Update 2/23/2015 – The Metal on the Lathe goes Round and Round, Round and Round

Hi all,

Initial material orders are slowly flowing in (or rather, we slowly bused across town in -5 degree weather to carry 40 lbs of metal back to campus and “build character”). Raw Aluminum and Riley 02202015

We’ve gone through safety training (note the stylish set of safety glasses Riley is modeling here), so machining has begun. Below is a picture of what will eventually be our injector on the lathe. Don’t worry, there’s someone operating the machine just out of frame!

Lathing the Injector

Lathing the Injector

This week, we held a design review with some mentors and then put in a large order to several online vendors, biggest of which being to McMaster-Carr. By the time this is posted, we should have another couple dozen pounds of metal and electronics on their way. For next week’s update, we might even have some pictures of a partially assembled version of the pressurized “plumbing” system we’ll use to feed fuel and oxidizer to the engine!


Engineering Subteam Spotlight: Sensors/Ignition/Control

This week we fashioned some homemade igniters for the ignition of the rocket engine.  We started with 22-gauge wire, which we stripped at different lengths.  The two ends were connected with nichrome wire, as show below.  Both ends were soldered together in order to prevent the nichrome from detaching from the 22-gauge wire. Igniter Schematic

We then dipped the wires in a paste of dissolved nitrocellulose and black powder.  Each wire was dipped multiple times to add additional layers of the flammable material.  After the igniters dried, they were tested for continuity.  Finally, two of the igniters were tested with an ignition system.  Video vlcsnap-2015-02-23-14h23m51s149

The igniters were designed to burn for a longer than standard time and produce a flame as opposed to producing a large number of sparks.  As seen in the video, the igniters accomplished this goal.  During actual operation, the igniters will also be wrapped in cotton balls dipped in kerosene so as to produce a longer sustaining flame.

– Alex Pratt


On the business side, we won the small success of securing $50 from TeslaWorks (and thus from the University) to 3D print two ¼ scale, cutaway demonstration pieces. We’re also working hard on Romeo the Rocket setting his branding and interaction strategy. And finally, TeslaWorks likes to use Basecamp as their project management software, so we’re exploring to see whether Basecamp could be integrated into our current operations or whether we want to go a different route. We’re of course also keeping our Twitter up to date and full of cool facts, but you already know that because you already follow @LprdRocketry, right?

As always, we’d love to hear from you, so email us at LprdRocketry@gmail.com or comment below and let us know your thoughts!

-David Deng

2/23/2015

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Update 2/15/2015: Happy Valentines!

Hi all

Happy belated Valentines! As promised last time, we have some CAD pictures from our engine design! We might 3D print some scaled-down cutaway demonstration pieces to play with.

Happy Valentines!

Happy Valentines!

Cutaway of our engine design

Cutaway of our engine design


Engineering Subteam Spotlight: Propellant

The Propellant Team has been busy at work designing the oxidizer and fuel feed systems for the liquid-fueled rocket engine. After some initial discussion, gaseous oxygen and liquid kerosene were chosen as the oxidizer and fuel and gaseous nitrogen was chosen to pressurize the fuel tank. Once these decisions were made, calculations were performed to determine the oxidizer and fuel flow rates necessary for a 100 N thrust engine. From this, pipe diameter (1/2″ NPT for oxidizer, 1/4″ NPT and operating pressure (400 PSI) were decided upon. Finally, safety measures such as over-pressure relief valves, check valves, and purge valves were incorporated into the design in order to ensure safe operation.  Most of the components of the system have been chosen and budgeted although a few key items remain.

Propellant System Schematic

Propellant System Schematic

Currently, electronic valves to control oxidizer and fuel flow rates into the engine are being researched and sources of oxygen and nitrogen tanks, fills, and regulators are being examined. After these tasks are completed, ordering of parts will commence followed by assembly and hydrostatic testing of the system.

-Mike Siirila [For those of you who don’t know, Mike was the charming lad in the picture last time – DD]


We also tested out our igniter for the first time this week (video), and we did some flowcharting and made this time lapse video.

Before

Before

During

During

After!

After!

Things are starting to ramp up! Let us know what you think of everything. Email us at LprdRocketry@gmail.com or tweet at us (@LprdRocketry) or just drop a comment!

– David Deng

2/15/2015

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Update 2/8/2015: Romeo, Romeo?

Hi all!

Work is well under way, and we’re excited because we’ve begun ordering parts! Over the last week, all the subteams have been working hard to hash out general design specifications we can place those orders. Look at this charming fellow drawing out our propellant schematic. Aren’t we so lucky to have both brains and beauty.

Propellant Team - Mike Drawing a Schematic

Next week, we’ll be specifying exact dimensions and getting ready to machine. With any luck, we’ll have some CAD screen captures to show next time.

Good news on the safety front: the project is clear through cold pressure testing, but not hot firing. We’re inclined to take what we can get and press it again once we get to that point. That’s something to work on, but at least we can now pursue funding and have some legitimacy through the University!


Engineering Sub-team Spotlight: Injector/Chamber/Jacket

The Injector and Chamber/Jacket teams met together last week to work on the holistic design. Our guidebook wasn’t too specific on how the parts assembled, and we’ve also modified the engine slightly from the guidebook. It now features what we lovingly call our “O-ring sandwich” to seal the gaps between the jacket, chamber, and injector pieces against pressure. Unfortunately, we made a big mistake as well (can you find it?)

Engine Schematic 02062015 - 1

We originally wanted to seal the bottom of the coolant jacket and combustion chamber with another O-ring and bolts. Unfortunately, by putting another flange out at the bottom, the piece becomes physically impossible to assemble, so we’ll just leave it like it was in the book and braze it together.


Our business and communications team has set in place an accounting system to keep track of our finances, took a shot at a stakeholder analysis to help us with make informed decisions with stakeholder management, and are taking a look at some project management software we could use to streamline operations. We have also been been working on a designing a mascot (Romeo the Rocket?) to personify our project. We’re working on creating a character that fits our culture: a can-do attitude, a little quirk, and a love for space.

Romeo, Romeo, wherefore art thou Romeo? Because how could we better express our love for space and engineering than by using the name of that star-crossed lover himself? Email us (lprdrocketry@gmail.com) or write a comment and let us know what you think about the name!

David Deng

2/8/2015

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P.S. Good luck to SpaceX tomorrow on their launch of the DSCOVR satellite and re-landing of first stage booster!

Update 2/1/2015

Hi all!

First, I would like to introduce you to our blog, in which this project hopes to keep you updated and supply you interesting reading material and media. Also, we have chosen the name LPRD Rocketry (Liquid Propellant Rocket engine Design), which we hope reflects the fast-paced and ambitious nature of the project. If you don’t know who we are and want to know, our about page should be able to remedy that!

Our logo

Our logo

LPRD Rocketry has made significant progress in the past few weeks (and also run into significant roadblocks), and we’d like to keep you updated and interested. We expanded the project group and are now almost two dozen in student members! We had our first large group meeting on Sunday (2/1), though not everyone was able to attend. About seventeen members are working on engineering, and about six are working on the supporting structure behind that. We know organizing and communicating between so many people will be a challenge, so we’re keen on using business administration principles to make sure this project runs as smoothly as possible.

Meeting 2/1/2015

So, a little bit about how we’re organizing: Engineering is split into two main subteams (see org chart) – Engine, and Test Stand. The engine team then splits into the Injector and Chamber/Jacket teams. The Test Stand team splits into the Sensors/Electronics and Propellant teams. Once propellant tanks and plumbing are set up, the Propellant team will later on work with the engine team on regenerative cooling.

Basic organization chart

Basic organization chart

We’re working on getting budgets and designs done and hope to purchase materials after this week! With luck, there will soon be design drawings and pictures of parts to show soon. We’re currently working on crunching some numbers for the chamber and injector and making some judgement calls on our ability to machine precisely (0.6 mm injector holes, anyone?). Over on the test stand side, we’re working on figuring out how to control the valving and propellant flow from afar. Any suggestions, anyone? We’d love to hear your ideas.

On the business/support side, we’re setting up a communications system (tah-dah!) including blog updates and Twitter (Follow us @LprdRocketry!) to help keep interested parties in the loop. We plan to keep you updated with cool stuff (including things from outside our project like this video from SpaceX)

Unfortunately, we also have some bad news.  Projects like this must pass through a safety committee at the University of Minnesota has a safety committee funding and support, but this liquid propellant rocket engine project has been denied. Something about the combination of those four words is spooking the safety committee, despite the fact no hot firing would be done on campus, and in fact would be done with ATK at their proving grounds. Of course, we’re working hard to see if we can allay the safety committees fears or find some way to modify the project to suit their boundaries.

As project members, we are all firmly committed to continuing the LPRD Rocketry project. We hope the safety committee will change their minds, but we would also like to build up contingency options. The project will go forward self-funded if need be. With that in mind, we would like to ask for help from anyone who could help in any way. In particular, if anyone has worked with liquid propellant rocket engines in the past (or currently) as part of their job and could lend credibility, that might help sway the safety committee to reconsider their decision. Additionally, if anyone has access to machining equipment (in particular a lathe), we would be exceptionally grateful for the use of that.

In any case, thank you for taking an interest in LPRD Rocketry! We’re excited, and we hope you’re excited by this project too. Please don’t hesitate to engage with us at lprdrocketry@gmail.com or through Twitter!

– David Deng

2/1/2015

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