Lander Update: Q1 2025

oops I'm bad at posting, here are some pix

I did a lot of stuff, made a lot of progress, more work to come. I'll be static firing this year. This is the last year I'll be working on the lander, I'd like to tend to my other technical interests.

I remade the press system plumbing in all stainless hardware. NEVER use aluminum flared tubing, it's just not worth it.

Stainless printed engine parts came in...

Pintle annulus with film cooling. The top plate of the injector was lathe machined rather than printed. The printed annulus section was post machined to tolerance. The pintle tip was also 3d printed. It includes orifices that are lower than the resolvable feature requirements from the manufacturer, but if you keep tweaking sizing, you can get there with a knock down factor. Cheapo mode.

Oh, I redesigned the TVC actuators.

I also wired up everything. 

Oh and Masten let me come watch one of their test flights behind the scenes. What a spectacular vehicle and group of engineers. If a younger me knew I'd be seeing one of these flights in person...

The sunset was beautiful. The flight was dramatic...

Back to my own crap here..

I also redesigned like half the avionics, got it manufactured, and rewrote all the firmware. But this is the only single photo I have to prove this lol. I got rid of all the messy wiring, valve/relay power distribution, and the entire relay board itself. They're replaced with MOSFETs and drivers. I reduced my footprint to 10 channels, and 10 ADC input channels.

Also i made a static fire engine structure. I dont have pictures of the load cell and all the accoutrements, but those are figured out now.

See ya next time.

12 Exposures with the Minolta Autocord

 The Minolta Autocord is a twin lens reflex medium format camera from the 50s and 60s. It was made by Chiyoda Kogaku Seiko company of Japan. As with all TLRs, there are two lenses through which you compose and expose your photograph. The 'taking' lens in this case is a 75mm focal length, 4-element Rokkor lens with a minimum aperture of f/3.5. These lenses are extremely sharp, you'll see in photos later.

I have a couple of these, and have sold some as well. They often can be good fixer upper deals on eBay, and I find the apertures to be particularly robust to aging. The exposure timing is typically in excellent condition after a naptha cleanse. The one below had quite rought leatherette, so I replaced it with a blue leather for some character. 

I've been shooting these for a couple years now, and really love the lens. I find it performs well for both B/W and color. Here are 12 exposures, from different rolls.

12 Exposures on the Rolleiflex 2.8E

 The Rolleiflex 2.8E is a medium form at Twin Lens Reflex (TLR) camera produced in Germany in the 1950s. I picked this one up on eBay from a seller who had it in their family, and was unsure if it worked. I gave it a clean and lubricated some of the primary shutter components. Other than that, it was fully functional. 

Here are 12 exposures I took. 6 to show color rendering, and 6 in black and white for the vibes. I'm also not good enough yet with composing on a TLR to get a full contact sheet of bangers, but we'll get there. I've had a couple Minolta Autocords and YashicaMat 124Gs in the past, as I'd work on them and sell them. So I had been fairly familiar with TLR medium format. But I must be honest and say the work of Vivian Maier made me jump for the Rollei. And my, what a beaut this camera is. It's certainly heavier than the Minolta, but it feels right for the job. Can't explain it better than that. 

Lander Update June 2024

 It's been a bit since the last update. Damn. Guess that's how personal projects go when you are a real adult. That doesn't mean I haven't made progress! Here are a few pictures...

The Engine: Snort. It's been developed using this Master's Thesis https://ir.library.oregonstate.edu/concern/graduate_projects/76537857k and is in the public domain!

More information to come :) working hard to build and test and an engine this summer!

And I'm looking for sponsors! Please reach out on twitter 

Lander Update: Snort, the Engine

 So I've picked back up on liquid engine design for the lander. This is a brief of what I'm pursuing so far for the combustion chamber

Stats:

• Thrust: 500lbf (2.22kN)
• Pc: ~300 psi (2MPa)
• Propellants: Liquid Oxygen, Ethanol 70%
• Mixture Ratio: 1.35
• 20% fuel boundary layer cooling
• 15 degree conical half angle
• L-star of 1 meter
• 45 degree contraction angle on converging section, for manufacturability
• Chamber Inner Diameter: 81mm
• Materials: 304/316 Stainless Steel

I am first going to manufacture the chamber in two parts.. the cylindrical section, and then the printed or CNC'd converging-diverging section which I plan to weld on. The former is based on this affordable part from McMaster Carr. It's 304 stainless with a weld bead down the  center of it, and polished. I am a bit worried about the weld bead, but I know other chambers have been made similarly. The thickness is about 2mm, still checking to see if this checks out thermally. 

The ID of the chamber material is supposedly very accurate, so I've added a taper to the C-D section that traverses the inside the the tube, and can  be welded from the outside.

Here's Snort:

I've put out quotes for printing or CNC machining the C-D nozzle section and so far it only seems to be around $300 in stainless which is shocking to me.

If I can get each engine to be under $1k I'll be super happy. More to come on injector design and thermal analysis.. Need some friends to double check me :) Ideally, I'd like to print the injector and then weld it directly to the chamber, so I don't need to worry about fasteners, leaks, seals etc. Not sure if this is a good idea, but Armadillo had good luck with welding it all on there.