My First Build Thread

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Sprucejedi

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I hope this is in the right section of the forum. If not, I am sure the mods will move it for me. Anyway, I have recently returned to rocketry after about 25 years. I used my son's interest as an excuse to get back into it and to buy and build some of the kits I wanted as a young kid. I was always told "those are too expensive" when I was younger. Well, now I have a college degree, a good career and my own car to drive me to the hobby shop! So now I don't need to beg and barter with my mom and dad to take me to buy rockets!

I have purchased several kits that were always "bucket list" kits from when I was younger. I also had several kits that I had purchased or had gotten for birthdays, Christmas, etc... that I never ended up building. I have decided that I will just begin one kit at a time, take my time, perfect my skills and when I get to my QCC Explorer kit and my Galactic Interceptor kit, I will know what I am doing and they will turn out beautifully. Anyway, my kids and I have built several level 1 kits lately so that we can get our skills sharpened and get some rockets in the fleet that can be regular flyers. They have all flown well, had good recovery and have pretty much captured the interest of my 5 and 3 year olds.

Rockets by Patrick Mohney, on Flickr

We built a pair of Mini Honest Johns. One from a kit, one from scratch that will accept A, B and C motors.

Rockets by Patrick Mohney, on Flickr

I didn't have decals for the second build. So I just sort of made them up and cut them out on my wife's Cricut. I figure there is a good chance of losing this one, so I did not put a lot of emphasis on historic accuracy. Anyway here it is.

Rockets by Patrick Mohney, on Flickr

Once we completed those, I decided it was time to expand to something more complex and detailed. My son and I went to the store and came home with this. I have an original kit, but I just did not want to break into that, so I grabbed a new one. With a 40% coupon, it came to 15$. Cant beat that!

Rockets by Patrick Mohney, on Flickr

We have begun the build and the capsule is completed except for the decals. I am happy with the results. I had to break out the old airbrush and sharpen my skills.

Rockets by Patrick Mohney, on Flickr

Stay tuned! I am working on the fins now.
 
I took the wife and kids out and flew the Hot-Rod Ho-Jo this afternoon. It is a mini honest john, I scratch built so that it will accept A, B or C engines. I tried it with a B6-4. It came off the pad like.... well a rocket... Nice and straight, up about 350-400 ft, then began to nose dive.... about 50 ft above the ground the recovery charge went off, and it came down nice and gentle. No damage. I will probably try it with a C motor with a shorter delay on the recovery charge. This is a really fun little rocket and wow does it get up and go!
 
I took the wife and kids out and flew the Hot-Rod Ho-Jo this afternoon. It is a mini honest john, I scratch built so that it will accept A, B or C engines. I tried it with a B6-4. It came off the pad like.... well a rocket... Nice and straight, up about 350-400 ft, then began to nose dive.... about 50 ft above the ground the recovery charge went off, and it came down nice and gentle. No damage. I will probably try it with a C motor with a shorter delay on the recovery charge. This is a really fun little rocket and wow does it get up and go!

That sounds like a whole lot of fun. Once you're ready get a MPR and your kids will be impressed how big they get. Not much of a change in build techniques, and Estes makes some really cheap ones in their Pro Series II line.
 
I will need some clarification between LPR and MPR. I know the usual hobby kits are LPR, that makes sense. But when do they transition from LPR to MPR? I have several of the higher difficulty, large bodied and larger engine kits on the shelf waiting to be built. I may have an MPR kit already, who knows.
 
there is no real hard line between LPR and MPR...the forum says E - G motors are MPR, but given that one can get F motors in 24mm does tend to blur things a bit. if the rocket has a pad weight of 8oz. or more it should probably be MPR, 29mm (Dia.) motors are usually MPR(there are some HPR motors in 29mm flavor).
Rex
 
Nice job on the builds.

SUPER job on working with the youngsters.

Me Dad got me into rocketry...boy do I miss those days flying rockets with DAD!!!!!!!!!!!!!!!
Centuri rockets that is.
 
One question: on the HoJo with the 18mm mount, how much nose weight did you need?
 
One question: on the HoJo with the 18mm mount, how much nose weight did you need?

Thanks guys! My dad built rockets as a kid, I built them as a kid, now my chikdren build them with their grandfather and me. Pretty awesome to have 3 generations interested in the same hobby.

The Hot-Rod Ho-Jo took a lot of weight. I made the fins out of basswood. When I balanced it I made the CG about 1/4 to 1/2" ahead of the nosecone/body tube transition. It was probably about 3 of the clay patties. I used plumbers putty. It's pretty heavy. I wonder if I used too much as it did corkscrew a bit during flight. Overall it was a decent flight. It will just need some fine tuning.
 
Thanks guys! My dad built rockets as a kid, I built them as a kid, now my chikdren build them with their grandfather and me. Pretty awesome to have 3 generations interested in the same hobby.

The Hot-Rod Ho-Jo took a lot of weight. I made the fins out of basswood. When I balanced it I made the CG about 1/4 to 1/2" ahead of the nosecone/body tube transition. It was probably about 3 of the clay patties. I used plumbers putty. It's pretty heavy. I wonder if I used too much as it did corkscrew a bit during flight. Overall it was a decent flight. It will just need some fine tuning.

Nice line-up Spruce. My 18mm modded mini HoJo exhibits some instability as well, when I fly it on an A8 or on a C6 as the fuel depletes and lightens the aft end. I believe I too added a little to much nose weight.


"Coning
An unstable flight condition in which a rocket's spin causes the rear portion of the rocket to describe a circle. Coning greatly increases aerodynamic drag and reduces peak altitude.

Stability is often described in units of "Caliber" and a long, thin rocket with small fins may have several calibers of stability (because the Center of Gravity [CG] is well ahead of the Center of Pressure [CP]). But the small fins may not provide enough corrective force to overcome rotation around the CG until they are at a significant angle to the airstream. This slow reaction of the rocket to rotation around the CG causes coning.

A standard-shaped rocket will have the CG closer to the CP. Any rotation around the CG increases the Angle of Attack (and, therefore, the corrective force of the fins) more quickly than when the CG and CP are farther apart. This allows the rocket to react and correct its flight more quickly - eliminating the occurence of coning."


https://www.rocketreviews.com/coning.html

If you can, scrape a few grams of clay out of there and see if that improves the flight profile.
 
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I will need some clarification between LPR and MPR. I know the usual hobby kits are LPR, that makes sense. But when do they transition from LPR to MPR? I have several of the higher difficulty, large bodied and larger engine kits on the shelf waiting to be built. I may have an MPR kit already, who knows.

I may get destroyed for saying this, and this isnt a technical statement. But in general, if your using single use motors, probably low power or mid power. A good example of midpower are the Estes pro series and Single use motors that correspond with that line. There are reloadable motor systems for low and mid power, but generally these are used in high power applications. So if you can buy the motor at hobby lobby, Its low or mid power, think someone already said it, but A-D low power, E-G mid power.
 
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I will need some clarification between LPR and MPR. I know the usual hobby kits are LPR, that makes sense. But when do they transition from LPR to MPR? I have several of the higher difficulty, large bodied and larger engine kits on the shelf waiting to be built. I may have an MPR kit already, who knows.

I always just go by total impulse and the minimum spectator distances defined in the NAR safety code: 15 foot separation for motors up to D = LPR, then 30 foot separation for E through G = MPR. I agree with Rex that pad weight should be considered as well. A stock Estes Saturn V on a D motor might be better off at the mid-power distance.
 
I agree with Samb, some things to consider, you cant go by the physical size of the rocket alone. You can turn an Estes standard Low power kit into a High power rocket. Usually doesnt work the other way around. If you take a large high power rocket kit and try to fly it on a C engine, chances are it wont leave the pad.
 
I agree with Samb, some things to consider, you cant go by the physical size of the rocket alone. You can turn an Estes standard Low power kit into a High power rocket. Usually doesnt work the other way around. If you take a large high power rocket kit and try to fly it on a C engine, chances are it wont leave the pad.

Thanks guys for clearing that up! I don't see any HPR in my future as there are no clubs within 3 hours + of where I live. But.... I did just order a PSII Ventris.... So, thanks a lot for being bad/good influences!

I got the fins built, shaped, glued and filled on the Redstone. I will upload some pics tonight when I get home. It is shaping up to be a pretty nice little build. I have a feeling that Ventris may "rocket" to the top of my build list.

Here are my fins after rough shaping.
20160410_115919 by Patrick Mohney, on Flickr

Here they are after gluing to the body tube. They lined up pretty decent, now i am sealing, priming, sanding, sealing, priming, sanding..............
20160410_151843 by Patrick Mohney, on Flickr
 
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now i am sealing, priming, sanding, sealing, priming, sanding..............

Could you explain to be why you have to seal in-between coats of primer? I've never done that before but what others have done they prime, sand, prime, sand, then seal. Great progress by the way, looking good.
 
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Could you explain to be why you have to seal in-between coats of primer? I've never done that before but what others have done they prime, sand, prime, sand, then seal. Great progress by the way, looking good.

I mis-typed... I apply a coat of cwf, sand, prime, sand, cwf, prime, sand, etc. Until the wood grain is no longer visible.

I just tried my hand at papering fins for the first time. My daughter and I started a Baby Bertha so I figured we will give it a whirl. We will see how it comes out.
 
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We are in the heart of wild fire season, so my time has been limited lately. I did get a chance to mask and paint the Redstone the other night. It came out well. I used Tamiya tape and an airbrush. The airbrush was definitely the way to go. Made for nice sharp lines and detail work. I had a couple spots where it drifted under the tape, but nothing major. I am happy with the outcome.
20160419_223857 by Patrick Mohney, on Flickr

I stayed home with the kids today (which is why the house is a wreck in the picture) and decided that I would attempt the decals. Most of them went on real well, the large decal at the top of the body tube is as good as its going to get. A couple little dimples in the decal from imperfections in the white paint, but im just going to have to live with it.
20160420_104642 by Patrick Mohney, on Flickr

So as of now, the rocket is completed. I need to wait for some calm weather and the humidity to come up so I do not set any fields on fire from the launch. I cannot wait to see it fly! Thanks for all the help and input. Now the difficult thing is selecting what kit to build next!

I am thinking the V2 may be next on the table. My daughter's baby bertha is almost done, so I am anxious to get on to the next one.
 
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Wow. Your Redstone looks GREAT! There's nothing like building with your kids! So glad you are able to include them in this!
 
We flew the Redstone this weekend. 2 beautiful flights, perfect arc-over at the top of the flight, textbook parachute deployment and landing. I could not be happier. This is a really fun rocket to build and fly.
 
What paint did you use for airbrush? Also, what air pressure did you use to spray it? I have a nice IWATA airbrush that I need to use and get good with. Thanks!
 
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