I do for high power, but most of this thread is trying to print them. It is increasingly hard to find the big ones for Unistrut. As for the small ones, I print them mostly for mid-powder birds that are 3d printed.
3D Printing 3D Printed Rail Guides
- Thread starter cwbullet
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Guess I'll again post this picture of a 3D printed rail guide after launching a MD high speed rocket.
Careful how you use that 3D stuff. I bought this one online.
Careful how you use that 3D stuff. I bought this one online.
High speed (Mach) is probably one thing I would avoid. I wonder what the infill and materials are.
I think purchased buttons work great for #FNC rockets but there are a number of situations where being able to custom design and print buttons/lugs gives you many more options. For example, I often design buttons or lugs into 3D printed parts (boat tail, transitions, etc...) since this will have a much stronger connection than anything I could separately mount to the airframe and is one less thing to worry about getting the placement correct for (I am doing LPR). It also lets us use more different style launch rails without having a huge inventory of underutilized buttons. Anyway, those are my scenarios.
What is the benefit of leaving a slot in the rail guide? Why not just make them solid - I think that would avoid this issue.
Reduced drag and weight.
I have had no trouble with the rail lugs I've printed in ABS for sub-5lb rockets going at moderate speeds.
Given what we are learning about gapped fins and CP calculation that slot might increase drag due to more air turbulence.
I print all my rail guides solid but I am not going for any altitude records.
I have had the same experience. I also increase my infill to 60-80%.
beeblebrox
8 C6-0, 12 D11-9, 20 D20-0, 20 E5-0, 3 Cinerocs
Don't print the guides with that groove down the center, It is not necessary and makes the parts weaker. I have had a half of an Apogee one break off. Don't copy, make better. Make the rear end square, easy to print also... I print these with PLA+ and have had no issues, even in the 90 degree heat of summer. Print at 0.12mm layer height for stronger print. 0.02mm is ok too... I have used 0.4mm and 0.6mm nozzles. Both work fine. No supports...
If you want a longer base, just stretch them taller in your slicer...
If you want a longer base, just stretch them taller in your slicer...
caveduck
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The slot does nothing to reduce drag, for the same reason that tube fins act almost like solid plates. At typical sport rocket Reynolds numbers, stagnation in the slot makes them act as though they are dead solid.
As for round ones, you can machine them quickly out of round Delrin rod on almost anything that thinks it's a lathe, even a drill press.
As for MD rockets, I'd leave off the guides and fly them out of a tower. That lug on the side costs a lot of altitude at Mach 2.
As for round ones, you can machine them quickly out of round Delrin rod on almost anything that thinks it's a lathe, even a drill press.
As for MD rockets, I'd leave off the guides and fly them out of a tower. That lug on the side costs a lot of altitude at Mach 2.
