[Reaper93]

Surfing on YT I found an interesting video, here it is:

Starting from this idea I thought: "Why not shimming the entire receiver too?"

So the purpose of this MOD is to make the cycling more sturdy and solid, centering the cylinder perfectly into the hop up chamber and preventing dirt comes into the receiver.

Taking measurement with a caliber the diameter of the cylinder results of 24mm and the receiver 25.9mm (MB03, the Bar10 has a tighter receiver)
The 1,9mm left must be filled!

So I bought a 0,8mm plastic sheet for more on less 1€ and cut a strip from it about 7x12cm.
I folded it with a thermo-pistol (industrial phon) using an old VSR cylinder as a reference.

The plastic cylinder must be as regular and smooth as possible, so I helped myself with a pvc pipe used as a stamp, inserting the plastic shimmer inside, and inside of it i inserted the vsr cylinder, heating everything up with the termo-pistol.

Inserting the shimmer into the receiver I obtained this:

Then the receiver looked like this!
Remember to lube the shimmer with silicone spray

Now the cycling is really sturdy and solid, the cylinder head goes perfectly into the hop up unit and no dirt will get inside the receiver anymore! :tup:

 

[1tonne]

Great idea. When I originally thought of the ejection port cover, I never thought about making a complete cylinder to go inside.
Has it made the cylinder smoother?

 

[Reaper93]

Absolutely yes, the cylinder is smooth and feels really solid.

However use my measurement as a guide, but check your rifle before buying the sheet, as I noticed working with so small tolerances can be a problem.

 

[Crusoe]

Can you tel us what type of plastic this is? I'm wondering if different types will give different friction levels.

 

[Reaper93]

Good point.
Honestly I don't know what kind of plastic it is precisely.
It is really smooth and clean.
Feels like the plastic used to make book covers, or photo covers.
I just went to a brico and cut a piece from a roll, btw I will suggest that any kind of smooth plastic will work if you lube it with silicone spray.

 

[Crusoe]

Good point.
Honestly I don't know what kind of plastic it is precisely.
It is really smooth and clean.
Feels like the plastic used to make book covers, or photo covers.
I just went to a brico and cut a piece from a roll, btw I will suggest that any kind of smooth plastic will work if you lube it with silicone spray.

Yes i suppose any thermoplastic will work but there are plastics on the market that are made for their low friction properties, so if one of those were used then the bolt pull could be very light. Combine it with a teflon cylinder and it could be ridiculously smooth, to the point where the only resistance is the spring itself.

I will be trying a version of this before the weekend to game on Sunday.

 

[Reaper93]

Feel free to find the right plastic for you!

 

[Entropy]

Could also ask careful for what plastic he uses for this.

Though he uses his machines to machine pieces for inside of his vsr-x's.. So Maybe not so accessible.

 

[Shoushen]

Careful has made two of these for me. For my original VSR, he made one out of Nylon, on my VSR-X it is made from Delrin. They both work great, but I like the Delrin sleeve a little bit more.

 

[Reaper93]

I would also raccommend Teflon, but it's expensive and hard to work.

Btw the key is to "go cheap" when possible, so this is my solution

 

[Entropy]

Careful has made two of these for me. For my original VSR, he made one out of Nylon, on my VSR-X it is made from Delrin. They both work great, but I like the Delrin sleeve a little bit more.

Ah how I can't wait for mine

 

[Speedle]

Doesn't such sleeve add more friction compared to two separate narrow glide rings? I mean such sleeve has more contact surface.. Of course standard glide rings suck. Mine BAR10 even scratched teflon cylinder. But decent material glide rings look superior.

 

[Reaper93]

Not necessarily.
The purpose of this mod is to avoid yokes between the cylinder and the rings, making the cycling more stable compressing the spring on a precise axis.
Ideally there is no excessive contact between the cylinder and the sleeve, btw the lubrication would avoid friction between the parts.
I found this as an improvement for my rifles, and I've done this on every vsr I have.

Not only decent material rings, but you need the exact tolerance to make them work correctly with your cylinder.

 

[KillerDad]

Doesn't such sleeve add more friction compared to two separate narrow glide rings? I mean such sleeve has more contact surface.. Of course standard glide rings suck. Mine BAR10 even scratched teflon cylinder. But decent material glide rings look superior.

i think its more like if you tried to drag your friend around by his ankle. then put your friend on a sled and drag him around. the sled does have more contact area but will slide easier.

 

[1tonne]

I made my cylinder guide rings out of hard nylon and they make the bolt pull awesome.

 

[Reaper93]

Because standard rings just sucks! lol
If you check them they have an inner diameter too large for the cylinder, and they are made of some kind of shitty plastic.

I haven't the possibility to work with nylon or other materials atm, so I just made the sleeve out of a material I can work with.

I would say a rigid teflon tubing would work way better IMO, but it's really hard to work if you don't have the right tools and machinery.

 

[KillerDad]

Because standard rings just sucks! lol
If you check them they have an inner diameter too large for the cylinder, and they are made of some kind of shitty plastic.

I haven't the possibility to work with nylon or other materials atm, so I just made the sleeve out of a material I can work with.

I would say a rigid teflon tubing would work way better IMO, but it's really hard to work if you don't have the right tools and machinery.

What are you talking about with teflon tubing? the teflon coated cylinders are still made of steel. They make the rings out of delrin/aceatal because its the best plastic for reducing friction.

 

[Reaper93]

Making the shimmer out of teflon...

Have you ever tried frictioning teflon on teflon? It feels like ice on ice.

 

[Crusoe]

I have found a supplier of Teflon/PTFE pipe, as Reaper93 says...it is expensive compared to other options. i am just waiting to find if they can give the ID i want and what their tolerance is.

I have found delrin and Nylon6 tubes, a lot less expensive than the teflon/PTFE but the tolerances on them are shocking. it will require accurate machining to make them work.

I also had a bit of a chat with Careful (such a helpful guy!!), for anything more accurate than Reaper93's mod you will also need to look at boring out you receiver to smooth and slightly enlarge it. material costs and machining cost wise you will probably be better off having a pro do it and buying a receiver with sleeve fitted from Careful.

 

[Speedle]

Teflon is kinda soft as raw material. Nylon/PA6 isn't the best option for sliding. I used Ertalyte for receiver glide rings and piston glide rings. Now the bolt pull with teflon cylinder is very smooth. SPR380 spring feels like M150.

Regarding the tolerances (though diameter would be a more correct term here) - I left the same diameter as on original rings. Cylinder head acts as a base surface with hop up unit. So some clearance between rings and cylinder is not an issue. That gap even helps to reduce friction.