witnesses to the maiden as everyone has seen this plane out at the field but not fly
Enjoy your F-18's
My spotter and I were the closest to the airplane when she rotated and did her climb-out. Neither of us saw or heard a tail strike.
As for the ESC- it is in a perfect spot. I measured the efflux velocity with and without the esc in the exhaust tube (175mph with good batteries not the ones I was running on maiden) and it was impossible to see the difference on the efflux meter (FAA certified airspeed indicator 0-300mph). In my opinion, If the efflux is not changing you are not lossing any perceptable performance. Note: the efflux is taken from the tailpipes at the exit. The ESC sits about 6-8 inches forward of this position.
Any of the "respected" EDF Guru's want to offer any advice to me on the location of the ESC I would be glad to hear it.
For anyone who is building this plane put the retracts where I have them to start with and move them back based on your own experiences. Mine are staying put.
You will have no problems from a paved runway. Other runways( grass, dirt. etc) I don't think I would chance it with the small wheels and low intakes.
I know the factory made some changes based on my build so in the future you should not have to go through some of the extra work that I did.
Hope this helps you guys who are building this plane.
Matt
As for the ESC- it is in a perfect spot. I measured the efflux velocity with and without the esc in the exhaust tube (175mph with good batteries not the ones I was running on maiden) and it was impossible to see the difference on the efflux meter (FAA certified airspeed indicator 0-300mph). In my opinion, If the efflux is not changing you are not lossing any perceptable performance. Note: the efflux is taken from the tailpipes at the exit. The ESC sits about 6-8 inches forward of this position.
Any of the "respected" EDF Guru's want to offer any advice to me on the location of the ESC I would be glad to hear it.
For anyone who is building this plane put the retracts where I have them to start with and move them back based on your own experiences. Mine are staying put.
You will have no problems from a paved runway. Other runways( grass, dirt. etc) I don't think I would chance it with the small wheels and low intakes.
I know the factory made some changes based on my build so in the future you should not have to go through some of the extra work that I did.
Hope this helps you guys who are building this plane.
Matt
Quote:
Originally Posted by AceMigKiller  I mentioned that you had the landing gear too far forward. And just like I predicted, you had a Tail-Strike on rotation! (Rick saw it too)  Otherwise looked like it flew well.Now you need to take that big-fat ESC out of the exhaust. Killing your thrust for sure! |
Hey Guys hopefully Matt wont mind but I thought I would post some pictures from my build. Weight is pretty much the same as Matts, I am going to copy his power system with the exception of an ICE 100. few odds and ends that I need to take care of and then attach the verticle stabs and I will be good to go. I did end up rewiring one of the elevator servos to reverse it, this is temporary while I wait for the new JR 9503 to come out.
Here are a few shots from inside.
3 flights in today with the F-18. Even have a video or two 
Thanks Mike and Rick.
Flew flight number 2 with my old batteries which only produce 1000 watts and she flew around for 31/2 minutes using only 1700mah of the 5000.
Flew flights 3 and 4 with my good 20C batteries. The plane is fast with the 2000 watt setup - Prodesign fan /HET 600-37/ 7S5000 battery. My Mig15 was radared at 111 mph with 2000 watts. I beleive the F-18 to be a little faster on 2000 watts.
Flight 4 ( no video) tested the strenght of the landing gear. Flight was un eventful, even made a few short passes nose high harrier style which was no problem. On the landing I wanted to see how high I could keep the nose, over rotated back, she balloned up to 3-4 feet altitude on the runway and stalled landing straight down. Bent all three landing gear wire stuts but no damage to the plane or the landing gear, or gear mounts. MPope was amazed no damage. I will not do that again.
When this plane is on final it looks like it wants to land on a carrier. It is a real floater on landing as you will see.
Below video was on my good packs 2000 watts WOT
Thanks Mike and Rick.Flew flight number 2 with my old batteries which only produce 1000 watts and she flew around for 31/2 minutes using only 1700mah of the 5000.
Flew flights 3 and 4 with my good 20C batteries. The plane is fast with the 2000 watt setup - Prodesign fan /HET 600-37/ 7S5000 battery. My Mig15 was radared at 111 mph with 2000 watts. I beleive the F-18 to be a little faster on 2000 watts.
Flight 4 ( no video) tested the strenght of the landing gear. Flight was un eventful, even made a few short passes nose high harrier style which was no problem. On the landing I wanted to see how high I could keep the nose, over rotated back, she balloned up to 3-4 feet altitude on the runway and stalled landing straight down. Bent all three landing gear wire stuts but no damage to the plane or the landing gear, or gear mounts. MPope was amazed no damage. I will not do that again.
When this plane is on final it looks like it wants to land on a carrier. It is a real floater on landing as you will see.
Below video was on my good packs 2000 watts WOT
| http://www.vimeo.com/9714176 |
Here is the video of the flight with the old batteries. WOT was 1000 watts.
Not sure why the video is out of focus so much. Rick! what did you do to my camera
Not sure why the video is out of focus so much. Rick! what did you do to my camera
| http://www.vimeo.com/9715921 |
I just built this perfect looking F18 and plan to maiden her once I install the electronic retracts with shock absorbing struts.
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I use my 1000W power system from my previous starmax foamy F18. Will upgrade to 1600W power system soon.
I use my 1000W power system from my previous starmax foamy F18. Will upgrade to 1600W power system soon.
Put the entire ESC in the exhaust right in front of the "Y" transition.
Quote:
Originally Posted by bri6672 Well its going to be alot of work every form/ bulk head is broken  I am starting with rebuilding the main gear mounts and I am glueing everything in with Hysol which will hold up alot better than the epoxy that came from the factory (that cheap stuff doesn't adhere to the fiberglass very well) I have the new ESC mount cut out and half of the heatsink drops down in the exhaust tube which will help with the cooling. The elevator linkage seems fine but I thing I might pull them out and slide a carbon tube over them to stiffen the 4-40 steel pushrod. I will post some picks of the rebuild when I get some time. |
I had to cut out more of the fuselage to get in and repair the broken forms, I will be adding gear doors once she has earned it so these big holes wont matter. The main gear mount on the left has been completely rebuilt out of ply and is Hysoled in! I still have to make a support bracket to stiffen it up between the L and R mounts and sand out excess glue from the repair. The ESC has its new home, it is sunken down into the exhaust and now gets plenty of airflow over half of the heatsink and does not block much the fan exhaust, The guys at Castle said that should be more that sufficent so hopefully the heating up issue will be gone. As you can tell the bottom got pretty beat up, once I get her up to par in the air I will go back and repaint, do gear doors and scale her out!
We have pilot fly with RCLander 90mm 8s setup.
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[/IMG]The Wings
I will be using Hysol on all of the most important epoxy places; this is going to be stronger and lighter than using a 30min epoxy! The wings are now hysoled to the fuselage and I decided to lighten up the wing spar, the structural integrity, vertically will remain strong but the spar is going to be lighter by adding some holes along the side of each spar. I am tackling the weight savings incrementally by saving a few grams here and a few grams there!
Aileron Servos
All the servos are going on a diet 
I over killed the first jet with heavy metal gear servos when I found they where not necessary in some places! On the first jet I used HS 85mg’s they are a nice servo and provide 49oz of torque but at a weight of about 22grams! This time around I went with HS65HB’s the torque is down to 31oz which is still sufficient for an aileron but at a nice light weight of 11grams!
I built the aileron mounts out of light ply with a couple of carbon rods and a screw mount to hold them in place. I also modified the servo extension wire by cutting out the connectors and soldering them together and creating a custom length which eliminates any unnecessary wire sitting in the airframe! Again weight loss by grams
I over killed the first jet with heavy metal gear servos when I found they where not necessary in some places! On the first jet I used HS 85mg’s they are a nice servo and provide 49oz of torque but at a weight of about 22grams! This time around I went with HS65HB’s the torque is down to 31oz which is still sufficient for an aileron but at a nice light weight of 11grams!I built the aileron mounts out of light ply with a couple of carbon rods and a screw mount to hold them in place. I also modified the servo extension wire by cutting out the connectors and soldering them together and creating a custom length which eliminates any unnecessary wire sitting in the airframe! Again weight loss by grams
Taileron Mounts
I have hysoled the taileron mounts together, and decided to float them on Hysol to the fuselage and used some balsa tri stock to support them, this gives perfect alignment of the stabs compared to the wings! I have some Carbon linkages I built for the first jet and I will use them but I have changed the linkage mount for the stab to MattinAz’s method with Dubro ball linkages. So far they seem to be much more stable than the factory linkage! Again a servo diet and a big one this time!!!! I have set the linkage up with a mechanical advantage and replaced the heavy (55gram) Hs645mgs that I used in the first one with HS225mg’s The torque is down from 133oz to 67oz, with the mechanical advantage on the linkages and some research I have done this should be fine and in turn I have a weight savings of 54grams in the tail of the plane! I have already installed them and the servos have plenty of power for this application.
aa
The way explain is good.
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