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Speed,Combat,Scale,Racing => Carrier => Topic started by: john vlna on September 05, 2016, 08:57:09 AM
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For a while now I have wanted to build a Skyrocket. I decided this spring to try an electric 15, this would be quite a challenge due to the 2.5lb weight restriction. I have had pretty good luck with 3530 1400KV motors so I plan to use 2 of these. I don’t expect this plane to be a world beater but it should be fun. I have pushed these motors on 4S, but I may not be able to do that due the weight problem.
Right now things look good, what you see in the attachments weighs 8+ oz, with 4s batteries I should be around 2lbs. The Grumman has the same area as my Airedale, ~200 sq in. It should have a little less wing loading than the Airedale which flies very well. The biggest unknown right now is how well I could hang a twin. I have never tried it before. I am also afraid i may have made the plane to light, carrier planes take a beating.
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Definitely a unique project. Good Luck.
Wayne
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John, good luck. I had a ball designing and building mine. The 2.4 sysem was rather easy even if it was for a twin.
Joe
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Looks very nice Joe. Is it a 15 or 35 size. Not sure how wide your deck is,
John
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John, mine is a .36 size, using two .18's. As I use the European deck sizes the deck is 5 foot wide, 20 ft long and is only the take-off portion of the deck. The deck itself is made from supported 2" foam and is a lot of fun to use.
Joe
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Well I finally have gotten back to my Skyrocket. A number of non carrier, both model an unrelated, projects has kept me from finishing this challenging model.
As recent discussions have shown, building a twin for carrier is difficult and frustrating. Before all the recent commentary I had started my Skyrocket for 15 profile. I have built many twins of my modeling career and currently have 5 in flying shape. None are for carrier though. Two are glow and three electric, one of the electrics is a biplane. Perhaps the main problem for a carrier twin is weight. While an unofficial event, the NCS has been using a 2.5 lb limit. We also use this Rule at the Brodak FlyIn. So although you Skyrocket is smaller, the same issues Eric and others have had apply.
I think using electric power make meeting the weight limits harder. Right now, with still some work to complete the plane, it looks ok to be within the 2.5lb (40oz) limit. My current
Weight, including the power system, with still some covering to do, hook, pushrod and gear etc, is at 31 oz.
Planned power is Turnigy Aerodrive 3530-1400Kv motors and 3 or 4s batteries. I don’t have any experience with these particular motors, but I have used other brands of 3530 type on other planes and have found it to be quite flexible. My simulation program says with 3s I should be close to 70mph, and over with 4s. However 4s will bring. Me very close to the weight limit and maybe over.
Another option are the RCTimer 2212-6 2200 KV motors. I currently am flying a Sterling P-38 with these and they look like they would be fine for carrier. The P-38 while not for carrier flies well on these motors and is heavier than would be allowed (3# 2 oz). I will likely test with them on the Skyrocket at some point. They might represent a 4s solution since with 3s batteries RPM will be very high. I only use 2s on the P-38.
While I seem to have made the weight my concern is have I made it to light. I’ll have to wait for flight tests to find out. I’ll post some pics next week.
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I don't understand what you mean by "to light"? The glow .15s weigh anywhere from 24oz which gets blow away in any hard air and then up to 28 t0 30oz which makes them pretty good in choppy air. My e15 weighs around 32+oz and handles real well in any configuration. I think your plane should fly quite well and am looking forward to how it does. Looks like a nice job, hope everything goes your way.
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Eric,
I meant to lightly built, i.e. Construction may not be strong enough to withstand the rigors of carrier flying. It will probably be close to the weight limit in ready to fly mode.
John
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OK John, just keep gluing it back together every time it breaks (glue joints are strongest) and then maybe it will stay together and not be over weight (hoho). Keep us informed.
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Although only ONE prototype was built, it (unlike a several others) was definitely designed as a US Navy carrier plane.
The Skyrocket is a sure winner in ANY class.
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The trouble with ALL models of the Skyrocket is there no place to add nose weight. Heavy engines are the only cure.
The real cure for the tail-heaviness of the F5F was the F7F.
I had to dump the .020's and go to Black Widows.
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Here is my "Sky Rocket". I used two OS .15 CVA's on it and placed all the 2.4 stuff under the wing near the front. The wing was planked with 1/16" balsa and the plane balances without any added weight. Probably a miracle!
Joe
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Wish John V would tell us about his plane, has it flown, what do you think, things like that. I have completed my F7 and it is ready to fly, weight is below max with a 3 cell 4400 mah battery and I think a tiny bit over with a 3 cell 5000 mah battery (1oz?). Alas my wife fell and broke her left femur and I will be tied up for a while.
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Eric, sorry to hear about your wife injury. Hope she recovers quickly.
Wayne
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Eric
Sorry about your wife, I hope for a quick recovery. As far as my Skyrocket goes, no flight yet. My time has been take up by a variety of of issues, hopefully I'll get it in the air soon. Weight looks like I can go 3or 4 cell batteries.
John
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Eric, sorry to hear about you wife. Sounds like your going to be involved for some time as her caregiver. Ginny and I wish you and yours the best and quickest recovery.
Joe
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This project has been plagued with my I attention and now parts failures. I really wanted to fly it this last week end. I was bench running the motors and one failed. Actually it never worked at all, seems to have an open winding. So I am waiting on a replacement. This motors are cheap and I am sure there is no QA by the manufacture.
To be continued, but probably not until after the NATS.