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Stryfe Mk-13


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#1 TantumBull

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Posted 29 March 2018 - 05:18 PM

So, many of you are aware of Meaker's efforts with massive magazines/clips for flywheels. I was intrigued by the ridiculousness of the project and decided to roll with it. I took the idea behind his Mk-13 and stuffed it in a Stryfe shell, while also incorporating some fire control.
 
Labelled internals:
IMAG0421.jpg
 
The cage has a 41mm gap and is running Blasterparts wheels spun by OG Fangs.
 
A lot of this is pretty standard flywheeler electrical work. Some stuff that is less obvious:

  • There's an integrated Arduino that controls the servo gate. When the trigger is depressed, that little arm inside the clear PVC depresses to allow darts through.
  • The linear regulator included in the arduino sucks and wastes a lot of energy to heat when stepping down from the flywheel system's 12v to the Arduino's 5v. So I included a buck converter, which essentially steps down voltage but accordingly increases current so that the power value stays roughly the same (I think 80 - 90% efficiency on this model).
  • The push button that controls the servo gate was sourced from a lock IIRC
  • Obviously a lot of shell cutting going on here to fit the PVC.

Next I will just put up a bunch of pictures from throughout the build process.
 
IMAG0392.jpg
 
IMAG0393.jpg
 
IMAG0410.jpg
 
IMAG0414.jpg
 
IMAG0415.jpg
 
IMAG0416.jpg
 
IMAG0417.jpg
 
IMAG0418.jpg
 
IMAG0419.jpg
 
IMAG0420.jpg
 
Next some videos of the blaster in action. I'm going to post the second ever firing test first, because it worked better than the first test, and it seems like NH only does embedded vids for the first link.
 
2nd Fire Test:
 

1st Fire Test:
https://youtu.be/33D_ze4I4RA

Servo Gate Demo:
 https://youtu.be/WI7XwnQfBf0
 
Closing Remarks:
There is still some work that needs to be done regarding feed issues. I'd like to experiment with different coil materials and wrapping techniques. I also would like to see what overvolting the blower motor does for reliability. I'd also like the provide some reinforcement, particularly by connecting the blower outlet to the pistol grip.


Edited by TantumBull, 29 March 2018 - 05:36 PM.

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#2 Meaker VI

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Posted 29 March 2018 - 06:06 PM

Ha! That coil is great/not a coil at all. You should be able to get a tighter radius and maybe loop it backwards to get your input/output configuration to work without being so overly large.

 

I didn't use the blower's adapter, that may be causing you more grief than anything (just came straight off the housing). How many darts did you end up loading/firing?

 

I've noticed that a more complete (eg; no more darts will fit in the coil and all deadspace has been filled) load helps with feed rate, which should be obvious but wasn't.


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#3 TantumBull

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Posted 29 March 2018 - 06:43 PM

Ha! That coil is great/not a coil at all. You should be able to get a tighter radius and maybe loop it backwards to get your input/output configuration to work without being so overly large.

 

I didn't use the blower's adapter, that may be causing you more grief than anything (just came straight off the housing). How many darts did you end up loading/firing?

 

I've noticed that a more complete (eg; no more darts will fit in the coil and all deadspace has been filled) load helps with feed rate, which should be obvious but wasn't.

 

We will see. My first trial run had tighter bends and barely fed at all. But yes the final config needs to be something that I can actually use. I think that I can get more out of the blower if I run it at 4s.

 

And yeah the blower adapter sucks. I'm going to glue it on, the coupler provides enough interchangeability. I think I fed around 80 darts through, but on the second I noticed that there were about 10 I couldn't get in that I could the first time around. So definitely some deadspace in the coil.

 

I've noticed that as well. I'm pretty sure both trials had coil deadspace. It can be difficult to fill it perfectly, and it seems like using my lungs helps with that.


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#4 Meaker VI

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Posted 29 March 2018 - 10:03 PM

It's getting tricky to keep track of a conversation that is happening in four messenger-spaces. :ph34r:
 

You might also try spooling the coil on top of the blaster flat like a pan-mag, that helps with feed issues since gravity isn't fighting you as much.

 

And yeah the blower adapter sucks. I'm going to glue it on, the coupler provides enough interchangeability. I think I fed around 80 darts through, but on the second I noticed that there were about 10 I couldn't get in that I could the first time around. So definitely some deadspace in the coil.

I shaved the nubs that hold the adapter off the blower and just use the coupler. That works way better, it may be that that solid connection alone got me up to 20' no noticeable issues. Before when I was first testing it (pre-mk13 post; I think it was in the mag-thinktank thread) I just held the coil up to the blower and it cleared no issue, which is what gave me pause and drove me to keep playing with it. I built the first bench rig to test if the flywheel cage would work on the end, not so much to test the coil.
 

I've noticed that as well. I'm pretty sure both trials had coil deadspace. It can be difficult to fill it perfectly, and it seems like using my lungs helps with that.

Yeah, once I figured out to fill it all the way, goose the blower, then fill it again, goose it, rinse and repeat until the darts didn't budge I noticed a more even feed. In my setups, I'm sure that the darts are getting stuck at the bottom of a loop in an incompletely-filled coil and that is where I see the lag when firing.


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#5 TantumBull

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Posted 11 May 2018 - 12:55 AM

Went down a 10' coil segment, at Meaker's suggestion. I guess I was trying to run 20' before. Worked much better this time around. Starting playing with the servo gate a bit more and was able to control the fire. I was fluttering the trigger but you can see that this thing just really wants to spit out foam.

 

 

Interesting note: Pretty severe whirlybirding. It's possible that its hitting the inside of the stock orange muzzle, as I forgot to dremel it out like I normally do. However, I don't think that's all of it as AFAIK I'm the only person who is obsessive enough to do that to stock muzzles. I think the more likely culprit is the blower itself destabilizing the dart after losing contact with the wheels. Further evidence of this theory is the fact that the whirybirding increases as the tube empties, ie volumetric flow rate increases. It's an interesting problem to have, "muzzle blast" on a flywheeler. This might benefit from an extended Morpheus guide with venting. Or maybe some porting just before the cage.

 

Jerky camera at end is my mad rush to shut off the blower before my ears started bleeding. I really need to rig the blower to the flywheel mosfet circuit rather than just having an on-off slide switch.


Edited by TantumBull, 11 May 2018 - 12:57 AM.

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#6 Meaker VI

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Posted 11 May 2018 - 03:50 PM

Interesting note: Pretty severe whirlybirding.... It's an interesting problem to have, "muzzle blast" on a flywheeler. This might benefit from an extended Morpheus guide with venting. Or maybe some porting just before the cage.


Huh. Haven't noticed that issue on mine. I also have a more open/ported cage setup, so it's possible the blast is venting earlier. Also possible that I just haven't done a test at any kind of range because I don't want to hunt down 50-100 darts in the house/yard XD
 

Jerky camera at end is my mad rush to shut off the blower before my ears started bleeding. I really need to rig the blower to the flywheel mosfet circuit rather than just having an on-off slide switch.


Rev trigger. Or at least, a rev trigger. I've got mine wired up with the flywheels on one switch. Thinking about it, with how big that blower motor is, it's probably terrible for all parts involved, I should really try to set up separate wheel/blower triggers to stagger current flow a bit.


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#7 TantumBull

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Posted 11 May 2018 - 05:29 PM

Rev trigger. Or at least, a rev trigger. I've got mine wired up with the flywheels on one switch. Thinking about it, with how big that blower motor is, it's probably terrible for all parts involved, I should really try to set up separate wheel/blower triggers to stagger current flow a bit.

 

Yep, that's what I mean. The MOSFET powering the flywheels is controlled by the stock rev switch. MOSFET is rated to 195A so I'm not super worried about hooking up the blower to it: I use the same model to power on 4x wolverines in my 2 stage demo build. 

 

I am also thinking about giving it its own switch at the "foregrip", so I don't have to waste power on the FW motors when loading the coil. There are some functional advantages to having it on it's own circuit.


Edited by TantumBull, 11 May 2018 - 05:30 PM.

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#8 Meaker VI

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Posted 11 May 2018 - 10:13 PM

 

I am also thinking about giving it its own switch at the "foregrip", so I don't have to waste power on the FW motors when loading the coil. There are some functional advantages to having it on it's own circuit.

 

I had been thinking along the same lines originally. Mine now has a rocker that turns the feed to the wheels on/off. I'm not sure how useful it'll actually be though.


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