Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Page 1 of 2 12 LastLast
Results 1 to 25 of 36

Thread: CoroCub also


  1. #1
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    CoroCub also

    When a few others came up with the CoroCub I tuned right in. Thanks for those designs. I have had two Balsa Kit Sig J3-Cubs and loved them. I decided to build one and used the Sig plans as a starting point. It is a little smaller (71 inch wing span) and will fit better in my compact car. The Sig J3-Cub has a cabin are that is very weak in my opinion. I clarify this by stating that I believe a model should come out of a cartwheel in good condition. My planes tend to be heavy. Attached are 5 photos of the fuselage. All Coroplast is 4MM. I'm using 1/16 inch plywood inside the cabin area, reinforced with an additional layer of 1/16 ply at the top and the bottom of the sides. The firewall mounting is exceptionally strong as shown in the photos. The firewall is 7/16 POLY that sandwiches the 4MM Coro against another 7/16 POLY frame that has 7/16 posts for added screw attachments thru the sides and the 1/16 plywood. It is solid and a bit heavy. I hope to add a little more area to the wing to compensate and will use an OS 46FX engine. I would like to read more flying reports on the CoroCubs that are flying.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Vt58391.jpg 
Views:	6 
Size:	29.6 KB 
ID:	483183  

  2. #2
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    The above is about my 5th try at up loading the 5 photos. I keep getting an error message. Finally, a few minutes ago I just up loaded the first photo. Here is the second photo. I will follow with individual messages for each of the remaining three photos for a total of five photos.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Ca80886.jpg 
Views:	11 
Size:	24.6 KB 
ID:	483187  

  3. #3
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    I was just automatically rejected because I am posting too many messages in a short time. I'm sorry about that. I'm not trying to circumvent anything. Just trying to post five fotos. This time I will try to post the remaining three photos at one time. Could not post all three, so here goes just #3
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Zx70581.jpg 
Views:	15 
Size:	26.3 KB 
ID:	483198  

  4. #4
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Here goes photo #4.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Ay74387.jpg 
Views:	4 
Size:	25.7 KB 
ID:	483201  

  5. #5
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Here goes photo #5. I would appreciate learning what I may have been doing wrong. I hate to take up so much space.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Vt58365.jpg 
Views:	5 
Size:	56.7 KB 
ID:	483202  

  6. #6
    jamesg25's Avatar
    Join Date
    Dec 2005
    Location
    london, SINGAPORE
    Posts
    89
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    hi villa thats a good start,
    I look forward to seeing your finished product!
    and i realy like your firewall method!
    regards
    james

  7. #7
    Screamin_Injun's Avatar
    Join Date
    Apr 2003
    Location
    Moore, OK
    Posts
    263
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    No joke...great firewall. As far as how these fly...and their toughness. Cartwheeled mine a couple of times in about 20mph winds cause I tried to take off a bit too early and mine cartwheeled beautifully...lol. I know the design seems weak (the middle of the fuse mainly) but its tough as nails. Probably because it flexes so well under stress. Good luck...you'll love how it flies.
    Screamin_Injun }}====>

  8. #8
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Hi Screaming Injun. Do you have wing struts on your's? Are they needed? If you don'r use them, describe the wing spar you are using from a strength point of view. I still have the wing struts from my two crashed basa Sig J-3 Cubs. I'm planing on recycling them on the CoroCub. My main interest is to prevent having wing tip washout. I feel that is what causes snap rolling on a poor takeoff or landing with the J-3 Cub.

  9. #9

    Join Date
    Jul 2006
    Location
    Port Orange, FL
    Posts
    4
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Hi, I'm new to spad building and I've decided the coro cub should be my first build...But, I've had trouble finding 2mm coro...so I'm intending to substitute 2mm pvc komatex foam!

    Does anyone know if this works? I've spent 32 bux on it and before I cut it.....I was gonna try to get a few opinions.

    Thanks to any and all advice!

    Jesus rules!

  10. #10
    coolbean's Avatar
    Join Date
    Jul 2005
    Location
    liberty, MO
    Posts
    1,076
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Is that foam fuel proof?
    The cake is a lie.

  11. #11

    Join Date
    Jul 2006
    Location
    Port Orange, FL
    Posts
    4
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    well,the foam is in between two layers of something....i'm assuming that it would be fuel proof to some extent....It looks like pretty cools stuff to use for a wing.

  12. #12
    Screamin_Injun's Avatar
    Join Date
    Apr 2003
    Location
    Moore, OK
    Posts
    263
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    No villa....no wing struts. Wing itself is ofcourse as stiff as a 2x4 but i noticed no bending or swaying of the wing in any way. Funny story though on how tough this design is. Few flights back I was too busy yapping at my friend and didn't realize I had hardly even tightend the two plastic bolts that hold the wing down. I flew the plane like it was my last day on earth, landed it, started to disassemble it to load it into my truck, and with only about 5 turns pulled out the bolts. I actually could lift the wing up with about a 1/4 inch gap from the plane. Was shocked and thankful. Wing never fluttered or anything else. So I wouldn't worry about struts too much.
    Screamin_Injun }}====>

  13. #13
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Screaming Injun'
    Thanks for your comments. Please refresh my memory on what you use to make the wing as stiff as a 2 x 4. I have never made a wing this long. Mine will be only 71 inches in span.

  14. #14
    Screamin_Injun's Avatar
    Join Date
    Apr 2003
    Location
    Moore, OK
    Posts
    263
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Well...pretty much just your conventional yard stick spar wing...cept for the dow rods on the inside. Mine is the full 82inch wing. I just followed the instructions exactly as shown. The doubled up yard sticks prolly helped alot. I also didn't see a reason to cut out the windows and just used black trim stickers instead. I just couldn't see cutting out the area that supported the wing that much...but I'm an over analyzer too.
    Screamin_Injun }}====>

  15. #15
    jamesg25's Avatar
    Join Date
    Dec 2005
    Location
    london, SINGAPORE
    Posts
    89
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    hey villa any updates on your cub?
    regards
    james

  16. #16
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    jamesG25....I hope to get it in the air in 8 days. I put enough of it together a few days ago to determine that the CG will be OK.

  17. #17
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Screaming Injun.....Since I will do snap rolls with my cub I beefed up the spar with 3/16 inch strips of yardstick so the spar cross section at the center 36 inches is an I-Beam. Less weight gets added that way. What is your weight and engine? I will use an OS 46FX and hope to keep it well below 8 pounds. My wing is all 4MM. I cut out the ailerons from the top and the bottom of the wing. This was complex since I had to build up the ailerons and also the hole in the wing left by cutting out the ailerons. I'm using four Robart rod type hinges on each aileron, inserting the rods into the wing top surface flutes. A coating of Permatex Silicone Adhesive/Sealant holds the rods inside the CORAPLAST flutes.

  18. #18
    jamesg25's Avatar
    Join Date
    Dec 2005
    Location
    london, SINGAPORE
    Posts
    89
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    ouch, 8plbs thats .90size country. good luck having any aerobatic performance, your going to need it.
    what is the wing area?
    regards
    James

  19. #19
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    jamesg25.....The wing area is 5.12 square feet. The weight came in at 7 pounds wich surprised me. I have been up on three days with it. I forgot everything I ever knew about flying the J-3 Cub and have crashed it twice already. On the last crash if it had been balsa it would have been totaled ready for the garbage can. I'm still shifting weight to adjust the CG location. First flight was at 100 degrees F. and 95% humidity. The OS 46FX had no problem with it.

  20. #20

    Join Date
    Jan 2002
    Location
    Harvey, IL
    Posts
    153
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Please let us know exactly where your cg comes out to be. I made two corocubs per the plans and they both were so tail heavy I lost them. They were repairable but not looking new or "near new" any more. Pretty wrinkled up. I think I am going to try a "third" one soon but am concerned about cg. I made another spadet so I could have something else to fly again.
    upnflyin
    If you can\'t dazzle them with brilliance -- baffle them with bull&hit.

  21. #21
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Remember that I'm using my own plans. Wing cord is 10-3/8, span is 71, CG is at 3-3/4 of chord. That works out to 36% of chord which is considered high. It flys great. I'm still test flying it so the CG may change. The incidences are zero and the engine down thrust is 2 degrees. Mine was very nose heavy. I moved the wing back 9/16 inch plus I moved components back. It is a floater. Looks like it glides all day. Making a decent landing has been difficult since it does not want to come down. I'm using an OS 46FX idling lower than I have ever idled one. Prop is 11 X5 APS. I may go to a 12 X 4 APS to see if it will slow the plane more. I have been landing on the mains and frequently nose over. The main gear is centered about 1/2 inch front of the wing LE so it should be doing better. Last few landings I flared more and this was a big improvement. I have not been flaring because I was afraid of a snap roll. I picked up an elevator flutter at high speed. I was using a piano wire bent into a C between the two elevator halves. It was .072 diameter. I just changed it to .093 diameter and would recomend something closer to .11 diameter. I also added some weight near the elevator TE in the form of three bamboo skewers to serve as dynamic vibration dampers. You say you lost two COROCUBS because they were tail heavy. Did you get them up in the air and around the field? You do know that a lot of right rudder is needed at takeoff. My first take off was a snap roll into the ground. I had forgotten all about the rudder.

  22. #22

    Join Date
    Jan 2002
    Location
    Harvey, IL
    Posts
    153
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    thanks for the details.
    I had no problems taxi or takeoff but as soon as it was up on its own it was super pitch sensitive. Tail heavy indications as far as I could tell. I made the circuit up and down a lot. A little down and it would dive and a little up would put it in a nose high stall condition. Higher airspeed made it even worse. The control deflections were not excessively large. Attempted landing and lost them. On the second one I made the nose longer and put a saito 80 on it for more weight. Better but not good enough.
    I even broke out my incidence meter and checked everything including eng angles.
    Think I will give it another go but make some minor changes.
    upnflyin
    If you can\'t dazzle them with brilliance -- baffle them with bull&hit.

  23. #23
    Villa's Avatar
    Join Date
    Aug 2003
    Location
    Wilson, NC,
    Posts
    2,046
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Here are 4 photos of my CoroCub. I have had 3 bad crashes with it and a number of small ones. Even did a full cartwheel with no damage. Only the last crash required repairs.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Bz79165.jpg 
Views:	11 
Size:	100.1 KB 
ID:	523823   Click image for larger version. 

Name:	Wr55061.jpg 
Views:	8 
Size:	14.4 KB 
ID:	523824   Click image for larger version. 

Name:	Mr40684.jpg 
Views:	11 
Size:	15.3 KB 
ID:	523825   Click image for larger version. 

Name:	Fy72563.jpg 
Views:	7 
Size:	32.9 KB 
ID:	523826  

  24. #24
    Clean's Avatar
    Join Date
    Apr 2002
    Location
    Parkville, MO
    Posts
    1,376
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    Try aiming it at solid objects. The outhouse, a rock outcropping, big trees. I'm sure with enough effort and a little luck you'll be able to destroy that ugly cub so you can build an Aeronica like you should have started with anyways.

    Good luck on the future build.
    Intentional landings WITH a PBF are not
    the intentional design OF the PBF

  25. #25
    Smooth Spanky's Avatar
    Join Date
    Sep 2003
    Location
    Shelby Township, MI
    Posts
    155
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback

    RE: CoroCub also

    No such thing as an ugly cub in my book, Clean

    Villa: That is sweet! I GOTTA build me one of these things. How about some video now???


Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 10:59 PM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.