BAR Over building, Over thinking

I think I am over building my rockets. I used Fixit epoxy on my Apogee Aspire even though I never intend it to go over Mach one. I put Fixit epoxy clay on a small 18 mm Apogee Blue streak. I want to build well crafted rockets but I fear I am going beyond their need. Please tell me less is more.

Now I am working on an Orion Transport 24mm. I put a ton of diluted Minwax wood filler on the fins and am working with my dremel and hand saning 99 percent of it off. for a rocket I will put no more than an F30FJ-8 engine in. Yea, according to Apogee website it could go over 1200' but is it overbuilt? Fixit epoxied filleted wings, wood filler. Spent a day sanding. Am I wasting my time for no return.

The Orion Transport is classified by Apogee as a mid engine rocket.

Perhaps I am just getting impatient?

I mean, what do -you- want to do? Do you want to build kits, fly scratch, write papers?

Yes, some under or overbuild. Some never paint and some paint forever.

What do -you- want to do? Do more of that.

I would lay off the fix-it epoxy clay. To brittle for rocket applications.

I use 5 minute epoxy almost exclusively for all my builds, including MPR and HPR. Sometimes I'll use 15 or 30 minute, when I need extra setting time. I use JB Weld for retainers. I know a lot of people use wood glue, and it's plenty strong enough, but epoxy works better for me. I used 5 minute epoxy on the fins, centering rings, and coupler in Bomber Betty.

Klatuso said:

I think I am over building my rockets. I used Fixit epoxy on my Apogee Aspire even though I never intend it to go over Mach one. I put Fixit epoxy clay on a small 18 mm Apogee Blue streak. I want to build well crafted rockets but I fear I am going beyond their need. Please tell me less is more.

Now I am working on an Orion Transport 24mm. I put a ton of diluted Minwax wood filler on the fins and am working with my dremel and hand saning 99 percent of it off. for a rocket I will put no more than an F30FJ-8 engine in. Yea, according to Apogee website it could go over 1200' but is it overbuilt? Fixit epoxied filleted wings, wood filler. Spent a day sanding. Am I wasting my time for no return.

The Orion Transport is classified by Apogee as a mid engine rocket.

Perhaps I am just getting impatient?

Click to expand...

Are you having fun doing what you're doing? Then keep doing it.

Sent from my SAMSUNG-SM-G930A using Rocketry Forum mobile app

I use 5 min epoxy- thru wall fins and centering rings on about everything I build anymore, overbuilt- probably, but I have not picked up a rocket with a broken fin in a looong time
As other have said, if YOUR happy with it- keep running with it.

Klatuso,

Ok, I'd like to offer a general rule of thumb for you, based on my on experiences:

1. If the completed, ready to fly rocket will be less than 14 oz, you are fine with using balsa and aliphatic resin adhesives (e.g Titebond II), as well as good construction techniques such as double glue joints, UNLESS...
1.a. The design is high performance and will experience higher velocities,then see #2
2. The completed, ready to fly rocket will exceed 14 oz (or #1.a above), then "beef up" your materials, go with plywood, epoxy, and through the wall construction.

Sure there are cases where the rule of thumb does not work, but I'm just trying to create a broad framework that addresses most of the kinds of builds you are doing at the moment

As for the rest of you guys, don't attack me if what I am suggesting doesn't match what you do, I'm just trying to help Klatuso out with a broad guideline.

As for how to fill wood grain....well, that is a subject that can lead to religious wars! Everybody needs to find what they are most comfortable with. Most of what I have seen is some combination of filler material (e.g. Elmer's wood filler) and sandable primer. The application method and the amount of each material, varies by personal taste. If you want to start with a technique and then tailor it for your own taste, I recommend starting with John Boren's technique.

I hope this helps a bit

Klatuso said:

I think I am over building my rockets. I used Fixit epoxy on my Apogee Aspire even though I never intend it to go over Mach one. I put Fixit epoxy clay on a small 18 mm Apogee Blue streak. I want to build well crafted rockets but I fear I am going beyond their need. Please tell me less is more.

Click to expand...

My take is that you are *not* having fun, or at least are feeling like you're doing too much work.

There are two separate dimensions of "overbuilding": strength and finish. As for strength, I do think you are overbuilding. That may be totally OK; many folks overbuild intentionally, and I definitely overdo it in some areas myself. There is something to be said for a rocket that will survive whatever beating you hand out to it. However, epoxy fillets on an 18mm model are pretty excessive by any standard, and I would opine that it's probably unnecessary in the Aspire as well if you're staying under Mach. The Orion Transport could probably get away without epoxy fillets as well, but that's a big enough model that it's not unreasonable.

If I were you I'd try building some smaller models with lighter-weight techniques (i.e. using plain old wood glue for fin attachment and fillets (Titebond Quick and Thick is great for fillets)), so you're comfortable with a wider range of techniques, and won't automatically resort to the heavyweight strategy.

Oh, and yeah, Fixit epoxy clay is probably not ideal for fillets even if you're determined to use epoxy, but I'll leave epoxy recommendations to others.

As for finishing: that is all personal preference. However, if you spent a day sanding on rockets of that size then you might have gone astray with your technique. There are many, many ways to fill wood parts (I'm partial to papering with Avery label paper, as any reader of my build threads will know); if you feel like your current technique is taking too much effort than you should try some others and see which works best for you. However, "too much sanding" is a pretty common complaint from all rocket builders.

Bottom line: don't get locked into one set of techniques. Experiment and see what works best for you, and even more important, what is most enjoyable for you. In some cases you might be surprised.

neil_w said:

However, "too much sanding" is a pretty common complaint from all rocket builders.

Click to expand...

I second that. I don't think you will find too many people who are enamored with the process of filling and sanding.

If you are spending a lot of time overbuilding, be darn sure you also spend a lot of time on the recovery and tracking systems. Nothing worse than pumping hours/weeks/months into a build, then losing it on the maiden flight.

I tend to underbuild. Most of my kits use a thrust plate, which puts all of the motors force on the airframe and not the CRs. Forward CR needs to be able to resist the ejection charge, and be strong enough to carry the rocket under chute. Fins get internal and external fillets. I use 30-minute epoxy on canvas phenolic and RocketPoxy on fiberglass.

Klatuso said:

I think I am over building my rockets. I used Fixit epoxy on my Apogee Aspire even though I never intend it to go over Mach one. I put Fixit epoxy clay on a small 18 mm Apogee Blue streak. I want to build well crafted rockets but I fear I am going beyond their need. Please tell me less is more.

Now I am working on an Orion Transport 24mm. I put a ton of diluted Minwax wood filler on the fins and am working with my dremel and hand saning 99 percent of it off. for a rocket I will put no more than an F30FJ-8 engine in. Yea, according to Apogee website it could go over 1200' but is it overbuilt? Fixit epoxied filleted wings, wood filler. Spent a day sanding. Am I wasting my time for no return.

The Orion Transport is classified by Apogee as a mid engine rocket.

Perhaps I am just getting impatient?

Click to expand...

First things first... YES ! less is more.

Second thing is, in the land of TRF, everybody has an opinion and they are almost always right. Your question in this thread has been hashed out, chewed over, ruminated and regurgitated by the great minds of the Forum for years. And the answer is ... IT DEPENDS !

One thing I've found helpful when trying to answer this question for myself is to use the information provided by the kit manufacturer.

https://www.apogeerockets.com/Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/Orion

The Apogee Orion is designed to fly on 24mm diameter D, E, and F motors. It's commonly referred to as a mid-power rocket cause it's mid-way between low power A,B,C motor powered rockets and H motor and above high power rockets. One qauge used to determine overbuilding is the finished weight without motor. Apogee says 4.76 ounces for this puppy. Comparing that to your build is one data point to use. As far as finishing goes, that's even more of a slippery slope. My current feelings on the subject is that my rocket is done when I say it's done. Sometimes that may mean a little grain showin' or a divot in one of the fillets. Sometimes, another round of sandin' and fillin' and cussin'. IT DEPENDS ! :wink: Everybody has their favorite techniques but don't feel obliged to try every one of them at once. Relax, enjoy the process, and post some pictures of your Orion. And remember the words of our hero Alan Shepard: "Why don't you fix your little problem and light this candle?"

Everyone has their opinion on finishing: are you getting the desired outcome? Then it's worth it (at least to you). When you get perfectly "glassy" fins and nose cones after multiple layers of filler/primer/sanding, it's a great feeling. Also, what's your philosophy on building: making the "perfect" build, or just good enough? That should dictate the amount of effort you put into finishing.
As far as strengthening/overbuilding, there is a balance between bulletproofing and performance. Lightweight but strong enough is the goal. Definition of "strong enough" is up to you. Balance, balance, balance.

I tend to overbuild my rockets, because of that they tend to weigh more than they should. there is a small performance sacrifice due to that and I can live with that. I also tend to over finish some projects I get really excited about, I'm talking like every crevice filled and sanded for days, super nice paint. clearcoat like glass. another performance robbing technique but it makes me happy. other rockets I just slap a coat of paint on with no filler at all. And yet others where I couldn't just leave well enough alone, projects that were fine and I wanted to just touch up this spot here or clean up the grain a little bit better, and three or four hours later it looks worse than when I started. Perfect is the enemy of good.