Realistic M67 Fragmentation Grenade Model V2 by missing_string

missing_string

Props & Cosplays>Replica Weapon

Print Profile(1)

All

X1 Carbon

P1S

P1P

X1E

Optimized Layer Height/Wall Count

Designer

2.5 h

1 plate

4.7(9)

Boost

124

205

Released

Description

This is an ultra-realistic model of the M67 Fragmentation Grenade with M213 Fuse used by the U.S. and Canadian military, among others. I know, I know, that's exactly what I said about V1. Well, this time it's different.

V1 was based on dimensions from a dummy grenade that turned out to be not hyper realistic. For V2, however, I managed to get my hands on a real factory inert M67. For those of you not in the loop, that's a real fragmentation grenade body, just filled with inert resin rather than explosives. Several (many) hours of “CAD and Calipers” later, and I present this:

The most true-to-life fragmentation grenade you can download on the internet.

Just like my smoke grenade, this is a 1-1 scale replica of an M67 fragmentation grenade. Every piece of this model is able to be swapped onto an actual frag grenade (in size and shape, PLEASE do not mix 3D printed parts with live munitions). I have verified the accuracy using printed jigs that fit flush with both this model and the real grenade. please note that the new fuse and upper body are not compatible with the V1 due to the change in thread pattern to match the real grenade. This fuse and upper body may also not be compatible with some commercial dummy grenades.

This is perfect for both cosplay and display. For cosplay, it will fit in any real grenade pouch, including crazy kydex ones. For display, well, the cost of a dummy with the actual shape and size of a real M67 ranges into the hundreds. The real deal is undeniably better, but this model may well be the second best. It's certainly a lot more true-to-life than my last dummy.

Every part (except the pin and ring) has been improved from V1. The changes include:

o Lower Body

- Changed shape to match real M67, including weld seam

o Upper Body

- Changed shape to match real M67

- Optimized interior shape, no longer requires supports and reduces post-processing requirement for tight fit at the expense of a tiny bit of interior volume

o Fuse

- Added 90 degree confidence clip assembly introduced on post-2015 grenades (Note: This is extremely fragile and supports are not easy to remove. A pre-2015 version without the clip is coming with compatibility with this model and the updated markings, stand by.)

- Added factory markings to the fuse (Likely not consistent with every grenade, but accurate to the post-2015 example I have)

o Spoon

- Altered spoon geometry to match real version

- Significantly beefed up the spoon to reduce weak points

(NOTE: The spoon must be printed using arachne engine. The original design was divisible by the standard line width for a 0.4mm nozzle, the new version is not, and will likely fail if not printed with arachne in any orientation.)

- Changed orientation of spoon in print profile for easier support removal. The new spoon has added support painting that will rarely actually touch the model, but drastically reduces wobbling and leads to enhanced print accuracy.

Please note that this model may require some sanding to look awesome, specifically at the top of the confidence clip assembly after supports are removed.

As usual, this could easily be mistaken for a real munition. I am not responsible for your decisions. Be safe, and be kind.

While I recommend printing at least the grenade body in blue (the universal color for inert munitions), The actual grenade is OD green with black markings. Markings are painted along the top surface of the grenade to avoid marring from users taping the spoon to the body, which would render the grenade unserviceable.

The safety clip is made of about 2/3rds of a large paper clip, based on reference photos.

As always, I would greatly appreciate a like or a boost. Designing, printing, and testing accurate munitions models is not an easy task, and I greatly appreciate y'all's support. Big shoutout to Ironhorse 7 (I know for a fact you won't read this) for lending me the grenade to build this model. I'll be releasing some upgrades for this model, including a compatible pre-2015 fuse in case you want to throw it without breaking it, “pretty soon”. Stay tuned.

Comment & Rating (15)

@nikkolaus

While I'm one of the last people who likes to talk-down other people's work, and while I appreciate the multiple hours you put into measuring an actual device, I have to say that I think this project needs a bit of a re-work. The object you were measuring was metal. Those measurements, while they may be factually correct to the actual item, do not correspond well when being turned over to additive plastic production. The tolerances of the material simply don't hold up. Within 2 hours of light fidgeting and use mine was rendered inoperable. From the start, the keeper for the pin was pushed aside and broken off (could have been printer error), straight from the print bed. The holes for the pin had to be enlarged with a hot soldering iron tip, to accept the pin, because it was simply too large to pass the pin thru. The spoon has a super fragile pair of hooks for the fuse body and these were weak and snapped fairly quickly after a few uses. The tail at the bottom of the spoon took one grip and prompt sheered off. The space between the spoon hooks and the pegs where it slides under has more than enough room for expansion of added material. Why is there variable line height in the middle of the bottom base? The grenade halves fit together well. The grenade body is very thick feeling and pretty hefty. It made quite a loud thunk when it hit the carpeted floor I have. (49 grams / 1.7 oz !!) I had some issues with support taking off a decent bit of good surface material, but that's a printer/filament thing. If I was rich I'd have done supports in ASA or BL PLA Support material, but I went cheap for this trial run. I own 2 real, all metal, inert grenades myself and know how heavy they can be.. You could break your foot if you dropped on on it bare. So, I commend you on making a plastic model of one that feels rigid, tough, and weighty. Especially in the threads. Most models you feel like you're going to break the thing in half if you twist too hard to tighten down on the threads, but this one it takes all that you can give it. Part of that may be the filament, but I like to attribute it, at least in part, to the design. Thicker parts may cost more filament (and therefore cost pennies more) but it sure is worth it when you take it in your hand and feel the heft and rigidity. Like I said, I'm not here to dog on your work, so please don't take it that way. I am here to help you notice some flaws in the work piece that I believe can be quickly re-worked. Also, consider adding a type of printed spring (i've seen a few in other works, that are like a squiggle wave of filament) to go under the spoon and make it fly upwards. I love that you made this, and I hope to see improvements in the future. We only get better thru trials and error. P.S. I think you'd get more hits if you switched the tags "army" and "marine corp" out with "Military" and "Explosive". It's "Marine Corps" anyways... Printed on a Bambu Lab P1S, with AMS, at print profile defaults - 0.20 Standard, with modifications by maker. My Used Filaments: ERYONE High Speed Matte Olive Green PLA Bambu Lab Black PLA Basic DURAMIC 3D Smoky Gray PLA Yes, I realize in some of the pictures the pin is in the wrong side. If I could post more pictures, I would. Message me if you want them all.

(Edited)

The designer has replied

@missing_string

First off, thanks for the feedback! While I appreciate it, I don't think a lot of it lines up with the purpose of this model. There are a ton of more durable grenades both here on Makerworld and elsewhere. There are not, however, any other realistically dimensioned grenades as far as I can tell. I have a specific application that requires a dimensionally accurate grenade that I do throw, but the trade-off is that these only last a few tosses, and certain parts (like that ring retaining clip) will break immediately. A lot of the real parts are stamped steel, which I can't do at home. In general, this model is designed to be painted and sit on a shelf as a display piece, or hung on a cosplay kit. For those purposes, dimensional accuracy is far more important (to me) than structural strength. If you're looking for something to play with, this might just not be the model for you. I may rework the model to be more durable and upload a new version, or an upgrade kit for this one, but that's basically a completely different model, and would really take away from the realism, so that's a later project. For example, the actual thickness of the spoon is 0.6mm, which would most likely print in one 0.6mm wide line or 2 0.3mm wide lines, either of which would tank the structural stability even further from its current strength. The spoon in my model is around 1mm thick with some hidden reinforcements, and is still prone to falling apart. However, any thicker and it either requires a redesign of the fuse or becomes strikingly different visually to the real spoon. That being said, there are some of these that I will fix on this model, that don't affect the realism. The hole in the fuse for the pin fits on my version, but it's tight. I can loosen up the tolerances on that. Some kind of spring or magnet mechanism for the spoon could work well, aside from the fragility of some of the fuse and spoon parts. Also, I'm trying to figure out a way to remove the requirement for support material from the lower body for a cleaner fit. Great tag suggestions. I'm leaving "Marine Corp" tho, just to make Marines angry. Please do send me the pictures, it always helps having reference photos from multiple printers and filaments. Edit: Spelling

(Edited)

@nikkolaus

If you try to colorize it, it will throw a fit about "Prime Tower and Object Layer Height", even if you're just assigning PLA Support material from Bambu and not actually changing any colors.

(Edited)

The designer has replied

@missing_string

Interesting. A prime tower shouldn't be required for single-color prints. If your print is a single color, you should be able to just disable the prime tower. If not, you can either print each piece on a separate plate or change the layer height for all pieces to 0.16 or 0.12. The grenade body will take longer to print, but that should be fine enough to get good results on the rest of the pieces.