They seem enticing to me, but don't you still have to deal with the added friction, weight, and un aero-dynamics attributed during the stage when they are still on the rocket? Interested to know. Thanks now for responses!
Very interesting prospect.I've never used them, but from what I've seen and read, they should be used more often.
I've been brainstorming a way to create a modified FARG that can be used with a stock 1/8 or 3/16 launch rod.
Anything that allows me to get rid of a launch lug is worth looking into...
Cool. Whats that pad?Awesome to use, but if I get 5 uses out of one, it's a miracle - they break on landing. Never had on interfere with flight (hit a fin)
View attachment 532847
Very interesting prospect.
Cool. Whats that pad?
I've been brainstorming a way to create a modified FARG that can be used with a stock 1/8 or 3/16 launch rod.
Anything that allows me to get rid of a launch lug is worth looking into...
That's awesome, thanks for sharing!I used a KFLL fly-away lug from HPR in the past that worked great.
First run was made from poster board (curled by hand) with brass tube for 3/8" rod, attached with packing tape. The entire piece was then covered with packing tape for strength. I added two heavy rubber bands stretched tight to the back side to snap it away. Worked for H & I-power, but it did get closer scrutiny from the RSO the first time around.
It got nicked up by a fin, so I changed from poster board to denim. I don't remember how I attached the brass lugs to the denim. It seems like I wrapped the ends of the "Y" around them and used epoxy.
View attachment 532875
View attachment 532876
I've used several different flyaway rail guides from various manufacturers in various sizes... and they all broke. Some after one flight, some after 3 or 4 flights. I had a K2050 tear one to shreds at launch... fortunately it lasted just long enough for the rocket to get off the rail. And they don't like being dropped from a few hundred feet, either. It would be nice if somebody made one out of aluminum instead of 3D printing them, but there isn't one out there like that. YMMV, of course...Awesome to use, but if I get 5 uses out of one, it's a miracle - they break on landing. Never had on interfere with flight (hit a fin)
This seems like an exellent idea! I don't understand one thing. If The band around the rocket isn't tight, won't it slide down? and if its too tight, won't it creat execess friction?I used a KFLL fly-away lug from HPR in the past that worked great.
First run was made from poster board (curled by hand) with brass tube for 3/8" rod, attached with packing tape. The entire piece was then covered with packing tape for strength. I added two heavy rubber bands stretched tight to the back side to snap it away. Worked for H & I-power, but it did get closer scrutiny from the RSO the first time around.
It got nicked up by a fin, so I changed from poster board to denim. I don't remember how I attached the brass lugs to the denim. It seems like I wrapped the ends of the "Y" around them and used epoxy.
View attachment 532875
View attachment 532876
I just made my own KFLL this evening out of this flexible foam mat/sheet that you can get at craft stores. It's about 2mm thick and it has a bit of little stretch to it.This seems like an exellent idea! I don't understand one thing. If The band around the rocket isn't tight, won't it slide down? and if its too tight, won't it creat execess friction?
The only problem I see with my KFLL is that it has only a little "spring back" action. It's so light that I'm not worried about damage to the rocket if it hits a fin
This seems like an exellent idea! I don't understand one thing. If The band around the rocket isn't tight, won't it slide down? and if its too tight, won't it creat execess friction?
If you have some extra all thread or wooden dowels mix that with a centering ring that has a large enough inner diameter to fit around the rocket your launching and boom, should survive the fall.I've used several different flyaway rail guides from various manufacturers in various sizes... and they all broke. Some after one flight, some after 3 or 4 flights. I had a K2050 tear one to shreds at launch... fortunately it lasted just long enough for the rocket to get off the rail. And they don't like being dropped from a few hundred feet, either. It would be nice if somebody made one out of aluminum instead of 3D printing them, but there isn't one out there like that. YMMV, of course...
I think the answer to that question is, generally speaking, yes. But I think the answer depends on your rocket's design (high drag v. low drag), type of motor you're using (overall impulse and initial thrust) and type of fly away rail guide you're using.Is the initial drag on the rod/rail and drag until they come loose overcome by the lack of rail button/launch lug and actually provide higher altitudes?
Just an FYI:
Here's the prototype I made last night. The lugs are attached with CA glue and JB Weld. If it works, I'll do some tweaks, like seeing if I can find ways to reduce its weight and improve its "spring back ability." Tsmith1315's suggestions are one possibility, as is gluing a plastic strip to the outside of the orange foam. But I want to avoid adding any weight to the KFLL. This isn't b/c I care about performance as much as it is that I know a fin strike is inevitable and the less mass this has, the less likely there'll be damage to the rocket (or the strike will put the rocket into an unstable trajectory).
I picked up a sheet of that orange foam from Hobby Lobby last night. 99 cents. Unbreakable, easy to find, and enough material to make a bunch of units. I'm on board with you - if it works as well as it did for you, I see no reason to use a launch lug on any rocket I plan to build.Update:
I used the above pictured Fly-Away Launch Lug (FALL?) with my Estes Yankee and it worked flawlessly off of a standard Estes 1/8" launch rod and pad.
The launch took place with an A8-3 engine and the Yankee reached an apogee of about 195 feet (per Jolly Logic AltimeterTwo; the low apogee was due to the Yankee being heavily modified with a payload bay and baffle - its weight with the altimeter, but no engine was about 33 grams). I'd estimate that the FALL fell away from the Yankee rocket at somewhere from 40-60 feet and landed roughly 20-40 feet away (east) from the launch pad.
Launch conditions: moderate breeze from the west with an ambient temperature of 81 degrees F and about 60% relative humidity.
I'm going to further tweak the above pictured design to make it a little smaller and lighter. Oh, and any future rocket build that wouldn't require a stand-off launch lug will have no launch lug at all and use the FALL.
Thanks again @tsmith1315 for posting that article!
Great idea! I will try that...One thing I thought of is to store it wrapped the opposite direction of how it wraps around the rocket, to give it a little more spring away from the BT when it clears the rod.
Just an FYI:
Here's the prototype I made last night. The lugs are attached with CA glue and JB Weld. If it works, I'll do some tweaks, like seeing if I can find ways to reduce its weight and improve its "spring back ability." Tsmith1315's suggestions are one possibility, as is gluing a plastic strip to the outside of the orange foam. But I want to avoid adding any weight to the KFLL. This isn't b/c I care about performance as much as it is that I know a fin strike is inevitable and the less mass this has, the less likely there'll be damage to the rocket (or the strike will put the rocket into an unstable trajectory).
One thing to watch out for is FARGs that fit too loosely on your rocket. I've actually had rockets fly through a loose FARG and strip their fins.
I picked up a sheet of that orange foam from Hobby Lobby last night. 99 cents. Unbreakable, easy to find, and enough material to make a bunch of units. I'm on board with you - if it works as well as it did for you, I see no reason to use a launch lug on any rocket I plan to build.
One thing I thought of is to store it wrapped the opposite direction of how it wraps around the rocket, to give it a little more spring away from the BT when it clears the rod.
Thanks for your report on your observations with using a FALL (or was it a FARG?). I use these exclusively with my BT-20 rockets and get perfect launches every time. The only problem I get is that with some of the launches (maybe 66% to 75%?) the FALL will stay with the rocket until apogee/ejection. Then, as the rocket returns with a parachute, the FALL is slowly falling back to the ground like a large leaf in autumn.I have one launch on this, with an MD BT-20 rocket. Sent it up with an A8-5 for the first flight. It went sideways maybe 20-30 feet high and hit the ground near one of the farther-away racks. When I recovered it, one of the postage stamp-sized fins was missing. Looked around the launch area and the recovery area, didn't find it. The glue and fillets popped off the BT with minimal disruption of the surface. My test glue joints bent the fin and broke it above the fillet before the fillet came off the tube, so I'm not sure what happened. Still don't know whether the fin stripped due to interaction with the KFALL or rod at launch, or the ground at impact. The other two fins remain rock solid, so I'm hypothesizing that there was something different about the process or prep of the one that came off. I've fabbed a new fin and glued it using the original method. There was some crushing of the BT at the top, but I cut it off back where the tube is clean and OR says it's still stable with the shorter tube.
I'm kinda wondering about Gus' admonition to have an adequately tight fit. I thought my KFALL was "just right," giving good grip on the BT but not excessive drag on the 1/8 rod.
Looking forward to trying again.
There was substantial surface wind at the launch, so I'm also reading up on the papers out there dealing with wind-induced instability, but the OR sim said I was good with a C6-7 and I only had an A8-5 loaded, so I should have been more than good.
Might mess with fabbing up an inexpensive wire tower 18-24mm MD stuff if I keep having problems with this.
Enter your email address to join: