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Binder Design Tyrannosaur 50th BDay Present Build

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kcobbva

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I'm quite a lucky guy! My daughter had heard me mention the Tyrannosaur many times in the past and remembered to tell my wife, "Daddy would really be excited to get that for his birthday"! Love my girl!

Anyway, so initially I had plans to boost this on a 75mm motor with the option of a 54mm adapter and ordered the extra parts along with a dual deploy kit. Since that time, I've had a few discussions here and there and have decided to keep this one with the 54mm mmt. However I've also decided to add on an AeroPack Tailcone, so I've gotten a full length Loc Precision 54mm MMT on the way so I can extend past the upper fins with the extra lower required tubing for the tailcone. With some great advice by Dave A and rharshberger, I've also decided to try out the Soller Composites Fiberglass Sock with a veil layer over the top. I've never fiberglassed before, so it's something that's been on my "TO DO" list and figure now is the time to learn, although w/o a garage it's going to be a real pain!

Here's the unveiling. This is a very well made rocket from my initial inspection! I can't wait to see what it can do!
unboxed.jpg

A few days later I got to dry fit the pieces and see what it's going to look like. Took a shot out back, and then let my son and his buddy have a cool shot before taking my pack out to Mount Vernon. (Side note: Awesome time. These two boys got to carry a wreath into the George Washington Memorial Tomb last Saturday. One day I think my boy will understand how rare an opportunity that was).
dryfit.jpgdryfitkids.jpg

Another few days and I got it down into the basement and began peeling off the Glassine layer. Now once the MMT arrives, I'll begin the build. Hopefully I'll get a chance to bevel the fins this weekend and begin building out the fin can.
Remove Glassine layer.jpg

My thoughts on the glassing are: Cut out foam to the proper diameter to support the tube ends with PVC through the middle. On the tube with the precut fin slots place tape on the inside of the tube to catch any stray epoxy. Stretch the fiberglass sock over the tube and tie down at both ends and hit it with the West Systems 105 and 206 hardener. Then with a plywood board setup on a few stools, layout some butcher block paper, place the veil on it and then the epoxy and then roll it onto the tube as John Coker shows in his video. Of any of the steps, this is the one I'm most worried about getting right, then I'm planning to put preforated peel ply over this with breather material and saran wrap (Thanks for the tips Rich!)

Hopefully more work will get done this weekend.
 

kcobbva

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Question: Anyone recommend a specific type of Peel Ply over a fiberglass tube? I've looked all over the place and see all types. I'd like a smooth finish, so not sure where to go and what to order. Thanks.
 

kcobbva

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OK so here's another tip to tip fiberglassing question. I've read and researched and then started thinking last night about this. So when I watched TFish's video I kept thinking of the extra build up on the body when laying three layers of fiberglass. Especially with split fins and maybe not making the tube even throughout that area. Please help me if I'm going off the deep end here, but since the Tyrannosaur design is to build the fin can and then insert into the body tube, wouldn't it work to go ahead a tip to tip the fins to the MMT, and then insert into the body tube? With a rocketpoxy fillet on the final tube to fin build, I would assume that would be strengthened sufficiently and much easier to keep a uniform tube.

Second question, since this is a modular design (aka fin can separate) that means the fin slots are there already and the tabs will be cut when building out the fin can. When I fiberglass the lower body tube, I'm trying to think of a way to support that section without epoxying it into the body tube and being unable to remove it. I am building out a rotisserie and am cutting some foam circles to support the inside of the tubes when on the rotisserie, but thinking of those slots. Would using blue tape on the inside of the tube keep the epoxy from going through the inside and be easily removable after the fiberglassing? or maybe line the slots with Teflon tape and then tape over that? then I could slide in one of the foam supports and put it on my spit? I'm using a soller composites sock with a veil layer, but it's the support of that one tube I'm trying to figure out since I've never fiberglassed before.

Sure open to any suggestions on either question before I get started. Thanks.
 

markkoelsch

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I would paint the tube with epoxy, then roll the glass sock over the tube.

To start, the nosecone will be handy to get the sock onto the airframe. I like rolling the sock, forgive the comparison, like a condom. Unroll the sock onto the airframe. If the surface of tube is already wet out then wait a few minutes to see how the sock wets out. Then add additional epoxy with a disposable paint brush. Remove the nosecone once you begin unrolling the sock.
 

kcobbva

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OK so here's another tip to tip fiberglassing question. I've read and researched and then started thinking last night about this. So when I watched TFish's video I kept thinking of the extra build up on the body when laying three layers of fiberglass. Especially with split fins and maybe not making the tube even throughout that area. Please help me if I'm going off the deep end here, but since the Tyrannosaur design is to build the fin can and then insert into the body tube, wouldn't it work to go ahead a tip to tip the fins to the MMT, and then insert into the body tube? With a rocketpoxy fillet on the final tube to fin build, I would assume that would be strengthened sufficiently and much easier to keep a uniform tube.

Second question, since this is a modular design (aka fin can separate) that means the fin slots are there already and the tabs will be cut when building out the fin can. When I fiberglass the lower body tube, I'm trying to think of a way to support that section without epoxying it into the body tube and being unable to remove it. I am building out a rotisserie and am cutting some foam circles to support the inside of the tubes when on the rotisserie, but thinking of those slots. Would using blue tape on the inside of the tube keep the epoxy from going through the inside and be easily removable after the fiberglassing? or maybe line the slots with Teflon tape and then tape over that? then I could slide in one of the foam supports and put it on my spit? I'm using a soller composites sock with a veil layer, but it's the support of that one tube I'm trying to figure out since I've never fiberglassed before.

Sure open to any suggestions on either question before I get started. Thanks.
I would paint the tube with epoxy, then roll the glass sock over the tube.

To start, the nosecone will be handy to get the sock onto the airframe. I like rolling the sock, forgive the comparison, like a condom. Unroll the sock onto the airframe. If the surface of tube is already wet out then wait a few minutes to see how the sock wets out. Then add additional epoxy with a disposable paint brush. Remove the nosecone once you begin unrolling the sock.
Thanks. So is it difficult to roll it up like that? Does it stretch to much before rolling it back out?
 

MikeyDSlagle

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Sorry, slight highjacking.. What sock are you guys talking about from Soller Composites? You mean their sleeves? I ask because I intend to glass a tube in the future, just want to know what I am looking at.

I'm watching this build, the Tyrannosaur is on my Christmas list.
 

kcobbva

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Sorry, slight highjacking.. What sock are you guys talking about from Soller Composites? You mean their sleeves? I ask because I intend to glass a tube in the future, just want to know what I am looking at.

I'm watching this build, the Tyrannosaur is on my Christmas list.
Yes. It is the heavy vs light sleeve with a 2oz veil planned over the top.
 

markkoelsch

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Thanks. So is it difficult to roll it up like that? Does it stretch to much before rolling it back out?
No, not difficult at all. It should still compress nicely on to the tube.
 

kcobbva

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Made a little progress today. Got the extended MMT tube in the mail so I put the Aeropack together:
engine retainer.jpgretainer cap.jpg

Next after securing the aft ring in place I inserted the mmt into the tube, and then set about making a fin guide.
Fin Guide.JPGfin guide cut.jpg

Finally got the rear fins set in place. (I rounded them yesterday).
glue on fin.jpgfin alignment.jpglowerfin glue.jpg

Once they dry, I'll cut the rear tabs out, slide it out and glue the middle CR in place, then reinsert and start on the upper fins.
 

kcobbva

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The lower fins on the fin can look good. Cut out the tabs and slid out the fincan. Glued the mid-cr in place and will let dry overnight. I"ll work on the upper fins tomorrow after scouts. Also ensured I called out who allows me to have this passion and capability.
fincan-a.jpgstrength.jpg
 

BDB

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This is a great rocket! And it will look great with the tailcone.

After using foam to repair mine after a crash, it tips the scales at 8.25 lbs dry weight. I imagine that the glass will increase your weight quite a bit too. Not a problem, as long as you don't plan to use low thrust motors. After L1-ing before the crash with a H144, mine won't safely fly on anything lower than an I218 anymore. (But it flew great on a Loki I405 yesterday!)

As for glassing the booster tube, you may want to support the slotted end of the tube. I just glassed the airframe (2 x 6 oz wraps + peel-ply) for my Terrordactyl, and the booster tube became somewhat warped due to the long fin slots. It's hard to see in the pictures, but the tube flattened slightly near the slots. If I could do it again, I would apply some teflon tape to the inside of the fin slots and insert something to support the tube in the center of the slots--maybe a coupler or a round piece of foam.

That said, I think glassing this bird is a good idea. It's so darn big that it needs a little strengthening for the inevitable bumps that it will take. I don't know how many times I've whacked mine into the ceiling!

Good luck!

glassed booster 1.jpgglassed booster 2.jpg
 

kcobbva

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This is a great rocket! And it will look great with the tailcone.

After using foam to repair mine after a crash, it tips the scales at 8.25 lbs dry weight. I imagine that the glass will increase your weight quite a bit too. Not a problem, as long as you don't plan to use low thrust motors. After L1-ing before the crash with a H144, mine won't safely fly on anything lower than an I218 anymore. (But it flew great on a Loki I405 yesterday!)

As for glassing the booster tube, you may want to support the slotted end of the tube. I just glassed the airframe (2 x 6 oz wraps + peel-ply) for my Terrordactyl, and the booster tube became somewhat warped due to the long fin slots. It's hard to see in the pictures, but the tube flattened slightly near the slots. If I could do it again, I would apply some teflon tape to the inside of the fin slots and insert something to support the tube in the center of the slots--maybe a coupler or a round piece of foam.

That said, I think glassing this bird is a good idea. It's so darn big that it needs a little strengthening for the inevitable bumps that it will take. I don't know how many times I've whacked mine into the ceiling!

Good luck!

View attachment 305293View attachment 305294
Thanks. This absolutely addresses my concerns. I have cut three foam circles to do exactly what you are talking about. I'm even thinking of cutting a spare ply ring for the aft end and coating it in nylon tape so it won't stick, but also won't give at the aft end when the fiberglass tightens. When I slid the can back in tonight to start the forward fins I saw exactly what you said. I'm sure it will only be more so when I remove the next set of tabs

That being said. This thing is a rock solid kit. I'm only planning to use larger 54s in it, so the additional weight is all good. (If I do it right!!) :)
 

kcobbva

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So I got to thinking tonight, as I'm waiting on peel ply etc, maybe sanding down an extra coupler that I have, wrapping once with Teflon coated peel-ply, and then inserting into the rear body tube with the fin slots already cut out would give ample support for a good round fiberglass surface as well as a removable insert after it has dried. Any thoughts? Anyone try this?
 

K'Tesh

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Next after securing the aft ring in place I inserted the mmt into the tube, and then set about making a fin guide.
View attachment 305261View attachment 305260
Finally got the rear fins set in place. (I rounded them yesterday).
View attachment 305263View attachment 305262View attachment 305264

Once they dry, I'll cut the rear tabs out, slide it out and glue the middle CR in place, then reinsert and start on the upper fins.
For the future, I'd recommend that you cut the corners off of the fin/body tube joint on the marking guide, just to prevent it from getting glued to the fins/tube. This is more important for situations when you are gluing fins directly to the body tube.
 

Binder Design

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So I got to thinking tonight, as I'm waiting on peel ply etc, maybe sanding down an extra coupler that I have, wrapping once with Teflon coated peel-ply, and then inserting into the rear body tube with the fin slots already cut out would give ample support for a good round fiberglass surface as well as a removable insert after it has dried. Any thoughts? Anyone try this?
Just insert a balloon and inflate until it holds the shape you need, then glass the tube. Done correctly it will even keep the resin out of the tube. And I'd suggest putting the sock on first, pull tight and rubber band each end. Then work in your laminating resin. It will take awhile to massage it in to get it wet out but you'll be able to see when it all gets transparent and you'll know you did a good job wetting it all out.
 

BDB

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Just insert a balloon and inflate until it holds the shape you need, then glass the tube. Done correctly it will even keep the resin out of the tube. And I'd suggest putting the sock on first, pull tight and rubber band each end. Then work in your laminating resin. It will take awhile to massage it in to get it wet out but you'll be able to see when it all gets transparent and you'll know you did a good job wetting it all out.
That's brilliant! I'm definitely going to do that next time.
 

kcobbva

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Just insert a balloon and inflate until it holds the shape you need, then glass the tube. Done correctly it will even keep the resin out of the tube. And I'd suggest putting the sock on first, pull tight and rubber band each end. Then work in your laminating resin. It will take awhile to massage it in to get it wet out but you'll be able to see when it all gets transparent and you'll know you did a good job wetting it all out.
That is just brilliant Mike! I'm using a rotisserie spit so I'm not sure I'd be able to use the balloon and have the spit go through it; however my daughter ties balloon animals all the time so I have tons of balloons. Not sure how you came up with that idea, but definitely a moment of brilliance! BTW...LOVE this rocket. You've done a very nice job here!


That's brilliant! I'm definitely going to do that next time.
ahhh. You stole my thunder! :) I saw this post on the drive in and new I needed to respond. Beat me to it! :)
 

Binder Design

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That is just brilliant Mike!
Thanks, that's how I glass the insides of couplers. And you can do away with the rotisserie if you suspend from the ceiling from the sock on a rope, the other end tied with a weight on it to hold everything tight.
 

K'Tesh

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Thanks, that's how I glass the insides of couplers. And you can do away with the rotisserie if you suspend from the ceiling from the sock on a rope, the other end tied with a weight on it to hold everything tight.
Seems to me that you could do something similar using the rotisserie idea, just tying it off on both ends. I figure that with the body tube being rotated horizontally, you'd be able to prevent any thickening of the resin on one end caused by gravity pulling it down before it sets. Then again, I'm also thinking that this might take awhile to set, and that the resin may be able to flow.
 

kcobbva

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So here's my redneck Rotisserie stand for fiberglassing.

Used a motor I have and bought a longer bar and just made a stand today with my 9 year old. He loved cutting and figuring it all out. Foam inserts are tight on the bar an slide right into the tube. I think this should work and turn slow enough to ensure no high spots form after I'm done with the fiberglass.
rotisserie bare.jpgrotisserie tube.jpg
 

K'Tesh

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So here's my redneck Rotisserie stand for fiberglassing.

Used a motor I have and bought a longer bar and just made a stand today with my 9 year old. He loved cutting and figuring it all out. Foam inserts are tight on the bar an slide right into the tube. I think this should work and turn slow enough to ensure no high spots form after I'm done with the fiberglass.
View attachment 305611View attachment 305612
One thing that I could see happening (it happened with my clothes drying rack) is the parts pivoting, which could allow the body tube and all to twist down and come in contact with something. Some of holes drilled into the joints, and bolts dropped in stopped the problem with my rack.
 
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Binder Design

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So here's my redneck Rotisserie stand for fiberglassing.
That's cool but not really needed. You don't want to ever use enough resin to pool or flow, only just enough to wet out the fabric. So there's really no reason to mechanically keep it rotating. In fact, that is one of the purposes of peel ply. To soak up excess resin. The other purpose is to make it smoother and easier to sand out. Excess resin only adds weight, not strength. So if you have extra resin that didn't soak in, carefully squeegee or sponge it off.
 

kcobbva

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Thanks Mike. I might try one tube one way and the other the other way for learning purposes.
 

KenECoyote

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Maybe you can still use that nifty Roc-tisserie to spray paint! :)
 

kcobbva

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All the final extras finally showed up today, hours before we leave for Thanksgiving. :( At least I was able to plan the layers of fiberglass for the fins and cut the small sections for the wall to wall fiberglass I plan to do.
fins marked, fiberglass outlines, and fiberglass cuts. I've not cut the sheet that will cover the entire fin set on each side. Will have to wait until after turkey day and our return home.

fin lines.jpgfin fiber start.jpgfin fiber small.jpg

I have a few frays, but I think they'll be OK once fully covered if placed and wet out carefully.
 

Scoops

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I've fiberglassed a few rockets but by no means am an expert, but here's some tips that I've picked up...
For supporting the aft end with the fin cut-outs, wrap the coupler with wax paper and place it at the fin slots. Cut the wax paper long enough to cover all of the slots even if the coupler doesn't, and then tape it down inside of the body tube. As Mike said, you shouldn't use an amount of epoxy that you need to worry about pooling, so you won't have to worry about too much of it getting between the wax paper and the inside of the body tube. A little bit will be ok.

Use a mini paint roller with a foam roller for spreading the epoxy on the body tube. This is a little easier than foam disposable brushes. Then apply the fiberglass, then roll it into the epoxy until it's wetted out (the fiberglass will turn clear). You shouldn't need to add much epoxy to this to get it wetted out, it just takes a few minutes of work with the roller. Then apply the veil cloth. You probably won't need to add any epoxy to this to get it wetted out either.

I recommend using pourous teflon coated release (peel ply). I got a few yards from www.avtcomposites.com. It comes off much easier than regular peel ply. But if you already bought something go ahead and try what you have. Wrap the tube in peel ply then work that with the roller too until the excess epoxy soaks through it.

For fiberglassing fins, it appears you cut the fiberglass the exact size of the fins. I find it works out better to cut it about 1/2-3/4" larger in all dimensions except the root and then when the epoxy is mostly (but not completely) cured, cut off the excess with a sharp knife. Then you won't have to worry about the edges fraying as much.

Have fun!
 

kcobbva

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I've fiberglassed a few rockets but by no means am an expert, but here's some tips that I've picked up...
For supporting the aft end with the fin cut-outs, wrap the coupler with wax paper and place it at the fin slots. Cut the wax paper long enough to cover all of the slots even if the coupler doesn't, and then tape it down inside of the body tube. As Mike said, you shouldn't use an amount of epoxy that you need to worry about pooling, so you won't have to worry about too much of it getting between the wax paper and the inside of the body tube. A little bit will be ok.

Use a mini paint roller with a foam roller for spreading the epoxy on the body tube. This is a little easier than foam disposable brushes. Then apply the fiberglass, then roll it into the epoxy until it's wetted out (the fiberglass will turn clear). You shouldn't need to add much epoxy to this to get it wetted out, it just takes a few minutes of work with the roller. Then apply the veil cloth. You probably won't need to add any epoxy to this to get it wetted out either.

I recommend using pourous teflon coated release (peel ply). I got a few yards from www.avtcomposites.com. It comes off much easier than regular peel ply. But if you already bought something go ahead and try what you have. Wrap the tube in peel ply then work that with the roller too until the excess epoxy soaks through it.

For fiberglassing fins, it appears you cut the fiberglass the exact size of the fins. I find it works out better to cut it about 1/2-3/4" larger in all dimensions except the root and then when the epoxy is mostly (but not completely) cured, cut off the excess with a sharp knife. Then you won't have to worry about the edges fraying as much.

Have fun!
Thanks! That's great advice!! I hadn't thought about wax paper and will use that! Also like the foam roller idea! I can also do that. The initial fin cutout isn't the entire fin. It's a smaller center amount and then a full covering will go over that. Following the video TFISH had done but I'm not going to use three layers as his video showed, only two. Again, this is excellent advice and I very much appreciate it!
 
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