LOC Ultimate Build - How a 3D Printer Will Make Your Life Better

[patelldp]

In preparation for the arrival of baby #2 (any day now...) I purchased a 3D printer. I've been using a South Bend 13" lathe to make rocket parts for a few years now but have always been frustrated with the manual nature of the tool. Every rocketeer should own a lathe, but the time involved in making even a pretty simple part is significant. Since we'll be devoting a lot of time to taking care of the new arrival and making sure my almost 2 year old son gets plenty of attention, I wanted a CNC machine.

I purchased a Monoprice Maker Select from Amazon. This printer is quite remarkable for the $330 price tag. It has issues (weak z-axis, non-glass print bed, odd two-piece design), but it will give you satisfying results right out of the box. Couple that with robust support online (https://3dprinterwiki.info/wiki/wanhao-duplicator-i3/) and you can upgrade the printer relatively easily to really improve the print quality. So far I have added the z-brace to stiffen the printer, added a glass print bed, and added a few other peripherals.

Now that the printer is dialed in and ready for just about anything, it's time to start using it! Enter the LOC Ultimate kit that I purchased a bit ago. I've always wanted to build a 7x 29mm kit to use the EX cases that I make and sell on the aforementioned lathe. I've been having fun with some 29mm two-stage flights while staying under our small East Coast waivers, time for some cluster and air-start fun as well.

The kit will be built almost stock. The one exception will be the incorporation of an electronics bay just above the motor mounts. A Raven will reside there and control any air starts that I want to do. The rocket will also separate there for apogee deployment for a "zipperless" design.

The first print for this project is a fin alignment guide. I hate aligning fins (especially on this 6-finned rocket...), this will almost entirely eliminate that burden.

This is a view of the inside of the guide:

Here's the guide in place with a dry fit fin:

Next up: Designing and printing the Raven sled that will be modular in nature; usable for both this project and my upcoming MAC Canvas 54mm three stager.

 

[ttabbal]

I like the fin alignment jig. Funny that you posted one, I'm actually planning a rocket design to use the 4-grain motor I bought from you Dan. I was just thinking I should draw something up for that. If I can get time and weather to cooperate, I'll do test burns in an Applewhite saucer, but once I'm more confident in my motor-making I need a smaller rocket to fly them in.

The catch with printers, is you either have to have designs out there you can print, and there are a LOT. Or you have to be able to use CAD to draw some up. I'm still a bit of a noobie at the CAD side, but don't let it stop you. It looks complex, but isn't too bad once you get a feel for how 3D design works. I've only got a few hours of learning/experimenting and I could probably replicate the jig above. I've done a few other little things as well.

And printers are SLOW. However, they are hands off once you get them started. So it's pretty common for me to start a job and go do other stuff while it prints. I just check on it once in a while to make sure something hasn't gone wrong with it. I even have a Raspberry Pi with a camera mounted to it so I can check from my phone wherever I happen to be.

7x29mm....... oooookay... I want to see that fly in person.... Don't suppose you want to bring it to Utah?

 

[NateLowrie]

In preparation for the arrival of baby #2 (any day now...) I purchased a 3D printer. I've been using a South Bend 13" lathe to make rocket parts for a few years now but have always been frustrated with the manual nature of the tool. Every rocketeer should own a lathe, but the time involved in making even a pretty simple part is significant. Since we'll be devoting a lot of time to taking care of the new arrival and making sure my almost 2 year old son gets plenty of attention, I wanted a CNC machine.

I purchased a Monoprice Maker Select from Amazon. This printer is quite remarkable for the $330 price tag. It has issues (weak z-axis, non-glass print bed, odd two-piece design), but it will give you satisfying results right out of the box. Couple that with robust support online (https://3dprinterwiki.info/wiki/wanhao-duplicator-i3/) and you can upgrade the printer relatively easily to really improve the print quality. So far I have added the z-brace to stiffen the printer, added a glass print bed, and added a few other peripherals.

Now that the printer is dialed in and ready for just about anything, it's time to start using it! Enter the LOC Ultimate kit that I purchased a bit ago. I've always wanted to build a 7x 29mm kit to use the EX cases that I make and sell on the aforementioned lathe. I've been having fun with some 29mm two-stage flights while staying under our small East Coast waivers, time for some cluster and air-start fun as well.

The kit will be built almost stock. The one exception will be the incorporation of an electronics bay just above the motor mounts. A Raven will reside there and control any air starts that I want to do. The rocket will also separate there for apogee deployment for a "zipperless" design.

The first print for this project is a fin alignment guide. I hate aligning fins (especially on this 6-finned rocket...), this will almost entirely eliminate that burden.

This is a view of the inside of the guide:

Here's the guide in place with a dry fit fin:

Next up: Designing and printing the Raven sled that will be modular in nature; usable for both this project and my upcoming MAC Canvas 54mm three stager.

Very nicely done. Congrats on the new kid! They change your life for sure.

Your life is uncannily similar to mine. My 2nd son just arrive on the 17th and my new Robo 3D R1+ arrived today. Looking forward to making some rocket parts. It definitely makes life easier in a lot of regards. I make large format CNC routers for a living and have a wonderful metal mill and there are things they can't easily do like that fin guide you made. A 3D printer is a wonderful tool in the toolbox to have.

How are you handling the switch mounting on the avionics sleds?

 

[patelldp]

Now we get into some real fun with the printer!

The kit comes with three long and four short motor tubes. It includes two "rings;" one with three in-line holes and one with one massive hole and 7 crescents to accept the tubes. That's just not acceptable, and I wanted to design a ring to center all of the tubes. Here's the result:

This was a dimensional test ring and it passed with flying colors. I will be printing two rings that will have provisions for wire conduit and motor retention, more on that later...

 

[neil_w]

Nice work. What material are you printing in?

I've been designing a few key items here and there and getting them printed by 3DHubs, but I tend to limit what I do because of the cost. If I had my own printer I'd be going nuts with this stuff....

 

[mccordmw]

Won't the polymer melt at the temp it's exposed to as centering rings?

 

[patelldp]

Won't the polymer melt at the temp it's exposed to as centering rings?

The plastic will not be in direct contact with the motor cases nor will it be exposed to the exhaust. The PLA material is printed anywhere from 180C to 210C (356F to 410F). I'm not exactly sure what temperature my EX motors achieve on the OD but the rings will only experience what is transferred through the paper motor tubes. In addition to that, the plywood "ring" provided by LOC will be epoxied to the fore side of the aft plastic ring and filleted. The plywood fore ring will be used as well. This will preserve the structural integrity of the mount.

I'd guess that if there is any deformation it will be in the spans between the motors. Heat soak from 29mm motors should be comparably lower than larger motors. We'll see what happens!

 

[neil_w]

The plastic will not be in direct contact with the motor cases nor will it be exposed to the exhaust. The PLA material is printed anywhere from 180C to 210C (356F to 410F). I'm not exactly sure what temperature my EX motors achieve on the OD but the rings will only experience what is transferred through the paper motor tubes. In addition to that, the plywood "ring" provided by LOC will be epoxied to the fore side of the aft plastic ring and filleted. The plywood fore ring will be used as well. This will preserve the structural integrity of the mount.

Glass transition temperature for PLA is only 60-65 C. I'd be nervous about it around the motors, although I have no real idea how hot it'll get down there. ABS has a glass transition temperature of 105 C, which seems to make it a bit more suitable for that type of application (not so much fun to print, though).

I'd guess that if there is any deformation it will be in the spans between the motors. Heat soak from 29mm motors should be comparably lower than larger motors. We'll see what happens!

Please do report!

 

[ttabbal]

I suspect it will be fine with PLA. If not, PETG is almost as easy to print, but more high-temp tolerant like ABS. Another option is the high-temp PLAs that are out now, you anneal them in an oven after printing and they can handle close to ABS temps without deforming/melting. MakerGeeks Raptor PLA is one option. I think eSun makes some as well.

I'm having 29mm motor envy seeing that many tubes.

 

[claytonbirchenough]

They're a lot of fun. I'm working on some AV bay stuff for some buddies, when I'm not tied up with school work... They're just awesome though. Attached is a picture of the fin alignment guide for my big L3 (hopefully) Terminator build... it was printed on my Original Prusa Mk2. Took 30+ hours to print because I love the smaller layer heights haha...

Also, for anyone interested in using their parts they print in rocketry, I highly recommend the book Functional Design for 3D Printing: Designing 3d Printed Things for Everyday Use by Clifford T Smyth. Lots of great info in there!

Andddd all the pictures are sideways. Awesome.

 

[tim cubbedge]

I've had 3D printed products made of PLA severely deform/warp just sitting in my car.

 

[BLKKROW]

Glass transition temperature for PLA is only 60-65 C. I'd be nervous about it around the motors, although I have no real idea how hot it'll get down there. ABS has a glass transition temperature of 105 C, which seems to make it a bit more suitable for that type of application (not so much fun to print, though).



Please do report!

https://en.wikipedia.org/wiki/Polylactic_acid

PLA's Glass transition temperature is 150-160*c not 60-65*c. I am interested to see how well this holds up to the heat soaking through the materials. However, you do have to remember PLA is UV sensitive and can shatter. I would be more worried about the tail end of the rocket hitting the ground several times and cracking.

 

[neil_w]

https://en.wikipedia.org/wiki/Polylactic_acid

PLA's Glass transition temperature is 150-160*c not 60-65*c. I am interested to see how well this holds up to the heat soaking through the materials. However, you do have to remember PLA is UV sensitive and can shatter. I would be more worried about the tail end of the rocket hitting the ground several times and cracking.

No, the *melting point* is 150-160C; glass transition point is 60-65C, as given in that very Wikipedia page you referenced.

 

[patelldp]

https://en.wikipedia.org/wiki/Polylactic_acid

PLA's Glass transition temperature is 150-160*c not 60-65*c. I am interested to see how well this holds up to the heat soaking through the materials. However, you do have to remember PLA is UV sensitive and can shatter. I would be more worried about the tail end of the rocket hitting the ground several times and cracking.

Good points. Remember, West System 105/205 has an ultimate Tg of 142F, almost identical to the PLA that I am using (140). The CR's will both be internal to the rocket. The Aft CR will be encapsulated in AeroPoxy 2032 (Tg 196F) with black pigment, and then the motor retainer will protect it from exhaust. Here's the two finished CR's. Both have a hole for a wire conduit and the aft CR has 6-32 PEM nuts pressed in for the motor retention.

Here's the whole motor mount assembly dry fit together. Last piece needed is a 1/4" OD X 3/16" ID XX phenolic tube for the wire conduit which will extend the entire length of the motor tube assembly.

Since we're scientific here, I dove into my short scrap bin and found some extra 29mm and 54mm LOC paper tubing identical to what is used in this rocket. I also printed a pair of CR's for the two out of the same PLA as the Ultimate. I actually made them thinner (3/16" vs 1/4") and with less fill (50% vs 100%) to make them more prone to melting and deforming. I'll glue it up with CA only so as to not insulate it at all and static fire a 29-2G motor and see what happens. I'll make sure the locate one CR around the graphite nozzle of the motor as a worst case scenario for heat transfer and soak time.

My guess is I'll see very little to no deformation...but let's see what happens. Now to see if I can duck out for 20-30 minutes to static test a motor at the local park.

 

[neil_w]

Cool, science!

 

[Rocketjunkie]

Since we're scientific here, I dove into my short scrap bin and found some extra 29mm and 54mm LOC paper tubing identical to what is used in this rocket. I also printed a pair of CR's for the two out of the same PLA as the Ultimate. I actually made them thinner (3/16" vs 1/4") and with less fill (50% vs 100%) to make them more prone to melting and deforming. I'll glue it up with CA only so as to not insulate it at all and static fire a 29-2G motor and see what happens. I'll make sure the locate one CR around the graphite nozzle of the motor as a worst case scenario for heat transfer and soak time.

My guess is I'll see very little to no deformation...but let's see what happens. Now to see if I can duck out for 20-30 minutes to static test a motor at the local park.

Propellant type will make a large difference. Propellants with large bright flames (like White Lightning) will transfer a lot more heat than propellants with less bright flames (such as Blue Thunder). This is radiant heat transfer, also, obviously, burn duration matters too.

 

[marcusSRG]

Very cool Dan!

 

[Serpico]

3D ABS printed material does quite well in extreme heat. Most of the parts that survived my CATO were the 3D ABS printed pieces. Several were in DIRECT line of fire with the blowout gas plume and remained fairly intact. I was very surprised.

The base of the lander cooked for several seconds in non-direct heat - most of the damage is from the impact:



While yes it was obliterated; the rail button still sits on the 3D printed extender - this was directly in the gas plume the entirety of the CATO. You can see the cardboard burned away around the 3D printed part:

BEFORE:


AFTER:

 

[patelldp]

Build is on hold! Eli Christopher, born 6:15am today, 8lbs 10oz.



Everyone is doing great!

 

[neil_w]

Congrats!!!

 

[Serpico]

Build is on hold! Eli Christopher, born 6:15am today, 8lbs 10oz.

View attachment 304543

Everyone is doing great!

WOOT!!CONGRATS!!!

 

[rfjustin]

Congrats on the new addition! Glad to hear all are doing well!

 

[marcusSRG]

Congrats buddy!

 

[ttabbal]

Congratulations! Glad everyone is doing well.

 

[NateLowrie]

Congrats!!! You getting any sleep?

 

[davdue]

Congrats.

 

[dhbarr]

Awesome, congrats!

 

[Nick@JET]

Congrats Dan!