TWA Moonliner- Washington Aerospace Club Build
- Thread starter DirkTheDaring
- Start date
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going to be cool, post lots of pictures
jpoehlman
Well-Known Member
Today was a truly gorgeous day in the Seattle Area. We arrived at the 60 Acres Park to a very thin and low layer of fog at the surface of the dead calm field. The first flight of the morning was for a local SLI team needing to complete and document their subscale flight. The smoke trail from their rocket hung in the sky for several minutes, confirming the very calm conditions.
Next up, the 4 - Inch Moonliner. The Moonliner was prepped with a G79 with a delay drilled to 4 seconds, thanks to @Jim P. for 29/120 motor case and @bandman444 for the motor. A Flightsketch and Bear ESP32C-3 altimeter were placed on the parachute quick link. The Moonliner was loaded on the rail, ignitor leads connected..... the rest of the story is better in this video:
View attachment IMG_8223.mov
I don't think we could have asked for better flying conditions or anything more out of the WAC Group project Moonliner's first flight. The Moonliner reached 528 Feet before ejecting the 45" Top Flight chute for a gentle decent back to the soft turf.
This was a really great way to close out 2024 and be ready for 2025.
Next up, the 4 - Inch Moonliner. The Moonliner was prepped with a G79 with a delay drilled to 4 seconds, thanks to @Jim P. for 29/120 motor case and @bandman444 for the motor. A Flightsketch and Bear ESP32C-3 altimeter were placed on the parachute quick link. The Moonliner was loaded on the rail, ignitor leads connected..... the rest of the story is better in this video:
View attachment IMG_8223.mov
I don't think we could have asked for better flying conditions or anything more out of the WAC Group project Moonliner's first flight. The Moonliner reached 528 Feet before ejecting the 45" Top Flight chute for a gentle decent back to the soft turf.
This was a really great way to close out 2024 and be ready for 2025.
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rharshberger
Well-Known Member
Looks like a nice stable design with the clear fins, the mounting method of the fins definitely makes them unobtrusive. How thick is the clear material going to have to be on the upscaled version of the prototype? I am paying attention to the build as you guys post about it, please make sure all your pics and videos are available here (Dirk posted some in the 60acres thread but it might not be bad to include the link to the album here as well).
jpoehlman
Well-Known Member
Project progress continues! The first group build session is scheduled for this weekend. A 30" diameter cardboard tube has been acquired for fiber glassing at the build session.
Our 4" subscale prototype made a few more perfect flights at the January club launch on a G77R and a G78G. So we've build some more confidence with the basic design stability.
To engage our club members, I offered to create 20 kits. They were all spoken for in under a week, perhaps this photo helped:
All of the parts materials have been acquired, 3D printed parts printed, laser cut parts cut, etc. Final stages of the kitting processes are underway.
Last but not least, there's also a 12" version of the Moonliner in the works:
This project is getting both real, and real fun!
Our 4" subscale prototype made a few more perfect flights at the January club launch on a G77R and a G78G. So we've build some more confidence with the basic design stability.
To engage our club members, I offered to create 20 kits. They were all spoken for in under a week, perhaps this photo helped:
All of the parts materials have been acquired, 3D printed parts printed, laser cut parts cut, etc. Final stages of the kitting processes are underway.
Last but not least, there's also a 12" version of the Moonliner in the works:
This project is getting both real, and real fun!
Nice!
What size motor mount are you putting in the 12" version?
I need to get back to working on my 7.5" version... LDRS will be here soon if I don't hurry up
What size motor mount are you putting in the 12" version?
I need to get back to working on my 7.5" version... LDRS will be here soon if I don't hurry up
The fiberglassers
jpoehlman
Well-Known Member
We'll see, but @bandman444 said might as well go with a 98mm mount and step down for the smaller motors it will likely fly.
bandman444
Well-Known Member
Yeah. It should be light enough to fly on some 98mm 1 grain motors, and I have a EX case that size that I've never used that I'd like to play with.
bandman444
Well-Known Member
rharshberger
Well-Known Member
Looks like you guys are on track for SodBlaster VII!
Jim popped by the BEMRC launch today and showed me the 4 inch moonliner. Neat model. I wish I'd had a bit more concentration and time to chat with him.
Rondaview
Member
Answer to the questions, is it round and what's it weigh...
We trued it up using the cross bracing you see in the photos to plus/minus about an 8th of an inch. There still should be enough flexibility in the final assembly to mate with the nose and tail tapers at the joints. In it's raw state it was out of round by as much as 3/4". We forced it into a more or less true round before applying the glass by putting the cross bracing as near as possible to the worst dimension and then kept trimming away at the bracing until we got all measurements at the 1/4 points to within tolerance. We then drilled the holes for the center pivot, inserted them into the tube about 6" in from each end (w/a slight friction fit) and clamped them together at 90 degrees from each other before threading the entire unit onto the rotisserie bar. There was just enough slop in the holes to allow the entire unit to move freely on the bar during application of the glass.
Weight measurement is incomplete. We weighed it initially with all of the braces and rigging and recorded that number before glassing. We will be trimming the ends to final length once the FG cures. The sono-tube is not a precise material. It was not only out of round but not a square end cut (since we had our 48" section cut from a longer section of tube). We will be truing that up with the final trimming. Once we get to a final dimension we will need to weigh the assembly again and then weigh the rigging and braces to get to a final weight for the component (prior to painting).
This is just the first "real rocket" piece. We'll be trying to weigh each section as we go and then weigh the subassemblies as we build them so that we can get a reasonably accurate estimate of weight and distribution before we get to the final flight configuration.
This thing is going to have a "honking big motor" so the final weight distribution is arguably more important than the actual weight. It is either going to have a huge amount of thrust or a gargantuan amount of thrust. Either one will get it off the ground. We just want the weight in the right place to make it stable off the tower.
We trued it up using the cross bracing you see in the photos to plus/minus about an 8th of an inch. There still should be enough flexibility in the final assembly to mate with the nose and tail tapers at the joints. In it's raw state it was out of round by as much as 3/4". We forced it into a more or less true round before applying the glass by putting the cross bracing as near as possible to the worst dimension and then kept trimming away at the bracing until we got all measurements at the 1/4 points to within tolerance. We then drilled the holes for the center pivot, inserted them into the tube about 6" in from each end (w/a slight friction fit) and clamped them together at 90 degrees from each other before threading the entire unit onto the rotisserie bar. There was just enough slop in the holes to allow the entire unit to move freely on the bar during application of the glass.
Weight measurement is incomplete. We weighed it initially with all of the braces and rigging and recorded that number before glassing. We will be trimming the ends to final length once the FG cures. The sono-tube is not a precise material. It was not only out of round but not a square end cut (since we had our 48" section cut from a longer section of tube). We will be truing that up with the final trimming. Once we get to a final dimension we will need to weigh the assembly again and then weigh the rigging and braces to get to a final weight for the component (prior to painting).
This is just the first "real rocket" piece. We'll be trying to weigh each section as we go and then weigh the subassemblies as we build them so that we can get a reasonably accurate estimate of weight and distribution before we get to the final flight configuration.
This thing is going to have a "honking big motor" so the final weight distribution is arguably more important than the actual weight. It is either going to have a huge amount of thrust or a gargantuan amount of thrust. Either one will get it off the ground. We just want the weight in the right place to make it stable off the tower.
