In a large way rockets are just plumbing.
Tanks pipes, valves and showerheads.
Rockets are weight sensitive, traditional industrial plumbing is not.
It would be nice to use an off the shelf valve.
Off the shelf controllable valves are slow and heavy.
Real aerospace rocket valves cost more than the budget for this whole project.
So I've been trying to build valves.
The first attempt looked good they were reasonably light and fast.
My son and I built a whole test stand based on these valves, it was ready for a static fireing in late July The valves froze up when tested at liquid nitrogen temperatures.
In messing with these valves I now have a pile of dead hitec robot
servos. the servo is just not going to cut it in this application.
(I've been mostly working on other things in between July and now, so I have not spent 4 months playing with valves, more like a month.)
So I'm now back on to valves full time.
I'm a firm believer in the markets ability to optimize things and create cool engineering solutions at low cost if the volume is high enough.
One key is to discover these items and use them in the project.
In that light I've been looking for a tough lightweight valve actuator.
Whats lightweight, powerful and tough? Battery operated hand held tools.
After buying disassembling and destroying a large number of Home Depots finest
hand tools I've settled on a Roybi 18V P240 right angle drill, very tough well built and
not too expensive.
The first thought was to just grab the valve stem with the drill chuck and go from there.
this works when hand held as your body provides a little bit of compliance for misalignment.
When you build study brackets to tie the drill down it breaks/jams things.
The second thought was to remove the chuck and machine an adaptor that provides for some misalignment and threads on where the chuck used to go. I almost finished that assembly tonight. I'm short one hole, as the plate that mounts to the valve stem is stainless it work hardens and I broke off my last 8-32 tap drill in the bracket. I was hoping to test this tonight,
but I'll have to get some good carbide drills and redo that plate Friday.
If the ryobi drill does not work I have one more valve concept to try. I'll spend another 3 weeks on valves and if I can't make it work by then I'll bite the bullet and buy the heavy industrial valve actuators like armadillo is using. The results from this will effect my fundamental vehicle design as they are heavy and you need at least 2 per motor. I was hoping for a small 4 motor vehicle with fully differential throttling.
When I get a valve fully assembled I'll post pictures.
I need to move on to engine tests, igniter development and tanks.
I have bits and pieces ordered for all of these, most due in around the end of the month.
Kamis, 09 November 2006
Welcome to all
I started this blog as a personal journal to
document my quest to compete in the Lunar Lander Challenge.
I asked a couple of friends if I should make it public, they both said yes so here it is.
It is not a literary master piece.
Its not going to be an opinion journal, its going
to be a log of daily thoughts, decisions and experiences along the journey.
It will make much more sense if you start at the bottom and read your way to the top.
Paul
document my quest to compete in the Lunar Lander Challenge.
I asked a couple of friends if I should make it public, they both said yes so here it is.
It is not a literary master piece.
Its not going to be an opinion journal, its going
to be a log of daily thoughts, decisions and experiences along the journey.
It will make much more sense if you start at the bottom and read your way to the top.
Paul
Early morning with the FAA.
This morning at 6:00am I had a conference call with the FAA/AST.
I think it was a good first discussion.
One bit of good news is that they can still issue "burn time waivers"
or officially license waivers. This is a lot less onerous than doing the full
environmental review called for by an experimental permit.
I was hoping to get endorsement for my concept of drawing a bright line between operating and safety systems and qualifying the safety systems and leaving the operating stuff alone.
They did not really say no, but it was clear thats not the way they want to proceed.
In some places I was hoping for a little more direct guidance about whats acceptable.
Some of the conversation went like:
Question to FAA:What would you like to see to prove X?
Answer:Its your job to convince us of X.
The answer is completely correct and almost useless.
Its all part of the process and my current action item is to generate a hazards and hazard mitigation document.
My short version of the document:
Hazard: The Vehicle or parts of the vehicle can leave the defined operating area and hit
something it's not supposed to.
Mitigation: Add redundant safety abort systems that will Kill the vehicle before it does so.
They want a bit more detail, I'll have to work on that. :-)
I think it was a good first discussion.
One bit of good news is that they can still issue "burn time waivers"
or officially license waivers. This is a lot less onerous than doing the full
environmental review called for by an experimental permit.
I was hoping to get endorsement for my concept of drawing a bright line between operating and safety systems and qualifying the safety systems and leaving the operating stuff alone.
They did not really say no, but it was clear thats not the way they want to proceed.
In some places I was hoping for a little more direct guidance about whats acceptable.
Some of the conversation went like:
Question to FAA:What would you like to see to prove X?
Answer:Its your job to convince us of X.
The answer is completely correct and almost useless.
Its all part of the process and my current action item is to generate a hazards and hazard mitigation document.
My short version of the document:
Hazard: The Vehicle or parts of the vehicle can leave the defined operating area and hit
something it's not supposed to.
Mitigation: Add redundant safety abort systems that will Kill the vehicle before it does so.
They want a bit more detail, I'll have to work on that. :-)
Rabu, 08 November 2006
Time and commitment.
Monday night I worked all evening to make some nice aluminum brackets for our test valve.
I went to bed at 12:30 and got up at 5:45 to keep my appointment at the Gym.
By Tuesday evening I was useless and did no work. I see its going to be a challenge to
both keep the commitment and to throttle the effort so as not to burn out.
Today I finally got the FAA to engage in some discussion and learned a valuable fact.
They are much more open to talk rather than respond to E-Mails as it leaves no record.
I've scheduled a conference call for 9:am EST Thursday (6 am here) so maybe I'll finally make some progress. My agenda for the call is as follows:
Physically carry the box to the boundaries of the termination area. Establish a center point by physically transporting the box there and then draw boundaries. Enter the boundaries from a map or other source of geographic data. Can the boundaries be simple rectangles? Convex polygons?
From todays phone conversation it is clear that the FAA does not like my choice to
do all my testing at FAR under the 15 second rule. With a limited budget I just can't afford
to do it a Mojave without some external funding. If we get to the point where that becomes necessary maybe we will have enough visible results to attract some funding.
Specific Progress Tuesday and Wedensday
I finished up the PCB design for my helicopter tester.
I hope to fly an RC helicopter with the same telemetry and control as the rocket and
start testing and writing the command and control software. I will see is my tine Trex 400 can lift the equipment otherwise I will need to buy something bigger.
Tonight I hope to finish my first drill driven prototype valve.
Paul
I went to bed at 12:30 and got up at 5:45 to keep my appointment at the Gym.
By Tuesday evening I was useless and did no work. I see its going to be a challenge to
both keep the commitment and to throttle the effort so as not to burn out.
Today I finally got the FAA to engage in some discussion and learned a valuable fact.
They are much more open to talk rather than respond to E-Mails as it leaves no record.
I've scheduled a conference call for 9:am EST Thursday (6 am here) so maybe I'll finally make some progress. My agenda for the call is as follows:
Three specific Items I'd like to discuss, and a few more if time and personal permit.
1)Is my concept of having two redundant flight termination systems
that are completely separate from the vehicle operations hardware and software acceptable?
Specifically:
System 1 continuously calculates the instantaneous impact point at 5Hz
and terminates the flight if the IIP hits the predefined defined boundary.
System 2 Is a commercial PCM RC receiver that terminates the flight on command or on loss of signal.
2)What limitations are necessary for staying within the 14.99999 second rule.
Can I carry more than 14.999999 seconds of fuel with a hardware timer that terminates
thrust after 14.999999 seconds of burn time?
Is sensing valve position sufficient to establish burn times?
Is a post burn cool down purge with water and/or inert gas counted against the burn time?
I want to test the vehicle at full gross takeoff weight with the same dynamics as
a fully fueled vehicle. I'd rather not have separate non-sloshing weights as this is an
unrealistic test.
I'd like to set up two temporary metal road plate pads at FAR and
3)What are the requirements for tethered operation?
Rather than do serious worst case mechanical tether analysis can I have the tether carry an electrical circuit, if the
circuit is broken terminate the flight.
Additional items...
Hardware design items:
My intent is to make the safety termination systems separate isolated battery powered
units. The only external connection will be a fiberoptic status output so the units can report battery condition
and self test completion to the outside world. Fiberoptic is chosen as there is no physical way to transmit
electrical transients back into the units that will kill them.
I plan to do full environmental shake and bake qualification on all safety termination systems.
I'd prefer to do this with self constructed temperature chambers and vibration tables,
but If more formal methods are required I'm familiar with the process as I used to run a
"shake and bake" environmental stress screening operation that tested avionics for the Navy.
How would the FAA like to see positional IIP limits input into the system
Some possibilities:
I realize that calculation of Ec is not required for an experimnetal permit, but I expect that one will be done
in any case. Is there any benefit in qualifying sub components in a real world environment and
demonstrating a low probability of failure, showing operational reliability by test?
I'm thinking about putting the navigation,stability,control, and safety termination systems on a RC helicopter
and having them fly vehicle competition profile hundreds or even thousands of times.
Any benefit in having a RC plane or helicopter fly the boundaries of the IIP box for visual verification?
From todays phone conversation it is clear that the FAA does not like my choice to
do all my testing at FAR under the 15 second rule. With a limited budget I just can't afford
to do it a Mojave without some external funding. If we get to the point where that becomes necessary maybe we will have enough visible results to attract some funding.
Specific Progress Tuesday and Wedensday
I finished up the PCB design for my helicopter tester.
I hope to fly an RC helicopter with the same telemetry and control as the rocket and
start testing and writing the command and control software. I will see is my tine Trex 400 can lift the equipment otherwise I will need to buy something bigger.
Tonight I hope to finish my first drill driven prototype valve.
Paul
Senin, 06 November 2006
The first big single purpose check.
Today I sent the xprize foundation a 2K check,
my first downpayment on the project I'm on the way to being an
offically registered partcipant.
I'm also starting to make a slight bit of technical progress.
This weekend:
I met with seveal other rocket nuts at the FAR site and discussed designs and ideas
with Charles Pooley and Ken Mason.
I spent sunday finishing my Lathe. I have a 13x40 birmingham manual lathe.
I had the mechanics converted to CNC by Industrial hobbies, they did all the mechanical work and I did all the wiring and electrical. I've had the Lathe for a year and never got around to finishing all the wiring. Last night the lathe cut it's first metal, and all of the CNC parts seem to be working.
Sunday evening my son and I did some work on converting a Ryobi right angle drill driver to a
valve driver. We mounted GMW angle sensors on the end of the spindle and used a Netburner and a Scorpian XL driver to drive the valve. With simple proportional control it overshot
unloaded and did not do well when loaded up. In the next few days we will ad the rest of the PID
constants and see how it works.
my first downpayment on the project I'm on the way to being an
offically registered partcipant.
I'm also starting to make a slight bit of technical progress.
This weekend:
I met with seveal other rocket nuts at the FAR site and discussed designs and ideas
with Charles Pooley and Ken Mason.
I spent sunday finishing my Lathe. I have a 13x40 birmingham manual lathe.
I had the mechanics converted to CNC by Industrial hobbies, they did all the mechanical work and I did all the wiring and electrical. I've had the Lathe for a year and never got around to finishing all the wiring. Last night the lathe cut it's first metal, and all of the CNC parts seem to be working.
Sunday evening my son and I did some work on converting a Ryobi right angle drill driver to a
valve driver. We mounted GMW angle sensors on the end of the spindle and used a Netburner and a Scorpian XL driver to drive the valve. With simple proportional control it overshot
unloaded and did not do well when loaded up. In the next few days we will ad the rest of the PID
constants and see how it works.
Kamis, 02 November 2006
Decisions already made...
On my very first post I posted a list of questions and decisions
that need to decided and answered.
In reality some of the decisions have been made by defualt.
Where can you test a rocket?
All of the significat testing will be done at the FAR site.
I just don't know yet. All of the significat milestones can be tested under the 15 second non-licensed rules. The 90 and 180 second hovers can be done on a tether.
I've spent the last two years equiping my shop, so for me this is a no brainer.
I have a converted 13x40CNC lathe and a Tormach PCNC100.
What parts do you buy?
Anything youcan. In reality . Maybe some and some elctronics assemblies, but most of the stuff is built from scratch.
What parts you design and build yourself?
Almost everything.
While I've toyed with hydrogen peroxide, the reality is that the only resonable propellants are something and Lox. for ease of development something is almost certain to be good old moonshine otherwise known as
ethanol..
Whoose techncal advise do you trust?
I trust the guys at flowmetrics.
I trust the written wizdom of John Carmack and the Armadillo team.
I trust the Masten folks.
At some level I'll trust anyone that has actually built a biprop motor and run it.
Do you buy an almost working design form a competitor?
One of the other teams has a nice motor design they are willing to sell me at a resonable price.
the only problem is that its the wrong motor. It's the right size, but its too high of pressure to run with a pressure fed system capable of doing 190 seconds. It's damm tempting, but
not until I try on my own and fail.
Do you have the budget to do this at all?
I hope so, please see the previous post.
that need to decided and answered.
In reality some of the decisions have been made by defualt.
Where can you test a rocket?
All of the significat testing will be done at the FAR site.
I just don't know yet. All of the significat milestones can be tested under the 15 second non-licensed rules. The 90 and 180 second hovers can be done on a tether.
I've spent the last two years equiping my shop, so for me this is a no brainer.
I have a converted 13x40CNC lathe and a Tormach PCNC100.
What parts do you buy?
Anything youcan. In reality . Maybe some and some elctronics assemblies, but most of the stuff is built from scratch.
What parts you design and build yourself?
Almost everything.
While I've toyed with hydrogen peroxide, the reality is that the only resonable propellants are something and Lox. for ease of development something is almost certain to be good old moonshine otherwise known as
ethanol..
Whoose techncal advise do you trust?
I trust the guys at flowmetrics.
I trust the written wizdom of John Carmack and the Armadillo team.
I trust the Masten folks.
At some level I'll trust anyone that has actually built a biprop motor and run it.
Do you buy an almost working design form a competitor?
One of the other teams has a nice motor design they are willing to sell me at a resonable price.
the only problem is that its the wrong motor. It's the right size, but its too high of pressure to run with a pressure fed system capable of doing 190 seconds. It's damm tempting, but
not until I try on my own and fail.
Do you have the budget to do this at all?
I hope so, please see the previous post.
The background and the commitment.
I've always had the feeling that the "average" life
was somewhat of a waste. I've always had big dreams.
One of my earlier unfinshed projects can be found
here: Solar Glider
This was an insanely difficult project that consumed 5 years of my life.
As you can see on the web page I have a working design, but I
fell short of my record setting goal.
About the time I last flew the solar splinter I wandered into the
flowmetrics shop (www.flometrics.com) and discovered the SDSU rocket project.
Here were a bunch of inexperienced students building aliquid fuel rocket.
I was impressed, but on closer inspection it did not seem to look that hard.
So for the next two years I provided them electronics when they launched
and spent a lot of time talking to the wizards at flometrics.
I also bought every book on rocket motor propulsion design I could find
and this has been my bedtime reading for the last two years.
By reading, studying and watching others (principally armadillo) I've come to
believe that a normal humans with moderate funding can do significant
rocketry. As that realization slowly sinks in, I've equipped my shop
with what I think is necessary to actually build rockets. CNC lathe, Mill, and good quality welding equipment. As this realization slowly comes to be I also start searching for a worthy
goal.
My inital thought was to do ameateur sputnik. Build a rocket in a garage that can reach orbit. Not with any payload, just a 100 gram tranmitter that circles the globe and
transmitts "Normal mortals can reach space". This is a very hard goal it has significant technical
and significat regulatory issues. I also believe that done as an ameteur project it would take about 1M$. Too hard, too much $ and too lofty.
As I'm in the midst scheming how to do this, I hear about the Nasa/Xprize lunar lander challenge. It looks like the prefect project.
It's hard, but not impossible, the regulatory burden exists, but it is not insurmountable.
So this has become my quest. My guess is that it will take $100K to build a working vehicle that can do the task. I think it will also take another 50 to 100K to prepare for and campaign
the vehicle at the xprize cup. If I live frugally for the next year I can spend this much without
causing any permant financial hardship. the whole family is now on a budget.
I have done things like cancel my dish network subscription, if I'm going to do this I have no time for TV.
was somewhat of a waste. I've always had big dreams.
One of my earlier unfinshed projects can be found
here: Solar Glider
This was an insanely difficult project that consumed 5 years of my life.
As you can see on the web page I have a working design, but I
fell short of my record setting goal.
About the time I last flew the solar splinter I wandered into the
flowmetrics shop (www.flometrics.com) and discovered the SDSU rocket project.
Here were a bunch of inexperienced students building aliquid fuel rocket.
I was impressed, but on closer inspection it did not seem to look that hard.
So for the next two years I provided them electronics when they launched
and spent a lot of time talking to the wizards at flometrics.
I also bought every book on rocket motor propulsion design I could find
and this has been my bedtime reading for the last two years.
By reading, studying and watching others (principally armadillo) I've come to
believe that a normal humans with moderate funding can do significant
rocketry. As that realization slowly sinks in, I've equipped my shop
with what I think is necessary to actually build rockets. CNC lathe, Mill, and good quality welding equipment. As this realization slowly comes to be I also start searching for a worthy
goal.
My inital thought was to do ameateur sputnik. Build a rocket in a garage that can reach orbit. Not with any payload, just a 100 gram tranmitter that circles the globe and
transmitts "Normal mortals can reach space". This is a very hard goal it has significant technical
and significat regulatory issues. I also believe that done as an ameteur project it would take about 1M$. Too hard, too much $ and too lofty.
As I'm in the midst scheming how to do this, I hear about the Nasa/Xprize lunar lander challenge. It looks like the prefect project.
It's hard, but not impossible, the regulatory burden exists, but it is not insurmountable.
So this has become my quest. My guess is that it will take $100K to build a working vehicle that can do the task. I think it will also take another 50 to 100K to prepare for and campaign
the vehicle at the xprize cup. If I live frugally for the next year I can spend this much without
causing any permant financial hardship. the whole family is now on a budget.
I have done things like cancel my dish network subscription, if I'm going to do this I have no time for TV.
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