3D printing...

[JohnnyC]

@The Chairman your shell separation could be a couple things. Could be anything from extruder temperature to number of shells, to print speed, to z-axis calibration, etc. What printer? What filament are you using?

Non-scuba question. I teach stop the bleed courses and wound packing trainers cost 150-300 each, how hard would it be to 3d print a 4x 4 x 4 block (preferably with a somewhat soft material ) with a simulated gunshot wound and a cavity below it?

There are quite a few different types of flexible filament (TPU, PolyFlex, FiberFlex, etc.). Some require a specialized extruder, some can be printed with a normal extruder. They come in different levels of flexibility. Printing a wound packing trainer is easy, but a 4x4x4 100% infill cube is gonna take like, 3 days..... 100% infill takes a ridiculous amount of time for most things. Changing the amount of infill is going to change what it feels and acts like. Running a 3D printer for that amount of time is a long time for things to go wrong. It's fine if you catch it right away, but when you're 3 hours from completed print and you end up with a wad of spaghetti you've wasted both a TON of filament and a bunch of time. If time = money, you're screwing yourself twice in the event of a failure.

That being said, a dual extruder printer could be a cool tool. You could simulate different tissue mass by using two different types of flexible filament, or using some sort of flexible filament for tissue and PLA or ABS for bone could be interesting. In a large enough print you could really demonstrate effective application of a CAT. You could even demonstrate the differences in stopping blood loss with different types of tourniquet. As in, how a CAT differs from a SOFTT from a RATS, etc.

Your best bet is going to be to make your own by using some sort of mold. Pour it in, let it cure, and drive on. Silicone or something similar maybe? Check out dentist mold making stuff. I wouldn't use ballistic gelatin. It's not stable across the temperature range. It's really only good for simulating wound patterns in soft tissue, and even then, a roid monkey and Fat Albert are going to be different densities, which side will you lean towards when you're making them?

 

[The Chairman]

Just a random thought, would 26650s also fit in that space? Maybe 4-5 of them?

Yes, but almost all of my backup lights use the 18650s. A long time ago I learned that I could substitute 18650 for the wider 26650 by using a 60mm piece of 1/2" PVC pipe. As much as possible, I want one solution for my battery needs. In addition, if/when I deplete my main light, I don't have to wait for it to charge. I simply pop in 12 charged 18650s and I'm diving. Before I continue with my design, I need to see if this will slip into the two different battery cases. I think it will do just fine.

 

[The Chairman]

@The Chairman your shell separation could be a couple things. Could be anything from extruder temperature to number of shells, to print speed, to z-axis calibration, etc. What printer? What filament are you using?

I used PLA in a Maker Bot Replicator 2 printer. I used "fine" as the base profile, slowed the print speed by 20% and the extruder temp was kept at 230C.

FWIW, I have Translucent Blue TPU coming so I can print a phone case. The cost of the 2.2Kg spool is less than the cost of a single case. I'm hoping to work up to printing a multiple color format with the SB logo embedded,

 

[TheCoolBeans]

I made myself one of those long hose retainers for when I'm diving without my torch... even customised it a little with my name. works great!

 

[JohnnyC]

I used PLA in a Maker Bot Replicator 2 printer. I used "fine" as the base profile, slowed the print speed by 20% and the extruder temp was kept at 230C.

FWIW, I have Translucent Blue TPU coming so I can print a phone case. The cost of the 2.2Kg spool is less than the cost of a single case. I'm hoping to work up to printing a multiple color format with the SB logo embedded,

230 might be a little hot for PLA. We have a Replicator+ at work and 230 doesn't print well. It needs the temp to load, but actual print quality suffers when it's that hot. However, if that's what your spool of PLA calls for it's probably not the temp, although it is at the high end of the PLA range. See if you can get a screen shot of your settings, depending on your version of the software it might be in a couple places. It will be easier to diagnose if I can see exactly what they are.

TPU wants to print SLOWLY. And make sure you purge all the PLA before you try to print, and make sure you reduce the retraction. Our Replicator+ isn't rated for TPU so I don't get to play with it that often, only when a coworker brings his Prusa in for a particular print. That being said, the Makerbot TPU prints at like, less than half the temperature of PLA, so double check when you get your spool what it wants.

Good luck trying to print multi-color with a single extruder. It's possible but it's an iffy proposition at best. The biggest thing I can say is build each color as an individual layer in whatever CAD program you have with the same origin. Export each individual color layer as its own STL. When you add each file into the Makerbot program DO NOT MOVE ANYTHING as far as layout. Otherwise you will never get it aligned accurately. If each is built off the same origin, and nothing is moved upon import, you're as close to having good registration as you're gonna get. If you print with a full raft you'd have to recalibrate your z-axis to essentially see the top of the raft as its new zero for the next layer. You're going to want to print the largest piece first, which means the sidewalls of your phone case print might not work with the required reduced retraction distance. You've got a lot on your plate trying to do multicolor with a single extruder, good luck and please post your results. Consider your print order very carefully to avoid an extruder crash. I'm hoping it's successful!

A couple general points:
Shell number provides durability, infill provides rigidity.
Layer height is important, smaller is slower but much more reliable.
If you can get away with printing with a raft, it saves a bunch of time.
If you can use a brim instead of a raft, it's preferable.
Do a test print with one of the test STL's on Thingiverse to see how much you can get away with as far as overhang, required support, bridges, etc.
Pay attention to your layout. You can save a lot of time or increase your successful print percentage by planning out your parts orientation.

 

[The Chairman]

@JohnnyC thanks for your input. That was simply an amazing insight into my new "hobby". The Gainesville Hackerspace not only has a Replicator 2, but also a Replicator 2x which has dual filament heads. Printing in two heads is a bit in the future for me. In fact, I've been looking at the Tevo Tornado as an option for printing here on the farm. It's a 40 minute drive to the Hackerspace and I seem to be printing more and more. I have been told that you can add a second head to that with a simple mod, but again, that would something to think about "down the line". What's your favorite printer?

Thanks for the tip on the TPU heat requirements.

Rafts: when I printed the battery holder, adding the raft only added a bit less than minutes to the print time of over four and a half hours.

 

[emoreira]

Let me know what the change needed is, and I'll look into posting a version 2 if you want.

Hi James, this is the scenario I mean :

This is what I do :

This is what I would need :

The Inner flange thread should be 3 mm higher.
It would be great if you could make a new 3D model with those mods.

 

[JohnnyC]

@JohnnyC thanks for your input. That was simply an amazing insight into my new "hobby". The Gainesville Hackerspace not only has a Replicator 2, but also a Replicator 2x which has dual filament heads. Printing in two heads is a bit in the future for me. In fact, I've been looking at the Tevo Tornado as an option for printing here on the farm. It's a 40 minute drive to the Hackerspace and I seem to be printing more and more. I have been told that you can add a second head to that with a simple mod, but again, that would something to think about "down the line". What's your favorite printer?

Thanks for the tip on the TPU heat requirements.

Rafts: when I printed the battery holder, adding the raft only added a bit less than minutes to the print time of over four and a half hours.

The Tevo Tornado is a nice printer, and you can definitely do much worse (Makerbot) for a first printer. Really, the Makerbot printers aren't great. Check out the Creality CR-10 and the i3 Mega as well. They're all in the same class, essentially Prusa clones. The Creality printers have a HUGE user support base which may be more beneficial while you're starting out, they're essentially the baseline by which all other similar class printers are judged. And all 3 tend to have rotating prices and promo codes and accessory packages, etc. that depending on the day you might get a better deal on one than another. Any would be good for you. I actually like the Tevo a lot, especially the stock Titan extruder, and if I didn't already have a CR-10 at home it's probably what I would choose now, since I'm not as reliant on the community to get my knowledge level to where it's at.

So your "raft" setting on the Replicator 2 software is actually a brim. A real raft is basically a full printed base layer that covers the entire bottom of the print. A brim is what you have in your photo. The name is just an artifact of your Makerbot software not actually calling it what it is. In the software for the Replicator+ it's named correctly. A real raft will take much longer to print, but is very helpful when printing tall stuff and to prevent lifting and curling on large flat stuff.

 

[The Chairman]

A real raft is basically a full printed base layer that covers the entire bottom of the print.

That's what this does. When I separate the two, it's not just an edge, but the entire bottom that comes off that;s a couple of mm thick. I'll take a pic next time.

The biggest difference I see is the "Start to print" time due to the AC heated bed on the Tornado. They don't have an adequate ground, but the mod to create that is very straight forward. If I could definitely add a second head, I think it would be an easy choice.

 

[wwunder]

Hey, Late to the thread, but I have been printing some dive gear... Just started in January, but good results so far! I have printed wall mount din caps, a spool, a reel, a ball mount and clamp for my focus light. The din caps work great and I have my compressor adapters all mounted nicely now.

On version two of the ball mount as I didn't print solid on the first go around and it snapped at the narrow post. I reprinted with solid infill and it has lasted at least one dive. I have a lanyard on the light in case it breaks, but am also debating drilling it and putting a screw in to support the weak part.

So far just printing in PLA, but want to try PETG and TPU.

I think a TPU diaphragm cover for a couple of my sidelined Scubapro 109's would be cool, but not sure how supports work for TPU.