MLP (HB2.1) Rocket Flight to 63k ft, M3.9

[mannyskid]

This is sweet dude! 63K is VERY impressive for an N! You guys should bring this, or another cool project to Aeronaut. Hopefully I'll see you guys there.

Manny

 

[A5tr0 An0n]

Here ya go Mat.

View attachment 175660

Thank you for the response. I don't mean anything negative but I would think you would be able to save some more mass. Maybe around the 640 - 700g range from what I would think. I am watching your thread. I am very curious if the ablative in that area is needed. Albeit I am thinking of a low M3 flight where yours was much faster, but have you considered using an ablative paint instead? I have seen it used to around M3.2 with it only burning off at the leading edges of the nose cone and fins. I like you alls approach, keep us updated.

 

[patelldp]

Thank you for the response. I don't mean anything negative but I would think you would be able to save some more mass. Maybe around the 640 - 700g range from what I would think. I am watching your thread. I am very curious if the ablative in that area is needed. Albeit I am thinking of a low M3 flight where yours was much faster, but have you considered using an ablative paint instead? I have seen it used to around M3.2 with it only burning off at the leading edges of the nose cone and fins. I like you alls approach, keep us updated.

May want to reserve judgement. We haven't seen any after pictures yet

 

[A5tr0 An0n]

May want to reserve judgement. We haven't seen any after pictures yet

Judgement on what?

 

[CarVac]

Thank you for the response. I don't mean anything negative but I would think you would be able to save some more mass. Maybe around the 640 - 700g range from what I would think. I am watching your thread. I am very curious if the ablative in that area is needed. Albeit I am thinking of a low M3 flight where yours was much faster, but have you considered using an ablative paint instead? I have seen it used to around M3.2 with it only burning off at the leading edges of the nose cone and fins. I like you alls approach, keep us updated.

What is "ablative paint"? I've never heard of such a thing...

 

[butalane]

This is sweet dude! 63K is VERY impressive for an N! You guys should bring this, or another cool project to Aeronaut. Hopefully I'll see you guys there.

Manny

Thanks Manny, as you'll see it should have gone higher. We're planning on going, no project though - this thing took quite some time to put together - other than (hopefully) some propellant characterization motors for the next project.

Thank you for the response. I don't mean anything negative but I would think you would be able to save some more mass. Maybe around the 640 - 700g range from what I would think. I am watching your thread. I am very curious if the ablative in that area is needed. Albeit I am thinking of a low M3 flight where yours was much faster, but have you considered using an ablative paint instead? I have seen it used to around M3.2 with it only burning off at the leading edges of the nose cone and fins. I like you alls approach, keep us updated.

Honestly, I don't think there is any further mass reduction to be realized in the fincan. Without actually deriving aerothermal environments I wouldn't do a single thing differently with this fincan. HB2 flew to M3.1 and hardly had a shred of paint left anywhere and a substantial char depth in the samples we took from the fins and NC. The low spots in the fins would need to be filled even if we decided against the ablative, so the mass impact would be realized either way with this design.

We considered and used "ablative" paint (BBQ paint). On this rocket it was really a just a convenient primer - it doesn't stand a chance against the airflow.

 

[A5tr0 An0n]

What is "ablative paint"? I've never heard of such a thing...

I meant it as "ablative paint." Meaning just a high service temperature paint and not a paint that is meant to ablate away. I have recently fell into like with such paint as I think it is something overlooked.

Honestly, I don't think there is any further mass reduction to be realized in the fincan. Without actually deriving aerothermal environments I wouldn't do a single thing differently with this fincan. HB2 flew to M3.1 and hardly had a shred of paint left anywhere and a substantial char depth in the samples we took from the fins and NC. The low spots in the fins would need to be filled even if we decided against the ablative, so the mass impact would be realized either way with this design.

We considered and used "ablative" paint (BBQ paint). On this rocket it was really a just a convenient primer - it doesn't stand a chance against the airflow.

Maybe not in your design, that I cannot speak about and I am sure you know better about it than I. I was just meaning if reducing weight was a goal I think there is further reductions to be had.

I don't mean to derail your thread but I meant other than the rattle can paint. Here are some attached photos of Mad Max (composite rocket) after a ~M3.2 on the N5800. The paint he used was an automotive PGP acrylic 2 pack which was also post cured, I believe. It held up amazingly well.

 

[CarVac]

I meant it as "ablative paint." Meaning just a high service temperature paint and not a paint that is meant to ablate away. I have recently fell into like with such paint as I think it is something overlooked.



Maybe not in your design, that I cannot speak about and I am sure you know better about it than I. I was just meaning if reducing weight was a goal I think there is further reductions to be had.

I don't mean to derail your thread but I meant other than the rattle can paint. Here are some attached photos of Mad Max (composite rocket) after a ~M3.2 on the N5800. The paint he used was an automotive PGP acrylic 2 pack which was also post cured, I believe. It held up amazingly well.

Don't let bobkrech catch wind of your abuse of the word "ablative". Ablating apparently specifically refers to the material eroding away by decomposing into a gas, which insulates the surface. And you didn't even come close to its correct meaning; you were suggesting paint that doesn't ablate.

 

[A5tr0 An0n]

Don't let bobkrech catch wind of your abuse of the word "ablative". Ablate apparently specifically refers to the material eroding away by decomposing into a gas, which insulates the surface. And you didn't even come close to its correct meaning; you were suggesting paint that doesn't ablate.

Lol. Again, it was meant as a " " type statement. You are a real Sherlock Holmes.

 

[patelldp]

Let's all sit back and enjoy the thread, don't want to ablate your credibility any further.

 

[A5tr0 An0n]

Let's all sit back and enjoy the thread, don't want to ablate your credibility any further.

Agree. Just trying to make a suggestion for one to ponder on. Didn't know it would be open for scientific review.

 

[patelldp]

Agree. Just trying to make a suggestion for one to ponder on. Didn't know it would be open for scientific review.

Tends to happen when you get out of the "model" rocketry realm into this stuff.

There's lots of great things to come.

 

[daveyfire]

I was just meaning if reducing weight was a goal I think there is further reductions to be had.

...

I don't mean to derail your thread but I meant other than the rattle can paint. Here are some attached photos of Mad Max (composite rocket) after a ~M3.2 on the N5800. The paint he used was an automotive PGP acrylic 2 pack which was also post cured, I believe. It held up amazingly well.

So if I hear you correctly, you're implying that butalane and oberth did a poor engineering job on their rocket by comparing their vehicle with a rocket that used more total impulse to achieve a lower altitude and a lower peak velocity?

Dude, this isn't "scientific review", it's common sense.

 

[A5tr0 An0n]

So if I hear you correctly, you're implying that butalane and oberth did a poor engineering job on their rocket by comparing their vehicle with a rocket that used more total impulse to achieve a lower altitude and a lower peak velocity?

Dude, this isn't "scientific review", it's common sense.

You read incorrectly. I am merely speaking of a possible alternative to using an ablative in the future. You can see in post #17 that I said I liked their engineering approach.

 

[daveyfire]

You read incorrectly. I am merely speaking of a possible alternative to using an ablative in the future.

A high temperature paint is not suitable as a replacement for an ablative. As CarVac said:

Ablating apparently specifically refers to the material eroding away by decomposing into a gas, which insulates the surface.

The cooling effect of the ablative is critical for its use in a high temperature application. A thin coating of high temperature paint does not provide thermal protection to the parts beneath the surface-- it merely withstands the temperature itself. The heat is still conducted rapidly through the paint into the substrate, where it can do damage. Having worked on a vehicle that flew to M=4.2 at Balls in 2010, I can say without question that the fact that this worked on a M=3.2 flight is not indicative of it working on a M=3.9 flight. The thermal environments are quite different.

If you bothered to read post #17 you would see that I said I liked their engineering approach.

Yes, I certainly "bothered". Wow. Chill out, man!

 

[dixontj93060]

Tends to happen when you get out of the "model" rocketry realm into this stuff.

There's lots of great things to come.

So if I hear you correctly, you're implying that butalane and oberth did a poor engineering job on their rocket by comparing their vehicle with a rocket that used more total impulse to achieve a lower altitude and a lower peak velocity?

Dude, this isn't "scientific review", it's common sense.

Best for me to sit this one out... op:

 

[Oberth]

You read incorrectly. I am merely speaking of a possible alternative to using an ablative in the future.

I've pondered using a good automotive paint myself and think it can be useful in some cases such as sealing composites from airflow. But when you need something to ablate, paint wont work...this rocket didn't need the bbq paint, its purpose was mainly as a primer so we could get a nice annoying shade of pink for the top coat. Along with what daveyfire said, remember we went mach 3.9 in 3.04s so we were in a really low, dense atmosphere. Given all the structural components were made with aeropoxy which has a tg of around 200F, if our composite warmed up we could have had an issue.

Now moving on with the thread...the propellant and grain configuration was the same as last years so nothing really new. 83% solids with a dash of Fe2O3, totaling 16.5 lbs...we'll jack up the solids loading in future projects. Everything was glued in with r45/carbon. Our goal was to see how much altitude we could gain given the same motor, if we changed the motor then we wouldn't really get a good idea of how effective our improvements were (we gained around a mile)...our improvements were indeed effective.

 

[A5tr0 An0n]

I am chill. If you did bother then I do not think you would of asserted that I said they did a poor engineering job. Also I am familiar with your work on the silver spur 3 at USCRPL, and I must say that I love the work that comes out of that place. I was really sad to see the recent space attempt go south, I was sure you all would make this go around.

I agree that it is not an indication; I never stated that it would work on a Mach 3.9 flight, that is a lot faster. But I am not sure that I think it cannot be an alternative to an ablative; do not mistake this for me saying that they are performing/functioning the same. Now I am merely talking about a single use rocket to M3.x. Why the x, because I do not know what the limit would be. I am in no way saying this would work on a mach 3.9 or M4+ flight and honestly I do not know if it would or not; I have no experience in that realm. I would think that the heat on this scale would be relatively short lived and it is that thought that makes me think it is doable. Even if the paint did burn away, I would think that this would eat up valuable energy and protect the underneath material. Granted you would probably want to use a higher temp. epoxy for the laminating. To clarify the last two sentences, I am meaning to protect CF from delamination and significant strength loss. Do you know what the temperature of the fins (not the leading edges and under the paint) is at these flight profiles? I do not.

I understand that some might want to be safer than sorry but I think that a lot have not really tried to see whats what and I was curious of the thoughts and considerations other have.

 

[A5tr0 An0n]

I've pondered using a good automotive paint myself and think it can be useful in some cases such as sealing composites from airflow. But when you need something to ablate, paint wont work...this rocket didn't need the bbq paint, its purpose was mainly as a primer so we could get a nice annoying shade of pink for the top coat. Along with what daveyfire said, remember we went mach 3.9 in 3.04s so we were in a really low, dense atmosphere. Given all the structural components were made with aeropoxy which has a tg of around 200F, if our composite warmed up we could have had an issue.

Now moving on with the thread...the propellant and grain configuration was the same as last years so nothing really new. 83% solids with a dash of Fe2O3, totaling 16.5 lbs...we'll jack up the solids loading in future projects. Everything was glued in with r45/carbon. Our goal was to see how much altitude we could gain given the same motor, if we changed the motor then we wouldn't really get a good idea of how effective our improvements were (we gained around a mile)...our improvements were indeed effective.

Thank you for the response oberth. I agree with what you said. If you want something to ablate away paint is not an option. I think the paint can be used as an alternative to an ablative but to what limits and obviously you would want to use something more like 4460 or something for the laminating. Just some curious thoughts I have had. I am really looking forward to seeing the rest of your thread.

Wow.. that is really great work on your motor and your gain. I had not realized that it was the same motor as used on the HB2.

 

[CarVac]

Wow.. that is really great work on your motor and your gain. I had not realized that it was the same motor as used on the HB2.

Reduction in mass gives enormous altitude gains in this impulse range. That's why CCotner and I were so optimistic about BN's altitude: it was only 8.5 pounds excluding the motor. We'll certainly be referring back to this thread when we make a new fincan for that...

 

[butalane]

You guys should bring this, or another cool project to Aeronaut. Hopefully I'll see you guys there.

I meant to ask, are you coming? What are you bringing? I look forward to seeing whatever it is!

Mat - thanks for posting the pictures. I can assure you that we did a good amount of background research before starting either project. Oberth has extensive experience flying min diameter rockets. We also talked to Burner and tfish whose advice helped us in leaps and bounds. I also reviewed the USC Projects, Mike Passaretti's N5800 flight as well as the Mad Max flight among other. I was shocked at the lack of damage that Mad Max showed after a M3.1 flight. Honestly it was far less than HB1 or a few of Burner's rockets saw (Incredulous) at much lower mach numbers. Perhaps the capability was due to the paint, but a thermal analysis of a coating at paint thickness, even with a a low conductivity is almost negligible. That being said by the time we built this rocket we had a pretty good idea of the environment and understood what it took to survive it so we tried not to deviate too much from a working design.

In terms of the fincan being overweight: well, I look forward to your fincan build and flight report.

 

[butalane]

The HB2 case had quite a bit of margin at 0.125in thickness so we decided to thin the case down. This would give us a mass and drag reduction.

So began the search for a tube that was uniformly round and straight. We learned a lot about aluminum tube and pipe tolerances and after a few tolerance stack calculations we were sure there was no way we would ever get a good tube. We looked high and low for a DOM tube but could not get one. To reduce the risk of a crap tube, we bought a newly available 3.5in ID, .125 thick tube and had .010 taken off. It turns out the .125in wall tube had much better tolerances than the normal .1875 stock, we got a tube that turned out awesome.

Unfortunately the tube ended up a bit longer than we expected. Just so you all know, you can cut aluminum tube with a chop saw....

 

[butalane]

We thinned down the forward bulkhead and added an integral pin ring. We also added a phenolic plate to the aft to insulate the bulkhead.

Machining


The phenolic plate was bonded onto the BH and match machined


The eyebolt was attached through a threaded through-hole. The bolt was epoxied into the hole, to seal the threads.


Holes were match drilled

 

[butalane]

To lighten the nozzle, we implemented a bit of phenolic:

Turning the phenolic blanks.


Exit Cone being turned into the aluminum carrier


Adding an external profile to shave weight


Machining the entrance cone


Exit Cone finished


And done

 

[Oberth]

Unfortunately the tube ended up a bit longer than we expected. Just so you all know, you can cut aluminum tube with a chop saw....

...and lots of WD :horse:

 

[watheyak]

View attachment 175705

Absolutely beautuful.

 

[patelldp]

Does your lathe have an auto feed to cut the angled cones? If it does, I have extreme lathe envy, as the Heavy 10 I work on does not have such a feature.

 

[mannyskid]

I meant to ask, are you coming? What are you bringing? I look forward to seeing whatever it is!

Yeah, I'll be out there. I'll be flying my 3" MD on the CTI M2245, it should touch just under 50k and around M3.5. I'm also making the motor for Alex's (Aksrockets) 3" MD, a 7600 Tiger Tail load, around 8300 Ns for an M2160, his should top out around 40k. It should be a great weekend!

Manny

 

[prophecy]

Yeah, I'll be out there. I'll be flying my 3" MD on the CTI M2245, it should touch just under 50k and around M3.5. I'm also making the motor for Alex's (Aksrockets) 3" MD, a 7600 Tiger Tail load, around 8300 Ns for an M2160, his should top out around 40k. It should be a great weekend!

Manny

Manny-glad to hear you're heading back out to Black Rock. C'mon, go to Balls instead- I managed to do it 3 out of the 4 years in college! Got to resist Ryan's urging to go to the small launches out there in addition to Balls if I want to pay off my credit card.

I'll see you in Argonia in a few weeks, yes? FWIW - assuming your config on the 7600 is 36" of pro, 1" cores straight - you won't get close to 8300ns or 40k with a 2% Al load. The reason I know this - I once knew a guy that made a 5% Al 7600 load in 2010 and claimed 8300ns and quickly got put in his place https://tqc.yuku.com/topic/3272/The-Kid-that-Played-with-Fire#.U6wmyF5U2hM

Also FWIW, I've done the 7600/optimized 3" rocket combo a good number of times, and each time it's topped out around 30k. The best I've hit with that combo was actually with that same rocket from the old TQC thread, in Oregon in 2011: https://www.youtube.com/watch?v=MqRMjSBDWmM

The rocket I've been building for Argonia is an uber-light version of an optimized 3" MD. I've got two motors, a 7600 SPR (don't think that one will crack 30k) and a 7600 of 10% Al slow-burn stuff I normally make for Balls that should get it up a little higher. We'll see how it turns out, and should be good data to add to the set.

Looking forward to the launch-what are you bringing?

 

[Oberth]

Does your lathe have an auto feed to cut the angled cones? If it does, I have extreme lathe envy, as the Heavy 10 I work on does not have such a feature.

No autofeed on the compound slide...that would be nice.

Butalane did an awesome job on the nozzle, it took several hours of machining...a real work of art