Starting construction on the H.L.P.L. Rocket

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Sep 24, 2016
Messages
18
Reaction score
0
What is the H.L.P.L.? It stands for Heavy Lift Powered Landing. The rocket will be capable of carrying a Quadra-copter (4 rotor like a drone) lander that will probably look allot like a lunar lander; to a height of 1500 ft and deploy it. The lander will then land under its own power under the direction of the launch crew. It will also have the ability to hover for a while to take pics and vids and do whatever else you want to do. Build pics and vids to come!!! Stay tuned.
 
I noticed on your site you had a Cato with an Estes E motor you plan to use for testing. Estes E motors (not sure the exact designations) are notorious for high failure rates. I would suggest switching to another motor, and if your going to do lots of tests it might be worth looking into the small reloadable motors.
 
I did notice a lot of the Cato vids on youtube were E engines. The rocket I used in that incident can take D's as well and is adaptable for C's. I was surprised that rocket made it through the explosion without a scratch except for a fried parachute.
 
LV 2 Concept Art2.jpg
This is a concept art rendering of the rocket. The payload bay will carry the lander. It will be a 2 stage rocket.
 
I noticed on your site you had a Cato with an Estes E motor you plan to use for testing. Estes E motors (not sure the exact designations) are notorious for high failure rates. I would suggest switching to another motor, and if your going to do lots of tests it might be worth looking into the small reloadable motors.

So we tested our 2nd stage today. Great success. Staged perfectly. That is until another E9 engine explosion, .2 seconds after the second stage ignited. The first stage was a D. I will no longer use E9s for launches. I'm probably better off clustering to get the same total impulse. Video Below for your amusement.
[video=youtube;mslWIQXeqlk]https://www.youtube.com/watch?v=mslWIQXeqlk[/video]
 
Be sure to fill out a MESS report a motorcato.org, hahaha just kidding, with the extremely high failure rate of the Estes E engines, if the MESS reports haven't helped with that situation then it's pretty clear that those reports are a waste of time.
 
Be sure to fill out a MESS report a motorcato.org, hahaha just kidding, with the extremely high failure rate of the Estes E engines, if the MESS reports haven't helped with that situation then it's pretty clear that those reports are a waste of time.

Well, at least my major reason for this launch worked. The staging actually went perfect. The slow motion video shows it actually released and continued on course perfectly. My last test before starting this rocket build.
 
I would stop messing with Estes E motors and go with the reloadable. At 24mm you can go as big as a G motor with the CTI 6 grain motors. The G65 would leave no need for staging. Lol
 
Be sure to fill out a MESS report a motorcato.org, hahaha just kidding, with the extremely high failure rate of the Estes E engines, if the MESS reports haven't helped with that situation then it's pretty clear that those reports are a waste of time.

Is this an issue with anything E or higher or just the E9's. Is there a better track record with the E12's? I would have to imagine it has something to do with the total impulse coupled with the small diameter. Considering the E12 and E9 have the same total impulse but the 9's are smaller and have a smaller diameter.
 
E9's are a bit notorious, especially across certain date ranges.

Please do continue to fill out MESS reports. NOT filing them has no potential upside.
 
Is this an issue with anything E or higher or just the E9's. Is there a better track record with the E12's? I would have to imagine it has something to do with the total impulse coupled with the small diameter. Considering the E12 and E9 have the same total impulse but the 9's are smaller and have a smaller diameter.

E12s and E9s are the same size. 24mm x 95mm. The E12s have a better record. The E16s are the 29mm x 114mm. As far as I know, only the E9s have a bad reputation.
 
So here is the final concept art for the new rocket. Construction will start this weekend. Due to the 3 inch diameter needed for the payload bay, there was a vigorous debate between Amy and I (if you have ever debated a 6 year old you know how vigorous it can get) as to whether to have the rest of the rocket be the same diameter or have it taper inwards a bit. (She won the debate. Hence the more stream lined look.) This rocket will have a 1 inch section just below the payload module that will carry the electronics that will initiate the launch and time the deployment of the payload. The payload bay opens like flower petals and the payload is spring loaded. No ejection charge deployment to protect the delicate payload. The payload will be a 3 oz quadracoptor that will be RC landed down range. This is a 3 stage rocket.
LV 2 Concept Art3.png
 
So here is the final concept art for the new rocket. Construction will start this weekend. Due to the 3 inch diameter needed for the payload bay, there was a vigorous debate between Amy and I (if you have ever debated a 6 year old you know how vigorous it can get) as to whether to have the rest of the rocket be the same diameter or have it taper inwards a bit. (She won the debate. Hence the more stream lined look.) This rocket will have a 1 inch section just below the payload module that will carry the electronics that will initiate the launch and time the deployment of the payload. The payload bay opens like flower petals and the payload is spring loaded. No ejection charge deployment to protect the delicate payload. The payload will be a 3 oz quadracoptor that will be RC landed down range. This is a 3 stage rocket.
View attachment 302934

Very cool project, if a bit ambitious!

Have you done any simulations? The part that seems most difficult to execute is the three stage flight. Two stage rockets have issues, but it is fairly rare to see a three stage rocket fly successfully, in my experience. Also, I would be concerned with stability issues with all that weight in the aft end, also not sure if an E12 has the thrust to get that design off the launch rod/rail with enough velocity.

Again, I love the project and don't mean to be a nay-sayer, just giving my two cents as to where you may run into difficulties.
 
I see the staging issues with other ones. It seems to have to do with the way the CG and CP changes when the rocket stages. I have been doind allot of sims to figure out how these properties change with staging. Trying to get it to change as smoothly as possible with staging. The fin shape is done for this reason. Also, the way we will build it, we can test it with 1 or 2 stages to iron out the flight characteristics. Also, it will be boosting off of an F engine to ensure maximum takeoff speed as velocity smooths out instability. Im also running sims with differing engine configurations for each stage. On paper things are going to work. But of course paper doesn't fly the rocket. I am even thinking of flying the full craft as it would be weighted but with just the 1st stage launching then just the first and second. This way we can see how it works before risking the loss of the most expensive part, the payload.

But definitely keep the critiques comming. I love the open source way this is going. Lots of great ideas.
 
So, after much simulations and debate, we decided to make the rocket into a 2 stage rocket. The altitude gain was at best 262 ft. Not worth the head ache of stability issues that come with 3 stages and initial take off speed. Well, here is the first pic of the 1st stage. The fins go all the way to the inner engine tube and is fixed to it with zip ties like Luna Star. The outer tube is a "Smart Water" bottle covered with a vinyl faux metal adhesive sheet. We are using lighter materials making this thing lighter than Luna Star by 1/2 ounce, even though it is 3 times the diameter and taller. You can look at "Luna Star" in the background for reference. I will be posting a vid about how the staging works, as it is slightly different than the normal "cellophane tape" staging.

Compared to the concept art, the fins are wider by an inch and of course the final product will be 2 stages.

We are not done with it. We still need to add a parachute on it and need to close up the corrugated holes on the leading edge of the fins.

I was asked about the hot glue gun holding the fins. Wondering if the stress would rip off the fins. The fin's aerodynamic stress are carried by the two zip ties in the inner core tube. The hot glue only holds the outer tube to the fins. The second stage will be similar and I will post step by step photos for reference.

###Suggestions Needed###
Would there be any advantage at all of leaving the corrugated plastic holes on the leading edge of the fins or would it be unneeded drag?

1stage.jpg
 

Attachments

  • 1stage.jpg
    1stage.jpg
    87.5 KB · Views: 56
Last edited:
I would stop messing with Estes E motors and go with the reloadable. At 24mm you can go as big as a G motor with the CTI 6 grain motors. The G65 would leave no need for staging. Lol

This^


I've never flown an Estes E motor, and likely never will.
If you don't want to get a reloadable, there are single use composites, but you will need more payload for the staging circuitry.
With your lofty ambitions that should not be an issue.
Best of luck with what sounds like a fun idea.
 
###Suggestions Needed###
Would there be any advantage at all of leaving the corrugated plastic holes on the leading edge of the fins or would it be unneeded drag?

If you close up the leading and trailing edge of that coruplast, you should gain some stiffness to the fins. Packing tape, for instance. Very little air will flow through at flight speed anyway.
 
So here are some pics of the construction of the second stage. I have made the rocket able to take any payload module I can design. The idea being, that the rocket should be able to be used for all sorts of different types of launches. Simulations indicate that this rocket should be able to adequately lift up to a 7 ounce payload. There are still some things to add to it. The launch lugs and inter stage cover is not yet on. The white payload module is not "part of the rocket" but is interchangeable. The module in the picture is not the one that will carry the Quadra-copter. The first launch will be a test launch at its limit. This module is designed to carry a GoPro camera and altimeter. This will be exactly 7 ounces and will test the rocket at its absolute limit.

20161018_161037.jpg20161018_161044.jpg20161025_220653.jpg20161027_082035.jpg20161027_082054.jpg
 
So here is the video of the first test launch of the Rocket now called "Jane". Didn't go so well. But it allows us to make some changes to the rocket and launch procedures to get a better launch.

[video=youtube;ZnkpOFjK9Ec]https://www.youtube.com/watch?v=ZnkpOFjK9Ec[/video]
 
At least you learned something, and will apply it forward, so not that bad.

In your video, causes #1 and #3 are related. As a rule of thumb that I use, take the weight in oz, multiply by 1.1 to get bare minimum calm-day average thrust. Multiply oz by 1.6 to get the good-to-go safe average thrust. As a general-rule-of-thumb that is.

For windy days, like this past Saturday with winds 12mph+, I pick shorter delays and don't do staging :y: or overstable rockets.
 
Back
Top