Building a Dynaflite Super Decathlon
#1926
Senior Member
Guys.
I removed one ounce from the tail by removing the 2 - 56 rods I used as flying wires and replacing with 4 - 40 pull/pull cable. As a result, the model balances at 3 3/4 which is 3/8 behind the center but 1/8 in front of the maximum rear range. Also, the reduction in lead on the nose dropped the overall weight of plane from 20 lbs 3 ounces to 19 pounds 13 ounces. So removing the one ounce off the tail right next to the elevators and rudder saved me 6 ounces in overall weight. Thanks for the help Srtelemaster. Worked late on the model so didnt fire up my computer. Cant post pics from this Kindle. I'll try to send supporting pics tomorrow night.
I removed one ounce from the tail by removing the 2 - 56 rods I used as flying wires and replacing with 4 - 40 pull/pull cable. As a result, the model balances at 3 3/4 which is 3/8 behind the center but 1/8 in front of the maximum rear range. Also, the reduction in lead on the nose dropped the overall weight of plane from 20 lbs 3 ounces to 19 pounds 13 ounces. So removing the one ounce off the tail right next to the elevators and rudder saved me 6 ounces in overall weight. Thanks for the help Srtelemaster. Worked late on the model so didnt fire up my computer. Cant post pics from this Kindle. I'll try to send supporting pics tomorrow night.
#1927
Senior Member
The first couple of pictures are of the Vanessa balancer I built to check the weight. Now that I've tried it, I think, It's really the only way to go on these heavier planes.
#1929
Senior Member
As you can see, I centered the bubble on the level which happens to be in line with the center line of the plane by twisting the handle on the balancer to get the correct attitude. The second and third picture is of the Model as it it sits cradled in the balancer. The last picture shows the weight prior to some changes I made to the tail wires.
#1930
Senior Member
Removed the flying braces and cut about 1.5 inches off of the tail wheel bracket. Replaced the braces with 4-40 pull/pull cable. As you can see, one ounce was removed from the tail assy.
#1931
Senior Member
Don't laugh at the lead weights I used. They fit in such a way that the cowl fit without interference. also, I was able to add six less ounces than before as a result of removing only one ounce from the tail.
#1932
Senior Member
I tilted the plane's attitude again to level the bubble then found the CG was 3/8 inch aft of the center of the range. Still had 1/8 inch to spare before max. aft CG. Also, the total weight has dropped to 19 Lbs. 13 ounces verses the original 20 Lbs 3 ounces. The very last picture shows it balanced.
Last edited by WILDCRASHWILLY; 06-17-2014 at 03:01 PM.
#1933
Senior Member
Success! The plane was maidened today. With the current CG it flew perfectly. Almost had a terrible incident on the first takeoff as the plane lifted off before it was really up to speed. After a few severe wing dips and raised blood pressure, the plane gained enough speed to start flying properly. Still think i may have it a little overproped because the rpm is not where i would like to see it however, it pulls extremely hard. Did have one rather abrupt landing (pilot error), and the landing gear splayed out a little. We have a vise at the field so i removed and had it repaired in 15 minutes. Very happy with the final outcome. Thinking about plansbuilding a gyrocopter next from some RCM plans i have. Then maybe a 55 cc scratch build of some plans i'm drawing up myself. Good flying to all.
Last edited by WILDCRASHWILLY; 06-21-2014 at 01:27 PM.
#1934
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responce to WILDWILLYCRASH
Sounds just like the first flight on mine - I had a the recommended size fuel cell in mine and Saito 180 and it was way too nose heavy and sluggish in handling. On landing it spread the LG but not too bad (was hand bent back in position) and I have reduced the tank back to a 15 0r 16oz (can't remember) and am still changing stuff. Now I'm looking at them tail brace wires too! Congrads on your first flight hope you have many more! SR/CP
P.S. Bill thats one impressive workshop you have I must say its nice! Doug
P.S. Bill thats one impressive workshop you have I must say its nice! Doug
Last edited by ScaleRCpilot; 06-22-2014 at 11:37 AM. Reason: added text
#1935
Senior Member
Thanks Doug,
Srtelemaster put me on to the tail weight resolution. Removed one ounce off the tail which allowed me to drop 5 ounces off the front. Reduced over all weighf by 6 ounces. 1 oz off the tail and 5 off the nose equal a 6 oz total reduction. Wished i could have found another 3 or 4 ounces to pull off the tail but it just wasn't there. Thanks for your comments on the shop. I travel for a living and it's a great get away and de-stressor when I'm home.
Srtelemaster put me on to the tail weight resolution. Removed one ounce off the tail which allowed me to drop 5 ounces off the front. Reduced over all weighf by 6 ounces. 1 oz off the tail and 5 off the nose equal a 6 oz total reduction. Wished i could have found another 3 or 4 ounces to pull off the tail but it just wasn't there. Thanks for your comments on the shop. I travel for a living and it's a great get away and de-stressor when I'm home.
#1936
My Feedback: (2)
Well that was a great four flights....I wonder how it will fly with even shorter wings.. :-P
for years now I've used either tied string, electrical tape or shrink wrap to secure connectors to each other... never had an issue, then I found these....
They are neat! They are clean! they look a hell of a lot better than string and tape! ...
They take all of 5 minutes of flight for the battery -> switch connector to work its way out of the retaining clip and disconnect itself. I don't really know how.. but I do know the end result...
painful lesson learned.. sometimes neat and tidy doesn't mean better... its back to string and tape and shrink-wrap for me....
Fortunately no one was hurt... came way to close for comfort though
for years now I've used either tied string, electrical tape or shrink wrap to secure connectors to each other... never had an issue, then I found these....
They are neat! They are clean! they look a hell of a lot better than string and tape! ...
They take all of 5 minutes of flight for the battery -> switch connector to work its way out of the retaining clip and disconnect itself. I don't really know how.. but I do know the end result...
painful lesson learned.. sometimes neat and tidy doesn't mean better... its back to string and tape and shrink-wrap for me....
Fortunately no one was hurt... came way to close for comfort though
#1937
RCU Forum Manager/Admin
My Feedback: (9)
Well that was a great four flights....I wonder how it will fly with even shorter wings.. :-P
for years now I've used either tied string, electrical tape or shrink wrap to secure connectors to each other... never had an issue, then I found these....
They are neat! They are clean! they look a hell of a lot better than string and tape! ...
They take all of 5 minutes of flight for the battery -> switch connector to work its way out of the retaining clip and disconnect itself. I don't really know how.. but I do know the end result...
painful lesson learned.. sometimes neat and tidy doesn't mean better... its back to string and tape and shrink-wrap for me....
Fortunately no one was hurt... came way to close for comfort though
for years now I've used either tied string, electrical tape or shrink wrap to secure connectors to each other... never had an issue, then I found these....
They are neat! They are clean! they look a hell of a lot better than string and tape! ...
They take all of 5 minutes of flight for the battery -> switch connector to work its way out of the retaining clip and disconnect itself. I don't really know how.. but I do know the end result...
painful lesson learned.. sometimes neat and tidy doesn't mean better... its back to string and tape and shrink-wrap for me....
Fortunately no one was hurt... came way to close for comfort though
Thanks
Ken
#1938
Senior Member
Mattnew,
Sorry for your loss. Glad no one was hurt. Thanks for sharing the failure. I've been tying kite string around my connecteors but had planned to give those a try. Guess I'll stick with the string for now. Not as convenient but won't separate if tied well. I used shrink wrap years ago until i had to separate a connector that had been wrapped about six months. I discovered some type of oil had excreted out of the wrap and left an oily film on my connections. Is your model repairable? If so I hope the repair process goes smooth for you. That can be a pain and many times adds weight if your not careful.
Sorry for your loss. Glad no one was hurt. Thanks for sharing the failure. I've been tying kite string around my connecteors but had planned to give those a try. Guess I'll stick with the string for now. Not as convenient but won't separate if tied well. I used shrink wrap years ago until i had to separate a connector that had been wrapped about six months. I discovered some type of oil had excreted out of the wrap and left an oily film on my connections. Is your model repairable? If so I hope the repair process goes smooth for you. That can be a pain and many times adds weight if your not careful.
#1939
Banned
Easy to install improperly
Hello,
I have used these connections locks in all my installations.
I never had any one fall off.
It is easy to think they are properly installed. They have to be pushed in fully to engage their own locking.
In the attached pictures I intentionally left it NOT fully pushed in and not locked.
We have to verify that the tabs are preventing the item (the lock) to slide back out under vibration if any.
Hope this helps.
Zor
Editing to try to add a picture with the lock fully pushed in. We can see the device shape that prevents it from sliding out.
Zor
I have used these connections locks in all my installations.
I never had any one fall off.
It is easy to think they are properly installed. They have to be pushed in fully to engage their own locking.
In the attached pictures I intentionally left it NOT fully pushed in and not locked.
We have to verify that the tabs are preventing the item (the lock) to slide back out under vibration if any.
Hope this helps.
Zor
Editing to try to add a picture with the lock fully pushed in. We can see the device shape that prevents it from sliding out.
Zor
Last edited by Zor; 06-23-2014 at 06:21 PM.
#1940
My Feedback: (2)
Rcken.... the retaining clip came off in flight... and then the connection must have vibrated loose. It's my best guess... the clip wasn't broken.... just sitting in the bottom of the plane.
Couple thoughts...
As it was an a123 battery with 20 gauge wire... while the clip appeared to have latched solidly....it may have been less than ideal due to the thicker wire. i double checked it twice ... i thought it was secure.... obviously it wasnt secure enough. I have these in 3 planes now.. ill be swapping them out this weekend.
Only the wing was damaged... as a tree caught it about 3 feet off the ground. So I need to order some wood to build a new wing....
the plane isn't done... it will fly again somewhat soon...
zor.... Not sure if brand of retaining clip matters here....personally I'm just going back to using kitchen twine...Not going to give it a second thought
Couple thoughts...
As it was an a123 battery with 20 gauge wire... while the clip appeared to have latched solidly....it may have been less than ideal due to the thicker wire. i double checked it twice ... i thought it was secure.... obviously it wasnt secure enough. I have these in 3 planes now.. ill be swapping them out this weekend.
Only the wing was damaged... as a tree caught it about 3 feet off the ground. So I need to order some wood to build a new wing....
the plane isn't done... it will fly again somewhat soon...
zor.... Not sure if brand of retaining clip matters here....personally I'm just going back to using kitchen twine...Not going to give it a second thought
#1941
Banned
#1942
My Feedback: (2)
Ultimately thats what we have to all do right? This crashed at a fly-in and missed 2 children by about 15 feet. I was completely mortified, especially since there was nothing I would have been able to do about it. I'm just glad no one was hurt...
I've never had one of these clips come undone either... I'm a bit at a loss, because I like them, I like them a lot... This is the first gasser I've had them in, I wonder if it was a vibration issue...
sorry to sidetrack the thread... just double check your connections folks and make sure things are secure...
#1943
Banned
Comments building a Decathlon or any model.
Ultimately thats what we have to all do right? This crashed at a fly-in and missed 2 children by about 15 feet. I was completely mortified, especially since there was nothing I would have been able to do about it. I'm just glad no one was hurt...
I've never had one of these clips come undone either... I'm a bit at a loss, because I like them, I like them a lot... This is the first gasser I've had them in, I wonder if it was a vibration issue...
sorry to sidetrack the thread... just double check your connections folks and make sure things are secure...
I feel that the best vibration detector and evaluator is our finger tips.
I keep all electrical connector away from any surfaces that have vibration. I leave them touchng nothing but their own wires. All wiring is fastened to a structure part within 2" to 3" from the connectors on both sides.
It may be visualized that the wires are holding the locked connector in thin air or where no vibration is finger detected.
Sometime it is a small puzzle as to how to route the wiring. All the fun of solving small problems during electronic installation.
I have seen many pictures with good examples of wiring dressing and I have seen pictures of wiring that looks like random spaghetti all over the space.
To each his own.
Zor
#1944
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On last sunday i did maiden flight of mine SD. Everything was excellent: total weight 6kg, selected CG as per manuall and etc. The engine: AGM30 is powerfull enaugh.
The landings I made was very soft and stable..Everything is O.K..except elevator two HD analog servos , they are bad centered. Decided to orderer another two. Hope will work much better, it is Digital Servo Graupner DES 708 BB MG, 7946. NO LOSE! (-:
And of course the last thing is Final looking(-:...Set the engine coil and the wheel pants.
.
.
The landings I made was very soft and stable..Everything is O.K..except elevator two HD analog servos , they are bad centered. Decided to orderer another two. Hope will work much better, it is Digital Servo Graupner DES 708 BB MG, 7946. NO LOSE! (-:
And of course the last thing is Final looking(-:...Set the engine coil and the wheel pants.
.
.
Last edited by Valius; 07-09-2014 at 10:38 AM.
#1946
Senior Member
Well guys,
The bugs were finally worked out and the model flew perfectly. However, the pilot made a very dumb move. He thought the plane was closer than it was and the tree line was farther away than it is. Need I say more? Wrapped it around a large limb about 75 feet off the ground. The power company was in the area and got it down for me. By the way, the pilot in question was me. I'll rebuild it again since I have the plans and made templates but I'm taking a year or so off from it. Have some others to build. Still, it was a great build and I enjoyed it.
The bugs were finally worked out and the model flew perfectly. However, the pilot made a very dumb move. He thought the plane was closer than it was and the tree line was farther away than it is. Need I say more? Wrapped it around a large limb about 75 feet off the ground. The power company was in the area and got it down for me. By the way, the pilot in question was me. I'll rebuild it again since I have the plans and made templates but I'm taking a year or so off from it. Have some others to build. Still, it was a great build and I enjoyed it.
#1947
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Sorry to see your plane like that Bill, like you said......take a break and slowly rebuild a new lighter fuse! I think the wing might could be repaired and the tail section could be reused. You really have a great garage/shop to make the repairs.....when you are ready to fix it. Good Luck!
#1948
Senior Member
#1949
My Feedback: (2)
Well guys,
The bugs were finally worked out and the model flew perfectly. However, the pilot made a very dumb move. He thought the plane was closer than it was and the tree line was farther away than it is. Need I say more? Wrapped it around a large limb about 75 feet off the ground. The power company was in the area and got it down for me. By the way, the pilot in question was me. I'll rebuild it again since I have the plans and made templates but I'm taking a year or so off from it. Have some others to build. Still, it was a great build and I enjoyed it.
The bugs were finally worked out and the model flew perfectly. However, the pilot made a very dumb move. He thought the plane was closer than it was and the tree line was farther away than it is. Need I say more? Wrapped it around a large limb about 75 feet off the ground. The power company was in the area and got it down for me. By the way, the pilot in question was me. I'll rebuild it again since I have the plans and made templates but I'm taking a year or so off from it. Have some others to build. Still, it was a great build and I enjoyed it.
bummer.... Its always tough to see so much work end so quickly... but thats the way this hobby is, some planes last years, some last hours.....
something about decathlons and trees... I think between the two of us we now have a whole one... my body was undamaged from the tree, my wings were shredded.
Same here with taking a while off, it might be a project for next winter to fix the wings.....
#1950
Senior Member
Thanks guys, I had five flights on her. Actually four really good ones. It sheared the wing tube in half yet the wings are still in decent shape. I don't think I've ever seen a wing tube with a clean shear before. I'm thinking about scaling the size up to about 110" WS and going to an 80 or 90 cc engine. Haven't really given it enough thought yet. I have a Gas powered Spoiler and a GP 330L kit on the radar now. Will start the Spoiler in a few weeks and the GP Kit in the winter... if not before. I have to finish covering a little Hot Hots for a friend that I've been dragging along on.
Actually, I plan to use the engine out of the Decathlon for the spoiler. The plane in my Avatar is a Spoiler I built from plans seven or eight years ago and still flying today. However, it's got a lot of flight time on it and the age and rough treatment is really starting to show up. I'll probably put a DLE 111 on the GP Kit not sure yet as I'll have to see what's available and if any sales promotions are on at the time.
Actually, I plan to use the engine out of the Decathlon for the spoiler. The plane in my Avatar is a Spoiler I built from plans seven or eight years ago and still flying today. However, it's got a lot of flight time on it and the age and rough treatment is really starting to show up. I'll probably put a DLE 111 on the GP Kit not sure yet as I'll have to see what's available and if any sales promotions are on at the time.
Last edited by WILDCRASHWILLY; 07-16-2014 at 01:41 PM. Reason: additional info