I believe this makes sense. Thanks for your explanation! Is it correct to say that the best time scaler value for a given design is one that puts the projectile at the barrel exit at the 250th node? Overshooting the time scaler by a little bit probably doesn't matter much, but getting it too small ...

I started messing around with the TIme Scaler and noticed that it can have a pretty big effect on the results. Any guidance on how to choose a value? Any reason 0.5 isn't set as the default? Thanks!


The smaller the value, the better (more accurate results). However, if you go too small it will ...

LOTS of folks have used CO2. How it behaves depends greatly upon how you intend to use it. It could be anywhere from indistinguishable from air to a very exotic critter. You haven't really told us what you're planning on doing.

Onward we go... Version 0.2a is on the drive. Biggest change is support for Air, CO2, and Helium for non-combustion guns and Butane, MAPP, and Propane for combustion guns.

SDT 0.2 on Google Drive

I haven't done anything with MAPP gas (still thinking about how to best impliment it).

I did, however, realize that I left out a major bit of theory. I threw the spreadsheet together to get something working but forgot to make transonic corrections in the barrel. As long as the projectiles are ...

I’m on vacation at the moment and not in a good place to be working, but I still started to do some homework….

It seems that MAPP gas hasn’t actually been manufactured in the US since 2008. Is the MAPP that you measured performance differences with the “original” or something more recent. ‘Cause it ...

Buy a certified commercial product. If you need high energy for legitimate sport or research, use commercially manufactured devices that meet safety and legal standards (e.g., regulated airguns, commercial launchers, or research-grade combustion rigs). Sprunki


LOL. You’re in the wrong place ...

Franchement sdt est un excellent travail que L'auteur nous propose !
Il serait fun et génial d'avoir en gaz de combustion le mapp et l'hydrogène... Sauf si celà n'en vaut pas la peine j'ai pû faire différents essais et l'hydrogène le mapp proposent de réelles différences butane et propane plutôt ...

Does the old HGDT show a significant effect in a 1x gun with low versus high static friction?


I have no idea. Others would be better positioned to answer that than I would be. I wrote HGDT to model VERA. To date she's the only combustion/hybrid gun I've ever built. HGDT did a pretty good job of ...

Merci pour ce travail je n'arrive pas à l'utiliser car calc est dur à utiliser pour moi mais ton travail est fort très fort

It's an Excel format. If Calc is difficult for you to use, I imagine there's a spreadsheet out there that's easier. Heck, Google Sheets will run online natively. The plots ...

And there's another beta up - 0.1c. It should be the same link, but just in case...

Il à l'avantage d'être plus facile à allumer donc allumage moins puissant et concernant son énergie est il intéressant ? As tu pû faire des essais en mix hybrid air/h2?

No, I haven't done any experiments with air and H2. At least, not with spud guns. My day job has involved some experiments with ...

Je vais essayer d'apporter à notre science donc je ferais différents test avec différents carburant, de l'hydrogène que je vais faire moi même sans oxygène en hybride et comparer les performances pour un mélange donné ✌️,
J'en ferais un sujet propre et détaillée


I concede that hydrogen could do ...

Salutations et Merci pour ce fabuleux travail !
Je recherche comment l'utiliser, de souvenirs hgdt était un calculateur excellent avec plus de gaz disponibles il aurait été plus abouti 😁
Pour de l'hybride


From a performance perspective, there isn't much difference between different hydrocarbons ...

[oops, where's the delete button?]