Ballista (crossbow) print in place

by senns Jan 7, 2017
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the kickstand is not coming out, help me solve the problem?

hi ,first thank you for this design, I have some Sticking proplem with the arrow, I have try more then 10 time and its fail .
I have add a base to the arrow and cut it at the end, I attach the improve I did may some one have the same proplem like me.

Hi senns, your projects been chosen by my university as a mechanical engineering design project. Would it be possible to upload the .step files so we can produce some CAD drawings of it?


I have made a small modification to use screws to attach the string. I'm allowed to post this remix?

Эта штука стреляет!!! честно стреляет!!! с печатью не морочился на стандартных настройках A8 запилил... стреляем по малу...

Какие настройки вы использовали? Вы правы, стреляет действительно очень прилично.

Hi, I modified the design in Blender, because I sometimes had trouble with one of the locking pins releasing and the other not, resulting in a risk of breaking the bending part of the one released (which happened to me once).
I mitigated this by adding a center pin between the back arms that are squeezed to release, so the travel is limited to just slightly more than necessary to release the mechanism.

I wanted to post it as a remix, HOWEVER your chosen CC license variant does not allow derivatives. Could you please change this to allow me to post this remixed design, or accept the file (which I could send you privately) into your upload? After all, remixes are what many people love about this site and 3D printing in general. Or, of course you can implement this modification yourself. ;) Cheers!

(Also a side note, 90% infill as in description is absolutely not necessary, works great with just 15%, but walls 1.6mm thick to fully fill the bending parts af the arms).

Senns, is there any chance of getting some stls of just the forward bracket and the bolt cradle?

I'd like to make a bolt cradle that instead of being a hole is a hook-ish thing so that I dont have to run string through, but I can just pull behind the cradle to make it catch.

When the main body is printed with PETG its really easy to slide in replacement cradles plus it lets me make the cradles from a different color and material.

what type of filament does this thing take

I had very high hopes for this and then when I tried to pull the trigger back it snapped right off. Is there anyway of fixing this without making an entire ballista again

HI Senns, Do you have STEP files for this? Id love to integrate it as an accessory into my HackADay prize entry. I would provide attribution of course.

Awesome, thank you so much, my son loves it.
Printed the lower tolerance file "Balista.stl", which has enough tolerance already!
Used floss string. You can control the shooting strength by the length of the string (longer and loose means less power)

2 perimeters (more will make it solid and might break, or become very strong !!!)
15% infill
print time: 2:15

Hi, i managed to print it but the bit that slides back and forth didn't print properly. Is there anyway you could post just that part for me so i don't have to print the whole thing again?

Thanks for your time and the great design!

I never managed to print it. The moving part is attached to the main one, and it's impossible to separate them.

I saw your object, it's really beautiful.
I thought you might be interested in my project, it's a lamp printer.
what do you say?
thanks bye

Neat! I'm going to print one tonight. Thinking of upscaling it a little bit but I'll stick with the standard for the first print.

Works very fine. Fired about 20 shots and it still works. I am impressed. Great design!

This thing is awesome! I printed it at 150% scale and the release triggers didn't break. I am so surprised that the PLA doesn't break under all that tension!

I printed this off at 150% size and WOW does it have some kick! If you shoot someone at just 5 feet away it hurts a bit! It's definitely got some major kick, made the bolt fly at least 20ft! Not very accurate, but it does FLY!

So much fun with such a small piece. Thank you. One thing tough, the triggers are not very strong.

looks good but the triggers broke on mine unfortunately.

I've made a new crossbow which is based on your design and uses your arrow.
I would like to share it if you don't have a problem with that.
It uses a new trigger mechanism and is based on rubberbands to propell the arrow.
Just asking because you set it to non derivatives.

Left trigger broke immediately but otherwise it worked ok. Printed with PLA on an old Makerbot

Crossbow printed on Anet A8, PETG white filament, 1.5mm layer, on the raft.
Shoots perfectly with chopsticks)))) More than 100 shots, still like new)))
Twice I tried to print an arrow in red PLA, but both broke after the first shot.

do you mind if I use your crossbow design it's perfect for something I'm working on

Did you noticed that someone copied your Design? Link is https://www.thingiverse.com/thing:2461925

Greetings, BaumeistervonOsk.

best keyring ever (crossbow)

do I need to print this with supports

If you scale the crossbow and the arrow up, will it still work? Also will any string work?

Print is ok but same issue as others : moving parts melted with the track. When trying to separate them track has broken :-(
Any advice to avoid melting ?
Printed on Anet A8 in 0.2 mm with no support, no brim.

Try using a lower heat. Especially for PLA. i find 200C is the perfect temperature.

for me the left bow arm always breaks earlier than the right... I wonder why.

I had similar problems, but the right side. I found that slic3r worked better than cura, and I had to bump up the line width to make sure there were no voids in the arms. Voids really weaken the arms.

Tested the wider tolerance ver of this with my Flashforge creator pro, I did not work sadly the tolerances was too big.

Did you notice a guy just cloned your design without quoting you ?!


best keyring ever (crossbow)

A model without the stand would be nice, anyway great design.

When I printed the arrow only the tip of the arrow was printed. Does anyone know why?

maybe you took out the USB memory card too fast so only a part of the file got downloaded, this has happened too me.

Just printed this, and it come out perfect! Well done to senns the designer. I can't remember the last time that every moving part was functioning as soon as the print finished.

Printed the standard tolerance file with PLA, 0.2mm layers on a Mendel90.

Great design senns, thank you.

I'm having a dreadful time printing this. The center part that shoots the arrow consistently fuses to the track, and I can't get it to move. Everything else prints nicely.

So I have to issue printing this.

I have an Prusa I3.

Issue 1: The "feather" was to weak and broke easily. This was fixed printing with Colorfab HT instead of Prusa PLA.

Issue 2: the bracket in the middle. (The one the rope goes through) Loosens from the build platform around 80% of the print.
This happens with both the PETG and Prusa PLA. I even tried using an Brim.

It may seems like it warps up and then breaks away free, anyone else had issue with this?

stuck...i already have some mods for thiss build... ;

Printed twice and both times the leg would not come off and worse the trigger did not come loose from its printed possition...very sad!

I printed 3 times the Ballista with PLA. 1 Time the V1 and 2 times the V2 version with bigger Tolerance, but i every time it breaks apart at the end where you press the small little Arms together, to let it shot.
Th Connection of these two arms is to thin.
I used to print with an A8 Anet 0,4 mm nozzle.
Temp 210
Bed 55
i printed with 0,3 an 0, 2 an third time with 0,3 mm Layerwidth and Layerhight.
With 50 to 90 % infill.
Print Speed i tried 80, 60, 50 /s.

And the printed Parts (button between) is sometimes glued together...

But everytime it breaks apart at the same part.

Just printed one for my son, broke on the first try. I used the recommended settings with PLA. Wondering if I should print the V2?

edit: second print broke on the first pull as well in the exact same spot. What am I doing wrong? I may try printing with semi-flex but not sure if that will work with the moving parts and latch?


0.2 layer height
90% infill
Top, bottom layers and perimeter shells all at 4
Nozzle temp 230, bed temp 60
Speed 2700mm/min

Ballista (crossbow) print in place

I think your problem is in the infill I sometimes find that with moving parts 50% is the sweet spot it allows it to flex just right to not break I to has a breaking problem at 90% try 50% :)

bigger tolerance or not?

What orange filament did you use? Looks great.

great fun! Inland PLA @ 210C Bed @ 50C (Maybe not even needed?) Downloaded and clicked print, was ready to fire in under 2hrs! Minimal cleanup. Wan Hao i3 v2 w/Z-axis supports mod, Delta fan 40mm parts cooling fan, 8mm slider hack/Engraver (for making PCB's), Power supply 120mm fan adapter, stock firmware, Repetier Host/Server.
Xprint = 200
Yprint = 225
Jerk = 9.0
Xmove = 400
Ymove = 400
Filament diameter 1.73mm (dont forget to put this measured value in for every new spool into your slicer!)
Fan dialed in to MAX 50% (I'm using a 40mm Delta on custom ducting - blows like the WIND!)
If your printer isn't setup right, it will print fast but like crap! Google & youtube... jus sayin is all.

If you were to make a split version of this with the 'springs' separate from the bulk of the crossbow and assemble after printing it would be really cool. It would help with upscaling.

I printed this over a month ago and it's awesome!! really precise shooting.

The only two cons I have would be that the arrow broke on an impact against a target due to the cilinder being too thin.
the other one is that yesterday one of the "trigger" parts also broke. Will try printing again with a few mods

nice project!

I managed to make a crossbow that was 2x larger than the original. it works really well with wedo3dprinting PLA and it can fire 15m
thanks so much for this design
I would scale it up even more but my printer is not big enough

Whenever I string and try to fire, the knot in the string snaps. I am using cotton sewing thread. Tips? Thank you.

try dental floss or fishing line, much stronger

Hey would this print work with Makerbot

probably dude. most prints work on any dang printer. none are designed for one specific printer...

Printed with ABS, faced 2 issues.
1) The leg is hard to disconnect, please make a version with this peace separate.
2) The trigger should be harder, since this one doesn't hold the tension.
Thank you!

Works great in PETG

Love it. It worked so well, it took us half an hour to find the arrow because it flew farther than we expected! Well done.

I tried the version with bigger tolerance.
It works great. Only the stand on the front is too loose...

Mine broke after a day in school (the arms bent back and eventually broke)
i have shot around 100 times with it. how long do all your crossbows last?

Printed this and it came out great! Thanks! My arrows don't fly far but they certainly don't tumble... Any suggestions for getting it to possibly fly further?

This model is great, my kids are loving it!

Hi this is a really cool design.

I am having a strange issue when I pull the files into Cura. I don't think they are the right scale can you please post the overall dimensions for the 2 pieces?

Thank you!

Hi. I'm a noob to print in place.
But i can't seem to separate off the button or the handel.
Are there like simple tricks you use?
I can see that the parts were indeed layed out like that. I see the gaps. But there are no gaps.

Have you tried adding support?

No, I thought the instructions said no support but I can try next time.

I use fishing wire, which works great. The only issue is that the arrow doesn't fly straight but tumbles in air.

Very impressive. I made one at 0.3 layer height and 20% infill and it still worked pretty well (UM3 Ultimaker silver).

I will def need a few of these for the office...

Had an idea to make one of these as well, a few changes tho:
-I will see if I can get the bolts to whistle as they fly through the air.
-See if I can get the bolts a little more aerodynamic so they fly better (they currently tumble in the air).
-Make it in multiple parts and make the Bow out of nylon. Also make it larger.

If I ever get around to it i'll upload some shots of it.

after reading your comment I tried making one "whistling arrow".
The results:
1.- the arrow flies really straight and IMO is stronger
2.- the whistle whistles quite loud.
3.- the arrow doesn't whistle while flying (sadly)

I think it needs to be faster wo whistle (and I'm doing something wrong definitely)

+1 for the whistle idea :)

i have tried it two times (different filaments), but it won't works :/

can you please publish a version with more distance? (see picture)

layer high 0,2mm
infill 90%
material pla (white, silver)

added a new version with even bigger gaps and fixed the breaking point

works! thank you very much! (last updated: 01-11-17)
When it's finished, i'll post some pics (Made).

hi senns,
tested it: https://postimg.org/image/s76wyib41/
same printsettings

added a new version with even bigger gaps and fixed the breaking point


if still not working try to lower the material flow

thanks! .... i'm going to try it tomorrow :)

Used 4 layers think of dental floss, works great, love the design!

nice im about to print this do you have to use a string can i use a rubber band

Rubber band will do the job too, if you get it trough the 2mm hole.
I used four layers of cotton sewing thread.

do you have to put it in the hole