Was thinking about using flyaway guides, but they wont arrive in time for launch day.
So 3d print some rail guides and epoxy to airframe
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I don't wanna hijack the thread, but i would at least put a layer of fiberglass inside the LOC coupler. A 1.6" 'glass rocket on an I200 isn't super extreme, but the stock LOC couplers aren't very strong, unreinforced.I’ve been planning to use a LOC 1.6-inch coupler in my Wildman 1.6-inch fiberglass airframe with an I200. It has a fiberglass nose cone. Is this a recipe for destruction?
I’ve been planning to use a LOC 1.6-inch coupler in my Wildman 1.6-inch fiberglass airframe with an I200. It has a fiberglass nose cone. Is this a recipe for destruction?
If your talking LOC 38mm tube couplers , it depends on how long it is. Certainly longer then 2 inches is needed![]()
Neat thread, I'm enjoying this. Makes me think back to when John Buckley got his L1 on an Estes Big Bertha with a AT Single Use H124J motor. He did get his certification on that flight. It was pretty neat to watch!
You mentioned your tube not being as stiff as the rocket in the background. I suspect that is because your airframe is very thin, so there is not much material for the epoxy to wick in, therefore there isn't as much structure. I have used the Soller sleeves before, but not the type you used - just the conventional FG sleeves - and not had any issues. My 7.5" WAC Corporal is still flying after 13 flights.
As a prefect, I will say that I have concern with folks using 3D printed rail guides. I once tried the ACME Conformal rail guides in my younger days and had them snap off while loading a rocket. I learned a few things that day - surface prep is very important, and mechanical bonds are significantly better than chemical/thermal bonds. The last thing I want to do as a prefect is have to support resolution of an incident, and 3D printed guides give me pause. That being said, I'm not at the FSO table all day, so I can't catch 'em all, so a few have probably made it through.
In any case, I look forward to seeing pics of this in flight!! Keep on!
I'm more worried about the delamination of layers.Id be surprised if the 2 or 3 threads of a 4-40 screw that actually is in contact with the airframe provide more strength than the ~1insq epoxy bond.
I bet theres a way to calculate it.. but thats beyond my skillset.
Delamination of which layers? The epoxy? Can you elaborateI'm more worried about the delamination of layers.
As a prefect, I will say that I have concern with folks using 3D printed rail guides. I once tried the ACME Conformal rail guides in my younger days and had them snap off while loading a rocket. I learned a few things that day - surface prep is very important, and mechanical bonds are significantly better than chemical/thermal bonds. The last thing I want to do as a prefect is have to support resolution of an incident, and 3D printed guides give me pause. That being said, I'm not at the FSO table all day, so I can't catch 'em all, so a few have probably made it through.
This is a minimum diameter project though, so no real option for through-wall guidance hardware.My resin-printed aero rail guides are held on with steel flat head screws going into a printed backer inside the tube that holds a steel nut. I'm really only worried about wear, which is why I made it so easy to replace them.
Sorry - delamination of the printed layers.Delamination of which layers? The epoxy? Can you elaborate
This is a minimum diameter project though, so no real option for through-wall guidance hardware.
So, guidance is either flyaways, or surface mounted. PETG-CF is probably at least comparable in wear resistance as Delrin.
We never had issues with large diameter rods and cardboard launch-lugs for decades.
I print guides in a vertical orientation (i.e., z axis being the length of the rocket) for this reason.I'm more worried about the delamination of layers.
I guess I just assumed everyone did that because... flat surface means no supportsI print guides in a vertical orientation (i.e., z axis being the length of the rocket) for this reason.
Several college team mentors have told me of seeing buttons (not even guides) printed with the z axis up the center of the button.I guess I just assumed everyone did that because... flat surface means no supports
Id think that is ideal for the cylinder of the button.Several college team mentors have told me of seeing buttons (not even guides) printed with the z axis up the center of the button.![]()
Good point. I think you're right.Id think that is ideal for the cylinder of the button.
It may not be maximally rigid, but it is probably the most reliable print direction overall.... plus wouldnt the screw head provide compression to resist any layer peeling?
Probably best to not use your most expensive parachute in it.I’ve been planning to use a LOC 1.6-inch coupler in my Wildman 1.6-inch fiberglass airframe with an I200. It has a fiberglass nose cone. Is this a recipe for destruction?
Well, I'm using a Quasar in this rocket!Eggfinder Mini.
I'd not be too worried about a printed nosecone at Mach provided you could demonstrate it was designed well and was strong enough. And heating effects don't kick in till M2+.Well, I'm using a Quasar in this rocket!
We are pretty set. I may do ONE more round of ground tests, but I dont think that will be necessary.
All we need now is the 2nd Saturday in Feb and good weather. I'll plan to start her easy on an F or G 29mm motor. Just to test the guidance (I dont LOVE how my rail guides lined up) and recovery systems.
I got a LOT of feedback about breaking mach on this rocket saying I MUST have a fiberglass nosecone, including a sometime RSO... so I ordered one. It is too small. Toss it in the parts pile and maybe it will get its own rocket later.
In the meantime, Vagabond is flying with her original nose, and I'll add even more epoxy to line the nose and thicken it up if people REALLY think that will be a requirement.
This is just the estes cone... not a printed one.I'd not be too worried about a printed nosecone at Mach provided you could demonstrate it was designed well and was strong enough. And heating effects don't kick in till M2+.
Or print one undersized and glass it. It's pretty easy to get it smoothed/sanded to the right shape if you've got access to a lathe. Using a lathe and an angle grinder with a flapper disc will get you a shape quickly. But is messy.
Anyone who is saying you must use a fiberglass nosecone for a Mach flight is being way overly conservative. But M2 definitely.
There's a video somewhere of an M2 + flight with a printed camera shroud that melted.
Still, make sure the RSO is happy.![]()
It will be fine, apogee sells a kit specifically for Mach busting with a Estes nose.This is just the estes cone... not a printed one.