Search found 26071 matches

by jackssmirkingrevenge
Tue Nov 22, 2022 8:37 pm
Forum: Hybrid Cannons
Topic: Questions about pressure and flow rate
Replies: 5
Views: 198

Re: Questions about pressure and flow rate

theoretically, A and B should use the same amount of fuel, so their calorific values should be the same. They use the same amount of fuel, but B generates higher pressure and will therefore outperform A by a considerable margin, because projectile acceleration will be greater. Edit: here is a compa...
by jackssmirkingrevenge
Tue Nov 22, 2022 8:34 pm
Forum: Hybrid Cannons
Topic: Unable to run hgdt.
Replies: 2
Views: 141

Re: Unable to run hgdt.

Have you tried "run as administrator"?
by jackssmirkingrevenge
Sun Nov 13, 2022 11:16 am
Forum: BB, Airsoft, and Pellet Guns
Topic: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"
Replies: 17
Views: 10925

Re: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"

I would have left the resistor on a start capacitor, as it will live with charge on it - it's a shock hazard. there's also the risk of more arcing on the centrifugal switch as it switches, which could mean more wear and tear. I thought it might reduce performance but less wear and tear is good so I...
by jackssmirkingrevenge
Sat Nov 12, 2022 6:02 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"
Replies: 17
Views: 10925

Re: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"

I managed to source this capacitor locally: 270μF instead of the original 300μF but it seems to have done the trick ;D https://i.imgur.com/ThXUFgQ.jpg 270μF instead of the original 300μF but it seems to have done the trick ;D hurrah! https://youtu.be/9LjxU5QbVtE The capacitor came with a resistor be...
by jackssmirkingrevenge
Fri Nov 11, 2022 10:02 am
Forum: Hybrid Cannons
Topic: Is there a more active website than this?
Replies: 6
Views: 308

Re: Is there a more active website than this?

yyt wrote:
Fri Nov 11, 2022 9:54 am
Your love for this hobby is admirable!
Many things have come and gone, but the pleasure of blasting holes in things is difficult to beat :D

It's a shame that this sort of practical hobby seems to be in decline with modern generations.
by jackssmirkingrevenge
Fri Nov 11, 2022 9:57 am
Forum: Hybrid Cannons
Topic: A brand-new ignition method
Replies: 33
Views: 12734

Re: A brand-new ignition method

Looking good! I assume that in the interest of safety you've made sure that all the pipes and fittings are rated for the expected pressures after ignition ;) I note that while the paper you shared concluded that "When the volume of the initiation end is larger than that of the booster end, you can g...
by jackssmirkingrevenge
Fri Nov 11, 2022 9:19 am
Forum: Hybrid Cannons
Topic: Is there a more active website than this?
Replies: 6
Views: 308

Re: Is there a more active website than this?

I think the fact that this forum is slightly active at all is because it's more or less the only such forum left, at least in the Anglosphere. There is also the Francophone "Patator" forum that used to be very active but it's even more quiet now, there is a post from more than 5 years ago lamenting ...
by jackssmirkingrevenge
Wed Nov 09, 2022 11:41 am
Forum: Hybrid Cannons
Topic: A brand-new ignition method
Replies: 33
Views: 12734

Re: A brand-new ignition method

What is his method? I don't understand. Do you use electric heating wire to ignite? Using a hot wire doesn't really work well, I've tried this with an atmospheric combustion to make the point: https://youtu.be/OmLNm6Myg7s Compare the delay with a spark: https://www.youtube.com/watch?v=CyaMRqjAfKo W...
by jackssmirkingrevenge
Wed Nov 09, 2022 11:15 am
Forum: Hybrid Cannons
Topic: Questions about mixing multiples
Replies: 4
Views: 3795

Re: Questions about mixing multiples

The pressure doesn't seem to determine everything. A 10.5mm projectile has 1.36 times the base area as a 9mm projectile, this means for example that if you have 1000 psi in the barrel, then there is 99 lbs pushing on the 9mm and 134 lbs pushing on the 10.5mm, so significantly more energy for the sa...
by jackssmirkingrevenge
Wed Nov 09, 2022 9:41 am
Forum: Hybrid Cannons
Topic: About explosion pressure
Replies: 3
Views: 3377

Re:

But if my barrel is short, I may choose pure oxygen, because it burns fast enough, and compressed air is more suitable for long barrel. I think the difference is just like a pistol and a rifle. A pistol must use gunpowder with a fast burning rate to accelerate for a short time, while a rifle barrel...
by jackssmirkingrevenge
Tue Nov 08, 2022 9:46 am
Forum: Hybrid Cannons
Topic: Questions about mixing multiples
Replies: 4
Views: 3795

Re: Questions about mixing multiples

Firearms generate tens of thousands of psi of chamber pressure, so if you keep the same caliber and projectile weight, achieving similar power is impractical with a hybrid. https://i.imgur.com/32QQPsG.jpg Using a 50x mix and a 30 inch barrel with approximately 2:1 chamber:barrel volume ratio, I got ...
by jackssmirkingrevenge
Tue Nov 08, 2022 9:18 am
Forum: Hybrid Cannons
Topic: About explosion pressure
Replies: 3
Views: 3377

Re: About explosion pressure

I don't know if anyone has made a specific side by side comparison, but while the ratio of oxygen to propane is the same in both cases, there are important differences. Working with pure oxygen is a lot more dangerous so it is less practical, and there is a danger of DDT especially at higher mixes. ...
by jackssmirkingrevenge
Tue Nov 08, 2022 9:08 am
Forum: Hybrid Cannons
Topic: A brand-new ignition method
Replies: 33
Views: 12734

Re: A brand-new ignition method

I'm thinking of using 1mpa low mix to ignite 5mpa high mix. 5 mpa would be 50x, I haven't got any personal experience with it but I would say the wire method Larda used is a simpler way to go about it - you have to replace the wire every time, but it is easier than having to fill two separate chamb...
by jackssmirkingrevenge
Mon Nov 07, 2022 9:21 pm
Forum: Hybrid Cannons
Topic: A brand-new ignition method
Replies: 33
Views: 12734

Re: A brand-new ignition method

If in a closed chamber I manage to introduce propane and compressed air within the range of stoichiometric proportions, at 100 bar, with a proper ignition, will it explode? :? With the right ignition it should, and we have proof :) I don't know if you're aware of this example that was shooting at u...
by jackssmirkingrevenge
Mon Nov 07, 2022 9:08 pm
Forum: BB, Airsoft, and Pellet Guns
Topic: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"
Replies: 17
Views: 10925

Re: Benjamin Model 30/30 CO2 Carbine Repeater "Hot Shot"

I hope it is something simple the problem of your machine. It looks like it :) It's a doubIe capacitor motor, I took it apart to look at the centrifugal switch and nothing seems to be broken or dirty: https://i.imgur.com/Kr3p9NZ.jpg https://i.imgur.com/nWkxZTf.jpg Of the two capacitors however, acc...