Working on my first MPR/HP build..

[86mustang408w]

I have liked using a kevlar leader out of the air frame, then transition to tubular nylon.
In my L1 rockets case a pro series 2 elastic cord very similar to the spool from Amazon I assume.
I only have 6 flights on my L1 bird but check the shock cord regularly for wear and tear.
The elastic does make for a more energetic recovery event, I hope the rear swept fins hold up to landing.
I tend to make my recovery harnesses long, at least 2x the rocket length.

I'm gonna go for 3x on the length, just laid everything out. That's how I'm gonna do it ill post a picture in a minute. I don't see those fins breaking. It would take something harsh. And I'm gonna test it first on smaller motors but it shouldn't be that difference in landing..

 

[86mustang408w]

Here's everything laid out. Cut the tube earlier for the forward section, drilled and installed 2 screws 180° apart cut plywood backing pcs for the rail buttons, drilled those holes and installed them. The elastic cord will be longer its just in place to show its gonna be run. The shock cord coming out of the top centering ring mount will come out of the body tube about 14 inches, giving it a little extra for my chute protector setup so I can make a loop. Also cut the motor tube to square the motor retainer end, got those 3D printed retainers for $.99 from Rocketryworks(I know right!!?!) The 3D 29mm to 24mm is for test fits too. And yest flights if need be on E's. I messed with them and the best way to nake sure the retainer base get centered by having the motor adapter in an tight. Then ill use a little CA and "tack" it in place. 3D motor retainers are amazing. I bought 4. Probably going to put a swivel on the chute at the quick link imbgonna go to Coles and look around the hardware section. I went with 3/16 eyelet bolts and nuts, with the extra nit being 10x24mm bc Ace nor Coles sells 3/16" hardware they all start at 1/4. . And really thinking of a way to beef up the fins, I don't think I will have an issue landing on a soft surface, but hitting concrete or such would be a bad day. But nothing is epoxyed yet but its getting close to that. I'll leave the adt centering ring out then install it at the end. Theres about a 1/8" gap between that motor centering ring and the motor retainer. I didn't want it too close or you cannot tighten the female reatiner all the way. But thats about it, got the orange paint and Orangs sticker for the paint scheme. That Alpha III was the first kit I bought 5 or 6 weeks ago so this is what I'm using, I've always loved those rockets. Except for the Jollylogic chute release and their Altimeter 3, the chute release will be ordered soon. I'm using my Estes Olympus as a test mule. That threads over in LPR. It's about bed time, so I'm out. Thats enough for 2night..

 

[86mustang408w]

Getting there, working at it a little one day at a time..

 

[86mustang408w]

Thread has moved over here from MPR...

 

[86mustang408w]

Anytime you mentioned the word elastic then people get their panties all wadded up as they usually will make the comment "elastic is only good within the top of underwear", so usually just ignore that kind of stuff.

Yeah it just got me bc I ordered those spools so I can use it for other projects and got bummed thinking I got the wrong stuff. But a guy that has had his L1 for a long time has been helping me an I swear I watch at least one YouTube video a day on L1 builds. This is probably going to be the most in depth level one build I've seen. Its all basically custom with touches like my hand made chute protectors from nomex I got on ebay. Etc..

 

[Hobie1dog]

Here's everything laid out. Cut the tube earlier for the forward section, drilled and installed 2 screws 180° apart cut plywood backing pcs for the rail buttons, drilled those holes and installed them. The elastic cord will be longer its just in place to show its gonna be run. The shock cord coming out of the top centering ring mount will come out of the body tube about 14 inches, giving it a little extra for my chute protector setup so I can make a loop. Also cut the motor tube to square the motor retainer end, got those 3D printed retainers for $.99 from Rocketryworks(I know right!!?!) The 3D 29mm to 24mm is for test fits too. And yest flights if need be on E's. I messed with them and the best way to nake sure the retainer base get centered by having the motor adapter in an tight. Then ill use a little CA and "tack" it in place. 3D motor retainers are amazing. I bought 4. Probably going to put a swivel on the chute at the quick link imbgonna go to Coles and look around the hardware section. I went with 3/16 eyelet bolts and nuts, with the extra nit being 10x24mm bc Ace nor Coles sells 3/16" hardware they all start at 1/4. . And really thinking of a way to beef up the fins, I don't think I will have an issue landing on a soft surface, but hitting concrete or such would be a bad day. But nothing is epoxyed yet but its getting close to that. I'll leave the adt centering ring out then install it at the end. Theres about a 1/8" gap between that motor centering ring and the motor retainer. I didn't want it too close or you cannot tighten the female reatiner all the way. But thats about it, got the orange paint and Orangs sticker for the paint scheme. That Alpha III was the first kit I bought 5 or 6 weeks ago so this is what I'm using, I've always loved those rockets. Except for the Jollylogic chute release and their Altimeter 3, the chute release will be ordered soon. I'm using my Estes Olympus as a test mule. That threads over in LPR. It's about bed time, so I'm out. Thats enough for 2night..

 

[86mustang408w]

Thanks, I've had some scrutiny about the build, but I have a gew helping me and I'm taking it slow. I'm not a small rocket big motor guys kets see what happens. The Jollylogic will help with the altitude, and its gonna be tested a few times before its H flight next year, night not even make it last that but I dont see it failing. Big concern was the fins breaking, but I dont dee that happening easily with this smller lighter rocket landing in a grass field. I'm doing lots of homework, and its gonna be awesome. Its working out well by those who are opened minded and see that my L1 attempt means just as much as their L3, but yesterday talked to the SPAAR club president, looks like we are Ll good to go launch some G engines! Its gonna be blast July 29th at Halifax in PA. Ill have pictures for sure but its my first club meet, so I talked to him they have 1/8" to 1/2 setup for lugs, and a 1010 rail for my other ones. They have all the controllers etc, kade a small checklist and asked him some questions for about 10 mins, really nice guy. I got the rail buttons done last night with the backing plates, I nade then a bit thinner only due to my BT size. I'm wathcing an OpenRocket Tutorial right now to get more basics, but have been doing ok I just need to add all the little stuff, right now the stability is at 2.87. I'm told by some thats not good and others that its ok up until 5. So on a H engine it outnit about 2k feet with a bunch of other simulations. And I didn't use 1/4" eyelet bolts, went with 3/16" bc again of the 2.55" BT. So, thanks to all, if I had this many positive responses 10 years ago I'd be SO much further by now. But im here, ready for ny L1 goal! And had some conflicts about me using the yellow kevlar cord then elastic shock cord.. ofnits concerns about it ripping and not being strong enough its strong, trust me. Some don't like the Alpha III color scheme of Orange/Black, but thats what I'm doing. Its just off of a upscale by a little. Thanks guys, look for updates! Michael B.

 

[86mustang408w]

Watching a YouTube tutorial now and going back and making all the measurements correct on OpenRocket, the stability already dropped to 1.9 with the H motor in. Apogee at 1900 ft..getting cooler...

 

[86mustang408w]

From Milton, PA any of the clubs are a distance.
The PARA 520 club is another you may consider. We fly in central Bucks county. Probably same distance from you as the Lancaster club.
http://www.para520.com/
https://www.facebook.com/groups/paranar520/
Biggest issue we have is there are lots of trees (see photos on Facebook). If conditions (wind) is right then we do fly to over 2000 feet but with wind in wrong direction keep flights much lower.

Do you fly any hogh power H/I stuff? Thats what I need, might join URRG in NY.

 

[4regt4]

Its actually elastic shot cord i just got in a spool like the kevlar shock cord(550 lb test). I'm 265 and I hung on it.....Its gonna be fine....lol

I have been using elastic on everything. I'm convinced it has prevented many a zipper, as I've had numerous AT "bonus delays". Like an H165R that was drilled to 9 seconds, but still took the full 14 seconds to fire the ejection. And an H238T drilled to 9 seconds that took 12 seconds to fire.

For heavy rockets, I use a belt and suspenders approach. I parallel the elastic with Kevlar to prevent the elastic from hyper extending and breaking. The elastic I've been using stretches to twice it's "relaxed" length. So if I'm using 5 feet of elastic, I'll parallel that with 10 feet of Kevlar. Also, I'm not using just the elastic - I typically have a short piece of Kevlar exiting the body tube, then the elastic, then more Kevlar. Like 10' to 16' total, depending on the rocket.

For lighter rockets and most MPR, I don't go the parallel route, but just use Kevlar, elastic, more Kevlar.

Hans.

 

[86mustang408w]

I have been using elastic on everything. I'm convinced it has prevented many a zipper, as I've had numerous AT "bonus delays". Like an H165R that was drilled to 9 seconds, but still took the full 14 seconds to fire the ejection. And an H238T drilled to 9 seconds that took 12 seconds to fire.

For heavy rockets, I use a belt and suspenders approach. I parallel the elastic with Kevlar to prevent the elastic from hyper extending and breaking. The elastic I've been using stretches to twice it's "relaxed" length. So if I'm using 5 feet of elastic, I'll parallel that with 10 feet of Kevlar. Also, I'm not using just the elastic - I typically have a short piece of Kevlar exiting the body tube, then the elastic, then more Kevlar. Like 10' to 16' total, depending on the rocket.

For lighter rockets and most MPR, I don't go the parallel route, but just use Kevlar, elastic, more Kevlar.

Hans.

I'm gonna use the Kevlar shock cord for a foot or so out of the BT, then a quicklink to the Elastic shock cord and rest of the recovery system. Mocked it up last night, pic below. Thanks for the responses, its really appreciated!!

 

[4regt4]

I'm gonna use the Kevlar shock cord for a foot or so out of the BT, then a quicklink to the Elastic shock cord and rest of the recovery system. Mocked it up last night, pic below. Thanks for the responses, its really appreciated!!

You'll need to remove the spools before flight. Just kidding.

I prefer to not do the whole thing in elastic, if for no other reason than it takes up a bunch of room in the body tube. But if you can pack it all in, it should work!

Hans.

 

[86mustang408w]

You'll need to remove the spools before flight. Just kidding.

I prefer to not do the whole thing in elastic, if for no other reason than it takes up a bunch of room in the body tube. But if you can pack it all in, it should work!

Hans.

Haha, yeah it will work, I'm doing research. Paying close attention to all kinds of YouTube videos to see what all are using. But method was given to me by someone who has his L1. And had been doing it this way for years. Well find out on the shakedowns, but I forsee no issues with it.

 

[Art Upton]

If you do your L1 with this rocket (which it absolutely can), my only concern is the landing. But as long as the field is soft, it shouldn’t matter, but if the field is hard (like compacted sand/ dirt like down here, or in the desert) but that shouldn’t be a problem, but I’d say don’t round or airfoil the trailing edge to prevent splitting if it’s ply, or to induce more drag so you don’t lose it!

And as long as you do some big ol’ fillets, internal and external, almost anything could handle most small H’s like an H128 (reload), which doesn’t have Hazmat and you could probably even just borrow a case! And a J/L is a good idea, because of shorter recovery, and if it fails the chute is still out causing drag, so it might still be fine.

Shakedowns on G’s and F’s are a great idea. And a orange and black color scheme would be very cool, but I’m a bit biased on that.

Good luck!

You really do not have to do Big heavy Fillets for L1 rockets, it adds weight to the wrong side of the rocket.
I have flown an Estes Partizon twice on I205 with only the wood fins Gorilla glued to the internal motor mount paint the fins on the mount; then slit the end of the body to to slide it on the fin can after the body tube was painted.

A very thin coat of wood glue was used after the body was on the fin can only to seal off the slots to keep air out of it.
I flew it on an I205 at Octoberfest in Jean Dry lake twice, one on Friday and again on Saturday as folks did not believe it.

 

[4regt4]

Haha, yeah it will work, I'm doing research. Paying close attention to all kinds of YouTube videos to see what all are using. But method was given to me by someone who has his L1. And had been doing it this way for years. Well find out on the shakedowns, but I forsee no issues with it.

BTW, one of the arguments that many put out there as to why you shouldn't use elastic is that "snap back" will cause the nose cone or payload bay to snap back and collide with the body tube, causing damage. I've seen this happen with really short shock cords (like 24"), but not longer ones.

I have a friend that does a great job videoing some of my flights. He zooms in quite close, so I can easily observe the ejection event. I've never seen the snap back phenomenon happen. Stuff shoots out there, and stays out there. It might pull back some, but airflow keeps the parts well separated from each other.

Hans.

 

[86mustang408w]

BTW, one of the arguments that many put out there as to why you shouldn't use elastic is that "snap back" will cause the nose cone or payload bay to snap back and collide with the body tube, causing damage. I've seen this happen with really short shock cords (like 24"), but not longer ones.

I have a friend that does a great job videoing some of my flights. He zooms in quite close, so I can easily observe the ejection event. I've never seen the snap back phenomenon happen. Stuff shoots out there, and stays out there. It might pull back some, but airflow keeps the parts well separated from each other.

Hans.

I'm using Kevlar from the top centering ring, about foot out of the tube and then elastic, but i still understand what you mean. I asked around and this is what I liked the best. The person mentoring me has used this setup for years, with no issues. He did stress and I agree to make sure you use 3x the length of the rocket, so ill have about 9 feet of it. that should be enough to prevent that "snap back" from happening. But happy with OpenRocket, the stability is at 1.27 after I made some minor corrections. I'm not trying to be stubborn, but after looking around and noticing what people use for years, I'm gonna give it a go. But Thank you for the feedback, it's in my notepad for future reference..

 

[86mustang408w]

You really do not have to do Big heavy Fillets for L1 rockets, it adds weight to the wrong side of the rocket.
I have flown an Estes Partizon twice on I205 with only the wood fins Gorilla glued to the internal motor mount paint the fins on the mount; then slit the end of the body to to slide it on the fin can after the body tube was painted.

A very thin coat of wood glue was used after the body was on the fin can only to seal off the slots to keep air out of it.
I flew it on an I205 at Octoberfest in Jean Dry lake twice, one on Friday and again on Saturday as folks did not believe it.

Ok, thank you for that info and video!!

 

[86mustang408w]

Got OpenRocket printed out with the new stability and fixed weights and measures, but somethings off with the BT diameter because its supposed to be a BT-80(2.55" OD), well I entered that and the body tube is a little bigger with the actual rocket compared to the body tube i picked to match mine exactly(With OpenRocket)so it threw all the templates off. I'm not sure why, maybe its a dumb mistake I've been messing with this quite a bit and might need a breather, lol. But I won't take one I did this to occupy my time.

 

[waltr]

Do you fly any hogh power H/I stuff? Thats what I need, might join URRG in NY.

No, limited to G80 as per NAR "Model Rocket Rules". Full limits are on our web page.
The SPAAR club has the same limits.

This is why I also belong to MDRA and drive to Maryland to fly H and up.
URRG is probably much closer to you and an easier drive (a lot less traffic).

 

[86mustang408w]

Ok, watched 2 hours of 3 different peoples tutorials. Went thru and corrected all my mistakes, yesterday got the actual measurements because I already had the rocket started(b4 I even got to this program last week). I switched and went with Free-form fins instead of trapezoidal to be able to set them easier, and the only thing I don't know is the sweep angle, but going in and setting zoom at 100%. I can hold the fin up to the computer screen and got it close, lol. Anyways, switching to the unfinished 3D version really helped me, for some reason seeing it like that made it easier for me to tweak. But the stability is down around one with an H165R motor I chose in. I'm not so concerned about the chute opening right after apogee and it driving away. The JollyLogic will take cars of that. But I made the chute size bigger, gonna use my 42" spare from the Aerotech G-Force. I bought a custom 48" for that. But the landing velocity was 15ft/sec with the 30" i was gonna use, if it wasn't for the fin design I'd take that bc I'm gonna be landing in grass. But the 42" took it down to 9 something. But also got mass components places for things like the eyelet bolts and quick links. So thanks guys, you've been a help. Also Steven, BYU Rocketry, and RIT launch Initiative for the awesome tutorials. Thanks guys here too! Getting back into this has me just baffled(pun intended) by what this hobby has become since 1990..

 

[86mustang408w]

No, limited to G80 as per NAR "Model Rocket Rules". Full limits are on our web page.
The SPAAR club has the same limits.

This is why I also belong to MDRA and drive to Maryland to fly H and up.
URRG is probably much closer to you and an easier drive (a lot less traffic).

I heard thru the grapevine MDRA was launching a little too high, i heard you need some other license now? Maybe not. But MD is about a 5 hr drive for me, URRG is less. I think 2.5?? I have to look i may be getting them confused with MARS. I have it all written down, I'm glad I did..

 

[86mustang408w]

Well I got foam board at the Dollar tree(they had white and black and you haveto look and make sure they aren't creased badly) for $1.25, lol!! I didn't have a use for it, but decided to get rid of that old panel wood fin one I had. This was the 2nd try, idk why I went out to the garage but I have my new hobby mat in here(its been a minute since I had one) and in the garage marked it all out and was terribly off. But this time I started out with a 10" square piece, cut and traced it exactly, tape all 4 side so it won't move these boards are 20" so you just cut it in half. Then centered the BT for my build in the middle of the 2 pcs. Traced that, then measured 3 inches out from the tube and 1/8" wide using the degree lines in the mat. Did that one at a time after marking the lines on the mat, I started and marked them all but they moved, but I only had the other 2 marked bot cut yet. Best to do one then another, mock it up constantly, and mark/make lines only as you get to that fin. But my thinking was to double it(and put a bunch of small foam spacers in between the 2 pcs about 2 " thick) at the outermost 4 corners and tape it together. But one reason I chose this over cardboard or plywood today is that its foam, so if you cut it a little tight, this will push back and hold the stuff securely in place, I can pick this up and move it without issue. My last one everything would fall apart if you didn't hold it all. But just left the two pcs taped together. You can get w templates out of this board that size for $1.25, plus the obvious tools. But its better than cardboard for just that it almost holds it in place like glue!! But thats one thing I did on this rainy day.....

 

[86mustang408w]

Inside, pretty sweet...

 

[tsmith1315]

Big concern was the fins breaking, but I dont dee that happening easily with this smller lighter rocket landing in a grass field

Since you’re using JLCR, you can always be generous with chute size to set it down easy.

 

[Hobie1dog]

Inside, pretty sweet...

looks pretty strong

 

[86mustang408w]

Since you’re using JLCR, you can always be generous with chute size to set it down easy.

I had a 30 inch, but have my spare G-Force 42" chute I can use. In OpenRocket in went from 15ft/sec with the 30, then to 9 with the 42. So I have options. When I find a nice size that works ill get one made for it.

 

[tsmith1315]

I had a 30 inch, but have my spare G-Force 42" chute I can use. In OpenRocket in went from 15ft/sec with the 30, then to 9 with the 42. So I have options. When I find a nice size that works ill get one made for it.

42" ought to give you a nice comfort zone, if it doesn't open at apogee!

The large fins on this rocket are 1/8" 3-layer craft plywood, you can wiggle them easily. It's only flown the once, but a 36" LOC chute set it down from an H238 fight easy enough to survive perfectly:

https://www.rocketryforum.com/threads/what-did-you-do-rocket-wise-today.48649/post-2141390

 

[86mustang408w]

looks pretty strong

Thank you, I haven't dropped a ounce of epoxy on it, but I might have it ready for shakedowns July 29th. But that might be pushing it I still need to order the JLCR, JB weld for the motor retainer, loctite for the hardware and 5 min epoxy for the BT and couplersBut if inhave enough space I could just use normal ejection as deployment.

42" ought to give you a nice comfort zone, if it doesn't open at apogee!

The large fins on this rocket are 1/8" 3-layer craft plywood, you can wiggle them easily. It's only flown the once, but a 36" LOC chute set it down from an H238 fight easy enough to survive perfectly:

https://www.rocketryforum.com/threads/what-did-you-do-rocket-wise-today.48649/post-2141390

Thats what I'm going for. I'm getting my other collection in about an hour, so ny choice may open up. But this will fly on a H in the next year. Thats gonna happen! I'll watch that video when I get home later, thank you!!

 

[86mustang408w]

Got my collection today from 2013....wow...

 

[4regt4]

Got my collection today from 2013....wow...

I second that.

Wow!

Suspect the Gorilla glue might be a little past usefulness though.

Hans.