LOC Legacy, a good first mid-power?

LOC Legacy, a good first mid-power?

Post by Blaine Hilto » Sun, 07 Nov 1999 04:00:00



I have been doing Estes for awhile now and have done the D test.  I
think it is time to be moving up now.  I was loooking at the LOC Legacy
kit.  Have any of you built this?  If so how was it?  I'm not great and
need something thats kinda easy next step after doing D powered rockets.

I chose the legacy because it can take D-G engines.  Also it has a
payload bay which I need for some experiments I want to fly.  If you
have any other rockets that you think will work please tell me!

Thanks in advance
Blaine Hilton

NAR#(sorry forgot)

 
 
 

LOC Legacy, a good first mid-power?

Post by Gene Costanz » Sun, 07 Nov 1999 04:00:00


Fine choice, Blaine. Not sure about the D's, though; check its weight
after its complete to verify it's around the 10 oz. mark. Otherwise, E's
the minimum.

Should rip nice on a fat F or G. Good luck and ask away if you have
anymore questions.

 
 
 

LOC Legacy, a good first mid-power?

Post by Christiaan T Jacob » Sun, 07 Nov 1999 04:00:00


Quote:

>I chose the legacy because it can take D-G engines.  Also it has a
>payload bay which I need for some experiments I want to fly.  If you
>have any other rockets that you think will work please tell me!

The D is absolutely too small.  (from experience.  OUCH! )  The Parachute is
too small as well.   Other than those things  I love legacy's and have two
of them.  Fly regularly on G's   way out of sight .

Chris  TRA #4948

 
 
 

LOC Legacy, a good first mid-power?

Post by Paul Smit » Mon, 08 Nov 1999 04:00:00


Quote:

>I chose the legacy because it can take D-G engines.  Also it has a
>payload bay which I need for some experiments I want to fly.  If you
>have any other rockets that you think will work please tell me!

    Others have mentioned that the D is too small. Are you aware of the rule
of thumb that says that the average thrust should be at least 5 times the
rocket's weight? In other words, suppose you have a rocket that weighs 1 lb.
You need a motor with 5 lb. average thrust (of course, it's really initial
thrust that's important, and drag matters too - that's why this is a "rule
of thumb", and not a scientifically verified law). As you probably remember,
1 lb. = 4.45 Nt. Your 5 lb. of thrust is 22.25 Nt, and therefore you need an
engine with that avg. thrust. An F25 would be a good choice, but an F11
would not.

    Similarly, I've got a 36 oz. NCR Archer ready for its first flight.
That's 2.25 lb. It'll need an engine with at least 50 Nt. average thrust
(2.25*5 = 11.25 lb. = 50.0625 Nt.). The NCR F62s will work (barely, though),
while a G80 should be just about right. An F25 would be outright dangerous,
and any decent LSO wouldn't let me fly it.

    I think you're going to really like mid-power. I've sent up my Aerotech
Initiator a bunch of times on F62s, F20 Econojets, F25 SUs and E23 and F52
RMS engines. A real thrill on each flight. I'm dying to put the G80 in this
Archer, perhaps on Thanksgiving Day.

Paul Smith

 
 
 

LOC Legacy, a good first mid-power?

Post by Dean Rot » Mon, 08 Nov 1999 04:00:00


Quote:

>     Similarly, I've got a 36 oz. NCR Archer ready for its first flight.
> That's 2.25 lb. It'll need an engine with at least 50 Nt. average thrust
> (2.25*5 = 11.25 lb. = 50.0625 Nt.). The NCR F62s will work (barely, though),
> while a G80 should be just about right. An F25 would be outright dangerous,
> and any decent LSO wouldn't let me fly it.

My flight simulator says that a 6' launch rod/rail would result in
a end-of-rail/rod speed of 34 ft/sec, an altitude of about 460',
and recommends a 3.3 second delay. If I recall correctly the Archer
has a lot of fin surface. A day with no wind and a 6' rail
and I'd fly the rocket on an F25. The key is *no wind.*
Add any wind and an F25 is underpowered.

An AT F50 or G40 would work, too, as well as a G80.
Also consider the AT/RocketVision F72 and G55 single use motors.

A NCR F62 increases the launcher speed to 48 ft/sec, and the
altitude to about 500' with a recommended delay of 4.7 sec.
Use a 4 second delay.

If you like the black smoke of an NCR motor also consider an
AT H97J reload.

--
dean_roth at yahoo dot com
NOTE: Modify the return address to reply via email.

 
 
 

LOC Legacy, a good first mid-power?

Post by Paul Smit » Mon, 08 Nov 1999 04:00:00


(snip)

    Oops - did that go out to the list? I hope I got it right for the most
part. This was my understanding of what you'd told me (Dean) about that 5:1
ratio. Of course I interpreted it conservatively, ignoring things like
computer simulations (I've been looking for roughly 30fps at the end of a 4'
rod as a very conservative rule of thumb there).

Quote:
>>     Similarly, I've got a 36 oz. NCR Archer ready for its first flight.
>> That's 2.25 lb. It'll need an engine with at least 50 Nt. average thrust
>> (2.25*5 = 11.25 lb. = 50.0625 Nt.). The NCR F62s will work (barely,
though),
>> while a G80 should be just about right. An F25 would be outright
dangerous,
>> and any decent LSO wouldn't let me fly it.

    Obviously that was a pretty presumptious comment on my part, and Dean
knows far better than I about this kind of thing. The "no wind" thing is
definitely going to keep me from using F25s though.

Quote:
>My flight simulator says that a 6' launch rod/rail would result in
>a end-of-rail/rod speed of 34 ft/sec, an altitude of about 460',
>and recommends a 3.3 second delay. If I recall correctly the Archer
>has a lot of fin surface. A day with no wind and a 6' rail
>and I'd fly the rocket on an F25. The key is *no wind.*
>Add any wind and an F25 is underpowered.

Paul Smith
 
 
 

LOC Legacy, a good first mid-power?

Post by Dean Rot » Mon, 08 Nov 1999 04:00:00


Quote:

>     Oops - did that go out to the list? I hope I got it right for the most
> part. This was my understanding of what you'd told me (Dean) about that 5:1
> ratio. Of course I interpreted it conservatively, ignoring things like
> computer simulations (I've been looking for roughly 30fps at the end of a 4'
> rod as a very conservative rule of thumb there).

5:1 thrust-to-weight the general rule. Sometimes a larger ratio is
needed. Sometimes a smaller ratio can be used. The key is knowing
when you need more or can use less, and is usually related to
wind speed. In most cases the general rule of 5:1 is right.

Quote:
> The "no wind" thing is
> definitely going to keep me from using F25s though.

Believe it or not we do have windless days, or times of the day
without wind, in Wisconsin. Some winter days have been dead calm.
Or wait until 7-8 PM during the summer.

--
dean_roth at yahoo dot com
NOTE: Modify the return address to reply via email.