"Friendship 7" 50th Anniversary Dr. Zooch Mercury Atlas build...

[luke strawwalker]

Originally Posted by closet astronaut

Thanks for all the info. There seems to be alot more to the hobby than gluing some fins to a tube and stuffing an engine in the end of it. Sound like it could get to be quite an expensive hobby.

I've gotten the itch, I grow tired of having great looking static mods sitting around on shelves. I've been reading Yogi's threads on stomp rockets and all the enjoyment he's had with the kids building and launching them. I wasn't real inpressed at first but I've done some reading on the subject and recieved some education, some of the hights achievable are impressive and the rockets available now are quite impressive, I went on E-card models site last nite and bought the advanced kit with four rockets and a missle with two different graffics. For less than twenty bucks you can have several launch vehicles and launch system, rocket engines weren't cheap ten years ago I can imagine what they cost now.

I thought my daughters would get a real thrill out of it, I took them both to cape kennedy summer before last and my youngest was trippin on the whole thing, it's something I think we can both enjoy and spend some quality time together, it's hard to find things a father can do with a daughter unless you want to play with dolls or with the doll house.

Any way...thanks again for taking the time to give an education.

Oh, it's not too expensive... so long as you stay away from high power... that gets expensive in a HURRY... but then I won't mess with it. NO WAY am I going to get CERTIFIED and have mandatory membership in one of the national orgs just to participate in a HOBBY activity... some do and they're welcome to it. Not for me. I fly "A-E" low power rockets (okay, so "D,E,F,and G are considered "mid-power").

Motors aren't TOO bad if you know how to do it. Watch for the Hobby Lobby 40% off coupons and pick up a pack of rocket engines every time you're in there, and you'll soon have enough for a good weekend of flying. They're pretty reasonable with the coupon. The other thing is, order them online from a discount hobby warehouse-- there are a number of them, and sometimes even the manufacturers offer some pretty good discounts. Shipping costs can add up, so order "in bulk" (order what you'll need for a few months of flying at one time). Probably the worst place to get them is the local hobby shop (who usually focus mostly on RC planes/cars/helis, etc.) They usually have the highest prices of ANYBODY.

Kits can be expensive, but I don't usually like most kit offerings nowdays. I like Dr. Zooch's stuff-- I've bought every kit he offers and have been doing beta-builds for a year or so for him now, so I get free kits of his new releases before anybody else gets them-- I report back to him on any and all issues I find with the build, proofread the instructions, offer tips or suggestions where things might be unclear, build the rocket and test fly it for him, and post a build thread on the rocketry forum, Ye Olde Rocket Forum, and Rocketry Planet to help drum up some interest and guide anyone wanting to build the kit through the process step by step, sorta like "video instructions"... works out pretty well.

When I'm not building Zoochies, I'm working mostly on scratchbuilds... I'm doing a 1/152 scale Saturn V at the moment, based on the BT-80 tube (2.6 inch diameter) with a BT-60 S-IVB stage (same scale as the Dr. Zooch Saturn IB, in fact I got the capsule and SLA balsa transition and service module from Wes at Dr. Zooch awhile back). This is making a nice "medium sized" Saturn V-- not as big as the 1/100 Estes version, but a LOT bigger than the "sport flier" Estes or Dr. Zooch BT-60 based Saturn V previously mentioned... and in the same 'ant scale' as the gaggle of Saturn IB's and even the Soyuz produced by Dr. Zooch... In fact I'm also doing a parallel build of a "Saturn I-F", which is basically one of the proposals for a replacement for the clustered first stage tanks of Saturn IB, which would have used a new 260 inch diameter stage consisting of a single LOX and kerosene tank designed similarly to the S-IC stage of the Saturn V (and which was in fact proposed as a liquid rocket booster for the Saturn V), powered by twin F-1 engines, built in the same scale.

Scratchbuilding stuff is actually pretty cheap, as tubes are readily available at pretty low cost from Semroc Astronautics or Sunward Aerospace, amongst others... balsa is fairly cheap and available at local hobby shops or better yet Hobby Lobby, and nosecones are available pre-made or can be made using balsa or closed-cell house insulation foam, or even using papermodeling techniques, as can transitions and various parts... there are folks on the forums flying paper models of various rockets and missiles using Estes rocket motors... and they fly very well... this REALLY keeps the costs down!

Later! OL JR

[luke strawwalker]

Originally Posted by rmks2000

Just wanted to comment that the original Saturn V did have the option to launch via a single rocket or cluster, but it may have been the Centuri version. It was one of those coveted kits that I never got. You could probably check the JimZ site to see if the original plans are there. I currently have the the Estes kit reissue (still unbuilt).

Yes, some still have that option, or they can be refitted for it. Thing is, it was a "non-prototype" cluster-- IE instead of a single black powder "D" motor, a three-motor cluster using black powder "C" motors would be installed in it's place. OF course the REAL Saturn V flew with five first stage motors, not three clustered in a triangle in the middle, so those wanting more realism have often designed new motor mounts capable of holding FIVE black powder rocket motors, usually -0 type booster motors, in the 'outboard' positions, with a single larger "D" motor with a delay and ejection charge in the center engine position... this gives a neat flight with five flames out the back and more "smoke-n-fire"... but of course requires more attention to detail in prepping the five motors to ensure they all light correctly and simultaneously...

later! OL JR

PS. I've pretty much decided this is how I'm going to do my BT-80 scratchbuilt Saturn V... I even printed off some paper F-1 engines and resized them into the same 1/152 scale and figured out how to integrate them with the 18mm motor tubes in the motor mount, so that the rocket appears to have scale F-1 engine bells covering over the model rocket motors in the back of the Saturn V during flight...

[luke strawwalker]

Originally Posted by The-EDSEL

I have the "Semi-Scale" Saturn-V from Estes (The Smaller one)
I also remember the Larger kit having the Option of a Larger Single D engine or a Cluster of 3 B or C engines
Later re-issues omitted the Cluster option.

I have several Built Estes & Centuri Rockets.
Scout Italia, Mercury Redstone, Bomark, Nike Ajax (or smoke need to look at it again)
Honest John, "Scissor Wing", Screaming Eagle, Orbital Transport (Has glider tag-along)
Bandit (the one with Exhaust ducting), Space Shuttle
R2-D2, Buck Rodgers Thunder Fighter, USS Enterprise & Klingon
Colonial Viper(TOS),
I lost a Space 1999 Eagle due to Crash landing using a
Longer coast/exhaust delay than called for
Unbuilt/unfinished TIE Fighter (body tube crushed in the bag when I bought it)
I have several unbuilt that I got clearanced from a store dumping all kits!!

I think I still have Estes & Centuri catalogs from 75-80+ somewhere too.

You can pick up a new tube to replace the damaged one in your TIE fighter from Semroc... Semroc Astronautics Corporation Online Store
I'm not exactly sure of the size, probably a BT-20 I'd bet... there should be part numbers or a diameter size on the kit card or instructions somewhere, or just ask Semroc, I'm sure they'd know...

Tubes are only a buck or two apiece...

Later and good luck! OL JR

[The-EDSEL]

I think I had planned on getting the Custom design set from Estes to replace the tube, but never could get lucky enough to find one.
I need to dig that TIE Fighter out to see what tube it had.

Thanks.

[closet astronaut]

Hey Luke

I have a question for an experiaced rocketeer. I'm building a QCC Explorer that is set up for E engines however it is C and D capable. My question is this, the adapter for the smaller engines fits loose in the mount, is this supposed to be glued in making it C and D size useable only? It's recommended to use a D engine for first flight but the way it looks to me the smaller engine would push up deep into the mount and possibly burning out the bottom of the rocket.

One more question. I have a couple of E engines that have been packed away in a box up in my attic for about ten years, I'm curious as to how useable they might still be.

Any advice will be greatly appreciated.

[The-EDSEL]

As I remember Estes & Centuri kits that had similar engine size options,
the adapter for the smaller engine should fit into the larger engine holder snuggly.
The lock-down for the larger engine should hold the adapter in-place.

How is the larger engine held so it does not slide up into the body too far??
a thrust ring glued in at a certain location, or a metal lock spring?

[closet astronaut]

Actually there's a spacer that goes in to keep the D engine down and in the holder. There's no way you can use a C engine in this with what's provided, it's probably a mute point any way because the largest "C" I have is a 6-5 and it recommends an 11-3 for the smallest. I'm not real sure of the preformance from such a small engine any way, this thing is quite large and has some weight to it.

[The-EDSEL]

It has been a while since I worked on any of my Rocket kits.
I agree there is not enough supplied to properly use the smaller engines.
The adapter sleeve should have a way to hold the engine tight.
A separate lock like seen or another sleeve that glues inside at the top
to keep the smaller engine from ramming up into the body, instead of lifting
the entire bird.
I don't remember the largest C or B engines Estes offered either.

[luke strawwalker]

Originally Posted by closet astronaut

Hey Luke

I have a question for an experiaced rocketeer. I'm building a QCC Explorer that is set up for E engines however it is C and D capable. My question is this, the adapter for the smaller engines fits loose in the mount, is this supposed to be glued in making it C and D size useable only? It's recommended to use a D engine for first flight but the way it looks to me the smaller engine would push up deep into the mount and possibly burning out the bottom of the rocket.

One more question. I have a couple of E engines that have been packed away in a box up in my attic for about ten years, I'm curious as to how useable they might still be.

Any advice will be greatly appreciated.

Sure glad to help if I can...

I don't have a QCC Explorer so I'm not sure what exactly they're selling them with in the way of adapters. The "E" motors are 95 mm long, whereas the "D" motors are 70 mm long (both being 24mm diameter). SO, some kits come with an somewhat loose-fitting "orange spacer ring" that goes in the motor mount first with the "D" motor inserted after it, to act as a "spacer" to hold the motor down into the bottom of the motor mount. Is this what you're talking about?? It doesn't have to be very tight... in fact you really don't want it to be, to ease the operation of removing it from the motor mount tube.

Now, Estes is coming out with some new plastic motor adapters, which act like a 'clamshell' around the smaller rocket motor, which is then inserted into the larger motor mount (the main motor sizes are 13mm diameter "mini motors", 18 mm "A, B, C" size motors (typical size) and the 24 mm "D and E" motors (all using black powder propellant-- it gets more complicated sizewise and goes MUCH bigger when you start talking about AP composite propellant.) Again, the clamshell adapters won't be terribly tight going into the motor mount-- because you have to remove the adapter and spent casing after flight.

Now, in the old days, adapters were made by gluing a 24mm diameter ring on the outside of a "BT-20" tube that held the 18mm motor, "adapting" it to fit the 24mm motor mount in the rocket. Another "quick-n-dirty" method is, simply hollow out an spent 24 mm "D" or "E" motor casing-- once thoroughly cleaned of all spent motor gunk, the inside diameter of the spent 24mm casing is very close to 18 mm, meaning the smaller motor will slide right into it. One can just enlarge the nozzle hole in the packed clay of the old spent 24mm casing to open it up sufficiently for the ejection charge to blow the parachute out, and install the lower motor backwards in it (then install the 24 mm spent casing "adapter" in the rocket backwards, so its hollowed out nozzle end is UP, (opened up enough to allow the parachute ejection charge to pass when the smaller motor ejects the chute) with the smaller motor inside it, nozzle end down. Make sense?? One CAN simply remove ALL the clay nozzle from the spent 24mm motor casing to make an adapter of it, and cut about a 1/4 inch long piece of casing off the end of a spent 18mm motor and glue it into the end of the 24mm casing, to act as a thrust block to prevent the smaller motor from "ramming up" through the rocket under thrust, while still allowing the parachute charge to pass and blow the parachute out at the proper time.

If in doubt, you can ALWAYS "Shim up" the motor or adapter a little with some ordinary masking tape... that makes for a good fit pretty quick.

Later and good luck! OL JR

[luke strawwalker]

Originally Posted by closet astronaut

Actually there's a spacer that goes in to keep the D engine down and in the holder. There's no way you can use a C engine in this with what's provided, it's probably a mute point any way because the largest "C" I have is a 6-5 and it recommends an 11-3 for the smallest. I'm not real sure of the preformance from such a small engine any way, this thing is quite large and has some weight to it.

Ah, OK... I see... this rocket is intended to fly on 24 mm motors ONLY. I wouldn't use an 18 mm motor. Estes came out with a 24mm diameter "C" motor called a "C11-0,3,5,7" (choose one last number depending on the rocket and conditions... it's the number of seconds until the parachute comes out after the motor burns out, except the 0 which is used for igniting an upper stage). Anyway, notice the average thrust number is MUCH higher "11" versus the standard 18 mm diameter C motor, which is "6"... more power for bigger/heavier rockets.

The orange ring you have there is a spacer to keep the shorter "D" motor (24mm diameter by 70 mm long) pushed back against the back of the motor hook when installed in the longer "E" motor capable motor mount (24mm diameter by 95 mm long). The adapter doesn't have to be tight-- it slides in and just acts to keep the "D" motor from moving forward 25 mm to the end of the hook or thrust ring when the motor ignites. This prevents the back of the rocket motor mount from getting completely toasted by the rocket exhaust (among other things).

Slide the orange ring into the motor tube, then slide the "D" motor in behind it, nozzle end down, and you're good to go. If you want to fly the longer "E" motors, you put the orange ring in your motor box with your "D" motors so you'll have it next time you want to fly a "D" motor in the rocket...

Later! OL JR

PS... neat third pic... the spacer is basically paper tubing similar to that used for the 24 mm motor casing... an 18 mm motor will slide up inside it like I described previously, but that's not it's intended purpose... this orange spacer is just to make the "D" motor plus spacer the same length as the "E" motor without the spacer... (which is the length of the motor hook installed in the rocket).