An Air Rifle Assembly Tool

[nitroex700]

I recently opened two air rifles - my Hurricane Mod 15 and an old Diana 35 I got from a friend. Both have a (similar) strange trigger engagement module that sits behind the spring guide as shown below.

IMG_20171011_085658.jpg

This component of Diana guns has three 'bumps' for the piston to engage the three ball bearings held inside it. Diana 35 additionally has a recessed cut into it above the cross pins that prevents any circular washer like object from fitting properly on it, making disassembly still complex. The spring pressure was enough to scratch a Rs 2 coin I used as a washer.

IMG_20171011_215244.jpg

Another issue I have while disassembling air rifles is the extreme amounts of Indian Frugal Engineering technologies (aka 'jugaad') that one needs to do in order to disassemble one. Right from the jack to all kinds of inserts, its jugaad from the word go. Due to the large pressure involved, even slight misalignment or mistake can damage the gun, the equipment or the user himself.. A slight misalignment was enough to damage the particularly sturdy jack of my compressor!

Hence I decide to come up with an air rifle disassembly tool that can reach inside Hurricane and Diana 35 air rifles all the way to the spring guide, take the spring load and allow the user to assemble the guns without any danger of damaging himself or his equipment.

I did the measurements and finally decided on a tool of total length of about 6.5cm that will sit between the compressor jack head and the spring guide.
Considering all the scratching on that Rs2 coin, I decided to use high speed steel for my design. Though the machining would be a bit harder than mild steel or aluminium and cost of the metal more, it would be also yield a very sturdy tool, enough to take the pressure of any monster spring and heavy preload combination a user might throw at the tool.

This is how it looked post the initial machining operation. Will upload more pics tomorrow.

IMG_20171024_191048.jpg

[nitroex700]

So this is how the thing looks post heat treatment:

IMG_20171025_204241.jpg

IMG_20171025_204450.jpg

IMG_20171025_203746.jpg

It cost me a few hundred bucks for the HS steel, machining, treatment, petrol and about 24 hours' running around spread across 3-4 days. If anyone needs help with making one of these for himself, feel free to PM!

[snIPer]

Good job buddy. Keep innovating
/S

[nitroex700]

Thanks bro! The tool did drastically simplify the otherwise extremely tedious job of disassembling a Diana 35...

[snIPer]

how old is your D35? i have one from 1968. and yes i agree the ball bearing system on this is a little tricky to assemble

[xseven]

Hi!
Do you have a video showing how it works?