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Samurai kidd

Member Since 02 Dec 2012
Offline Last Active Jan 11 2017 11:17 AM

Topics I've Started

New Method for Reducing the Internal Diameter of PETG

18 February 2013 - 04:57 PM

First off, thanks to MIG for his spring-tightening method. Without it, this would not be possible. Also, thanks to Poptachi and his YT channel; I was watching it when I got the idea.

To begin, you need this stuff:
1/2 Brass
17/32 brass (optional)
Lighter or hairdryer

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Nest the 1/2 brass in the PETG. Use the 17/32 brass if you want to keep part of the PETG at it's original dimensions.

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Heat a section of the PETG with the lighter. This works best if you rotate the tubing quickly and keep the section between 1-2 inches.

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Pull (yes, pull) the two ends of the PETG apart. This stretches the tubing and shapes the ID to fit the OD of the 1/2 brass, giving the PETG a similar ID to 17/32 brass. The 17/32 brass keeps that section of the tubing at a 17/32 ID, or normal ID.

Move along, and do the same to the rest of the tubing.

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This is really easy to do, and has a great fit for darts. Unlike the spring method, the ID is a lot more constant so the dart seal should be a bit better.

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Alternative Sealing Method for Longshot Plunger Tubes

30 January 2013 - 08:05 PM

Attempt at contribootin':

While working on a 17/32 brass breech for my longshot, I was having problems with the internal o-ring to PT face seal. I figured out that the problem was the o-ring; it was torn. I had no way of getting to ACE and didn't have the right replacement on hand, so I decided to replace the sealing method altogether. I did this by using the same design concept as the breech itself; brass-to-brass coupling.

Essentially, I put a ring of brass inside the small endpiece on the PT face. The size I used was 5/8 brass. This ring of 5/8 sealed with another ring of 19/32 on the base of the bolt near the black plastic circle. The 19/32 encases the 9/16 that I used for the bolt. This concept should also work for breeches with a 5/8 bolt; just use a 21/32 base for the bolt base and an 11/16 piece on the PT face.
Here are some in progress pictures:

PT face with ring of 5/8:
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Bolt with piece of 19/32 over the 9/16 bolt:
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Some MS paint photos to better illustrate the concept:

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