This is awesome.  I'll totally be trying these out.

Concave would be a good idea for the non-canted wheel, but would probably fuck off the accuracy on the canted.  My suggestion would be flat in the canted position and concave in the flat position.

Bumping for significant discovery:

 

DO NOT USE 20V LIION PACKS.

 

For some reason I have no determined yet, the packs keep dying trying to run my NERF setups. I've got a rewired Barricade that just killed one. A BARRICADE! No idea why or what is going on, but every pack I've attempted to run the blasters off of has eventually shown a temperature fault and failed to charge. At first, I thought it was a mk13 problem, since that thing is sketchy for other reasons, but the Barricade tripping it made me rethink the approach.

I suspect that the issue may be the protection hardware in these cheap packs.  If the current drawn exceeds whatever the hardware is built for, it may damage something permanently, like a thermofuse.  We have that happen a lot with some fan speed control transistors, which I can then repair by just replacing the thermal fuse.  If you can exchange them, I would.  If you can't, I would open them up and look at the circuit inside.

I saw Walcoms thunderbow tag back. Were those your rings he was using?

Sorry I missed this over a month ago, but yes, those were my rings.  If you've seen any of Beret's fairly recent war footage where he was tasked with running a Tornado, those were mine as well.

You've got a heck of a head start on me then. I'll still be trying to design my own but if you need a beta tester I'd be happy to help. I've got a couple of vortex blasters lined up for purchase from a local collector - a tornado bow and a tornado x2 (pistol). Maybe they'll behave differently on a different blaster. 

 

Have you ever tried printing in TPU? That should check that floppy requirement. I've been looking for an excuse to buy some for a while. I think my printer will need a minor mod or two before it'll accept it though. Do the rings hook consistently? It'd take a little more practice but that could be a helpful trait if you're trying to tag someone hiding behind partial cover. 

It isn't a matter of performance from one blaster, but rather the hook from the magnus effect.  I've got Tornadoes and X/2s, and they perform identically.  There is a very consistent hook to the right, because the rotation of the rings is clockwise (from the shooter's perspective).
I am currently printing the rings in flexible PLA, which has a similar hardness to TPU.  They are pretty flexible, and I think TPU would be fine as well.

Doom's dissertation on it is here: http://btrettel.nerf...com/archives/78

I'm the only person, to my knowledge, who is designing and printing rings.  I wasn't going to release the design until I was happy with the performance, though.  Stock rings are quite floppy.  I've tried about fifteen different iterations, so far.  I can get original range, but the magnus effect causes them to always hook to the right.  By the time they hit the ground, it is up to about ten feet from the straight line.

Well, when you give up looking for replacement gears (because nobody makes them, because Slingfires are just trash) I have a Sentinel I would sell you.

The mag doesn’t necessarily have to be printed, you can just take apart a standard nerf magazine and cut the follower in half...

Printing would be the easiest method, but sure there are people who have successfully bisected existing clips.

...cut the magazine spring in half, and re-wind the springs...

You've never worked with spring steel, have you?  You can't just unwind and rewind a spring.  It isn't feasible, and making a new spring from virgin wire would be easier, but still a pain in the ass.  I've wound a couple normal spiral springs from thin music wire, but it is really easy to screw up.

Im sure there are some setups that are *way way more*, but using IMRs+ Charger appears to cost about what a Lipo/other pack + *basic* charger would.

My 20v Lion setup would have cost ~$50 if I bought it by itself, which is probably more than IMRs. But I instead paid ~$80 and got a drill AND the battery, charger, and sacrificial adapter.

I was going the other direction.  I power and charge a 2S Demo with stuff I've salvaged for about $5.03, which includes the three copper pennies I'm using for contacts.

 

Really, any battery setup will cost around the same as a correct setup. 

Oh man, I can show you some things.  They will make you sad.

it had 8A and 10A

Should be enough to handle a lower-end set of motors, or a higher end for a short amount of time.

Yes it does. You switch it to test continuity. They are made specifically to do that. 

That's not how meters work.  I have twenty-five years of experience using them, and I guarantee the you cannot test a switch's current capacity with one.  You don't understand electricity, do you?

I recently took apart a old DVD player and found out that the on/off switch is similar to a switch used in a top shelf mod I plan on putting my switch into my modded rayven but I am not going to do that until I know if it can handle a 3S LiPo and how to install it into my rayven here is a picture of the switch the switch says 250 V 

 

With better pictures, we might be able to help. Specifically if there are other numbers, like "2A" or similar.  But I strongly doubt that switch is going to be able to handle more than a couple of Amperes.  Even oooold drives wouldn't require more than a hundred watts or so.

Multimeter

#1, rude.
#2, useless suggestion.  A multimeter cannot tell you how much current a switch can handle.  Only specifications can do that, without surgery and mathematics.

Can confirm, Sceptor normally uses a hard tank.  I converted one of mine to use a bladder assembly from a Flash Flood, but it has not been an ideal solution.

You'd be better served by one pump that was longer.  Very cool project, though.  I'll definitely look at printing one when you are done.

I should have put this in my reply above. But Is the diagram above more or less how it would look wired up? And is it safe for these kinds of batteries?

Yes, that diagram is an accurate representation of one style of completed pack.  Alternatively, you could wire each pair in series, then the pairs in parallel.  Basically ends up the same, but if you pair them up well, you will have less charge balancing issues.  Laptop battery manufacturers typically build as you have described.  Hybrid/electric car manufacturers typically build as I have.

I got one of the select-fire kits they offer for the Stryfe.  Seems well designed, though I have yet to install it.

Yes, you can run cells in parallel to increase the current supply and charge capacity.  In that case, yes, your storage capacity doubles from 700mAh (proper capitalization is important for these units) to 1400mAh.  If you place them in series, then the voltage doubles, while the charge capacity remains at 700mAh.  The notation is thus: 1s1p = 1 x 3.7v @ 1 x 700mAh, 1s2p = 1 x 3.7v @ 2 x 700mAh, 2s1p = 2 x 3.7v @ 1 x 700mAh.

 

ABS's higher melting temperature means printing PLA won't melt any residual ABS in the nozzle and it'll clog. It may take awhile, and it may not always happen (it's also possible a nicer machine/nozzle wouldn't have issues), but my experience was trying ABS then going back to PLA fairly quickly resulted in printing problems (IIRC it foamed my prints) that I eventually resolved by swapping nozzles.

Ohhh, okay.  I solved that by running the PLA well above the ABS temp and pushing a decimeter or so through all at once.  Then drop back down to PLA printing temp.

 

Once you use ABS you can't go back to PLA with that nozzle.

I've never heard that, nor does it jive with my personal experience.  It would make sense, I suppose, I'm just saying that it is new information for me.

Okay, so it occurred to me that I didn't ever post anything about the indoor event we are running on Sunday morning.  If you are in the northwest, consider joining us for the second event at this location.  Last spring's event was spectacular, and we had a great time.

When:  Sunday, December 10th from 9:30AM to 12:00PM.

Where:  Oregon Airsoft Arena, 1600 NE 25th Ave, Hillsboro, Oregon 97124

From the event:
"--Cost--

$25/person

--Waiver--
Required for all attendees (need parent/guardian signature if under 18). Copies should be available there and online here: http://oregon-airsoft.com/waiver.pdf

--Gear--
Eye protection REQUIRED! Some should be provided, but I recommend bringing your own comfortable pair.

You are welcome to bring your own Nerf blasters and darts. Shields have no place here. No homemade darts or ridiculously overpowerd single shot blasters (if unsure, ask) but modded blasters and all paintjobs are welcome."

https://www.facebook...77277589141029/

*facepalm* i fail math yet again.

I get the friction and leak points (both come down to circumference), but could you elaborate on the spring limitations?

Pressure and flow rate are what drives the darts through the barrel and out on to the field.  Also, there is a practical limit to the force that a person can apply to a plunger to prime the mechanism.  Say, 10 lbs.  If your plunger face has an area of 1.0 in^2, then the absolute maximum pressure that the plunger can build is (force)/(area) = 10PSI, though that is far above what it will actually build.  The the plunger displaces 1.0", then the volume is 1.0in.^3.  If the plunger face has an area of 2.0in^2, but the same spring, the pressure drops to 5PSI, but the volume doubles to 2.0in.^3.  So great, that now drops the maximum force that is transferred to the dart from 7.85 pounds to 3.925 pounds, but allows the that pressure to be maintained for a longer duration.  Which is better?  In this case, probably the wider plunger,  but you'll need a longer barrel.

Worker makes short darts.  You make Stefans.

I get all that, what is throwing me is that other people have built them using these kinds of valve without trouble. Wait, have you - Youre in my region? If its a regional thing, maybe *all* the valves locally available are too large internally?

That is a distinct possibility.  The couple of 1/2" units I have handy at work have valves that are well over 5/8" wide, more like 3/4"

I was wondering if some sort of lever type system might work to decrease the effort required or magnify the trigger pressure applied.  It seems I'm getting away from the original intent of building a very simple gun.  I just can't figure out how anyone else has made this work easily, not to mention how they have gotten repeated shots out of the tank without re-pumping.

Absolutely,  you will just need to devise a mounting method allowing a longer throw on the finger-end of your lever.

Well, think about it this way:  The force required to open your valve is calculated like this:

Force = (Pressure * Area of valve face) + valve return spring force

In the case that it were actually a 1/2" diameter valve with a 1 pound spring (1-2 is common), that would be an absolute minimum of: (0.25")^2 * pi * 20PSI + 1 pound = 4.93 pounds.

In reality, most 1/2" check valves have a diameter of about 3/4" to 7/8", depending on the quality, making the range of more like 9-14 pounds on the low end, or 14-20 pounds on the top end.  That's not exactly an easy pull, but you can see how it varies wildly.

Congratulations, you're done with your project.  Unless you tear it all out and start over.

I've only seen 2 cycletrons in my life... The hydro-blastzooka's are few and far between as well. 

I've got three Cyclotrons and a Hydro-Blastzooka (from my childhood!).

However, the original sharpshooter would also be pretty rare (first dart blaster). 

I have my original blue, plus I've been able to pick up a maroon and another blue as an adult.

What is that? Does it work with regular ballistic balls?

Yes.

The rarest attachment is critical thinking ability.

I really wish I had some of those.

For my money, it would totally be the Maximizer.

...whereas my Artemis with no hop up throws balls with spin in all directions, so it is less accurate.  Shots go down, left, right and up with the Artemis...

 

  Aaaaactually, the Artemis (along with all of the other Rival blasters) does have a hop-up tab present in all four barrels.  It appears to be made of a dense orange rubber, and may be too small.  The one on the Apollo is hard plastic, molded into the barrel.  One of my Zeuses happens to be missing the flap, and it definitely makes a difference in the performance, both in accuracy and range.  I'm going to try EVA craft foam for that one.
 My other Zeus is running a 5S battery, though, and has too much hop up for the ball speed.  I can shoot people around corners and trees, if I rotate the blaster 90 degrees around the axis.  If I happen to get one of the super-light EVA Cornucopia brand balls in a clip, that one will exit about twenty feet and curve straight up in the air.

Will I be executed publicly on a NH livestream, with captain slug and you sipping my blood from wine glasses?

Nerd blood is more of a chilled mug kind of beverage.

If you haven't already, you should join our Pacific Northwest group on Facebook. https://www.facebook...49391212073139/

I think I have to paint all of my Rival blasters now, because teams based on blaster color are stupid.

Heads up, folks, less than a week remaining!  Still plenty of time to get ready, though I probably should have made some darts.

They are of smaller size than the original Koosh rings.

Though they are the same size as the Mini Spinfire Rings.  They won't fit the Tornado/Firestorm, but they do fit the Fast Fire, Power Strike,  Spin Sight, and Viper Shot.

So, recently I've become very interested in the Koosh Vortex line and an ammo source that would readily supply Spinfire rings.

I'm working on it.  The current design gets better range than the original rings, if only by a few feet, but they curve to the right.  Also, my printer is down at the moment, so I haven't been able to print and test new designs lately.

I don't collect, so what I end up keeping is what I use (or my son plays with). So I only have 7 at the moment.

This throws me off so much.

The only data you listed there that I would trust is the one in real units.  In general, Nerfwiki has always been terrible for false data and false history.  And OMW is no better for reliability.

Wow...
I have some questions. What kind of pressures can this thing take, how durable is it, how comfortable is the shell and when will we be seeing it for sale online or in stores worldwide?
I really want to get my hands on one as i kind of have a huge obsession with stupidly impractically powerful blasters that lead people to shit themselves as soon as they lay eyes on them.

We won't have answers to these questions for a while, because they are brand new.

As stated in my first post, I know that kg is not a measurement of force (newtons is), but the vast majority of the NIC measures spring loads in kg so that's what I did.
From what I can understand from your post, the shortened spring requires 10.4 lbs to compress 4 inches; 10.4lbs is 4.7kg. Does that mean the shortened spring outputs more power then the stock one? Meaker VI confirmed that my calculations were correct, but you contradict that so now I'm confused... Does that mean my Longshot has a 9.2kg spring load? It sure doesn't feel like that, and the ranges/fps are only 7.5 kg LS level.
I've heard something along the lines of a shortened spring being stronger in some area, but most research I've done contradicts that. When people cut coils off springs, they loose power. Many mod guides recommend that you cut the most you can to get more power. Also logic says that the less you compress a spring, the less energy is required. It'd require less energy to compress 3inches of a [[k26]], then the whole 11inches. Another important fact is that I ran the cut down spring dimensions in an online spring constant calculator, and got 3.1kg for the total spring. Fully compressing a cut down spring should require less force then the full one. Say I needed x Newtons to fully compress 10 inches of spring. Then I cut the spring down to 5 inches, to fully compress that, I'd need less Newtons; it's basic physics. Since the constant is the same throughout, by cutting the spring I reduced the draw length, thus reducing power. Finally, the spring should have the same constant throughout. I determined that the Magnus spring is roughly 0.7kg/inch. This matches up with the full 6.5 inches being 4.5kg, and the way Meaker VI showed me. If my reasoning is in fact wrong, please correct me.

Just because some people in this community, well, less here than elsewhere, refer to force in kilograms, does not make it correct.  The only reason they do is because the fucktards at OMW started using it because the wanted to be edgy and metric.  But they lack a theoretical understanding of how the springs they commission and sell actually operate.  And referring to a dynamic entity like a spring with a set value, makes it worse.  The only set value in this entire mess is the spring modulus, based on the material cross-section, orientation, and stiffness.  The force you are trying to label these springs with is only constant at a specific displacement distance relative to the full free length.  Say there is a hypothetical spring which has a free length of 10.0", and it requires a 10.0lbs force to compress it completely.  If you cut that spring in half, it will still require 10.0lbs of force to compress that half completely.  If the original spring required 4.0lbs of force to compress it 4.0", the half-length spring may also be able to compress 4.0", but that will take 8.0lbs of force.  The spring did not become less stiff because you made it shorter.  It can be confusing, I understand, but you have to be wary of nerf pages when you are trying to answer a physics question.  There is a great deal of misinformation which has been disseminated through this hobby, and it becomes worse when people use the incorrect nomenclature.

First off, I'm a designer and not an engineer. I've got more engineering background than many in my profession, but I may be 100% off base on this so I'll defer to Drac, who IIRC is an engineer.
 

That said:

 

This is where he looses me as well. If the spring constant is.. well, constant, shouldn't it output less force if you remove 1/3 of it?

Not yet, but getting there.  My progress through engineering school is slow, due to work and such.  I probably won't graduate for a few years.

The spring constant is only constant for the whole unit.  The spring modulus is constant for the material (ish).  If you cut a spring, the force required to compress the two to the same percentage of total length remains the same, but it acts over a shorter distance.  There is less stored elastic energy.  I would not be surprised if the "rate constant" supplied by McMaster-Carr is a usable approximation of the spring modulus, since they suggest finding the "rate" by dividing the constant by the length, and that is the same equation I outlined in the second portion of my first post.

Yes, it doesn't make sense. I asked my dad this and he said that if you cut a spring, but the constant is the same throughout, there'll be less power at full compression (vs original full compression).
Keep in mind that I ran the cut down spring through a constant calculator, and got 0.81 kg/inch. That matches up with the original length being 4.5 kg, and the cut down one being 3.24 kg.
I also:
Figured it out through my estimate way
Figured it out with Meaker VI's method
Confirmed it with a spring constant calculator
Confirmed the numbers with my dad
Contacted an OMW employee about it

EDIT: After hunting for every spring related forum on Nerfhaven, the vast majority tends to use Meaker VI's method. Where constant=Force/(full length-compressed length)
So:
constant=4.5kg/(6.5-1)
constant=4.5kg/5.5
Constant=0.81/inch of compression
Therefore, 4 inches of compression would give 3.24kg.
For you politically correct people out there, I know that you don't measure force in kg, but the majority of the NIC does it like that. So, I measured in kg so I won't confuse or mislead anyone.

Well, either your father is misremembering physics, or there was a miscommunication.  A shorter version of the same spring will store less energy, but that is because the distances involved changed, not because the spring did.  And I'm sorry, but OMW is a useless company.  From what I can tell, they do not actually employ engineers, only designers.  And they don't manufacture springs.  They order springs made to fit an inner and outer diameter, which will require a set amount of force to compress to a specific length.  These aftermarket parts supply companies would perform a much greater service to the community by adding more information for the people who care.  WIthout any excessive effort on their part.

I know that the stock magnus spring had to move ~5.5 inches (6.5 to 1) inside the magnus plunger tube. When the spring had to compress 5.5 inches, it exerted 4.5 kg of power. Now in the Longshot plunger, the spring has been cut down to 4.5 inches, and has to move 4 inches to fully compress. That means I cut off 2 inches from the free length spring, and made it compress less by 1.5 inches.

If 5.5 inches of compression gave 4.5 kg, then that means that the spring gives out roughly 0.81 kg per inch of compression. Therefore at 4 inches of compression, the stock magnus spring will exert 3.24 kg of power; that number is roughly the same as my estimate. 

That means that the spring load in my Longshot is around 7.74kg. 

Is that correct?

No. Also, the fact that you are mixing your units is a real pain in the ass, especially given that kg is not a measure of force.  I am going by your numbers, and have never bothered to measure the spring rate on any spring, but here goes.

Hooke's law is basically this equation: F= kx
If the force is 9.9lb (4.5kg * 2.2 lb/kg), and the displacement is  5.5", then our spring constant is:

k =  F/x = (9.9lb/5.5") = 1.8lb/inch of compression.

However, you are changing the constant k when you cut the spring, because the free length changes, but the spring modulus remains the same.  

k = spring modulus (λ)/ free length (l), so λ = k * l = 1.8 * 6.5 = 11.7

The new k = 11.7/4.5 = 2.6lb/inch

If you are compressing this shortened spring by 4 inches, then your new force F = 2.6 * 4 = 10.4lb