BL 520 inspired build

[David1110]

Few questions. I recently discovered the BL-520 and it sparked an old flame with cannons I had while I was younger. Questions are as follows:

1. Can I use a centered coaxial barrel and load it in the back still? or will it have to be offset as in the BL-520?
For instance, use a reducer/bushing for a barrel instead of an offset cap.

2. When I calculate the chamber:barrel volume ratio, do i subtract the volume the barrel in the chamber takes up and then increase volume of chamber to compensate.

3. What is the most powerful ratio for my C:B ratio

[grock]

Besides looks, the barrel is offset to allow for a mixing tube to run parallel with the barrel inside the chamber

You would subtract the volume of the barrel, because the barrel is taking up that space that gas/air is not in

ehh.... it varies depending on who you ask. usually between .75:1 and 1.1:1

[David1110]

Is a mixing tube really needed?

[Moonbogg]

Is a mixing tube really needed?

no. thats what fans are for.

[David1110]

Thanks guys, and any regular thermal fan for a CPU will work just fine?

[jagerbond]

Is a mixing tube really needed?

It really is.. Not so much for the mixing, more for the venting. The dead space at the front is difficult to cycle the deoxygenated air out with that configuration. You could put a port near the front to help vent. I have built one with a "T" at the front and 2 caps.

or..

We do sell the offset <a href="http://ultimatespudgun.com/offset-coaxi ... ml">kit</a> with fan, switch etc...

Best,

[Technician1002]

Long chambers have the difficulty of end to end circulation. I suspect some of the soot issue with Vera is related to this very topic. Part may be lean and other areas rich. A pipe lengthwise the chambers and fed by the fans would ensure a blend the full chamber length. Short fat chambers have less issues with this.