Skymaster 1/5 Scale F16 Build Thread
#251
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Made big OOPS today. Won the prize of the day for stupid.
I installed flaperon servos and then drilled and tapped the servo arms for the M4 threaded ball stud drive nipples. With out checking for the proper fit I got in a hurry and cut the threads off flush with the back side of the servo arm to give clearance from the fuse side. Well the studs were too short and needed a washer under the base to properly engage the drive slot in the flaperon with out slipping out. Just like in the photo in the manual!
Now I'm stuck. Does anybody know where I can get this size ball stud with the M4 thread?
I have already searched McMaster Carr with no luck.
After this mistake I put the wings away and started working on installing the 300N pipe for the B300F.
Thanks,
Gary
I installed flaperon servos and then drilled and tapped the servo arms for the M4 threaded ball stud drive nipples. With out checking for the proper fit I got in a hurry and cut the threads off flush with the back side of the servo arm to give clearance from the fuse side. Well the studs were too short and needed a washer under the base to properly engage the drive slot in the flaperon with out slipping out. Just like in the photo in the manual!
Now I'm stuck. Does anybody know where I can get this size ball stud with the M4 thread?
I have already searched McMaster Carr with no luck.
After this mistake I put the wings away and started working on installing the 300N pipe for the B300F.
Thanks,
Gary
#253
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Location: Baton Rouge, LA
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well mine at least had those already, its like the tail cone where they mount and then are pushed back.
Did you figure out your issue with the slat servos, where did you cut? I have been delaying this because I wanted to see what others have done.
Did you figure out your issue with the slat servos, where did you cut? I have been delaying this because I wanted to see what others have done.
#254
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[QUOTE=Alkaline;12201468]well mine at least had those already, its like the tail cone where they mount and then are pushed back.
Here are my wing tips. No holes. Holes are in the missile rails but not in tips. Did you guys have to drill holes in the wing tips? Are there hard points in the wing tips to mount the rail?
The slotted holes on the outside of the missile rails appear to be for holding the missile on the rail.
Suggestions appreciated.
Gary
Here are my wing tips. No holes. Holes are in the missile rails but not in tips. Did you guys have to drill holes in the wing tips? Are there hard points in the wing tips to mount the rail?
The slotted holes on the outside of the missile rails appear to be for holding the missile on the rail.
Suggestions appreciated.
Gary
#255
My Feedback: (6)
Gary,
its a a pretty simple process. Draw a center line from center of leading edge to center of trailing edge. The rail extends past the edge of the wing and you can find some pictures online to get the scale amount or eye ball it... Then just set the rail on the wing and mark the spots for drilling on that line and you are good... They are meant to be screwed on, that's why the wing bag had accounted for them.
its a a pretty simple process. Draw a center line from center of leading edge to center of trailing edge. The rail extends past the edge of the wing and you can find some pictures online to get the scale amount or eye ball it... Then just set the rail on the wing and mark the spots for drilling on that line and you are good... They are meant to be screwed on, that's why the wing bag had accounted for them.
Last edited by bri6672; 04-13-2016 at 06:01 AM.
#256
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Cut hole in the wing root matching the one in the fuse wing root. You have to cut through the fiberglass skin and the plywood rib, about 3/8" deep. I used a perma grit bit.
Then I used a piece of flexible wire with a small hook on the end to snake into the LEF servo well routed under the front spar with wing upside down.
Fish the wire around the servo well mount and out of the wing.
Tape over the servo plug to keep it from hanging up on the pull out.
Route the servo wire being the servo mount.
Pull the servo wire out the root rib.
Don't forget to beef up the servo mount per Anton's post #710 in the "It's Coming…F-16 ARF PRO" thread. I have not done mine yet.
Hope this helps.
Gary
Just for info the leading edge is a leading edge flap not a slat. On the full scale it is controlled by the flight control computer for max wing performance and the pilot has no input at all except normal side stick inputs.
Last edited by Viper1GJ; 04-13-2016 at 05:59 AM.
#257
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Gary,
its a a pretty simple process. Draw a center line from center of leading edge to center of trailing edge. The rail extends past the edge of the wing and you can find some pictures online to get the scale amount or eye ball it... Then just set the rail on the wing and mark the spots for drilling on that line and you are good... They are meant to be screwed on, that's wing the wing bag had accounted for them.
its a a pretty simple process. Draw a center line from center of leading edge to center of trailing edge. The rail extends past the edge of the wing and you can find some pictures online to get the scale amount or eye ball it... Then just set the rail on the wing and mark the spots for drilling on that line and you are good... They are meant to be screwed on, that's wing the wing bag had accounted for them.
bri,
Am I correct to assume you used wood screws into a plywood tip rib?
Thanks
Gary
#261
My Feedback: (20)
Thanks for the help with mounting the wing tip missile rails.
Worked on the 300N pipe install today. Will post some photos since it is not stock.
300N and 200N stock Skymaster pipes side by side. The 300 pipe is 3/4" too long and much larger. Inlet ID is 120mm and exhaust ID is 110mm. Bell mouth is much larger.
I trimmed 1/4" from the exhaust end outer tube that extended past the inside tube and 1/2" from just behind the bell mouth funnel. Perfect fit now.
I bolted the bell mouth to the front of the pipe and taped aluminum mounting tabs to the bell mouth to mock up the pipe mounting concept.
Temporary wood engine mounts were cut to fit the B300F and mock up the engine and pipe mounting concept.
Engine mounts extend through the rear former to hold the pipe bell mouth mounting tabs.
Pipe bell mouth fits nicely between the engine mount rails and just aft of the rear former.
Good news today, John at Skymaster is sending me a new center tank with the hole in the proper location and some new ball studs to replace the ones I messed up.
Gary
Worked on the 300N pipe install today. Will post some photos since it is not stock.
300N and 200N stock Skymaster pipes side by side. The 300 pipe is 3/4" too long and much larger. Inlet ID is 120mm and exhaust ID is 110mm. Bell mouth is much larger.
I trimmed 1/4" from the exhaust end outer tube that extended past the inside tube and 1/2" from just behind the bell mouth funnel. Perfect fit now.
I bolted the bell mouth to the front of the pipe and taped aluminum mounting tabs to the bell mouth to mock up the pipe mounting concept.
Temporary wood engine mounts were cut to fit the B300F and mock up the engine and pipe mounting concept.
Engine mounts extend through the rear former to hold the pipe bell mouth mounting tabs.
Pipe bell mouth fits nicely between the engine mount rails and just aft of the rear former.
Good news today, John at Skymaster is sending me a new center tank with the hole in the proper location and some new ball studs to replace the ones I messed up.
Gary
Last edited by Viper1GJ; 04-13-2016 at 04:15 PM.
#262
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Rear pipe mounting ring opened up to fit the larger diameter pipe.
Nozzle cone test fit.
Pipe alignment looks good on mockup. I will adjust final alignment after final mounting.
The larger 300 pipe prevents use of the stock AB LED ring. I will order and install a larger one after test flying. This will require cutting the nozzle leaves out and making a larger fiberglass ring. The current nozzle is molded in the closed position like it would be in non AB flight. I will reattach the leaves in the open position like the nozzle would be on the ground or in AB. This will allow a larger LED ring to fit inside the nozzle cone. I would then repaint the leaves to look like the F-16 Block 52 F100-PW-229 engine with composite carbon fiber leaves. I think this is what the Thunderbirds are currently flying.
The B300F fits nicely on the wider engine mounting rails. The final engine rails will be aircraft 5 ply laminated on top and bottom with carbon cloth in a vacuum bag.
Aft intake tube test fit looks good.
#263
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Hey,
I'm using the stock 200 pipe, I ran a bench test on it with the P300, ran fine, no issues. I think this pipe will be ok, the stock Skymaster pipe is larger than the tamjet pipe which is rated for 300N.
I'm using the stock 200 pipe, I ran a bench test on it with the P300, ran fine, no issues. I think this pipe will be ok, the stock Skymaster pipe is larger than the tamjet pipe which is rated for 300N.
#264
My Feedback: (20)
Made engine and pipe mounting rails today. It's poor man's DragonPlate made from on hand shop supplies. I call it "GaryPlate"
Laminated two sheets of 3/32" aircraft 5 ply between two layers of 5.6 oz carbon cloth in a sandwich between two glass plates weighted with shot bags.
Laminations removed from glass plates. 10 plies of wood between carbon cloth on top and bottom.
Dust collection setup for cutting and trimming. Downdraft table, shop vac, dust mask, and ear muffs kept carbon dust away and noise down.
Plate is squared up for cutting.
Engine rail pattern ready for tracing.
Cut lines marked with silver Sharpie pen.
Cutting done with Perma Grit saw blade. Worked great.
Final engine rails, edges painted black. Looks like the real deal. Not sure the carbon adds much but it looks cool. Whats a jet model these days with out some carbon fiber to look at!
Gary
Laminated two sheets of 3/32" aircraft 5 ply between two layers of 5.6 oz carbon cloth in a sandwich between two glass plates weighted with shot bags.
Laminations removed from glass plates. 10 plies of wood between carbon cloth on top and bottom.
Dust collection setup for cutting and trimming. Downdraft table, shop vac, dust mask, and ear muffs kept carbon dust away and noise down.
Plate is squared up for cutting.
Engine rail pattern ready for tracing.
Cut lines marked with silver Sharpie pen.
Cutting done with Perma Grit saw blade. Worked great.
Final engine rails, edges painted black. Looks like the real deal. Not sure the carbon adds much but it looks cool. Whats a jet model these days with out some carbon fiber to look at!
Gary
Last edited by Viper1GJ; 04-20-2016 at 06:51 PM.
#265
The Permagrit saw blade is a fantastic little tool to cut raw carbon fiber or glass fiber plates.
I have a tutorial on how to cut thick laminates in the pipe. Need to take a bit of time to publish it...
http://www.ultimate-jets.net/collect...cutting-blades
I have a tutorial on how to cut thick laminates in the pipe. Need to take a bit of time to publish it...
http://www.ultimate-jets.net/collect...cutting-blades
#266
My Feedback: (20)
Finished Leading Edge Flap (LEF) install today. I found my LEF linkage did not work correctly if installed per instructions in the manual. Details are below.
First, after my understanding of how the LEF linkage worked I highly encourage everyone to accomplish the modification to beef up the servo mount per Anton's post #710 in the "It's Coming…F-16 ARF PRO" thread. Photo in my post #256 above. The reason for this as I see it is because all of the lifting force on the LEF during flight is transmitted through the LEF hinges, carbon control horn, into the servo arm, and into the servo body. This force is trying to literally pull the servo down and out of the mounts in the wing. During high G turns at high speed this force has got to be strong. I have no idea how much but Im sure its a lot.
The only thing holding the LEF in position are the wood screws. In a normal servo installation the force is perpendicular to the screws but here it is trying to pull the screws out of the holes. This is why Anton says put wood under the existing mounts and use longer screws.
I have seen a LEF blow up failure in the full scale F-16. It is barely controllable and then only because of the fly-by-wire flight control system. It would not in my opinion be controllable in the RC model. I do not know if the LEF would fully blow up but at the hinge stop it is several degrees leading edge up. Therefore I encourage all flying this jet to do the mod to the LEF servo mounts.
I added shaped plywood and hysol under each servo mounting tab and also on the inboard and outboard sides of the servo well just to help bond the two wing skins together around the stress area.
Mod Alert!
When installing the LEF servos I prepared the servo arm as per instruction manual and drilled the hole for the bearing stack at 10mm from servo spline center.
When I installed the servo and checked the LEF movement I found that the down travel was restricted to about 1/2 of full travel. LEF full down is where the carbon control arm is touching the top wing skin and can move no further. The reason was that the bearing stack was hitting the end of the bearing slot and movement stopped.
My fix was to move the hole for the bearing stack on the servo arm from 10mm to 13mm. This allowed full control arm travel and the bearing stack does not contact either end of the slot.
1st photo: Shows left wing LEF at full down position with carbon control arm touching the upper wing skin. (Aft is at top of photo and left wing is upside down in photo) A close look will show the bearing stack is not contacting the aft part of the slot with the LEF full down. A closer look will show the first bearing stack hole at 10mm just behind the bearings. You can tell from this photo that if the bearings were at 10mm the stack would not fit into the slot at the LEF full down position.
2nd photo: Shows left wing LEF in mid position with servo arm parallel to servo body. This position is where the bearing stack is furtherest forward in the slot. Note it is slightly forward of the center of the slot but not contacting the forward end of the slot. You can also see the first hole in the servo arm at 10mm which would put the bearing stack too far aft.
3rd and 4th photos: Same for right wing.
Also I had to use two washers under the bearing stack to get both bearings into the slot. The supplied 3mm bolt was not long enough to stack all the washers and bearings and have the elastic safety nut fully engage the threads. I replaced the bolt with a 3mm x 16mm socket head bolt.
Lastly I will replace both servo arms before flying. I do not have confidence that the new holes at 13mm have enough metal around them for use in this high stress application. I just wish I had figured all this out before I cut them off.
Recommendation: Use the suggested 10mm distance as a starting point and measure your set up before drilling and cutting off the servo arm. With the variances in servos, manufacture of the wing, LEF, mounts, control arm installation, and etc, I recommend a hole that places the bearing stack 1-2mm forward of the center of the carbon control arm slot. This will allow full up and down travel of the LEF without the bearing stack hitting either end of the slot and restricting the travel.
Hope this helps.
Gary
First, after my understanding of how the LEF linkage worked I highly encourage everyone to accomplish the modification to beef up the servo mount per Anton's post #710 in the "It's Coming…F-16 ARF PRO" thread. Photo in my post #256 above. The reason for this as I see it is because all of the lifting force on the LEF during flight is transmitted through the LEF hinges, carbon control horn, into the servo arm, and into the servo body. This force is trying to literally pull the servo down and out of the mounts in the wing. During high G turns at high speed this force has got to be strong. I have no idea how much but Im sure its a lot.
The only thing holding the LEF in position are the wood screws. In a normal servo installation the force is perpendicular to the screws but here it is trying to pull the screws out of the holes. This is why Anton says put wood under the existing mounts and use longer screws.
I have seen a LEF blow up failure in the full scale F-16. It is barely controllable and then only because of the fly-by-wire flight control system. It would not in my opinion be controllable in the RC model. I do not know if the LEF would fully blow up but at the hinge stop it is several degrees leading edge up. Therefore I encourage all flying this jet to do the mod to the LEF servo mounts.
I added shaped plywood and hysol under each servo mounting tab and also on the inboard and outboard sides of the servo well just to help bond the two wing skins together around the stress area.
Mod Alert!
When installing the LEF servos I prepared the servo arm as per instruction manual and drilled the hole for the bearing stack at 10mm from servo spline center.
When I installed the servo and checked the LEF movement I found that the down travel was restricted to about 1/2 of full travel. LEF full down is where the carbon control arm is touching the top wing skin and can move no further. The reason was that the bearing stack was hitting the end of the bearing slot and movement stopped.
My fix was to move the hole for the bearing stack on the servo arm from 10mm to 13mm. This allowed full control arm travel and the bearing stack does not contact either end of the slot.
1st photo: Shows left wing LEF at full down position with carbon control arm touching the upper wing skin. (Aft is at top of photo and left wing is upside down in photo) A close look will show the bearing stack is not contacting the aft part of the slot with the LEF full down. A closer look will show the first bearing stack hole at 10mm just behind the bearings. You can tell from this photo that if the bearings were at 10mm the stack would not fit into the slot at the LEF full down position.
2nd photo: Shows left wing LEF in mid position with servo arm parallel to servo body. This position is where the bearing stack is furtherest forward in the slot. Note it is slightly forward of the center of the slot but not contacting the forward end of the slot. You can also see the first hole in the servo arm at 10mm which would put the bearing stack too far aft.
3rd and 4th photos: Same for right wing.
Also I had to use two washers under the bearing stack to get both bearings into the slot. The supplied 3mm bolt was not long enough to stack all the washers and bearings and have the elastic safety nut fully engage the threads. I replaced the bolt with a 3mm x 16mm socket head bolt.
Lastly I will replace both servo arms before flying. I do not have confidence that the new holes at 13mm have enough metal around them for use in this high stress application. I just wish I had figured all this out before I cut them off.
Recommendation: Use the suggested 10mm distance as a starting point and measure your set up before drilling and cutting off the servo arm. With the variances in servos, manufacture of the wing, LEF, mounts, control arm installation, and etc, I recommend a hole that places the bearing stack 1-2mm forward of the center of the carbon control arm slot. This will allow full up and down travel of the LEF without the bearing stack hitting either end of the slot and restricting the travel.
Hope this helps.
Gary
Last edited by Viper1GJ; 04-17-2016 at 05:25 PM.
#268
My Feedback: (20)
ARF Alert!
While fitting the engine mounting rails I found two high stress areas that would have quickly failed in normal use.
1. The glue joint on the engine rail screw tab on the back side of the center fuse former failed when drilling due to no glue in the joint. This is where the engine rail transfers all the force from engine thrust to the fuse former. 50+lbs of thrust would have torn it right off.
Mounting tab broke off when drilling. Examination shows no glue in the joint allowing the soft china plywood to split and tab to fall off.
My fix was to hysol the factory joint and add a 1/4" aircraft ply doubler on the bottom with wide hysol glue fillets on all corners.
2. Center fuse former joint cracked. This is the joint that transfers all the engine thrust force to the fuse structure.
Center fuse former joint to side of fuse looking through the bottom of main gear well, nose to right. This joint appears to be a plywood to fiberglass butt joint with epoxy filler in the gap. The plywood has broken away from the filler.
My fix will be first cover the gear door hinge with vaseline and then apply a fillet of hysol in the corner on both sides. Then I will lay epoxy wetted carbon fiber cloth over both sides lapping over the plywood and fiberglass.
While fitting the engine mounting rails I found two high stress areas that would have quickly failed in normal use.
1. The glue joint on the engine rail screw tab on the back side of the center fuse former failed when drilling due to no glue in the joint. This is where the engine rail transfers all the force from engine thrust to the fuse former. 50+lbs of thrust would have torn it right off.
Mounting tab broke off when drilling. Examination shows no glue in the joint allowing the soft china plywood to split and tab to fall off.
My fix was to hysol the factory joint and add a 1/4" aircraft ply doubler on the bottom with wide hysol glue fillets on all corners.
2. Center fuse former joint cracked. This is the joint that transfers all the engine thrust force to the fuse structure.
Center fuse former joint to side of fuse looking through the bottom of main gear well, nose to right. This joint appears to be a plywood to fiberglass butt joint with epoxy filler in the gap. The plywood has broken away from the filler.
My fix will be first cover the gear door hinge with vaseline and then apply a fillet of hysol in the corner on both sides. Then I will lay epoxy wetted carbon fiber cloth over both sides lapping over the plywood and fiberglass.
Last edited by Viper1GJ; 04-19-2016 at 04:48 PM.
#270
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I put in an hour for the scale guys here and added a engine inlet strut. My jet will be for sport fun flying so won't do much of this stuff.
Inlet struts in full scale big mouth and a regular small mouth inlet.
I used a K&S airfoil shaped aluminum tube left over from the same use from my old 1/6 F-16.
Cut the holes in the inlet with a dremel carbide bit.
Polished it with Mothers aluminum polish.
Hysol used to glue the tube in place
Gary
Inlet struts in full scale big mouth and a regular small mouth inlet.
I used a K&S airfoil shaped aluminum tube left over from the same use from my old 1/6 F-16.
Cut the holes in the inlet with a dremel carbide bit.
Polished it with Mothers aluminum polish.
Hysol used to glue the tube in place
Gary
Last edited by Viper1GJ; 04-19-2016 at 05:52 PM.
#271
My Feedback: (86)
Look good!
I put one in but for function in the back portion of the intake. A few of the guys that had the first ones mentioned to me the intakes were collapsing at full throttle near the intake extension. It was suggested to put the vertical brace in and wrap the intake extension with 5oz CF cloth right before it touches the bypass.
Rex
I put one in but for function in the back portion of the intake. A few of the guys that had the first ones mentioned to me the intakes were collapsing at full throttle near the intake extension. It was suggested to put the vertical brace in and wrap the intake extension with 5oz CF cloth right before it touches the bypass.
Rex
#272
My Feedback: (20)
Hi Rex,
Thanks. My intake strut is non functional and only for looks.
I saw your photo and write up and saved it in my iPad idea file. I like to copy everyones cool ideas. I'm not very original but I can copy real good!
I had planned to wrap carbon cloth all the way around the inlet and the extension all the way back to the engine. Today I was pushing on the intake under the nose gear well and was thinking about laying two layers of carbon where where it is real "squishy" just in front of the extension joint.
Gary
Thanks. My intake strut is non functional and only for looks.
I saw your photo and write up and saved it in my iPad idea file. I like to copy everyones cool ideas. I'm not very original but I can copy real good!
I had planned to wrap carbon cloth all the way around the inlet and the extension all the way back to the engine. Today I was pushing on the intake under the nose gear well and was thinking about laying two layers of carbon where where it is real "squishy" just in front of the extension joint.
Gary
#273
My Feedback: (3)
Seeing the inlet without the strut makes me cringe!
Glad you added one!
JS
Glad you added one!
JS
I put in an hour for the scale guys here and added a engine inlet strut. My jet will be for sport fun flying so won't do much of this stuff.
Inlet struts in full scale big mouth and a regular small mouth inlet.
I used a K&S airfoil shaped aluminum tube left over from the same use from my old 1/6 F-16.
Cut the holes in the inlet with a dremel carbide bit.
Polished it with Mothers aluminum polish.
Hysol used to glue the tube in place
Gary
Inlet struts in full scale big mouth and a regular small mouth inlet.
I used a K&S airfoil shaped aluminum tube left over from the same use from my old 1/6 F-16.
Cut the holes in the inlet with a dremel carbide bit.
Polished it with Mothers aluminum polish.
Hysol used to glue the tube in place
Gary
#275
My Feedback: (20)
Are there any instructions for servicing the landing gear struts, how to and what kind of oil to use?
Are there any instructions for servicing the nose gear steering system and what kind of oil to use? How do you get the oil in and the air out?
I have the intake tubes wrapped in carbon fiber today. Photos tomorrow after epoxy cures and trimming. Intakes are already much stiffer now.
Working on a simple holding bracket system to secure all the fuel and smoke tanks and intake extension in place and be removable with just two bolts. How are you guys holding the bottom center tank in position?
Thanks
Gary
Are there any instructions for servicing the nose gear steering system and what kind of oil to use? How do you get the oil in and the air out?
I have the intake tubes wrapped in carbon fiber today. Photos tomorrow after epoxy cures and trimming. Intakes are already much stiffer now.
Working on a simple holding bracket system to secure all the fuel and smoke tanks and intake extension in place and be removable with just two bolts. How are you guys holding the bottom center tank in position?
Thanks
Gary