Intro:
Over on another thread in the 3D Printing section, there's a friendly competition going on: TRF Challenge #1: Estes Menace and I thought this would be a great opportunity to push myself to learn more Fusion 360.
I started back in March 2023 to 3D print small parts, and started designing in TinkerCAD which really helped me get my designs to the printer, faster. There were just some things that were not easy to do. I tried OnShape and had some success with that, building simple nosecones, fins, and centering rings but I still struggled with some other things, like knurled textures for retainer caps or threads. There is nothing wrong with either app and everyone will come at this activity with different perspectives. For me, Fusion360 just seemed intimidating, so I kept putting off learning with it.
It's a great tool for me now and I can do all thing things that I wanted to do, so when this challenge presented itself, I got right to work. This thread will document the build along with the final launch performance against the simulated design.
NOTE: All the designs were done against LOC/Precision tubing (Body and MMT). I have failed to make this distinction in the past, and caused some people using my designs some bit of grief. My sincerest apologies for that.
Design:
The challenge presented by @cwbullet did not have a readily available OpenRocket/RockSim file. I wanted to build something bigger but I needed a frame of reference, so I found some scans on JimZ's website and some details on RocketReview.com that allowed me to put together a rough OR sim at scale. I didn't have specifics for the fins or intake, so I eyeballed them. Once I was happy that the sim roughly resembled an Estes Menace, I scaled it up and started tweaking. The forward fins seemed a bit too narrow, so I gave them a more triangular shape. The aft fins seem a bit small, but the sim showed stable flight once I completed the design. I created an Ogive nose cone but I may have overcooked my grits with that. However, the design "Looks" really good.
With the nosecone, it was way bigger than my printer would allow and cutting and gluing parts together is not something that I enjoy. I wanted to do something with threads, so I build a 2 piece nosecone similar to Arogen67's Big Red Max nosecones. I loved this design but it didn't work out well for me because it was too thin. I created beefed-up versions and put them on Printables, but the idea of creating them from scratch was beyond me. Time to fix that. I also love IPL's nosecone ebay and I have exclusively adopted this for my rockets, where applicable. There were some things that I wanted to modify, so I originally took the same approach and remixed the original. For the Menace, I have redesigned both the nosecone, shoulder coupler and the nosecone sled from the ground up. The thread pattern on the ebay sled was engineered so that it would work in both my existing designs and this new one, so I have backwards compatibility.
For the intake, I took the aft fin and used it to get a rough idea of the shape. My first prototype looks much like the others and that is fine and functional. Being a Sci-Fi geek, I like long, fast-looking designs so I stretched out the leading vertical supports to an exaggerated amount. I will often do this then reel it back into something more sane but the look really had a Star Trek vibe and I liked it, so I kept it. The forward fins also deviate from the original but I think that they look good too.
I was curious about motor retainers that have a flange to hold the threaded ring on the the back of the rocket. I realized that I could design it so the flanged ring doesn't need to be epoxied rather, it can be mechanically fastened. I designed a 38mm retaining ring with flange and companion cap that should be able to take the abuse from the hot and hairy end. Also, if they burn up, I can replace them and get back in the game (theoretically).
I also created centering rings of various types. One as a mate for the flanged retainer, a flat one, and one with two holes. All the holes for this model are either 3mm or 6mm. For the CR to mate with the retainer, I plan to use 3 or 4mm heat-pressed inserts then I can use the same machine screw with some Loctite.
Pre-build:
Before I can build, I need to print out the parts. I elected to prep the parts from Fusion360 (saved as .3mf files) using OrcaSlicer, since I like that you create multiple plates and it integrates my Klipper UI so I can slice, print, and monitor in one environment. PrusaSlicer has been my main slicer and since Orcaslicer is a fork, they are nearly the same. OrcaSlicer just has some quality-of-life features that I like.
The nosecone, centering rings, and retainer were printed in PETG. I printed the fins and the intake in PLA+ (because I ran out of PETG). Though, I didn't really have to, I printed everything 100% infill. They are just a bit bigger than the perimeters that set (6), so it really isn't much savings unless I go with 5%. It makes me happy. The fins and centering rings are 6.3mm thick. I was able to design and print everything in a weekend, as I would design one part, then print it and start on the other while the first was printing.
I took a break from designing parts and switched over to the Cricut to design the decals. I have a few different methods for doing this. If I can find a decal scan, I will convert it to SVG and port it into Cricut Studio. Often times, the quality is garbage, so I go hunting fonts on 1001fonts.com until I find something close. I can usually reproduce designs in PaintShopPro pretty close, like on my Mega Red Max. Once I imported the decals, I noticed most were pretty decent with only a few too small or not good enough. This isn't scale and my designs are definitely not in the accuracy ballpark, so I left some out.
Build Part 1:
And now we are caught up. Today, I started laying out the fins and centering rings. I designed a fin slotting jig and that was really helpful. It was designed for the aft fins but helped with the forward fin slots. I did goof up by not drawing a centering line down the tube and the forward slots were off. I also cut 4 slots for the forward section when I got distracted and forgot what I was doing. I had an extra tube so it was not catastrophic. the fins fit perfectly in the slots, but for some reason the fin tabs are short. Not sure what happened as I translated the values from OpenRocket. now I need a solution for that (did someone say 'Print something'?)
Once I get a solution for the tabs, I will begin glue-up. I will not be gluing in the forward or aft CRs so I can get the goop on the tabs but I will insert them to keep the MMT centered then pull them out for epoxy.
Fixes:
I will need to design a solution for the tabs. I have an idea that might work. If it pans out, I will share it. If it doesn't, then it will never see the light of day! J/K. I document my wins and fails so others can learn from me. I'm just a walking cautionary tail. I will also modify the intake to take off the excess on the aft end so its flush. The fin slot is tailor fit for the fin round-over and angle, so I just need to get some measurements and lop off the excess.
That's it for now. Below are a bunch of pictures with captions. I will continue to post as I make progress. I am hoping to launch this this weekend on an H250. It will be a straight shakedown flight, then I will add the electronics for DD.
The Big Nuke Duke'm was supposed to be my DD practice rocket, but since I have something just as cool and capable, The Menace will do nicely. Once I'm confident with the DD, I will start looking at 38mm I motors. Once the contest is completed, I will post all the .STLs, .3mf, and CAD drawings for anyone to use as they will.
Thank you for reading.
The Menace-3D Concept
OpenRocket Design
Slicer Layout after Design
Parts are Printed (mostly)
Decal Design for Cricut
Fin Slotting Jig Aft Fins Done Marking for Forward Fins (with blood sacrifice)
Dry Fit the Intake to Aft Fin Intake Overhangs by about 8mm
Final Mockup
Over on another thread in the 3D Printing section, there's a friendly competition going on: TRF Challenge #1: Estes Menace and I thought this would be a great opportunity to push myself to learn more Fusion 360.
I started back in March 2023 to 3D print small parts, and started designing in TinkerCAD which really helped me get my designs to the printer, faster. There were just some things that were not easy to do. I tried OnShape and had some success with that, building simple nosecones, fins, and centering rings but I still struggled with some other things, like knurled textures for retainer caps or threads. There is nothing wrong with either app and everyone will come at this activity with different perspectives. For me, Fusion360 just seemed intimidating, so I kept putting off learning with it.
It's a great tool for me now and I can do all thing things that I wanted to do, so when this challenge presented itself, I got right to work. This thread will document the build along with the final launch performance against the simulated design.
NOTE: All the designs were done against LOC/Precision tubing (Body and MMT). I have failed to make this distinction in the past, and caused some people using my designs some bit of grief. My sincerest apologies for that.
Design:
The challenge presented by @cwbullet did not have a readily available OpenRocket/RockSim file. I wanted to build something bigger but I needed a frame of reference, so I found some scans on JimZ's website and some details on RocketReview.com that allowed me to put together a rough OR sim at scale. I didn't have specifics for the fins or intake, so I eyeballed them. Once I was happy that the sim roughly resembled an Estes Menace, I scaled it up and started tweaking. The forward fins seemed a bit too narrow, so I gave them a more triangular shape. The aft fins seem a bit small, but the sim showed stable flight once I completed the design. I created an Ogive nose cone but I may have overcooked my grits with that. However, the design "Looks" really good.
With the nosecone, it was way bigger than my printer would allow and cutting and gluing parts together is not something that I enjoy. I wanted to do something with threads, so I build a 2 piece nosecone similar to Arogen67's Big Red Max nosecones. I loved this design but it didn't work out well for me because it was too thin. I created beefed-up versions and put them on Printables, but the idea of creating them from scratch was beyond me. Time to fix that. I also love IPL's nosecone ebay and I have exclusively adopted this for my rockets, where applicable. There were some things that I wanted to modify, so I originally took the same approach and remixed the original. For the Menace, I have redesigned both the nosecone, shoulder coupler and the nosecone sled from the ground up. The thread pattern on the ebay sled was engineered so that it would work in both my existing designs and this new one, so I have backwards compatibility.
For the intake, I took the aft fin and used it to get a rough idea of the shape. My first prototype looks much like the others and that is fine and functional. Being a Sci-Fi geek, I like long, fast-looking designs so I stretched out the leading vertical supports to an exaggerated amount. I will often do this then reel it back into something more sane but the look really had a Star Trek vibe and I liked it, so I kept it. The forward fins also deviate from the original but I think that they look good too.
I was curious about motor retainers that have a flange to hold the threaded ring on the the back of the rocket. I realized that I could design it so the flanged ring doesn't need to be epoxied rather, it can be mechanically fastened. I designed a 38mm retaining ring with flange and companion cap that should be able to take the abuse from the hot and hairy end. Also, if they burn up, I can replace them and get back in the game (theoretically).
I also created centering rings of various types. One as a mate for the flanged retainer, a flat one, and one with two holes. All the holes for this model are either 3mm or 6mm. For the CR to mate with the retainer, I plan to use 3 or 4mm heat-pressed inserts then I can use the same machine screw with some Loctite.
Pre-build:
Before I can build, I need to print out the parts. I elected to prep the parts from Fusion360 (saved as .3mf files) using OrcaSlicer, since I like that you create multiple plates and it integrates my Klipper UI so I can slice, print, and monitor in one environment. PrusaSlicer has been my main slicer and since Orcaslicer is a fork, they are nearly the same. OrcaSlicer just has some quality-of-life features that I like.
The nosecone, centering rings, and retainer were printed in PETG. I printed the fins and the intake in PLA+ (because I ran out of PETG). Though, I didn't really have to, I printed everything 100% infill. They are just a bit bigger than the perimeters that set (6), so it really isn't much savings unless I go with 5%. It makes me happy. The fins and centering rings are 6.3mm thick. I was able to design and print everything in a weekend, as I would design one part, then print it and start on the other while the first was printing.
I took a break from designing parts and switched over to the Cricut to design the decals. I have a few different methods for doing this. If I can find a decal scan, I will convert it to SVG and port it into Cricut Studio. Often times, the quality is garbage, so I go hunting fonts on 1001fonts.com until I find something close. I can usually reproduce designs in PaintShopPro pretty close, like on my Mega Red Max. Once I imported the decals, I noticed most were pretty decent with only a few too small or not good enough. This isn't scale and my designs are definitely not in the accuracy ballpark, so I left some out.
Build Part 1:
And now we are caught up. Today, I started laying out the fins and centering rings. I designed a fin slotting jig and that was really helpful. It was designed for the aft fins but helped with the forward fin slots. I did goof up by not drawing a centering line down the tube and the forward slots were off. I also cut 4 slots for the forward section when I got distracted and forgot what I was doing. I had an extra tube so it was not catastrophic. the fins fit perfectly in the slots, but for some reason the fin tabs are short. Not sure what happened as I translated the values from OpenRocket. now I need a solution for that (did someone say 'Print something'?)
Once I get a solution for the tabs, I will begin glue-up. I will not be gluing in the forward or aft CRs so I can get the goop on the tabs but I will insert them to keep the MMT centered then pull them out for epoxy.
Fixes:
I will need to design a solution for the tabs. I have an idea that might work. If it pans out, I will share it. If it doesn't, then it will never see the light of day! J/K. I document my wins and fails so others can learn from me. I'm just a walking cautionary tail. I will also modify the intake to take off the excess on the aft end so its flush. The fin slot is tailor fit for the fin round-over and angle, so I just need to get some measurements and lop off the excess.
That's it for now. Below are a bunch of pictures with captions. I will continue to post as I make progress. I am hoping to launch this this weekend on an H250. It will be a straight shakedown flight, then I will add the electronics for DD.
The Big Nuke Duke'm was supposed to be my DD practice rocket, but since I have something just as cool and capable, The Menace will do nicely. Once I'm confident with the DD, I will start looking at 38mm I motors. Once the contest is completed, I will post all the .STLs, .3mf, and CAD drawings for anyone to use as they will.
Thank you for reading.
The Menace-3D Concept
OpenRocket Design
Slicer Layout after Design
Parts are Printed (mostly)
Decal Design for Cricut
Fin Slotting Jig Aft Fins Done Marking for Forward Fins (with blood sacrifice)
Dry Fit the Intake to Aft Fin Intake Overhangs by about 8mm
Final Mockup