Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

FDL-2 Blaster

by JesseKovarovics, published

FDL-2 Blaster by JesseKovarovics Oct 16, 2016


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25751Views 3180Downloads Found in Robotics


The FDL-2 is the successor to the FDL-1 Robotic Foam Dart Lancher. It is similar in function but instead of "Mega" sized darts firing from a revolver, it is designed to accept Nerf brand magazines and Nerf "Elite" size darts. It is fully automatic with an adjustable rate of fire up to about 8 darts per second. It also has select fire allowing you to fire in bursts of 1, 2, or 3 shots in addition to full auto. The entire FDL-2 is controlled by a Particle Photon microcontroller. The Photon is very similar to an Arduino except it has built in wifi allowing you to flash new code to it without plugging a USB cable into it. Darts are propelled by brushless outrunner motors which are powered by electronic speed controllers (ESC's). The FDL-2 uses a stepper motor based pusher mechanism to push darts between the flywheels. Between the microcontroller, stepper motor, and speed controllers the FDL-2 has a limitless set of tuning options. The entire blaster can be reprogrammed to operate in any way. Having wifi also opens up the possibility of using a phone app or web page to fine tune the function of the blaster on the fly.

Please visit projectfdl.com for more info. I have a web shop there selling assembled blasters, kits, electronics bundles, and bare pcb's to pair with your printed shell. If you just want to print an FDL-2 shell and not worry about soldering and sourcing parts, the electronics bundle is ideal for you. I provide everything you need to easily work into your print and finish off your blaster. I will preflash your Photon and test the entire bundle as a whole to ensure it works properly before you get it.

FDL-2 Introduction Video (Full drum firing demo at 20:15)

FDL-2 Blaster Assembly Part 1

FDL-2 Blaster Assembly Part 2

There are three different versions of the FDL-2. The original stepper motor version, the 2+, and the 2X.

If you are building an FDL-2+ print all the files in this thing and the 2+ remix:

FDL-2+ Blaster Remix

If you are building an FDL-2X print all the files in this thing and the 2X remix:

FDL-2X Blaster Remix

If you are building an original stepper motor FDL-2 print all the files in this thing but use the versions in the stepper motor remix instead. Then print all the parts in the 2+ remix.

FDL-2 Original Stepper Version Remix

Requires a 3S LiPo battery with an XT60 connector capable of safely delivering at least 25amps for a sustained period. An example being a 1000mAh battery with a 25C constant discharge rate. 1000 * 25 / 1000 = 25amps rating. It must also be able to fit inside the grip of the blaster in a cavity measuring 24mm x 36mm x 94mm.

Print Settings

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Simple Black










The FDL-2 in the pictures is printed at a .2mm layer height with 20% infill. Support isn't required but a wide brim is recommended for tall parts or parts without a lot of surface area touching the bed. All parts have been oriented how they should print best but feel free to arrange and orient them however. You shouldn't need to do much post print finishing aside from some minor cleanup. The holes in the barrel to attach the motors and the ones in the barrel cap need to be drilled out. The "counterbores" face up so it's cleaner to print a couple layers of bridging across them rather than circles in mid air. Each of the receiving screw holes should be tapped to accept the machine screws. #6 wood screws would probably work but I personally prefer tapping.

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The store is sold out on the electronics. Is there alternatives for the custom PCB boards, I do not mind soldering.

I've been checking the store every day now for 3 weeks.

I'm now trying to solder on (pun intended) without the boards - however getting stuck on the trigger pcb wiring. Any help on this would be greatly appreciated. Happy to pay $10 Au for fuller instructions.

The store just released the bare PCB boards as well as electronics kit this morning. It looks like the electronic kits are sold out but not the bare PCB's

what are you using to tap the screw holes?

Hi! I saw this thing at Endwar and I want to make one! However, your BOM only lists the PCBs, but provides no gerber files or PCB BOMs. Is there another link I am missing to the gerbers/pcb BOMs?

Comments deleted.

On the new fdl 2+.
What motor are you using?
Looks like a brushed motor.

It is. It's a 25mm gear motor. The front PCB with the stepper driver is replaced with a motor braking PCB to match it. I'll put all that info into the 2+ Thing when I get it up.

how much mitereal does it coast and how much money does coast exept the filament

idea fdl-3 shotgun style ah ah

Just curious, will you be posting the file for the electronics cover thumbscrews?

Yep, I can do that. I've stopped using them because they stick out pretty far and get caught on stuff but I can put them up this evening.

Hi JesseKovarovics, will you please post the thumbscrew files? I am almost finished printing the parts and I would like to have those. I understand that you must be busy, so no worries!

Just a heads up, I tried 20amp race spec Afro ESC's and had sync issues out of the box/bag. I had to reflash them with the latest SimonK. The 12amp versions seem to come with the latest version already.

Comments deleted.

Great project. FYI, I just printed the mag block, catch and post and they don't fit together. Printed at the same time, same material, same settings. The catch and post have some clearance issues in the block. They were printed on an Ultimaker 2+ which normally gives me great dimensional accuracy. You may just want to check the clearance on those parts.

New versions are up. The catch may still need a bit of sanding but it shouldn't be much. The button is a little bigger too.

Yep, thanks, I have some changes coming for the mag release and a few other parts in the next couple days. I enlarged the button a bit and tweaked the clearances so things fit better right off the printer without sanding.

For the Brushless motors, should you get one CW and one CCW? I see they sell them that way. Or should both motors spin in the same direction?

I think the major difference is the thread direction on the prop adaptor but there may be internal differences as well. I am using one of each on my FDL-2s since they do turn in opposite directions.

Do you have a link to the exact motors that you ordered? The 2300kv ones i purchased are rotated with the wires out the side if i line the mounting holes up.

I'm guessing you have the Non-Elite version of the Multistar 2204 2300kv motor. I have one setup with these motors as well. You will also need a slightly modified flywheel. That motor has a 2mm motor shaft and the flywheel mounting holes are on a 9mm diameter instead of the 10mm used for the Elite version. An adjustable flywheel is available at: https://cad.onshape.com/documents/58c6d81e63ebf60f914688fa/w/7d371f6599001d1f860082a9/e/6b9abf31c4c5db1832010584

I'm still working on getting the dart 'crush' just right but it is very close now. The default drawing is for the non-elite motor and you should be able to easily adjust it to fit other motors that can bolt to the barrel.

Jesse, I was going to message you on this topic as well. Would you please rotate the barrel motor mounting hole pattern 90 degrees and upload an alternate barrel STL?

With that addition and the parametric flywheel, we can adapt for most motors that will fit.

Sure, I'm in build mode for a few weeks so I can't right away but when I get a minute I will.

There is only one version of Multistar Elite motor that is 2300kv. Multistar Elite 2204 - 2300kv

Jesse, There is a new Elite 'Vortex' version which I am planning to use on my 3rd FDL-2. I don't have any yet so I don't know where the wires will exit on the Vortex version.

Oh nice, let me know how it goes. I'd love to have those as an option if they fit almost just because they're red instead of green.

Agreed, planning a nice color combo for them. Looking at the photos and specs they should bolt in but looks like they will need the mount rotated 90 degrees like the non-elite version to keep the wires neat-n-tidy.

More Power and Good Looks! That's a Win Win!

Just got a pair of the vortex motors in. The hole positions match the regular elites but the two inner holes are a smaller size. 2mm I think. I don't have any 2mm screws but I can test with just the outer bolts. I'll let you know how they are.

I see my error, mine are not the elites. thanks

there appear to be mesh errors in the barrel_main part.

I'm looking into it. It should still print ok for now then you can trim off the artifacts with an xacto.

it's causing some weird layer separations. It's worse than just little bits I could trim off: http://i.imgur.com/rFvnGM0.png

I think I got it. It looks good in slic3r. Can you download it again and confirm in your slicer?

just checked the new file and it looks good. Thanks :)

Awesome, thanks for checking.

Very impressive! I was led to this by Lord Draconial and Make Test Battle.
Before I make this I have a few questions. Can I print this on a 5.9/5.9/5.9 build plate? Roughly how much filament does this take up? Lastly, I'm 14 and I'm wondering if setting up the electronic parts would be too much for me. Thanks!

I'm pretty sure your printer is big enough. You can try bringing some of the larger parts into your slicer and see if they fit that way. The side panels are pretty long and the magwell is tall. I would check those two first. If you are intending on building this from scratch you're looking at a project roughly equivalent to building a drone or rc car from scratch. You need to be able to do somewhat delicate PCB soldering and wiring harness/loom soldering as well as heat shrinking. The people who have built these from scratch have either not needed to ask me questions or were good after a couple minor clarifications. If you have a lot of questions looking through this page and the other Project FDL resources, you may want to consider having me put an electronics bundle together for you. It's hard for me to justify offering a lot of support if you haven't purchased a bundle or assembled blaster.


Finished the project the day after I received your electronics kit. The STL files you posted worked very well and all fit together nicely. I used PETG by Sun which I really like to print with because it is strong with little warpage. The electronics cover is a transparent PETG so I can program a pulsing LED to show the gun is armed. Your videos are excellent This is an excellent piece of work by you and is so interesting to me because it pulls together the many technologies and interests that lots of us share in different proportions and combinations......3 printing, drone brushless motors, stepper motors, micro-controllers, open source, Internet connectivity, and I understand from your video you are creating a phone app (Android I hope) that will allow remote control and programming on the fly and also safety for limiting the awesome power. Thanks again for your work, this is an excellent project that ends in a fun to use Nerf gun. I bought a nerf with 25 dart clip for around $37 at target and it empties it in a few seconds (my poor dog)

Very cool thank you, I'm happy everything came together nicely. I'm going to start shooting some videos around getting new code onto the Photon and getting it hooked up to your phone. That'll get everyone prepped and ready for the web app or if they want to tinker with the code.

Hello Jesse what a great work from you. I print all the FDL-2 Parts and now i stop with the electronic.
I am not an electrician, so i have some problems with the FDL-2 Trigger PCBv1. Your pic here dosent help me.
Do you have an circuit diagram from the Trigger PCB that you can upload here?
Thanks a lot for all and greetings from germany..

Thanks! I have bare PCB sets available on my Etsy shop. They are designed specifically to fit the FDL-2. To be honest it would be really challenging to build one without them. There are other options there too if you don't want to deal with soldering.

Hello. Thanks for the answer. Unfortunately I do not come to the shop with you. I would be happy to order the PCB Set. If it is only the circuit boards. But somehow the shop does not go. I just see a blank picture.

Bummer, it looks like the test integration isn't working well on the site. You can just go straight to Etsy. Sorry about that.

Great. Already ordered..Thanks a lot...;-))

Good afternoon. 1st I need to say I like your work. Near the end of your over view video, when you test fire the gun, there is a work bench to the left, on the bench there look to be a home made pvc tube, dart gun. What can you tell me about that?

Heh, I was wondering if anyone would notice that. I made a couple of those for "NIC" wars which are a more "no holds barred" version of the average Nerf war. We make our own darts out of foam backer rod, hot glue, and bb's and all the blasters are designed to fire at paintball velocities. That was my first attempt at making a blaster like that. The plunger head and catch are printed as well as the grip and pull back handle. The main body is just a pvc pipe with a reducer on the end that the barrel attaches to. Inside is the heaviest spring I could find in my local hardware store. I'm tempted to post the design here but there are a million better designs on nerfhaven.com.

thanks for your reply....can you tell me about your trigger..may be a picture?

It's a very simple trigger with a piece that extends forward an inch or two with a triangular shape on the end that reaches into the plunger tube trough a dremeled slot. The plunger has a rim around it that the triangular piece catches on to until you pull the trigger. It's not the best design at all but allowed me to use a threaded rod as the plunger rod. The better way is to create a rainbow type catch. You'd cut a slot in the plunger rod, usually a square delrin rod, and have a catch piece with a spring that pushes the catch into the slot when the plunger is pulled bach. Pulling the trigger pushes the catch up and out of the slot and allows the plunger to move forward.

How much modification do you think it would take to get it to fire Rival balls?
I'm mainly interested in the wheel cage and pusher mech.

The FDL-1 pusher and cage aren't far off from being able to fire Rival balls as is. They would need to be scaled up a bit but not a huge amount. The bigger challenge would be the feed mechanism. Would you use the Rival stick mags? A hopper? The throw on the pusher is probably long enough to push two rounds at a time. Could a magwell that accepts two stick mags work?

The other issue to get around is backspin. Rival blasters have a flap that puts a little backspin on the balls like golf balls. Either that flap would have to be included or the motors would have to mount vertically with the lower spinning just a touch faster than the top. That's a fairly large redesign.

My idea is to use a custom clip ive designed. Also yeah ive been taking into account the "flap" and i think im going to use a trick i learned back in my robotics day. Simply we used a free spinging
Bearing in the launcher for the basket ball event. It would give the balls a backspin, as it left the mouth of the launcher.

Put for what im using im probably going to used the vertical set up.

This is wonderful. I'm trying to print out some flywheel blaster parts, I'm curious as to how you fixed the issue with centering the flywheels, I can't quite seem to get the holes perfectly centred. Is it a matter of just having good resolution, or is there any other method you're using?

Thanks J_yang! I should point out the flywheels on the FDL-2 mount to the motors with screws. They don't friction fit on a shaft like stock flywheels do. I wouldn't recommend trying to print flywheels unless they mount like these do or you will have trouble getting them balanced and keeping them from wondering off the shaft of the motor. I don't do anything special printing FDL flywheels. I just make sure each one prints near perfect on a well leveled bed and they usually come out balanced without much issue.

Hey Jesse,
This looks awesome!
I am printing myself one right now, but with a couple of modifications - it will be more like the nerf stryfe (semi auto only, no pusher) and i was wondering what ESC's and motors you used, and how you wired them in relation to the lipo and the switch. Do you have a guide for the build, or a link for the ESC's and motors?
Thanks a bunch!

Hi Lylle,
I'll have a parts list up in the next couple weeks as well as an assembly video like I did with the FDL-1. The FDL-2 is designed around Multistar Elite 2300kv motors like the FDL-1. The new ESC's on the FDL-2 are 12amp Afro's w/ BEC. That's just a motor/ESC combo I know works but others would too. The flywheels are designed to fit onto the Multistars though. There is a wiring diagram in amongst the pictures up above that should help. The lipo connects to the ESC's. The ESC's power the Photon. The switch is connected to the Photon.

Thanks for the reply. those items look great and are reasonably cheap. Do you of any way of using the ESC's without the photon or another board in the gun? I have done some mild research and nothing turned up. My thought would be to put the positive of the LiPo through a microswitch and then into the ESC with it always "on" so the motors fire up on a button press, but there is no board in the gun. Thanks a bunch!!

I'm not sure you can send just a constant voltage to it. I may be wrong, I've just never honestly tried it. Using a microcontroller of some sort is really just the best way to go. Running your motors at full speed won't always get you the best performance. There's a sweet spot that you need to find where you're not losing so much to dart slippage. Your maximum accuracy may be at half that. The cost and space a small microcontroller would take up well exceeds the advantages it provides, even if you have to write some code to make it happen.

Hi, awesome project by the way. I'm more of a rc guy and the first thing i thought of is your spull up and down time si really long, have you tough about using the OneShot125 functionality that afro esc-s should have. It is basically a active brake system so your motos stop really fast. I have LDPOWER D250-2 that has oneshot125 on my quad and the motors stop with propellers attached from a max rpm to dead stop in about half a second or faster.

Thanks! As far as I know OneShot125 is a BLheli feature and it requires communication with the flight controller that I don't quite know how to do with a Photon quite yet. These are SimonK. I tried a pair of DYS ESCs at one point that had BLHeli and while they did spin up faster, there was just enough of a lag before it happened that it kinda cancelled out the quick spinup. It was even more pronounced with braking on. With a single fire button it's crucial that the user feels something happen immediately when they press the trigger. I'd like to try a pair of KISS ESCs at some point but right now their cost is too high to put into the kit. I'll try the BLHeli ESCs again though. Maybe I was missing a setting somewhere.

Looks awesome ...saw parts and pricing on etsy would love to order the electronic package but can't bring my self to spend that much for those parts

I'll have a bill of materials up in the coming week. You're welcome to pay whatever you'd like for parts. They don't have to come from me. What you're really paying for in those bundles is the various wire harnesses that I hand make, a preflashing of your Photon, and a thorough testing of the whole thing as a unit. That kinda leads to better support from myself if I know it all worked right at some point. I have the bare PCB boards available too as a good starting point to an entire build.

Hi Jesse.

Very nice work!!!

Can the FDL2 be fired while upside down?
I can see a really nifty auto sentry cannon in the future.

Mounting FDL2 upside down would simplify mag change out.

Thanks! It definitely can be fired upside down. The FDL-1 was originally designed on a turret base. I'll most likely make some sort of adapter piece for the FDL-2 to go on it as well. It would be pretty straight forward to turn that into a motion sensing turret. I've just been focusing on various real time control types like RC and wifi.