Comfy Chair nearly destroyed my Mega Der Red Max

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mooser

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Hello! I need some advice. You see, we lifted up my comfy chair so it could be vacuumed under it. I then heard that awful sound of wood cracking. My Mega Der Red Max clone was behind it. One of the fins cracked. I “cleaned” it up and it was cracked all the way through. Me bad - It was behind the chair as it was by the front door as I was going to take it out on the deck soon for another coat of paint. Anyway, I really want to avoid “digging” out the plywood fin root if possible. I am wondering if I can glue the fin back on with epoxy or another glue. Then I would use fiberglass tape or fiberglass cloth on each side of the fin and body tube. Is this a sound approach? One thing though, I have not worked with fiberglass in over 50 years when I helped my dad repair a kayak, so my knowledge is limited. If this is a good way to repair it, what type of fiberglass tape or cloth would I use? I have some 15 minute epoxy. Could I use that to coat the tape or cloth? Where could I buy a small amount of the tape or cloth, enough to do the fix?

As for me, I launched my first rockets back in 1967 or so. The space program has been a major factor in how I see the world. Waiting for the mail from Centuri or Estes was always exciting. There were no tracking numbers. Engines would arrive by 3 in mailing tubes that you could make a rocket from with a little imagination. I have been in and out of this hobby over the years. In the late 80’s and 90’s I was back doing rockets with my boys and with the Scouts. In 2000 everything came to a halt as my wife battled Hodgkins. She won! Her “21st” Birthday is Aug 10th. It has been 21 years since her Stem Cell transplant. I was back at in 2008 or so. Then my eye disease developed. Retinal detachments, glaucoma, a valve implant and a cornea transplant. So-so sight in my left eye and no sight in my right. I developed osteoporosis from years of prednisone. 3 years ago I fell a lodge and some lumbar vertebrae fractured. I had some surgeries. I get around with a walker. I’d love to put a gas engine on it, but I can dream. I started building, although slowly, 2 years or so ago. I am especially fond of scale models. LJ II and the IB’s. I have a trove of unbuilt kits that I really need to create a spreadsheet of.

I joined this forum years ago. I do get the daily email. I see that many of you are extremely knowledgeable, thoughtful and helpful. I thank you in advance for any help that any of you may offer. - Steve

Fin5.jpgFin4.jpgFin3.jpgFin2.jpgFin1.jpg
 
Uuugh. . . I misread the title and thought that somehow the Mega DRM had almost destroyed your chair. Sorry to see the damage.

Depending on what/how you plan to fly it, probably dictates the repair method.

If you're going to be flying low and slow (G's or small H's) then you probably could clean things up, get rid of the paint for 1/2" near the fin root, use wood glue to re-attach the fin and then fillet with epoxy.

If you're going to be flying harder hitting motors, I would likely do more aggressive surgery. I've repaired a similar problem on a smaller rocket flying I motors by using thin tip to tip fiberglass. I wouldn't recommend anything thick and heavy, just low weight glass, even when flying an I435, which is a pretty hard hitting motor (for me at least). I wouldn't recommend this method, however, if the end goal is to fly low and slow - overkill, too much work, adding weight where it doesn't belong etc.

Post a little more about your likely flying scenarios and I'm sure someone will help guide you to the most logical fix.

Sandy.
 
You could also try inserting a dowel. Drill a 1/4'' diameter hole through the fin root that is still inside the rocket and drill a matching hole in the fin that broke off. Glue or epoxy a wood dowel in the hole and then attach your fin so that the 1/4'' slot on your fin mates up with the dowel pin. I would recommend at least 2 dowels. This will add shear strength to the fin and make a stronger joint.
 
Couple thoughts. Are you good with a dremel? I have slotted the fin at the root and the tab that is inside the tube before. Then glue in a piece of 1/16th" G10 or even thin ply. 2nd, the fin looks intact, get some better epoxy and just glue it back in place.
 
Or... thinking outside the box.. design a ring fin, it will make the fin can rock solid strength wise.



Der Red Max R Large.jpg
Der Red Max... throws his "Hat In The Ring"​
Der Red Max R Small.jpg
___________________________________________________________________________________________________________________________________________________
Or maybe some struts or wires going from fin to fin... you know... like WWI bi-planes had.

Der Red Max Strutter.jpg



Der Red Max "Strutter"

___________________________________________________________________________________________________________________________________________________

Der Red Max Wired.jpg

Der Red Max "Wired"
Thanks to @K'Tesh... these are all his handiwork. All I did was add the rings and struts​
 
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Hello! I need some advice. You see, we lifted up my comfy chair so it could be vacuumed under it. I then heard that awful sound of wood cracking. My Mega Der Red Max clone was behind it. One of the fins cracked. I “cleaned” it up and it was cracked all the way through. Me bad - It was behind the chair as it was by the front door as I was going to take it out on the deck soon for another coat of paint. Anyway, I really want to avoid “digging” out the plywood fin root if possible. I am wondering if I can glue the fin back on with epoxy or another glue. Then I would use fiberglass tape or fiberglass cloth on each side of the fin and body tube. Is this a sound approach? One thing though, I have not worked with fiberglass in over 50 years when I helped my dad repair a kayak, so my knowledge is limited. If this is a good way to repair it, what type of fiberglass tape or cloth would I use? I have some 15 minute epoxy. Could I use that to coat the tape or cloth? Where could I buy a small amount of the tape or cloth, enough to do the fix?

As for me, I launched my first rockets back in 1967 or so. The space program has been a major factor in how I see the world. Waiting for the mail from Centuri or Estes was always exciting. There were no tracking numbers. Engines would arrive by 3 in mailing tubes that you could make a rocket from with a little imagination. I have been in and out of this hobby over the years. In the late 80’s and 90’s I was back doing rockets with my boys and with the Scouts. In 2000 everything came to a halt as my wife battled Hodgkins. She won! Her “21st” Birthday is Aug 10th. It has been 21 years since her Stem Cell transplant. I was back at in 2008 or so. Then my eye disease developed. Retinal detachments, glaucoma, a valve implant and a cornea transplant. So-so sight in my left eye and no sight in my right. I developed osteoporosis from years of prednisone. 3 years ago I fell a lodge and some lumbar vertebrae fractured. I had some surgeries. I get around with a walker. I’d love to put a gas engine on it, but I can dream. I started building, although slowly, 2 years or so ago. I am especially fond of scale models. LJ II and the IB’s. I have a trove of unbuilt kits that I really need to create a spreadsheet of.

I joined this forum years ago. I do get the daily email. I see that many of you are extremely knowledgeable, thoughtful and helpful. I thank you in advance for any help that any of you may offer. - Steve

View attachment 474375View attachment 474376View attachment 474377View attachment 474378View attachment 474379
Any 20 / 30 minute 2 - part epoxy should work fine. Put a light coating on both the tube and the root of the fin and reattach.
 
If you're going to be flying low and slow (G's or small H's) then you probably could clean things up, get rid of the paint for 1/2" near the fin root, use wood glue to re-attach the fin and then fillet with epoxy.

Thank you Sandy - I will be using the Aerotech F50. I will use epoxy. Thank you! Steve

Are you good with a dremel?

Hi David - No Go on the Dremel with my eyes. I do like your idea of using a biscuit. I will epoxy it back on. Steve

Thank you all.
 
I wish you the best of luck on your repairs and sorry to see the damage.
The best way of coarse is to totally replace the fin.
Much more time and care than you may want to put into it, but it's the best way in my personal opinion.
I hope this lifts your spirits. I have neither a comfy chair or MDRM. I'm just too poor.
 
Reminds me of something I did once. Was building a 1/4 scale Bf-109 from plans and a stack of balsa. Had the wing and fuselage framed up. The fuse was sitting on my table in the garage. I was done working on it for the day and hit the button to close the garage door only to hear a sickening crunch. The door crushed the rear of the fuse and broke it off. I was so pissed I threw the whole plane in the trash. About an hour later I came to my senses and pulled it out of the trash. Fixed it with no problem, finished the build, and flew the heck out of it.
Meister '109.jpg
 
Thank you Sandy - I will be using the Aerotech F50. I will use epoxy. Thank you! Steve



Hi David - No Go on the Dremel with my eyes. I do like your idea of using a biscuit. I will epoxy it back on. Steve

Thank you all.

For an F50, you'll be fine, IMO. You're likely to get more damage during transport or a fouled chute landing. That is a good motor size for the rocket.

I would say to try and clean the loose bits out as well as practical before doing the epoxy. A new set of epoxy fillets to unpainted surfaces will put you in good shape for sure.

Sandy.
 
This is off this particular topic a bit... I have had the old 4" Cardboard and balsa finned Mega Der Red Max for many years, as pictured here with me. I still like to fly it. It has gotten banged up a few times but I happily repaired it because I really like the rocket. But, here is my question, a number of years ago I came across a fiberglass version of the rocket that utilizes colored fiberglass components, should be like a tank when it is finished. But, I hope to fly it yet this fall, weather permitting. But, I do not recall whom I purchased the rocket from. I want to run some sims on it to get some idea of which 54" motor to use in it and how high it will be expected to fly. I have not had any luck searching on the internet for the kit, I don't think it is sold any longer and I don't think it was actually sold with the MDRM name attached to it. I am hoping to find a Rocksim file so I do not have to create it from scratch. Might anyone have any leads for me?
 
You could drill out the fin tabs, then install a new fin. Some masking, careful painting, and sanding and you should be good to go. I'm sure someone could help you find replacement decals.

[EDIT] Then I see the date of the OP... D'OH!!!
 
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Wow, thanks for the information on my rocket folks, it IS the Red FiberMAX. I tried sending an email to AMW but it bounced back. Are they still in business or is information on their web site out of date? Anyway, I will get busy and finish my my rocket up and perhaps attempt to make my rocket appear something like SkyFire's but I know when it comes to applying decals and the like, I usually mess them up somehow. Happy flying!
 
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