Caliburn/Talon Claw Prophecy spring drop-in kit

thingiverse

### Introduction This is a drop-in kit to allow you to use Worker Prophecy-R "power" type springs in the [Caliburn blaster](/thing:2376150) from CaptainSlug. Tested and confirmed working so far: * Worker 25N spring (W0233) * Worker 28N spring (W0323) * BlasterTECH BT27-Plus spring I personally recommend using the 28N spring -- it's the perfect length for the Caliburn, and delivers good performance while not being overly difficult to prime. This kit is designed for the standard Caliburn as designed by CaptainSlug. I do not have access to a Worker Caliburn for testing, so I'm not sure if these parts will fit that model. **As always, use at your own risk.** ### How to use this You'll need to print 3-4 new parts: 1. a spacer (**`PlungerSpacerPr`**) that fits inside the stock 3D-printed plunger. This will prevent the Prophecy spring from flexing and bending too much (which would make priming and catching impossible). If you're using the Worker Caliburn metal plunger or the Containment Crew (CC) acetal plunger, there are custom-fit spacers available for those as well -- see the corresponding ZIP files. 2. a custom **`BackButtPr`** piece with a guide rod that fits the narrower ID (inner diameter) of the Prophecy springs. **Important:** This piece is NOT compatible with the [Caliburn Adjustable Stock](/thing:3209370). If you're using the adjustable stock, please print [perfnerfer's remixed back butt piece](/thing:3661993) instead. 3. One or two of the **`BackButtSpringRest12mm`** pieces which will fit onto the BackButtPr guide rod. You'll most likely need 2 spring rests for the 25N or the BT27 due to their very short length. The Worker 28N spring will usually only require 1 spring rest. **NOTE 1:** Some of these Prophecy springs (particularly the BT27) have a tendency to shorten dramatically after initial use. Bear in mind that you may need to install additional spring rests after this shortening takes place. You will most likely have to experiment with different spring rest sizes to determine the optimal spacing. Check the **`extra_springrests.zip`** file to find more spring rests in different sizes. **NOTE 2:** Your 25N and BT27 springs may shorten to the point that even a very tall spring rest does not sufficiently bridge the gap (while still allowing the spring to compress and catch), and it's likely that there will be a small amount of dead space between the end of the plunger head and the ram base after firing. I haven't found a solution for this yet, so bear this in mind if that bothers you. The dead space doesn't seem to impact the performance very much. Note that the 28N spring is sufficiently long that it does not experience this problem, even after extensive use. ### Installation 1. Remove the Caliburn's rear butt piece in order to gain access to the plunger and spring. 2. Remove the existing spring, then prime the Caliburn to move the plunger back to its rear-most position for easy access. 3. Insert the **`PlungerSpacerPr`** into the plunger, then hold down the trigger and insert your Prophecy spring, pushing the plunger all the way until it sits in the forward-most position. The spacer should be a very slightly loose fit within the plunger, and the spring should be able to rotate freely within the spacer. 4. Insert one or two of the **`BackButtSpringRest12mm`** pieces onto the BackButtPr guide rod. These will be a snug friction fit, to prevent any movement. 5. Swap the stock BackButt out with the custom **`BackButtPr`** piece, and reassemble the rear of the Caliburn, ensuring all nuts are tightened and secure. If your spring sits too loosely, add another spring rest piece to the BackButtPr guide rod, or remove one if your spring is compressed too much and is bending/flexing prematurely when at rest. ### General performance **My test setup:** * Caliburn with 18" long 0.509" ID PETG coupler barrel from Remzak, Slug aluminum ramrod with 1 o-ring on the tip, combined with Worker metal ram base and Containment Crew Acetal plunger. This setup gives me a confirmed 100% air seal. * BlasterTECH MkII SCAR with fishing line set to 2/8 twist. * Worker half length darts (yellow Gen 1) * Xcortech X3200 chronograph Average fps readings: * **Worker 28N (W0323):** 265 fps (sample size of 34) * **Worker 25N (W0233):** 260 fps (sample size of 34) * **BlasterTECH BT27-Plus:** 294 fps (sample size of 34) **NOTE:** testing was done with brand new springs. I expect performance will gradually decrease over time as the springs wear out. ### RELEASE NOTES/CHANGE LOG **NOTE:** for archival purposes, outdated parts can be found in **`old_files.zip`**. **26 March 2019** Extra spring rest sizes added (10 mm and 20 mm) to cater for spring shortening and other odd spring lengths. Refer to the **`extra_springrests.zip`** file. **9 February 2019** Update 2: also fixed some manifold errors in the STL for **`BackButtPr_v1.2`**. Tightened tolerances to reduce slop (**`BackButtPr_v1.2`** and **`PlungerSpacerPr_v1.1`**), and separated out the spring rest as individual pieces to provide modularity (**`BackButtSpringRest12mm_v1.0`**). Also added plunger spacers that fit the Worker Caliburn metal plunger and the Containment Crew (CC) acetal plunger. These can be found in their corresponding ZIP files. **6 February 2019** Significantly raised the height of the spring rest on the **`BackButtPr_v1.1`** as a fix for the BT27 spring not being long enough and causing the spacer to partially slide out of the plunger. I have not tested this extensively yet, but can confirm that my Caliburn still primes and catches correctly. **5 February 2019** Initial v1.0 release. Still has a minor issue where the BlasterTECH BT27 spring can be too short and thus allow the spacer to partially move in and out of the plunger. I thought I fixed this by lengthening the shelf/spring rest on the BackButtProphecy piece, but it seems my spring is still settling and shortening. I will use my BT27 some more to allow the spring to settle, and then attempt to solve this issue once and for all. In the meantime, it doesn't seem to be an issue in practice, and my Caliburn still performs extremely well.