Mit freundlicher Genehmigung von Chiumanfu (ion.chiumanfu.com). Übersetzt von dt3ft.
I always thought the biggest draw-back to the Smart Parts Ion was the difficulty to tear-down the firing assembly. It requires regular maintenance to keep operating at peak performance but the parts (ie banjos and hoses) do not like the repeatative stress of being disassembled over and over again. This mod allows you to remove the firing chamber and bolt from the back of the shell by just removing two screws then winding the firing chamber out. The stress on your hoses and threads is eliminated and you can lube the bolt after every game if you wish ;)
All credit for this idea goes to Vengador from PbN. His original thread can be found here.
This mod requires some specialized tooling and skills to do a proper job. Neither I nor Vengador are responsible if you do irreversable damage to your Ion.
Layout the materials needed.
A 5/16" Smart Parts Banjo fitting
A Stock Ion Shell
A stock Ion Frame
A 1/2 inch 10-32 screw
Here's a list of the tools I used:
Drill press and vise
11/64" drill bit or a 5/32" drill bit and a 10-32 tap
?? drill bit
Dremel with cutoff wheel and drum sander.
You need to first modify the rear banjo. It is marked with 5/16 on the gray collar. Seperate the banjo spool from the plastic housing by using a large flat screw driver/chisel/butter knife. Wedge it in between the metal top collar and the plastic housing then twist to seperate them. It should pop out pretty easily.
Remove all three orings from the banjo spool with a dental pick.
Protect the banjo spool with paper towels and clamp it in a vise. Drill a 5/32" hole only as deep as the existing allen key hole. If you go any deeper, and you will have to properly seal the threads with loctite or teflon tape.
Thread the hole with a 10-32 tap. Cut a one thread at a time then back it out, then cut one more thread. This is the proper way to tap a hole.
If you do not have a tap, you can drill the hole with a 11/64" drill bit. That's the exact size to allow the screw to self-tap securely. Apply red loctite to the end of the 1/2" screw and thread it in.
Here's the finished banjo spool. It should be ??? in total length. Go ahead and reinstall the orings. Remember... all three are a different size. The smallest one goes closest to the threads. The middle size goes next and the the largest one goes closest to the top lip.
Next we have to modify the banjo housing. Our aim is to remove the thin plastic lip at the very bottom. I used a file to remove the lip. I've also tried a large drill bit which worked well also. Just hand turn it like your removing flashing from a freshly drilled hole. Just be careful not to remove too much material or the banjo will leak. Do not scratch or damage the inside! Do not touch the stepped lower portion. A gouge or scratch there will cause the orings to leak.
Lip removed. The picture makes it look messy but it is actually a very clean job. :)
Put some lube on the orings.
Insert the banjo spool the same way it came out. It should be able to slide in and out of the housing with little effort.
Remove the banjo spool again and place the banjo housing into the rear cavity of the frame. Mark the center point of the banjo housing on the frame.
Center tap the mark and clamp the frame in a vise. Make sure to clamp on the flat part of the frame and not the raised part that the On/Off button sticks to. If you clamp on the section that is raised, the frame will squish and the board won't slide in anymore.
Drill with a 7/16" drill-bit. A 13/32" is probably closer to the correct size and may look cleaner. I didn't have one in my drill-bit set so I went the one size up.
Use a file to clean off any sharp edges that may damage orings when the banjo spool is inserted.
(Yes, I know my hole is 1/2mm off center... no ones perfect!)
Now it's time to mod the shell. We need to remove the back and sand down the inside of the tube. Use a dremel and cut off wheel to slice off the rear of the shell.
It should look like this with the rear removed.
Use a sanding drum attachment to smooth out the inside. Quite a lot of material must be removed to allow the firing can to slide in and out freely.
There is a small ring and a large wedge on the inside of the shell. The wedge is responsible for making sure the donut is straight when the firing assembly is inserted. They must be removed for this mod.
Insert the firing assembly into the modified shell backwards. It should slide in and out easily. Keep removing material from the inside until it does.
Install the board with modified banjo housing into the frame. Make sure the banjo is sitting with the modified edge up.
Assemble the firing assembly to the frame like normal. Make sure the modified banjo housing and the donut line up or the rear screw will not go in.
Insert the modified banjo spool. Push it into the banjo housing and screw it into the donut. Do not overtighten. Do not cross thread it.
Check for leaks. If the read banjo is leaking, make sure the orings on the banjo spool are lubed. Check the inside of the banjo housing for scratches.
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