Mini-Hand Crossbow (V3) (LARP / Combat Sport)

Placeholder for V3 LARP crossbow.  Designed to fire bolts with a narrow shaft (~6mm), typically fiberglass.  While it's technically possible to fire bolts with a nock and/or fletchings, with this device, these features are in no way required and typically not used.  It's also possible for this device to fire those inexpensive and mass-produced pistol crossbow bolts, typically made of brass or aluminum with no nock, plastic fletching, and point tip for targets, but there's generally better devices for doing so.  It's pretty easy to convert lightweight fiberglass LARP arrows to be used in this device, just use a hacksaw to cut the shaft down the appropriate size, and then sand the fiberglass to make it smooth and level at the end.  Just be sure to use a N95 mask or respirator of some type while doing so to avoid breathing in any fiberglass dust.  

You will need various M3 and M5 screws to build this device, as well as an extension spring and a compression spring.  There's a variety of screw kits and spring kits on Amazon but these are the ones I used.  I know this device uses a whole bunch of different screw sizes and types, honestly it was designed around what I already had on hand.  Note this is not a not a notch crossbow and failure of any of the trigger pieces can easily lead to a misfire, so don't skimp when it comes to reinforcing the trigger pieces especially.  

Spring Kit:  https://www.amazon.com/gp/product/B000K7M36W

M5 Screw Kit:  https://www.amazon.com/iExcell-Stainless-Socket-Button-Assortment/dp/B08HXLQ7K5

[note:  some longer M5 screws also required, catalog them]

M3 Screw Kit:  https://www.amazon.com/iExcell-Stainless-Metric-Socket-Washers/dp/B0812TYT5L

M4-25mm Screw:  https://www.amazon.com/s?k=M4+25mm+screw

This device uses a simple 2-piece trigger.  There is no auto-lock function, you must hit the trigger with your hand to lock it once you have the string pulled all the way back.  I don't plan on adding any kind of auto-lock function due to the complex it would require, loading this device is quick and easy once you get the hang of it.  

This devices uses a modular front that can accept a variety of prods easily.  Prods can be made using round fiberglass rods, flat carbon fiber rods, or some other method.  Cover the prod with some foam for dampening purposes and then use the brackets to secure it.  While most of these prods will be flat, straight, and not tapered in any way, they have proven very reliable over several days of use.  

There are two different fronts each aimed at a different type of Prod.  The “type 1” front is designed for twin-arm prods which may be weaker or break in the center.  This front is wider and the pressure points are on sides to avoid stressing the prod in the center.  The “type 2” front is for more traditional prods made from a continuous piece of metal, fiberglass, or the like that will flex throughout the prod.  It has a single pressure point in the center which keeps things as narrow and compact as possible.  Regardless of the front used, the prod should be dampened in some way at the pressure points, for instance covered with foam, rope, or something else to cushion it.  Both front types allow for a centering adjustment, with the “type 1” front the prod can be moved to the left or right, and with the “type 2" front the prod should be centered in the mount as much as possible, and then the rope binders on the left or right can be tightened or loosened to keep it aligned.

Three common configurations I use are pictured, personally I prefer configuration (1) using the “Cobra" crossbow Prod, this one is the most compact but still performs equally to the standard size configurations (2) and (3).  On the downside it is the most difficult to load, requiring around 50 lbs. of force.  Then you have configuration (2), which is powerful and relatively compact but not terribly efficient, and (3), which has the widest prod and is the most efficient of the three, meaning it requires the least amount of force to load.  

Especially with the Micro size, there can be issues with how the bolt balance issues which result in a forward spin or other less than optimal performance as the bolt comes off the rail. This behavior is most common with smaller, heavier bolts, such as bolts with larger heads or those weighing more than 850 grains or 55 grams.  To solve this issue, two longer bolt clips, and double over/under bolt guide that works with 6-7mm diameter bolts has been added. These options may also improve accuracy for any setup, but may also make loading a bolt slightly more difficult.  The bolt guide options are designed to be covered with a layer of craft foam so that only the foam interacts with the bolt, no plastic part directly touches the bolt.  

Carbon fiber flat rods:

(12x3) https://www.amazon.com/dp/B09Q88LPJF?psc=1&ref=ppx_yo2ov_dt_b_product_details

(15x4) https://www.amazon.com/dp/B09Q8379TP?ref=ppx_yo2ov_dt_b_product_details

“Cobra" hand crossbows with 50lb prods:

https://www.amazon.com/dp/B00E4TXW6M

(the crossbows themselves are pretty bad, but the prods and bowstrings they come with are quite usable)

M5 screws of the respective length (or close) can be used instead of the 3D printed mount pins, if desired.

[STL files should all be here, but I haven't fully checked everything yet]

Trigger Piece, Lever:  Uses 1x M3-20mm Socket Head screw, 1x M3-14mm Socket Head screw, 3x M3-40mm Socket Head screw

Trigger Piece, Trigger:  Uses 2x M5-30mm Button Head screw, 2x M3-50mm Socket Head screw, 2x M3-25mm Socket Head screw

[Description Pending]