Dave's Rocket Shop

Your home for High Performance Rocketry

Author: dcarter

Saturn V Part 3 Printing the SLA

Below the CSM comes the SLA (Service Module to Lunar Module Adapter). In this video I discuss some basic printing tricks that can significantly reduce the amount of plastic used and time required to print. Don’t forget to like and subscribe!

 

Printing with PETG

For the most part, I’ve been a PLA guy. My goal was never to make 3D printing a hobby but to use it as a tool when making rockets. I’ve always had the intention of using ABS for a lot of reasons, but primarily due to the ventilation requirements I have only dabbled up to this point.

I can’t remember why I’d bought the PETG spool. It’s sat unopened for quite a while. From a rocketry point of view, it doesn’t like to be glued or painted so it’s not much use for a lot of what I wanted to do. At this point, I’ve been struggling with the Robo 3D for quite a while and it’s time to consider making my own. PETG is a good candidate for making the printed parts I need.

The first time I tried, I noticed that my old heater was worn out and tired. The project went on the back burner until I got that replaced. When that was done, I started on my Saturn V so that got placed on hold. Well, when I needed to print some test pieces for fit and size, my PLA was running low so it seemed like a good time to roll out my unused PETG.

My first impressions are good. PETG has a reputation for sticking so I put painters tape on my glass bed so there would be no damage. And stick it did. The downside is that I only have narrow tape, so the surface is uneven as it overlaps between strips. The large test pieces I printed came out great!

My next print was a reusable spool for filament purchased without the spools. Also great! I love the feel. The surface is smooth and it feels more like plastic than the rigid PLA prints do. Next was a spool holder for nylon (I’m getting adventurous now!) again with great results.

But back to PLA to print some pieces. And boy do they look like crap. I was blaming my printer with its known hardware issues. Then I looked at the PLA prints I’d just completed without the same issues and started to rethink things. Maybe it was the filament. You know the filament I’d bout 2 years previously that had spent half that time in storage and the other half idle on the spool holder. I printed the same part in PETG and I’m not blaming the printer anymore. It really is a shame you can’t glue or paint it!

As I write this my first spool of PETG is winding down, and I got a replacement supply of PLA today so it’s back to printing rocket parts. But PETG will have its place as well. If it can be screwed or fastened in other ways, like EBay sleds, and 3D printer parts, from here on out it will be PETG.

I still need to try the nylon, and I’m sure it will have its place, and ABS is definitely something I need to get back into. I’m now a multi-filament printer!

Macro for creating nose cones in FreeCAD

On twitter I noticed someone struggling with OpenSCAD to create nose cone shapes when it occurred to me that I had a macro. I’d originally developed mine in OpenSCAD but quickly moved to FreeCAD and finalized development there. Sadly I have no idea what became of my OpenSCAD original.

It does have some FreeCAD specific stuff, but it’s written in Python so should be usable in other contexts. So it’s time to share.

You can download here

Saturn IB Part 9 – Recovery

Designing the recovery system is a challenge for any build. For the Saturn IB there are structural challenges, and concerns about maintaining the scale look of the final rocket. Don’t forget to like and subscribe!

Quick Build: Estes Centuri

It was time to take a break and build a rocket! In this video I build the Centuri, a skill level 2 rocket from Estes so it’s pretty easy. I’ve helpfully sped up most of the build and removed the parts where I waited for glue to dry.