Instead of putting this all on the LGLF site, I'm just going to put it here.
If you're looking for a bit of exigence, I just finished a before/after getup on a crossbow for someone:
A large majority of this information is going to refer to what I consider to be one of the most important parts in a working springer - the plunger head.
As a general rule, if you're using a replaced plunger tube via the writeup, using the stock plunger head is a great option, but only if it's in good condition. Tears are fixable with goop, though it may need to be redone after 2-3 wars I've noticed. I have not found a good solution to wrinkles in the skirt.
Instead, I've found a mcmaster part that suits our applications perfectly. It's just like the skirt part I found for the +bow, but this one works extremely well in both the replaced and original plunger tubes.
It's part number 9562K45 and looks like this:
It works really well on replaced plunger rods too. Getting plunger heads onto replaced rods has been an issue I've seen lately. My solution is pretty straight forward:
You need a 1.5" length bolt with thread matching the plunger rod, two washers and a spacer matching the inside of the plunger head.
-For the stock plunger head, use washers 9/16" OD and matching the thread of your bolt. I used mcmaster part 91090A102 for the one in the photo. The spacer you'll need is 90309A028, set to whatever thread you need.
-For the replaced plunger head, use washers 7/8" OD and matching the thread of your bolt. I would use mcmaster part 95630A460 here. The spacer you'll need is 92510A795 plus 90309A027, set to whatever thread you need.
Another part I never really felt was adequately covered were crossbow catches. My attempts to make one out of 1/4" thick polycarbonate weren't really successful, so I turned to another material. What follows is the template to make a replacement catch from 1/16" steel, part number 9516K165:
(Should be up soon)
I also drew up a template of an actual crossbow catch. I'm not sure if the jpeg will print out exactly scale for you guys, so if you need to adjust, the center thickness should be 1/16"
Some other quick notes:
When finding the part for a replacement plunger tube, remember that the pipe extensions work off of the OD, not the ID, so there is some variance in it. Some are bigger, some are smaller. I've worked with both; both have worked fine. Put a quarter wrap of e-tape around the coupler, or however much, goop it up, and run some screws/bolts through it to keep it steady and you should be fine. It may be helpful to bring a coupler with you to see how well it fits into the part.
Don't hesitate to use electrical tape around the rings to hold the plunger tube in place. It creates tension and friction, which in turn keeps the plunger tube from spinning - useful for speedloaders.
DT3 arrow shooter springs are getting harder and harder to find. For a nearly identical replacement, try a section of 9637K25, also known as the +bow spring's little brother. 8" seems to work well, but feel free to experiment. You're encouraged to post your individual results here.
A quick refresher on removable 2k turrets - OMC Petg fits right over the inlet perfectly. Goop it up, and run some pvc over it for a turret to go into pvc couplers. Have a looksee.
Edited by Split, 09 October 2009 - 10:24 AM.