SpudFiles

If you've read THIS THREAD, then you know I'm writing a replacement for GGDT/HGDT. The replacement is a single spreadsheet to replace *both* GGDT and HGDT. Why a spreadsheet? Because it maximizes portability. Where GGDT/HGDT were Windows apps, spreadsheets can be imported into office tools on any platform out there. It's in an Excel Workbook format. I prefer that format and everything works best in it's native format. Note that I've imported it into Apache Open Office and it works there but the plots aren't quite as pretty. On Google sheets? The text parts work OK but the plots are complete shit. Still, the basic functionality appears to be portable. I'm at the point of needing people to test it out and giving me feedback (maybe even pointers on how to make the plots more app agnostic). Blah blah blah....

Wanna try it?

The Spudder's Design Tool may be found on my Google Drive.

Let me know if you have problems!

Thanks for making the new tool. I haven't had much of a chance to look at it yet, but I wanted to make a quick comment as SpudFiles has been down more often than not lately. On that note, it might be worth putting some contact information in the spreadsheet itself so that you're not so reliant on SpudFiles.

I'd recommend adding barrel friction, particularly static friction as it's particularly important in Nerf blasters. I didn't see any friction being taken into account. Correct me if I'm wrong.

You're correct. Friction isn't in there. It was one of those, "Doesn't seem to matter" things from my perspective, but then, I've never dealt with a Nerf blaster. It's easy enough to do, however. Thanks for the feedback and look for both contact info and friction in the next iteration.

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

To get more specific, static friction matters when the projectile mass is low (like with Nerf darts) because it allows the pressure to build up before the projectile moves. If the projectile mass is low, then the projectile might move a lot initially, which would keep pressure lower for the duration of the shot because there's more volume available for the gas. That in turn reduces muzzle velocity.

Je l'ai essayé mais je n'arrive pas à m'en servir...
Je suis pas doué avec calc

[oops, where's the delete button?]

Turbine32 wrote: ↑

Tue Sep 09, 2025 8:28 am

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. It's been a long time, but I recall reading a paper wherein the performance of different hydrocarbons (methane, ethane, propane, and butane) were studied in gas gun applications. There was a measurable difference, yes, but it was also small enough that the author concluded that one should simply use whatever fuel was easiest/cheapest for them to get. The biggest issue is that you're limited by the oxygen content in air no matter what fuel you use. If you start using supplimental oxygen, things change, of course. But if you're using oxygen enrichment techniques you're asking for a detonation and playing games at a high enough level that you shouldn't need HGDT (or SDT).

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

Turbine32 wrote: ↑

Wed Sep 10, 2025 2:22 am

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 some interesting things thanks to its low molecular weight. Understand, however, that it is all but certain to detonate (hydrogen/air mixtures detonate easily!).

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?

Turbine32 wrote: ↑

Wed Sep 10, 2025 11:26 am

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 that mixture and it's not a question of IF that mixture will detonate. It WILL detonate. Can you do this safely? Sure, but it's much easier to botch it and I'm not willing to go down that road for a hobby. If you wish to, by all means, but you're on your own.

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

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

Turbine32 wrote: ↑

Fri Sep 12, 2025 1:55 pm

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 will be ugly, but the math bits work.