The booms used are basswood, not balsa. Note I have had reports that gluing to CF with either epoxy or normal CA tends to not be strong, fractures off easily. I do intend to use CF booms on my new design, but will either glass the parts on, or perhaps wrap the boom with thread and CA to provide an interface. Just a heads up. May want to glue a small trial piece of balsa to CF and test the strength of the joint.
Will look for that glue. With proper trimming, you should get way more than a minute with a B engine. Remember, you don't have the radio on it, so is lighter and has less drag. Just hope you don't catch a thermal.
Normal CA glue works just fine on pultruded CF. I use it all the time. The only time you see it popping loose is when it's used to reinforce a balsa tailboom. Even then, just check it regularly to make sure there aren't any loose spots. No big deal on a rocket, actually, but popped strands do change the trim on hand launched and catapult launched gliders just enough to hurt performance. If it's too big of an issue, a spiral wrap of kevlar tow secured with duco or ambroid is a lightweight option.
Where do you source pultruded CF tubes and are they more expensive? Any downside to using square tubes, as I find them easier to mount flight surfaces on?
You should try 1&1 hosting, only about $140 a year. And the simple editing program is so easy even I can run it, a computer klutz. Brought up in the DOS days, no wonder I hate the damn things. Now if you have a fancy shopping cart and stuff it may cost more, I just use paypal buttons.
A pal building RG's for the World Team is having the gluing problem.
I have not verified this problem, but will pass all these tips along to him.
It does seem like any glue does not penetrate into CF like it does in wood, but I see many people gluing to it, maybe he was using crummy glue, or too much accel, or something. Humidity or greasy fingers, who knows.
NEW THOUGHT. He is using really skinny RODS I think, only for mini-A motors. I bet deformation
or bending of the rod cracks the joint. If so, he should use a tube type rod. I sent him this thread ref. May get some feedback.
So you gave up on dying? Seemed cool, although messy and troublesome.
Yes, cleaning CF and sanding sounds good.
Yes, the 3/32 thick balsa could be a challenge to airfoil. HLG wings are normally 1/4", gives you more to work with. Here is a somewhat mind numbing ref on Ancient HLG Secrets:
https://www.modelresearchlabs.com/legacy.htm
The plane shaver is new to me, wish I knew about it long ago. Have worn out many a sanding block and paper. Today, foam cores are all the rage, with vacuum bagging and CF skin. Not good for small gliders, and tricky to master. I have done some foam cutting with hot wire, for electric planes. Rocketeers should experiment with foam wings, some manufacturers actually embed CF tubes in them when molding. And HLG, many lessons can be learned about construction and trimming. In the old days, hand launch gliders were used for BG by just adding a rocket pod.
A caution on the carbon booms, early RBG protos had problems with the 18mm engine ejections, were like a shot gun, and imparted enough force to the airframe to knock off the pod and sometimes the wing. Why I added 1/64" ply reinforce to the pylon. And the 1/4" hole in the pod to vent some gasses. It might be helpful to only use 1/2 the ejection charge, they really are too powerful. Mqke sure your joints are strong, perhaps reinforce with thin fiberglass.
Eric
Nice build
I like the dye job, I am curious as to whether the soaked balsa grain swells up and when dries becomes a bit coarser (more coarse?). My first thought was you can’t sand it after you dye it, but maybe if dye penetrates deep enough, you can sand it smooth AFTER dying and still retain that bold even color. Obviously flew well. So point may be moot.
A zero delay engine will eject just fine. May be an interesting deployment, as without the delay the rocket will be at full velocity when engine kicks (as opposed to slowing a bit during delay from standard engine.). My guess is it will probably do a loop, should be cool.
I would like to know if the dye goes deep enough that you can sand AFTER dying.
I have flown versions of astron falcon boost glider and the ejection charge has broken the spar. Never tried scraping out part of ejection charge. I'd be afraid I would mess it up.
When you tissue the balsa does it leave surface smooth or does it require finishing and sanding?
You might want to put a dehumidifier in your build room!
I have lost some balsa from not storing right. Wrap the stack with rubber bands, seems to help. Trying to flatten warped wood by putting weights on does not seem to help. Also,use Sig lite-coat clear dope.
The HLG guys would yell at you for airfoiling such thin wood.
They use at least 1/4" thick. But that won't fly on an A motor.
Very nice glider build.
Just make sure you do have that good sized field to launch with a B engine. Especially if there's any kind of thermal action going on. Back in the day many folks used to experience fly-aways with the original well-trimmed Bumblebees on mere 1/2A motors!
I have never had a problem using a 1/8" flat screwdriver. There is nothing to create sparks. Just dig in and dump it out, one half or a little more. The delay train top is hard and you can't hurt it.
The BumbleBee was only 1/2A engine, so 1/16" wood was fine.
Sweet looking bird! No, I don't have kits anymore, but some pieces parts are lurking around.
Was that a 5 minute flight, or 1 min, 5 seconds???
The wood is so thin that just rounding the edges is adequate, for a good airfoil you really need thicker wood, get out the razor plane, just not used on this design. Yes airfoiling the stab can create radical results, the boost trim of this model is delicate and sensitive. It took a few flights to refine the angle of the Vector Pod. The free flight version will boost the best. When you hang the radio pod on it, the flow disruption causes a slight "S" path, although still generally up! That is why I tried enclosing the radio in a box balsa fuselage, certainly helped but a lot more work, and the Vector angle changed, this is posted elsewhere.
You did not mention thermals, another great way to lose a bird. I would say wind is the biggest enemy, I watch the weather reports and jump on days that are less than 8 mph.
Remember that modifying engines in any way is not allowed at NAR launches, that trick being needed shows that many of the Estes engines EC's are sized for big rockets, and often are way too powerful for smaller tubes and volumes. On their composite motors there is a cap you can remove and just dump some out.
Good flying!
Congrats on a good flight.
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