10 replies to this topic

[andtheherois]

Hello NH! I present to you: Cerberus

(I wasn't sure if this belongs in mods or homemades)

Little Back story:

I made a Chimera titan rifle following Fenixharth's instructions on NH. It came out great with a custom breech I made. However, as I was looking through the thread, I spotted a grenade launcher that he had posted with CAD. I loved the way it looked and thus set my mind to creating that in the real world. This is the first (recorded) endeavor I took upon myself to do without using any sort of guide. I went to my local hardware store to look for 1" FBR but alas there was none to be found. Dismayed I went home thinking I'd have to scrap this project. However I soon found Renegade's Tri-Barreled Titan. And so I thought to myself "Why not make a shotgun turret instead of a grenade launcher!? And thus, Cerberus (in mythology, a Hellhound with three heads) was born. A 5 barrel, 3 shot (5x3=15 shots!) rotating turret. I documented the process and now bring it to you as a write up, so what you see here is the first of it's kind.

So lets get started!

What you'll need:

4.5" length of 5/8 wooden dowel/rod
3" length of 1/2" PVC
3" length of 1" PVC
3" x5 Lengths of 1 1/4" PVC
3" x15 Lengths of 1/2" CPVC
1/4" length of CPVC
1" length of CPVC
~1.5" length of 1 1/2" PVC
Cardboard (The kind that nerf blasters come in should suffice)
Sheet of thin (2mm or less) plywood (If regular copy paper sized, then 2x sheets of plywood)
3/8x3/16x3 rectangle of basswood
Foam craft sheets (2mm thick) (If you can find the kind with a sticky backside, that would be best)
E-Tape
Superglue/Hot glue/Epoxy
1/2 or smaller FBR
1 1/4 - 1" Coupler (Or really any coupler depending on what you're coupling to, so long as the coupler reduces to 1")
Foam gasket (Or something similar) with ID of at least 1"

Note:
Any of the wood can be replaced by acrylic, Plexiglas, or whatever other hard plastic you like to use. I used wood materials because 1. there's a craft store 5 minutes from my house. 2. It's cheap. 3. I don't have the necessary tools to machine plastics. However if you are able to make this out of entirely plastics, PLEASE let me know because I would love to see how sexy that looks
End Note.

Now onto the good stuff.
(Sorry about the picture quality. My iPhone sucks.)

1. Take your wooden dowel/rod and sand it down until it fits inside the 1/2 PVC. You want it to be able to turn the PVC on the dowel with a bit of resistance . If it's able to spin freely you've sanded too much. You want enough friction between the two so that it takes a little nudge to turn the PVC.
[img http://i1232.photobu...us/IMG_1395.jpg[/img]

2. Remove your 1/2 PVC from the Dowel, add enough e-tape around it so that it snugly fits into the 3" length of 1" PVC


3. Slide it into the 1" PVC and glue in (mine isn't glued in because I forgot and didn't do it until near the end ) This will become your rotation mechanism.


4. Take 3 of your 3" Lengths of 1/2 CPVC, and hot glue them into a triangle. (In this picture I taped them together, but its actually just easier to hot glue them together) Then add the 3rd one on tip with a LOT of hot glue in the middle, enough so that no air escapes between them.


5. Take some of your FBR and put it between each side of the triangle, then jam it into one of the 3" lengths of 1-1/4" PVC


6. Hot glue in the open spaces (NOT IN THE CPVC D: ) (Sorry, this is the only pic I have of it with hot glue)


7. Do steps 4-6 4 more times so that you end up with 5 of these barrels. Then arrange them in a flower formation around your 1" PVC core. DON'T GLUE THEM TO THE CORE YET! Use E-Tape to keep them together for the next step.


8. Put your flower on a piece of cardboard and trace around the "flower" of turrets until you have something like this:

This will be a die, and part of the side panels for your Cerberus.

9. Take the die and cut out another section of cardboard like that. Do this 3 times with your plywood. Do this 2 times with your foam craft sheet.
(no pic of this, sorry)

10. Take your 1 1/4" - 1" Coupler (Or whatever coupler you use) and put a 1" PVC pipe into it so that it lies all the way down into the coupler. Mark it at the top of the coupler, and cut it. Then place it back into the coupler so that it sits flush inside it. This is to give the coupler more surface area on which to be glued on.

NOTE: no matter what coupler you use, it HAS TO REDUCE TO 1".

11. Take one of your cardboard pentagons and cut a central hole through it for the dowel. I would recommend using the ID of a piece of 1/2" PVC. Lay down your Flower and put the dowel in the middle, then slide your cardboard into it. Make sure your flower and cardboard are aligned. Then take your 1 1/4" - 1" coupler (WITH THE 1" PVC IN IT) and measure out a hole using the ID of this piece. This will be the back of your turret. This hole will be where your air will flow through.

Note: Your hole should not be that big, I messed up the pictures because I did things a little backwards while I was actually making it, but for the sake of clearness this is how it will be.

12. Take an empty piece of 1-1/4" PVC and measure out the ID of it and cut it out on the cardboard. This will be where you rear load it from.

Note: The bigger hole is your rear load, the middle one is for the rod, the smaller hole is for airflow.

13. Use the holes on this die and do this to 2 TWO of the plywood pentagons and 1 of the craft foam so that you get something like this;


14. Take these 4 pentagons and sandwich them together (In this order: foam, cardboard, wood, wood) with some sort of glue. I used epoxy. Then cut yourself 1/4" piece of 1/2" PVC. Put this at the end of your rod and superglue/epoxy it in place. Then take your sandwich and put it on the rod (foam facing in, plywood glue to PVC) and glue it in place. You've just finished the back of your turret.

Note: these holes should line up with barrels, maybe not perfectly, but close enough. Mine is off center in this picture.

15. Now take your remaining pentagons. Using the cardboard as a die again, make a center hole for the rod. Choose a corner and measure out a circle from the OD of 1 1/4" PVC. Take this pentagon and use it as a die for the remaining plywood and foam. Then sandwich them together. (Again; foam, cardboard, wood.) This will be the front of the turret. Set it aside.


16. Take your back panel and put some foam gasket around the holes. This will create a seal on the air hole and give the turret stability on the rear load hole.


(img limit, don't post yet!)

[andtheherois]

17. Now comes the hard part. Take your turrets and glue them into place on the core. Making sure that at least one side is COMPLETELY flat. Or as flat as possible. Go in with a razor blade if you have to and flatten it out by scraping bits off. I did this for about an hour. Get it as good as you can, the gasket should take care of the rest. This flat side goes up against the back of you turret.

Note: This is the same picture as before, I know that. However when I did this I thought that level of flatness was enough. I was mistaken. I had already glued them together at this stage and had to take them apart to level them, then re glue them one by one, making them as flush as possible with the air hole on the back.

18. Now take your turret assembly and stick it on the rod, then place the other pentagon sandwich (foam side in) on top. Be sure that the large hole aligns with on turret, which should be aligned with the air hole so that you can see straight through it all.


19. Take your 1" length of CPVC and stick it at the other end of the rod. Super glue or epoxy it into place, being sure that the holes always stay aligned. You should be able to look through one side to the other clearly. It should also be stable enough where the only thing that moves once everything is dry is the inner turret. Everything else should stay aligned.
(sorry no pic)

20. Take your coupler with the 1"PVC piece in it and glue it on the back, so that you can still see through the air hole. The 1" PVC give the coupler more surface area with which to glue onto. Then take your ~1.5" length of 1 1/2" PVC and glue it on the front, again flush with the exit hole on the front. If you did it correctly it should look something like this;



21. Almost done! Measure 3 lengths of 3/8x3/18 basswood so that they sit flush from the tip of the barrel to the lip of the coupler, but not extending into the part that does the coupling. Glue these onto the top and layer them. This is for added strength and stability.


Congratulations! If you followed my instructions you should (hopefully) Have a working 15 round, 5 turret shotgun style barrel!

Here's a pic of mine, I gave the front a little slope


And on my Chimera;


And there it is, all nice and done.

Pros;
-You get 5 turrets with 3 shots for a total of 15 shots.
-Gets about 50 feet of range on my Chimera with 4-5 foot spread, so it's tight.
-Accepts stefans.
-Rear loading
-Faster than switching between shotgun attachments
-Can be adapted to any coupler so long as it reduces or expands to 1"

Cons;
-Kind of heavy for an attachment (about 1 1/2 lbs)
-Manual advance
-Loading takes a while
-Slugs are a little too tight on the CPVC, and wont fire out.
-Probably wont work with springers. It needs a lot of power to propel the darts.
-Can't use streamlines

So there you have it, Cerberus. Thanks to Fenixharth for the Chimera rifle write up and his CAD design of the system and Renegade for his Tri-Barrel idea (honestly, I would have never thought to put that together!) Once again this is my first write up, so please let me know if I missed something.

Questions? Comments? Flames?

[andtheherois]

Here's part 2.

the basic structure is the same, you're only replacing the backs with polycarb/acrylic/whatever material. this isn't really a write up, so much as showing how it came together.


i used acrylic. I do have a template that i used that i will put up, however i cant get my scanner to work for whatever reason.


i left about 1=2mm of 1" PVC in the coupler so that it would go into the acrylic, giving the coupler more surface area to stick to.


I made the air hole the same size as the OD of the coupler so that the 1" PVC could fit inside it.


I used a few washers for space.


I used some scrap 19/32s brass I had since that fit inside the 1/2 PVC perfectly. I wrapped some E-tape around it to give it a bit more friction.

This is basically the same setup as v1, only with a few minor improvements to correct air seal and the such.


Here's the finished result. everything else is mostly the same. I used a few washers to give a bit of space between the turret and the Foam. The foam used to create a seal is actually insulation foam that can fit over 1" PVC. It's a tad bit heavier now because I used some metal washers as spacers, but at least I can see which barrels are still loaded. This was my first time "machining" plastic but overall I think it went well. I don't think I'll do another revision but i would love to see any improvements made by others!

Remember that this system is easily adapted to whatever you need it to be, given a bit of brain power and creativity.

[GeshmanWG]

This is pretty awesome. I'm not sure if I would be able to replicate it myself (although I may try as I am currently looking into building a shotgun blaster with decent ROF).
My main question is why not cut more holes for rearloading so you can rearload all the barrels at once, not just one?

[SlightlySane813]

Absolutely BRILLIANT

That is genius.

This will be such a help with reloading when playing capture the flag.

[utahnerf]

Sweet attachment, looks awesome too, and I also love the rotation!

[cheyner]

Thats awesome, I think I just found my new fav DTC barrel setup.

[andtheherois]

This is pretty awesome. I'm not sure if I would be able to replicate it myself (although I may try as I am currently looking into building a shotgun blaster with decent ROF).
My main question is why not cut more holes for rearloading so you can rearload all the barrels at once, not just one?

Truth be told, it's a matter of preference. You can drill additional holes in the back and make them all rear loading (minus the current "live" turret of course) but I just thought it looked better with one rear loading hole. It's all up to your personal preference. There was also the matter of stability with having to many holes in the back. I was only using wood and cardboard for V1 and then Acrylic for V2. If i had double layered the acrylic in V2 for the back and front that might have been possible. Just keep in mind the strength of your material if you decide to make it and have all the turrets rear loadable.

And to everyone else, Thanks for your kind words!

[soloz1]

Recon box, right?

[erfig]

Just a question,
Could you possibly use more than 5 and just tweak it, or would an entire new center piece be required.
I just imagine the possibilities, also could this work with a nf or longshot, capacity wise.

Looks great

Edited by erfig, 26 March 2011 - 07:11 PM.

[andtheherois]

Just a question,
Could you possibly use more than 5 and just tweak it, or would an entire new center piece be required.
I just imagine the possibilities, also could this work with a nf or longshot, capacity wise.

Looks great

This could easily be scaled down to use less or more than 5. In fact 5 is probably the worst possible number I could have gone with because it took me forever to get a pentagon close to perfect. Even then the sides aren't all the same. a hexagon and a square are very simple to draw in a circle compared to a pentagon. Just remember that more drums = more weight.

I was playing around with the idea of a minuature one for a NF using a smaller axis and 4 turrets, each drum containing 2 barrels. I've refined the design a bit based on the mods I've done for other turret related blasters and might attempt to build it sometime over the summer.

Also, I hope this isn't too much of a necro.

Edited by andtheherois, 25 April 2011 - 02:17 AM.