L1 cert rocket that can also be flown mid-power at home?

[mo2872]

So, uh, you fall for the banana in the tail pipe trick?

 

[Saint_Tiki]

Pretty rocket. Not exactly the the easiest to find color scheme, however.

I do like the nose cone paint that changes color when it is in the sun versus in the garage!

Hahaha. Yeah I decided it was a bit too grey and re-did both nose cones in copper metallic. I hadn't use plastic primer the first time so the paint would not have lasted long anyway.

 

[Saint_Tiki]

So, uh, you fall for the banana in the tail pipe trick?

That's my Fingertech Robotics Official Banana For Scale!

 

[mo2872]

That's my Fingertech Robotics Official Banana For Scale!

I had to look that up........after hoping you’d get MY reference!!!! LMAO!

 

[John_461]

North Coast Rocketry Hobgoblin!

I've flown mine on everything from an F27 to and H256!

 

[Saint_Tiki]

Alright, well some bad news, silver lining, and good news.

First, the bad. I flew it again on the G76 and unfortunately, the Mantis Launch Pad is just not built to handle the weights/impulses that the box advertises. The thrust from the G motor essentially knocked the launch pad sideways during boost, which cocked the rocket sideways while still on the rod, then the rocket snapped back the other direction after leaving the rod and tumbled unstable, did some skywriting, then belly flopped and snapped in half. Seems like it’s pretty well understood in the community that this pad is not heavy duty enough or at all suited to the ratings on the box (3.3lbs, up to G motors). Slow-mo clearly shows the pad deflecting from the exhaust force. Guess I got lucky with the first launch but video shows the same phenomenon during that flight as well.

The rocket snapped clean about 2” above the MMT and the top of the body tube zippered and fractured the top 5”.

I used a chop saw and removed the top 5” of the tube. I cannibalized the coupler for my AVBay and used that to epoxy the tubes back together down by the MMT. I ordered a new coupler to redo the AVBay in the next week or two. I was able to repair the rocket but it’s a bit shorter than it was before. With my planned motors, it was still technically stable at around 1.2-1.3 cal but I didn’t feel confident in that. I drilled a hole in the bottom of the nosecone and used some weight and some expanding rigid polyurethane foam to add about 75g to the nosecone which brought stability to about 1.6 cal and increased my confidence factor.

So that was the bad and the silver lining.

The good news is I brought the rocket out to Tulsa and flew it on an H152 for a successful L1 cert!

I didn’t have an altimeter but it simmed to about 2500’ but was probably closer to 2200’ based on the sim usually overestimating my altitude and underestimating my drag, in my limited experience. I flew it with a ChuteRelease but the 1.3g of CTI ejection charge BP threw the NC out with enough force that the parachute ejected out of the ChuteRelease rubber band so I had a nice 2000’+ main deployment under a 46” elliptical canopy. It took about 2.5 minutes to descend. The sim had it at about a 14-15fps descent rate which checks with the altitude estimate. It drifted 0.5 miles and barely missed some power lines and touched down gently in a soft dirt field.

That was awesome!

The custom conformal rail guides worked well. They were a little snug from all the buildup on some well-loved rails, but I brought a metal file with me to the range and filed down the plastic rail guides to get a looser fit. I also tested another set on my Aerodactyl which only flew an E23 and still left the rail easily.

So I guess now I’ll build my own 1010 rail based pad so I can actually launch mid-power without breaking stuff.

Oh and I named it "Atomic Number 29"

 

[Neutronium95]

The good news is I brought the rocket out to Tulsa and flew it on an H152 for a successful L1 cert!

Congratulations. Now it's time to break open your wallet for more motors.

 

[mo2872]

Alright, well some bad news, silver lining, and good news.

First, the bad. I flew it again on the G76 and unfortunately, the Mantis Launch Pad is just not built to handle the weights/impulses that the box advertises. The thrust from the G motor essentially knocked the launch pad sideways during boost, which cocked the rocket sideways while still on the rod, then the rocket snapped back the other direction after leaving the rod and tumbled unstable, did some skywriting, then belly flopped and snapped in half. Seems like it’s pretty well understood in the community that this pad is not heavy duty enough or at all suited to the ratings on the box (3.3lbs, up to G motors). Slow-mo clearly shows the pad deflecting from the exhaust force. Guess I got lucky with the first launch but video shows the same phenomenon during that flight as well.

The rocket snapped clean about 2” above the MMT and the top of the body tube zippered and fractured the top 5”.

I used a chop saw and removed the top 5” of the tube. I cannibalized the coupler for my AVBay and used that to epoxy the tubes back together down by the MMT. I ordered a new coupler to redo the AVBay in the next week or two. I was able to repair the rocket but it’s a bit shorter than it was before. With my planned motors, it was still technically stable at around 1.2-1.3 cal but I didn’t feel confident in that. I drilled a hole in the bottom of the nosecone and used some weight and some expanding rigid polyurethane foam to add about 75g to the nosecone which brought stability to about 1.6 cal and increased my confidence factor.

So that was the bad and the silver lining.

The good news is I brought the rocket out to Tulsa and flew it on an H152 for a successful L1 cert!

I didn’t have an altimeter but it simmed to about 2500’ but was probably closer to 2200’ based on the sim usually overestimating my altitude and underestimating my drag, in my limited experience. I flew it with a ChuteRelease but the 1.3g of CTI ejection charge BP threw the NC out with enough force that the parachute ejected out of the ChuteRelease rubber band so I had a nice 2000’+ main deployment under a 46” elliptical canopy. It took about 2.5 minutes to descend. The sim had it at about a 14-15fps descent rate which checks with the altitude estimate. It drifted 0.5 miles and barely missed some power lines and touched down gently in a soft dirt field.

That was awesome!

The custom conformal rail guides worked well. They were a little snug from all the buildup on some well-loved rails, but I brought a metal file with me to the range and filed down the plastic rail guides to get a looser fit. I also tested another set on my Aerodactyl which only flew an E23 and still left the rail easily.

So I guess now I’ll build my own 1010 rail based pad so I can actually launch mid-power without breaking stuff.

Oh and I named it "Atomic Number 29"

It was a great flight. My son and I kicked ourselves for not bringing our high powers. We thought it was supposed to stay windier than that all day!

Come back next time!

 

[dhbarr]

Atomic Number 29 looked great. I brought four hooligans and zero rockets, they had a great time until the 4yo ran out of steam.

 

[BABAR]

Alright, well some bad news, silver lining, and good news.

First, the bad. I flew it again on the G76 and unfortunately, the Mantis Launch Pad is just not built to handle the weights/impulses that the box advertises. The thrust from the G motor essentially knocked the launch pad sideways during boost, which cocked the rocket sideways while still on the rod, then the rocket snapped back the other direction after leaving the rod and tumbled unstable, did some skywriting, then belly flopped and snapped in half. Seems like it’s pretty well understood in the community that this pad is not heavy duty enough or at all suited to the ratings on the box (3.3lbs, up to G motors). Slow-mo clearly shows the pad deflecting from the exhaust force. Guess I got lucky with the first launch but video shows the same phenomenon during that flight as well.

The rocket snapped clean about 2” above the MMT and the top of the body tube zippered and fractured the top 5”.

I used a chop saw and removed the top 5” of the tube. I cannibalized the coupler for my AVBay and used that to epoxy the tubes back together down by the MMT. I ordered a new coupler to redo the AVBay in the next week or two. I was able to repair the rocket but it’s a bit shorter than it was before. With my planned motors, it was still technically stable at around 1.2-1.3 cal but I didn’t feel confident in that. I drilled a hole in the bottom of the nosecone and used some weight and some expanding rigid polyurethane foam to add about 75g to the nosecone which brought stability to about 1.6 cal and increased my confidence factor.

So that was the bad and the silver lining.

The good news is I brought the rocket out to Tulsa and flew it on an H152 for a successful L1 cert!

I didn’t have an altimeter but it simmed to about 2500’ but was probably closer to 2200’ based on the sim usually overestimating my altitude and underestimating my drag, in my limited experience. I flew it with a ChuteRelease but the 1.3g of CTI ejection charge BP threw the NC out with enough force that the parachute ejected out of the ChuteRelease rubber band so I had a nice 2000’+ main deployment under a 46” elliptical canopy. It took about 2.5 minutes to descend. The sim had it at about a 14-15fps descent rate which checks with the altitude estimate. It drifted 0.5 miles and barely missed some power lines and touched down gently in a soft dirt field.

That was awesome!

The custom conformal rail guides worked well. They were a little snug from all the buildup on some well-loved rails, but I brought a metal file with me to the range and filed down the plastic rail guides to get a looser fit. I also tested another set on my Aerodactyl which only flew an E23 and still left the rail easily.

So I guess now I’ll build my own 1010 rail based pad so I can actually launch mid-power without breaking stuff.

Oh and I named it "Atomic Number 29"

Somehow the landing part of the video reminded me of @Bat-mite ‘s flight. Probably just a coincidence. Congrats on your success.

 

[Saint_Tiki]

Congratulations. Now it's time to break open your wallet for more motors.

Yeah, I made some contributions to Glenn and Paul's motor business while I was there, haha.

It was a great flight. My son and I kicked ourselves for not bringing our high powers. We thought it was supposed to stay windier than that all day!

Come back next time!

Was really fortunate the winds calmed down. Especially since the parachute opened at 2000'+. I'll be back! I got a DD AVBay to plop on top of the rocket for next event.

Atomic Number 29 looked great. I brought four hooligans and zero rockets, they had a great time until the 4yo ran out of steam.

Yeah, I left my clan at home so I could focus. My experience with bringing my kids to my hobby events is that it comes at a cost, lol. I have to tell myself that the event is for them and not for me, otherwise I just get grumpy at chasing the circus around.

 

[thzero]

First, the bad. I flew it again on the G76 and unfortunately, the Mantis Launch Pad is just not built to handle the weights/impulses that the box advertises.

I have a Knight Manufacturing base with 8020 1010 rail, then a few other 8020 "lego" components to make a collapsible rail - still have to move it to change direction, but certainly better than un-masting it to stage the rocket.

 

[Saint_Tiki]

I have a Knight Manufacturing base with 8020 1010 rail, then a few other 8020 "lego" components to make a collapsible rail - still have to move it to change direction, but certainly better than un-masting it to stage the rocket.

Looks great. Nice use of the turnbuckle. I was just gonna make an X shaped based out of 1010. Might borrow the turnbuckle style angle adjustment.

 

[thzero]

Yeah, I saw that from a couple of others.

I had thought of doing the X based out of 1010 too. If you do, use some type of leveling casters on the corners. I have some I got from McMaster Carr that are for the 1" tubing, that I am hoping will give me ability to level this out at one of the club's launch spaces which isn't perfectly level.

 

[K'Tesh]

Design and build your own!

That's what I did.... Deep Space OFFL first flew on an Aerotech G67R-M Redline.



EDIT: I didn't see this thread before, so I didn't realize that the OP has since built and flown his rocket yet... D'OH!!!

Congrats on the Cert!!!

 

[Saint_Tiki]

Yeah, I saw that from a couple of others.

I had thought of doing the X based out of 1010 too. If you do, use some type of leveling casters on the corners. I have some I got from McMaster Carr that are for the 1" tubing, that I am hoping will give me ability to level this out at one of the club's launch spaces which isn't perfectly level.

I was planning to have adjustable feet that are just 6" segments of 1010 on the end of each of the X legs. They'd be connected with a 90 degree angle bracket and using a quick release locking handle so I can adjust them on the fly. Was going to use this to control the angle of the road but just tilting the whole pad, nice and simple.

 

[TheBru]

Alright, well some bad news, silver lining, and good news.

Congrats on the flight!

I am slowly working that way myself and started on a LOC Graduator that has worked pretty well for me so far. Started with an E23 to test flight stability and it went to ~300ft just fine. Worked my way through a few other motors with progressively higher apogee and ended with a G64 which took it to 1472.

The pre-painted weight (flew it naked) was 609g when including an electronics bay for my gps and beeper. I found that in OR I had to adjust the finish on all parts to get the sims to hit the correct heights after each flight. From what I have read the finish and fin shape are common adjustments to increase sim accuracy and I would suggest double checking the rod length for the sims as well.

Re the new pad: I use a Rockwell Jaw Stand and I find it has worked great so far. Easy stand to get from amazon for ~$60 and then order a 1010 rail from 8020,net for $0.23 per inch and a 4 inch square blank cover from home depot for < $1. After that it is just some screws and a short piece of wood to put it together.


Video below is the flight on the G64 and used a JLCR to have the chute open at 300ft, landed about 150ft from the pad.

 

[Saint_Tiki]

Video below is the flight on the G64 and used a JLCR to have the chute open at 300ft, landed about 150ft from the pad.

Awesome dude! Eggtimer telemetry? I've been looking into that, very interested.

609g empty? That thing is going to be orbital on an H motor, lol. Mine was about 1350g empty, canvas phenolic tubes. You're going to need that GPS. You gonna fly it on a 29mm H motor? Can get some lower impulse options in that size, keep it a bit lower for cert.

I'll take a look at the jaw stand option. Seems pretty good.

Just flew an E23 this past weekend on my aerodactyl. I think it's like 450g loaded up. Went up to about 700, was pretty solid.

You had good descent rate with the rocket separated there. When I used the JLCR, the tailcone went tail first and dragged the whole package into a streamline and was hauling ass straight down.

22fps on the chute though would worry me a bit. When you get an H motor case in there it's gonna go up a touch. I'd get a bigger chute since you have a JLCR anywere, it's not gonna drift.

 

[Rocketless]

Congrats on the flight!

I am slowly working that way myself and started on a LOC Graduator that has worked pretty well for me so far. Started with an E23 to test flight stability and it went to ~300ft just fine. Worked my way through a few other motors with progressively higher apogee and ended with a G64 which took it to 1472.

The pre-painted weight (flew it naked) was 609g when including an electronics bay for my gps and beeper. I found that in OR I had to adjust the finish on all parts to get the sims to hit the correct heights after each flight. From what I have read the finish and fin shape are common adjustments to increase sim accuracy and I would suggest double checking the rod length for the sims as well.

Re the new pad: I use a Rockwell Jaw Stand and I find it has worked great so far. Easy stand to get from amazon for ~$60 and then order a 1010 rail from 8020,net for $0.23 per inch and a 4 inch square blank cover from home depot for < $1. After that it is just some screws and a short piece of wood to put it together.


Video below is the flight on the G64 and used a JLCR to have the chute open at 300ft, landed about 150ft from the pad.

That was perfect!

 

[TheBru]

Awesome dude! Eggtimer telemetry? I've been looking into that, very interested.

That was a featherweight gps. A bit more $ but I lost a few too many smaller BP rockets as I was getting back into the hobby and my wife agreed to let me continue with the hobby provided I lose fewer rockets and I kinda like the spoken telemetry so that you can keep an eye on the flight but still hear some fun data as it goes. I'm also not quite ready to start soldering my own electronics...yet.

609g empty? That thing is going to be orbital on an H motor, lol. Mine was about 1350g empty, canvas phenolic tubes. You're going to need that GPS. You gonna fly it on a 29mm H motor? Can get some lower impulse options in that size, keep it a bit lower for cert.

Yeah, not sure whats going on with the weight aspect . I reweighed everything this morning and the numbers are still pretty close the to the 609g. Its currently "in paint" so the primer and spiral filler added a touch but I suspect the actual paint will add a bit more weight. I have a plan to fly this on an H55 at some point and that should get me up to about 2400' according to the sim but I'll need to do another E and F test flight once painted to make sure I have the numbers right before sending it up... and you know, will need to find a club to launch at so that I can actually get my cert. For that I am actually hoping to use a LaserLOC 223 on an I65WN but I still need to work my way up to DD and fiberglass on MPR before I take that step.

Just flew an E23 this past weekend on my aerodactyl. I think it's like 450g loaded up. Went up to about 700, was pretty solid.

Thats great! any pics of the flight?

You had good descent rate with the rocket separated there. When I used the JLCR, the tailcone went tail first and dragged the whole package into a streamline and was hauling ass straight down.

Interesting. I do have electronics in the payload section near the nose which may have helped me out but I'll need to keep an eye on that!

22fps on the chute though would worry me a bit. When you get an H motor case in there it's gonna go up a touch. I'd get a bigger chute since you have a JLCR anywere, it's not gonna drift.

Luckily the pasture that I was in is pretty soft so it wasn't a huge concern. I think that when I start traveling to launches I will try to get that down a little but I think I read somewhere that 15-25ft/s is a decent descent rate

 

[TheBru]

That was perfect!

Thanks!! Mostly due to launching on low wind days