LOC/Precision Weasel 29

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DynaSoar

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This was my first heavy duty bird (heavy tube, ply fins, etc.).

I was impressed at the sheer strength of the materials. Obviously it could handle more than the Gs which were it's highest rating. I beefed up the motor mount for this purpose. I epoxied on some slabs of body tube scrap to spread the stress on the motor tube to the ends of the mount rings rather than depending on the ID/OD surface epoxy. I also loaded up the lower MMT ring with enough epoxy to run out before inserting it, so it would bond to the main tube from above and below.

Rather than epoxy on glass for fin reinforcement I just gave it good, thick fillets, at least 1/4" thick. I used Devcon 5 minute epoxy throughout. I wish I'd had some syringes to work with, but managed fairly well using only 1 foot by 3/16" bamboo skewer stick for stirring and application.

I spent anout 1/2 hour planning, adding my estimates of how much epoxy to mix when to their (rather skimpy) instructions. It paid off. It went from parts to primer in less than 6 hours.

My two complaints with this bird, one probably specific to my parts, the other to the design:

1. The cone didn't fit precisely parallel. I inserted the cone into the payload tube and gave it a roll test. It wasn't a smooth roll. I figured out where the low spot was and beefed up the shoulder a bit. That took care of it.

2. The parachute is maybe 12 inches, is thick cloth and has thick cords. I can't believe they expect this thing to safely lower a bird that's going to be pushing a pound when loaded. As always, I put the chute on a locking snap swivel, so it'll be trivial to swap chutes in and out. I'm just afraid to try this one by itself. Maybe with a second 12" maybe, or one 18".
 

Chilly

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I just finished a Weasel a couple months ago and am waiting to fly it at the next Tripoli launch.
It was built stock. Considering how high this thing's going to get, I'd just as soon keep the smaller chute on it. I believe the rear end is strong enough to withstand a fast landing, especially with a spent motor casing in there to beef it up.
Even stock, it'll probably handle an H128. But I don't know if it's worth risking a motor casing...who knows if I'll get it back? For now I'm gonna stick to single-use F & G's.
 

RocketboyG80

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I really don't like LOC's little 14" chute. I find that rockets drift way to far on them. I would recommend putting in a small X-type chute or a streamer if you plan on using G and/or H motors.
 

Hospital_Rocket

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I wish I'd had some syringes to work with, but managed fairly well using only 1 foot by 3/16" bamboo skewer stick for stirring and application.
Oh come on, some of us know where you hang out (at least in the afternoon). If you can't get a syringe they must be frisking people.



;)
 

DynaSoar

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Originally posted by Hospital_Rocket
Oh come on, some of us know where you hang out (at least in the afternoon). If you can't get a syringe they must be frisking people.



;)
Oh, we use syringes in the lab, for injecting conductive paste into the EEG cap. For no particular good reason our lab tech ordered 1cc tuberculin syringes. It'd take 3 refills of these to do one fillet. I've talked him into ordering 10cc's next time.

If I were to ask someone at the VA hospital other than us Yale folks for syringes, they'd take advantage of the situation to, as the current popular federal employee saying goes, run around with their hair on fire. Of course, I look far more like some of the patients than someone with extra title letters on both ends of my name, so their reaction would be both logical and predictable.

Besides, making do with those bamboo skewers makes me feel like a real arteest.
 

Rocketman248

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I love the Weasel! That thing is wicked fast on G's. I flew it on a G64 at NARAM45. Rocksim predicted about 3,500 feet. I'm sure it did all of that and more. Luckily I got it back. It didn't drift all that far on the stock chute.

Pic here.
 

DWW2320

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I have flown my weasal on and h128 and had a great flight
 

Stymye

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woah ,thats an east 4,000 ft flight !
glad you got it back !
 

Chilly

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GEEZ! And I almost lost mine on a Ellis Mtn. G35 last week! That motor, by the way, is just way too low-thrust for me. I like long burns and figured it'd be cool, but it wouldn't even keep the Weez going straight up. It arced over and went ballistic to nearly 3000' and came down about a mile away, sans nose cone. Picked up a new cone from Ross and it's good as new, but from now on it's gonna fly on Econojets only.
 

Robin

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I have been launching a Magnum Opus (Caveman) with E- and F motors. Then I wanted to try a rocket that fits 29 mm F- and G motors and purchased the Weasel. What a beast that is. Last July I tried my weasel on a F52-8T. The rocket weighs almost a pound so I expected an altitude of about 1800 feet. By my surprise the rocket disapeared from the pad in a blink of an eye and reached an altitude of about 2400 feet! That F52 blue thunder really made the Weasel punch a hole in the sky.
Later on I ordered a G33 blackjack reload. The package said the maximum liftoff weight for that type of motor was 450 grams. The Weasel weighs about 500 grams so I do not dare to launch my brand new weasel on such a motor, the thrust might be too low. Does someone have an Idea or experience with launching a Weasel on such a motor?
 

Missileman

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I launched mine twice on F20s for suprisingly fast and high flights.
The stock chute seems to be a perfect fit for this rocket.
Oh and WELCOME to TRF Robin:D
 

Robin

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Hi Missileman,

Thank you for your reply, its good to exchange experiences.
My experience with the F52 blue thunder was quite surprising indeed. F20's will do fine as well as long as they provide a short and powerfull thrust. Now I have this longburn G33 blackjack. I once had a bad experience with a F12 blackjack on my Magnum Opus. The thrust provided was dramatically insufficient. After a staggering climb to 5 meters it went horizontal and plowed into a field. I dont want that to happen to my Weasel. Maybe the mishap to my Magnum Opus was due to the age of the motor. The reloadkit was packed in 1999!
By the way, that stock chute Loc inclosed with the kit was in my opinion way too small for such a heavy bird. I replaced it with a 18" chute. The decend was rapid but okay, it didn't drift away too far as well.
 

JoJo

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i lost my weasel on its firs flight on a f20-7:( . but i did like its strong construction, all except it's stock shockcord mounting.
 

Missileman

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Blackjack motors typically have a lower thrust than other APCP motors.
The key is taking a look at the thrust curve for that particular motor.
People often make the mistake of taking the average thrust into account when looking at what motor to fly on.
Rule of thumb dictates a 5 to 1 ratio of thrust to weight.
But that refers to initial thrust not average thrust.
That rule of thumb was figured to get your rocket moving fast enough off the launch rod or rail for stable flight.
I look for motors that deliver at least 5 to 1 initial thrust and 3 to 1 through most of the burn.
The F20 worked well for me as I built light. I came in at 2 oz. less than manufacturers stated weight on my Weasel
 

Robin

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Hi Jim,

That 5 to 1 ratio guideline can prove very helpfull to determin if that motor will be adequate to push my Weasel upward. If I look back at my Magnum Opus incident, I might have made the misstake not to study the thrust curve.
Never the less, I prefer the White lightning and the Blue thunder motors to be sure there is enough thrust to punch a hole in the sky. :D

https://www.geocities.com/robint372003/

By the way I inserted the link to my modelling site. There are also some rocketry pages.
 

Chilly

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See my experience with the Ellis Mtn. G35 a few posts above...it taught me the difference between average vs. initial thrust! I was lucky to get it back.
I do, however, plan to pick up an Ellis single-use H or I long burn motor for the Weez. THAT should be a very cool flight. Might actually be time to spend the $$ for an altimeter.
 

lalligood

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Originally posted by Chilly
I do, however, plan to pick up an Ellis single-use H or I long burn motor for the Weez. THAT should be a very cool flight. Might actually be time to spend the $$ for an altimeter.
You might want to plan on taking a long time to look for it too! :p

Those EM H & I motors are like the Energizer Bunny. They just keep going and going...and going... IMHO, you'd even be pushing it in that rocket with the EM G35.

Those motors work wonderfully (& best) on lightweight rockets but the rocket design should be a little on the draggy side unless you have a LARGE, flat, open launch site. You've been warned ;)
 

Robin

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Hi Chilly,

Thank you for your reply. As stated in previous posts its worth checking the thrustcurve and the initial thrust in particular.
Like the real Buzz Lightyear I aim for the stars and beyond. If a G33 could come close to that, then it's worth trying that on the Weasel. Near my place I know a few wide-open fields so that should not be a problem.
I also plan on buying a altimeter for dual deployement, might come in use when I launch that Weasel on a G80.
Unfortunately Aerotech reloads and single-use motors are hard to get at the moment so I just wait until they are in store again.:rolleyes:

Robin Trap
Den Helder, Holland
 

Robin

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I launched my Weasel on a G33-7J today. According to Rocksim's calculations the Weasel should reach an altitude of a mere 1800 ft. That calculation wasn't right. I expected a slow boost but that Weasel went straigt up surprisingly fast and reached an altitude of at least 3000 ft. I even lost sight of the rocket for I didn't see any tracking smoke. After a while I saw a little dot of the parachute way up in the sky. I was glad I saw it back again. :cool:

Greetings

Robin Trap
Den Helder, Holland
 

DynaSoar

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Originally posted by robin
I launched my Weasel on a G33-7J today. According to Rocksim's calculations the Weasel should reach an altitude of a mere 1800 ft. That calculation wasn't right. I expected a slow boost but that Weasel went straigt up surprisingly fast and reached an altitude of at least 3000 ft. I even lost sight of the rocket for I didn't see any tracking smoke. After a while I saw a little dot of the parachute way up in the sky. I was glad I saw it back again. :cool:

Greetings

Robin Trap
Den Helder, Holland
I was launching mine this weekend on a G35-4. After reading this I did a sim. At 4 seconds it'll be going almost 300 mph. It'll coast for 12 seconds. I better rethink this.
 

Robin

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Originally posted by DynaSoar
I was launching mine this weekend on a G35-4. After reading this I did a sim. At 4 seconds it'll be going almost 300 mph. It'll coast for 12 seconds. I better rethink this.
Quite short 4 seconds delaytime, did your rocket come out of this adventure okay?
I had 7 seconds delay and the parachute must have deployed at high speed. One of the fins nicked the upper half (near the coupler) after separation. The fin and the upper part of the rocket were damaged but can easily be repaired with a bit of putty and paint.:rolleyes:
 

DynaSoar

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Originally posted by robin
Quite short 4 seconds delaytime, did your rocket come out of this adventure okay?
I had 7 seconds delay and the parachute must have deployed at high speed. One of the fins nicked the upper half (near the coupler) after separation. The fin and the upper part of the rocket were damaged but can easily be repaired with a bit of putty and paint.:rolleyes:
Hadn't launched yet.

I switched engines around. It's got an F21-4 now.

For fixing with putty, check out the epoxy putty from Apogee. Very cool stuff for all sizes of jobs.
 

Missileman

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I have flown mine twice on F20-7 and the delay was perfect. Deploy right at apogee.
 

Robin

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Originally posted by missileman
I have flown mine twice on F20-7 and the delay was perfect. Deploy right at apogee.
The F52-8T I used for the first flight of the Weasel was also perfect, deploy at apogee. For the second flight I tried the G33-7J. The delaytime of that motor prooved to be a bit short. High speed deployement made a deep cut in the upper bodytube. My Weasel is undergoing repairs now and is allmost ready to fly again.:)

Robin Trap
Den Helder, Holland
 

DynaSoar

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Originally posted by robin
The F52-8T I used for the first flight of the Weasel was also perfect, deploy at apogee. For the second flight I tried the G33-7J. The delaytime of that motor prooved to be a bit short. High speed deployement made a deep cut in the upper bodytube. My Weasel is undergoing repairs now and is allmost ready to fly again.:)

Robin Trap
Den Helder, Holland
I flew mine today on an F21-4. A little short of a delay, but not terribly so. Very pretty flight. Pics to come.
 

DynaSoar

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Originally posted by DynaSoar
I flew mine today on an F21-4. A little short of a delay, but not terribly so. Very pretty flight. Pics to come.
Bah. Pics no good. Too far. Those little throw-aways aren't good for much. I need a digital with zoom.
 

DynaSoar

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Originally posted by DynaSoar
Bah. Pics no good. Too far. Those little throw-aways aren't good for much. I need a digital with zoom.
This one turned out, sort of. It's well in the background and blurred from speed, but you can see how the sky and the ground burn from the exhaust.
 
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