There Is No Why (screw it, I'll try a P)

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prophecy

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And you all thought you could get rid of me for a while.

My retreat into obscurity to attend to other areas of my life lasted about 10 days, at which point I was told in no uncertain terms that I'd have a lot more free time (and a little bit more money!) at my disposal moving forward, with this notice coming largely as a byproduct of the Sunday Silent/Balls effort. So, with that in mind:

Background

I let the "right person, wrong time" ship sail about a year ago - I have goals I want to accomplish that to me are what life's about. I did not make the choice lightly, and have woken up thinking about it most days since. One thing is clear to me - I have a responsibility not only to myself, but actually to the both of us to see these aspirations realized and to let no subsequent challenge or conflict stand in my way. So, I plan to live up to that. Verruckt and Sunday Silent were steps toward that effort, but that's just the beginning. I have a long way to go, and once I've realized my rocketry goals, I have some Himalayan goals to chase that are far more taxing on a domestic situation than a rocketry project; the period of no contact is measured in months, not days or weeks, and there's always the very real possibility of never coming home. So, I'd better get going on writing my story before it's time to turn in the keys.

Over the weekend, I drove 802 miles to visit an old friend and mentor of mine, a friend who's flown a rocket or two in his day (understatement of the year). We got to talking about my Balls project, and how some friends and I have been spitballing about getting a high-altitude launch together for mid-January. We talked about big motors and the waiver I have to work with (75k'). "It'd have to be pretty damn inefficient to stay under 75k' with a big motor," I thought. But I already have a 1/4" wall P motor case (it's heeeeaaaavy); I've had it for years. Doing a mass inefficient P project would ironically be far cheaper than the hyper-efficient two stage I had been thinking of, and plus, who doesn't like the visceral effects of a big motor. I had a Rambo-like torture recollection of writing the check to the machinist that made the Sunday Silent thin-wall motor parts, and the deal was sealed. My Class 3 app is due in 5 days, saddle up.

I'll have a couple months to put this together, so it'll be pretty chill, and it'll be far less customized than my last project (basically it's a 6" Verruckt). Early sims on the motor show a 58,400ns P6400 with the Sunday Silent propellant. The numbers look awesome - oh, the joy of non-super high L : D motors, how I've missed you. Hopefully we can add about 10k' to the Sunday Silent total, make a cool big motor, take full advantage of the waiver, and put another notch in the belt. Upscale of the Sunday Silent fincan, electronics in the nosecone, yada yada yada.

The name is a famous quote from someone I've looked up to since I was a child (who was actually recently portrayed by Joseph Gordon-Levitt in "The Walk"). After breaking in to the World Trade Center overnight and walking a tightrope from tower to tower with no safety harness during the early morning rush hour, Philippe Petit was arrested and brought to court. When told he'd be let go if he provided sound reasoning for his stunt, he replied "there is no why...people ask why I risk death, but to me, this is life."

When I was 13, I went to climb Washington's Mt. Rainier (later turned out to be the start of a lifelong obsession). After being the youngest one on the summit to that point that summer and feeling my life's first delirious exhaustion and the accompanying irrevocable accomplishment that I would come to crave, I met Beck Weathers at Base Camp (ironically, also recently portrayed in the "Everest" movie). Beck lost an arm, both feet, a hand and his nose chasing his dream in the Himalayas. He was one of the lucky ones. This stuck with me; chase your dreams at whatever cost is required and let nothing stand in your way. No sleep, some money and some loved ones, that's what I've given so far. That's nothing. Onward we go.

In 1924, George Mallory stood on Sandy Irvine's shoulders at 28,250 feet and free-climbed the notorious second step of Everest's north ridge in patent leather boots. His oxygen had run out. While never proven, the evidence all points to his summiting after nightfall against all protocol, burying a picture of his wife and son on the summit, and attempting to downclimb the mountain's uncharted South side since he'd be unable to downclimb the second step with Irvine having descended. He was to die on the way down, and Hillary (climbing 29 years later) would be credited with the first ascent. The only reasoning he ever gave for the goal that ultimately took his life is, "I will climb it because it is there."

Mallory and Petit go a long way in illustrating my approach to things...my "it" that is there for the taking is the opportunity to do some pretty cool things in the aerospace field as a complete and total amateur in the short term, and eventually, the same "it" Mallory referred to. Then we can turn in the keys and get on with a "normal" life. Maybe.

Documenting the journey is important to me, hence the series of lurid threads. Sorry if it doesn't fit the vibe of the forum, but it's either here or Microsoft Word, so figure I might as well share. Now to work on the C3 app.

-steve
 
You have to live life as you choose. Chart your own course. Sadly, few do.
 
Steve-I had a pretty wild life before settling down and tried to instill in my sons the 'rocking chair test' where when you are old and all used up and you are sitting on the porch you have to ask yourself if you regret not taking any opportunity or adventure in your life. You seem to be doing fine in that aspect. Chase your dreams and let the naysayers miss all the fun. What good is a long life if you die from boredom? "If you're not living on the edge-you're taking up too much space". Much admiration and good vibes your way for your future endeavours!
 
Funny enough... I thought the title was some star trek reference "do or do not, there is no why"....

This is gonna be a cool thread. I'll be watching.
 
Just when you thought it was safe to go back into the High Power forum :D

More seriously - your builds are never boring so I'll be watching with interest.
 
Yes leads to life lessons, no provides what you already have. Like I told a friend in college, say yes to the P.
 
Subscribed, like I did with your last two. Your builds are incredibly inspirational and always leave me on the edge of my seat waiting to hear more of what's to come. Now, I'm not L3 (yet) but I can tell a P motor is no small feat. Good luck.
 
I'd love to know how you pulled that feat off. That's something I've been after for about the last 25 years. :wink:

I was told in no uncertain terms that I'd have a lot more free time (and a little bit more money!)
 
My retreat into obscurity to attend to other areas of my life lasted about 10 days, at which point I was told in no uncertain terms that I'd have a lot more free time (and a little bit more money!) at my disposal moving forward, with this notice coming largely as a byproduct of the Sunday Silent/Balls effort. So, with that in mind:


I'd love to know how you pulled that feat off. That's something I've been after for about the last 25 years. :wink:


Every time I quit smoking....within 3-4 days whoever I was married/dating/ummm whatever with bought a pack and threw it at me. (I've quit now for 7 months woo hoo!)

I'm guessing it's something like that.
 
LOL!

Every time I quit smoking....within 3-4 days whoever I was married/dating/ummm whatever with bought a pack and threw it at me. (I've quit now for 7 months woo hoo!)

I'm guessing it's something like that.
 
Just awake and thinking about this. Amazing how much time one has when it isn't wasted doing insignificant stuff designed only to pass the time. I think I'll live like this for a while!

This project has changed from a 6" 1/4" wall mid P motor to a 5" 1/9" (yes, one-ninth) wall mid O motor. Basically, I wasn't super stoked about lobbing a 39 pound pipe up "just because," but as denoted in the initial post, I talked myself into it because it made the most sense for the application. But when the first deadline came - the 90-day Class 3 application deadline - the fire just wasn't there to get the app done and submitted for such an inefficient project that was basically wasting chemicals to get to the same altitude I could get for so much less propellant and not having to do the C-3 app.

That same day, Rocketry Warehouse had their Bargain Bin sale with 60% off 5" x 60" airframes. If I were to fully optimize a 5" motor like I did a 98mm motor for Balls, it would do six figures easily, so if we're going to do a 5" motor, it'll have to have an airframe and be built "hobby-style" to fly at our 75k' waiver launch. The blemished airframes being discounted were gunmetal grey, a bad batch of black pigment for the usually black tubes. As it turned out, I think the grey is badass and way cooler than the black, and there's nothing I like more than buying a random cheap part and saying "this is the defining parameter, we're now going to make it work." The tube was on its way.

That night, one of my buddies flying from the east coast for this launch called. This particular friend had a run of XX phenolic liners made for a 1/8" wall 5" case years ago, and told me he insisted on finding a way to return the favor of hosting him. Since we aren't aware of any nice steak joints in the desert where we're launching, he asked if I was going to case bond the motor, and I said yes, for lack of another option. A 5" liner set was in the mail the next day. Guess we're building a 5"!

It's a nice way to bring things full circle. Sunday Silent was making up for this inefficient catastrophe: https://tqc.yuku.com/topic/2466/BALLS-Project?page=1#.VixjyDEo6Uk (Holy crap, a kid born the summer I built that is now in their eighth year of life. That was the summer before I went down to DC and slept on the street for Obama's first inauguration. Time flies, that's seriously weird). That project was pretty cool when I was 17, but the guy who made the motor for that flight is a god among men when it comes to propellant making, and the damn thing still only went 37k'. A few years later, I made a motor for it and it went 33k'. Holy inefficient.) Anyway, Sunday Silent made up for that.

In the 5" realm, last year I slammed together a 5" composite cased motor with the same total propellant mass and grain config as this project will have. That was back when I had other priorities in life and crammed rocketry into the hours after she went to bed, so I didn't have time to do anything the way I wanted to. The rocket was built in the manner that was most convenient, and was flown at our first 75k' launch last year. Some graphite that was already on hand (coarse grain) was used for the nozzle, and in addition to being ridiculously heavy overall, the nozzle exit cone gave up the ghost at motor shutdown, costing us significant altitude and resulting in a 38,000' apogee. Lol. So, hopefully this project, while far from optimized, will redeem us a little bit from that effort, much like Sunday Silent showed marked improvement from my 17 year old endeavor. Here's a video of last year's flight, because why not: [video=youtube;89hlKxTMfeM]https://www.youtube.com/watch?v=89hlKxTMfeM[/video]

The final reason I wanted to do this 5" is I want to push the case wall even thinner than 1/8", and the numbers say this can be done while pretty easily maintaining requisite safety margin for the conservative pressure I want to run in the motor. Standard hobby 5" airframe has an ID of 5.00," same OD as the case material I'll buy, so we'll need to shave down the pipe .006" on each side, leaving us with a roughly 1/9" case. This coupled with the lower hoop strength of the larger diameter tubing will pose a nice challenge, continue to progress the learnings regarding efficiency of our cases in the right direction and giving some tangible engineering value to the project despite being deliberately inefficient in design otherwise.

There's zero chance I'll use the professional oil & gas machinist I used in a pinch for Sunday Silent; I swore I wouldn't do another single use hardware project back to back with SS, and now that I am, the requirement is that I find a cheaper alternative. I received a solid lead when I was at work the other day, and jotted the guy's number down on a post-it note which was left in my office. When I went to get in touch with him this weekend, I realized I had no way of doing so. Hurricane Patricia kinda put a damper on any other plans this weekend, so I got in the car and drove two hours roundtrip to fetch the post-it note, and then two hours roundtrip in the other direction to meet with the guy. #commitment or #boredom, depends on how you want to look at it. Very promising lead, he thought the video of Sunday Silent was cool and says he can fit within my budget. Sweet! Dan Patell here on the forum will make the forward closure and turn down the two pin rings to fit, this guy will make the nozzle and shave the case, and I'll drill the pin holes myself. Should make the cost more bearable. When messing with such thin-wall stuff, the temper on the metal is completely shot with one burn especially at the metals content I'm running. Some people's priority with hardware is reusability, which comes at the cost of efficiency; load-n-go is not my MO, so I'm fully aware of what I'm getting into when I make single use hardware.

No transition rings will be required, because the rocket will essentially be an upscale of I'll Have Another: https://www.rocketryforum.com/showt...4in-to-3in-Two-Stage&highlight=stage+prophecy

I'll enjoy having a legitimate excuse for not having to optimize the crap out of the design and just gluing fins on a tube. I got some high modulus carbon to try out, electronics and chute in the nose cone, yada yada.

Parts will start being machined in the next few weeks, and the mix party for all motors to be flown at this launch will happen Nov. 15. My >50k' app will be due Dec. 1.

This 3 month timeline thing is awesome. Stay tuned.

SH
 
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Sounds great, Steve! Following along with great interest...

A few weeks ago, Steve and I were chatting about this particular launch. It's not really geographically close to me, but he gave me his "pitch" which involved shipping a project to him, flying out, and mixing the motor at his place. (Though the propulsion plan seems to have changed to the mixing-marathon mentioned earlier.) Less than a week after that conversation, I bought a plane ticket. Funny how those things happen...
 
Funny enough... I thought the title was some star trek reference "do or do not, there is no why"....

[ tangent] OK someone has to say it....... Whut? [/ tangent]

Back on topic, I've found the journey in life is unpredictable. Everytime I try to head somewhere, by the time I get there..... I'm heading someplace else I couldn't have predicted. I read my old logs and laugh at my own thoughts, wondering why I thought that, or seeing my own naivety.
 
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[tangent[tangent]] I thought it sounded like "Do or do not there is no try" [/tangent[/tangent]]
 
Just a thought...if you are having to shave 6 mils off the outside of the case (0.012" total diameter) have you thought about instead taking that off the inside of the composite tubing? The tubing will already have the motor supporting it and it should be much easier and cheaper than turning the case. Getting things concentric can be quite a pain. I almost never try to touch the OD of a motor. A college group I work with turned down a 5" case and didn't do it right. It burst on a test. I have built a jig to do that when I had some off spec composite tubing. It consisted of two sets of centering rings with ball bearings in a groove on the outside and a slightly eccentric sanding drum. You put it on a drill and went through the tube, increased the eccentricity, then did it again. I needed to enlarge a tube by 0.025" diameter. Took me about three hours to build the jig and an hour to enlarge the tube. I, like you, had an off size motor (3.5") and had some composite tubing that was close, but no cigar.

Edward

Edit: Also, what about trying to find some off-spec tubing. We have a local aluminum supply surplus house that buys stuff like that. I've found off-spec 3"x1/8" wall that was a perfect match for 75mm tubing. Might be worth a chance to look around.
 
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Hey Edward,

Thanks for the suggestions - both of those are options I'd considered, and every night I sleep less and less well with the notion of shaving the case. Runout is my main concern.

Off-spec tubing, of course, is the most attractive option. My issue is that where I am (Houston) almost all of the industrial supply/machine shops etc are geared almost entirely to cater to massive O+G corporations and will laugh at a guy rolling up in a sedan with a tube asking to come inside and test fit their stock. My friends in LA rave about IMS, friends in Oregon about Tubing Supply Co., I've just never been that lucky. Maybe I'm not looking hard enough. One thought was to call Online Metals (where I was going to get the tube) and ask if they had any tube on the lower end of the OD tolerance (.020"). Even half that would make my life much easier. But, I can't imagine a cheap online metal reseller will send someone out there with calipers for some guy buying a $96 tube.

I think I've decided against shaving the tube for sure, but I'm kinda at an impasse when it comes to next steps. I'll let a paycheck or two accrue before hitting the button on the tube and certainly on any machining, but I haven't really come up with a better option than buying the tube, seeing what I get (maybe I get lucky and it's off spec small...better hope it's not off spec large), seeing how straight it is, etc. Assuming it doesn't fit, can't come up with a better plan than getting some coarse flapper wheels from McMaster and a 4 foot length of allthread and just going to town. Another option is to do what Manny did and switch to a fincan/upper airframe arrangement and only shave the case at the ends where runout will be less, but that's of course where my pins are and the main issue here is the shear strength of the tube, so I don't love that idea though the numbers say I could get away with it and maintain 1.5x margin (Manny used a 3/16" tube).

One of those things where the amount of variables becomes overwhelming so you just shelve it...don't really know what my next move is.

Thanks again for the thoughts.

-s
 
Having used expanding mandrels in the past, albeit for smaller sizes (up to 2" diameter, non-rocketry use), I wouldn't be surprised if you could find someone with an expanding mandrel that would work for the length of tube you've got.

Another option is to have a mandrel made up for your tube, then chuck that mandrel up between centers. A lot of the time, people make mistakes of chucking up a tube in the lathe, making the assumption that the chuck is true, as well as the tailstock. It would take some time to do the work, but once it's done.... You should be able to ensure accuracy.

How long is your motor?

Other option is to shave some of the ID off of your airframe. That's risky too, as the tube could collapse... May want to consider a bulkhead directly on top of the motor to provide some structure to the airframe...

Just some thoughts here.
 
Try these guys - Tony is awesome to work with and I'm sure he'd check to see if he could get something for you.

https://www.industrialmetalsales.com/

Also - what is your MAX OD and tube length you would want? I go to Denver (where the surplus place is located) often and I could drop by and check when I'm there picking up other items.

Edward
 
The process you've described is called portable line boring. This a common practice for maintaining large machinery on site. Usually these setups use a single point HSS or carbide tool. There should be tons of information available on the web about it.
 
Try these guys - Tony is awesome to work with and I'm sure he'd check to see if he could get something for you.

https://www.industrialmetalsales.com/

Also - what is your MAX OD and tube length you would want? I go to Denver (where the surplus place is located) often and I could drop by and check when I'm there picking up other items.

Edward

Hey Edward,

That would be awesome, thanks so much!

The tube is a flat 5.00" OD, so 4.988" would be the max OD to allow for the .006 that in my experience is necessary for a decent slip fit.

Looking to purchase a 5 foot length, nominal 1/8" wall 6061-T6 (tube, not pipe).

Would gladly pay you some commission for your troubles.

Best,

Steve
 
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