# couple mid power q's...

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#### rabidsheeep

##### Well-Known Member
err... just a few questions... what are some good online sites to buy midpower engines/rockets/equipment from?

the highest non liscened is 24 mm correct? or is it 29? if it is 24, and you get a kit that has 29 w/ a 24 adapter, can u take the adapter out so it is 29 again?

is there a certain launch rod you need? how thick are the rods you use becuase i think i could make one for cheaper than buying one...

for a launcher could i use an old one i hooked up to a 12v battery (the one i use for my cluster shots)

also if you have any kit suggestions...

thanks

--sheeepy

#### edwardw

##### Well-Known Member
When I saw this title "Couple of midpower q's" I was thinking - hmmm...I thought Q's were a bit bigger than midpower....pretty much hardcore high power engines there.....silly silly me.

Edward

#### nOrM

##### Member
err... just a few questions... what are some good online sites to buy midpower engines/rockets/equipment from?
Here are some I have delt with directly and can recommend. Other good ones exist but I just haven't delt with them.

http://www.magnumrockets.com/
http://www.hobbylinc.com/index.htm
http://www.wildmanrocketry.com/index.php
http://www.apogeerockets.com/
http://www.pratthobbies.com/

the highest non liscened is 24 mm correct? or is it 29? if it is 24, and you get a kit that has 29 w/ a 24 adapter, can u take the adapter out so it is 29 again?
Licensing does not depend on motor diameter but on propellant weight with the magic number being 62.5g of propellant. So, supposedly you can get a 29mm G80 or G64 but not a G33 (72.2g propellant) without a LEUP (Light Explosives Users Permit).

Besides the BATF LEUP situation, you need to get certivied by NAR or Tripoli to fly more than a G. There is another quirk that requires certification if the average thrust is over 100 Newtons so for instance, you need Level 1 certificatino to fly a G104T even though it is not an H motor.

is there a certain launch rod you need? how thick are the rods you use becuase i think i could make one for cheaper than buying one...
The closest thing to a standard for Mid power would be a 1/4" rod but launch rails are also very popular. These are stiff aluminum extrusions. You install two "buttons" on the rocket that interface with a slot in the rail for guidance. These were commercially pioneered by:

http://blacksky.safeshopper.com/

If you launch with a club, chances are they will have the rods/rails you need. If you go it alone then you can use what you want.

For rods, it's hard to beat the prices from
http://www.mcmaster.com
Just watch out for the shipping charges on long items.

for a launcher could i use an old one i hooked up to a 12v battery (the one i use for my cluster shots)
The easiest path is to convert the Estes Electron Beam to connect to a 12 VDC sealed lead acid battery. Here is one of many places describing the conversion:

http://www.rocketreviews.com/reviews/mods/est_electron_beam.html

also if you have any kit suggestions...
The Aerotech kits are pretty good and a quick build. The low end stuff from LOC/Precision and PML are more of a traditional type build and also very good.

Good Luck and welcome to the club

#### Dwight

##### Active Member
I am in the middle of building a full blown Mid power rocket myself.

I am building this kit

http://binderdesign.com/exceljr.html

I am also building a new launch pad for it based on an extruded 4 sided rail that is 6 feet long that you can get for $19.95 + shipping. You can get information on that rail here http://www.railbuttons.com/rb/faq.asp#compatibility For me half the fun is building my own stuff. I am using also a home built launcher that works with both estes and copperhead igniters and runs on 2 small 9V batteries. #### Missileman ##### Well-Known Member Most of your questions have already been answered but I can add my 2 cents and answer the one question you asked that wasn't answered yet. 29/24 adapter= there are different styles of these such as a screw in adapter similar to the PML quickswitch. another style uses a C clip to hold the adapter in place. The most common just slides in and is held in place with whatever motor retention you are using. Not as complicated as it sounds, you will understand after looking around a bit. Yes the adapter can be removed for 29MM flights. Mid power rods, depending on what kit you use, 3/16" and 1/4" are both common. alot of people just buy a solid length of stainless steel rod from the local hardware or steel supply. I personaly like scale military and have a number of Lanch Pad kits that are in the mid power range. Best of luck and welcome to MPR #### rabidsheeep ##### Well-Known Member thanks guys... just asked my mom and supposably if i clean my room we'll "talk"... kinda fell in love with this one: http://binderdesign.com/stealthjr.html now im alittle confused on engines so which would work with that, and be legal etc. etc. im sure this is like lpr where you get used to it over time... gotta go clean... #### loopy ##### Well-Known Member The Stealth Jr. looks like a great rocket, and I think you'll enjoy it. The things to keep in mind when deciding on your first mid power, however are these...You'll want something that is going to be fairly easy to build, as you'll be building with slightly different techniques for attaching things - CA and epoxy instead of white/yellow glue, stronger and bigger components, etc... I'm not sure if the Binder kits come with motor retention, which is important in mid power. You need a way to keep the motor in when the ejection charge fires. This is even more important when you're using reloads and have a$50 casing in the back of the rocket. Also, I think you need to cut your own fin slots on Binder kits. Not too difficult, but if you're not used to it, it can be kind of a pain.

Personally, I think Aerotech kits provide great insight into the world of mid power. They don't require epoxy for the build, the tubes are preslotted, and they use an engine hook for retention (like you're used to with the low power stuff). I have a few AT kits that I love, but other companies are just as good. I still recommend getting your feet wet with Aerotech, getting a few flights under your belt, then stepping out to other companies like Binder, Public Missiles, and bashing a few Estes kits for 24mm reloads (Executioner, Phoenix, Big Daddy...etc).

As for motors for the Stealth Jr, I've never flown one, but I think they would do well on F20 econojets. It says on their site that they include rocsim info - that should also include the motors and ideal delays in that information.

Good luck, and have fun!

Loopy

#### Dwight

##### Active Member
It is not on thier web site, but Binder designs sells their own motor retention system for \$13.

A very nice aluminum smap ring retainer.

Looks great.

But most high power kits do not come with motor retention, there are easy and cheap ways to attain that, 2 blind T nuts and a couple of screws in the aft centering ring and 2 small clips will do the trick.