"In the world of spuds today"

A place for general potato gun questions and discussions.
User avatar
daberno123
Corporal
Corporal
Posts: 594
Joined: Mon Nov 19, 2007 5:56 pm
Location: Ohio

Tue Mar 04, 2008 7:51 pm

Mine is supposed to be for 3 days but no one really keeps track if you come after the first one :)
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Tue Mar 04, 2008 7:54 pm

luckey you here they keep a list and check off each day if you are there or not and if they have to come look for you, you get another 2 days in the whopper(thats what we call it in school, no idea why )
User avatar
SpudUke5
Sergeant
Sergeant
Posts: 1099
Joined: Tue Sep 04, 2007 10:16 pm

Wed Mar 05, 2008 1:52 am

I also live in ohio, Cleveland to be more precise, i forgot where Fnord lives but its 2 hours awya from me, i think.

you can always find the topic that talks about where people live and it will give you a map that shows where people live.

also frogy lives in ohio, (Akron) and he is going to help me finish my 4 inch barrel sealing cannon, just so that i dont mess up again and spend another 10 bucks.
4SPC, My 4" piston 3" porting cannon
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
OuchProgramme
Specialist 3
Specialist 3
Posts: 371
Joined: Sat Jan 12, 2008 7:30 pm

Wed Mar 05, 2008 7:43 pm

Haha bigbob and daberno. Last week, i had trash duty for cutting in the lunch line. I mean..everybody does it all the time, and nobody else cares.
But..unfortunately, there was the ole fat vice principal on duty that day. So i got caught =/. 5 days of trash duty, but i finished :)
User avatar
bigbob12345
Staff Sergeant
Staff Sergeant
Posts: 1516
Joined: Sat Dec 01, 2007 9:13 am
Location: Mercer Island,Washington

Wed Mar 05, 2008 7:58 pm

Thats a stupid reason to get in trouble I mean i was purposly late for class to piss off the really annoying sub.
I would say that deserves punishment but cutting in the lunch line that just doesnt make any sense to punish. I enjoyed an hour in the 'whopper'
today and forgot to bring lunch so i starved.

in the world of spuds today i cracked the epoxy piston that i will be using in my mini coax and am going to go mold another one in a couple minutes. And thats it.
OuchProgramme
Specialist 3
Specialist 3
Posts: 371
Joined: Sat Jan 12, 2008 7:30 pm

Wed Mar 05, 2008 8:13 pm

bigbob12345 wrote:Thats a stupid reason to get in trouble I mean i was purposly late for class to piss off the really annoying sub.
I would say that deserves punishment but cutting in the lunch line that just doesnt make any sense to punish. I enjoyed an hour in the 'whopper'
today and forgot to bring lunch so i starved.

in the world of spuds today i cracked the epoxy piston that i will be using in my mini coax and am going to go mold another one in a couple minutes. And thats it.
Yep, i try to avoid the fat V.P. now. She's loud and anoyying.


I've also drawn some plans for a bolt action, mag fed gun. Quite simple if really thought about, some might even overthink it. I'll create a model first, and then later on i'll start the real gun.
User avatar
Bubba05
Corporal
Corporal
Posts: 518
Joined: Wed Mar 21, 2007 9:05 am

Thu Mar 06, 2008 5:04 am

Im making a bb gun out of a fire extinguisher?
well i hope to and i hope i dont loose and eye in the process.

Bubba
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Thu Mar 06, 2008 8:33 am

Back to topic:

In the world of spuds today...

...Well, in the last few weeks, progress stalled on the Range Calculator because of other, more important tasks and deadlines I had to keep.

However, I'm back to work now - and to make up for the already pretty large delays, I'm working in some extra features you might find useful.

These are mostly going to be chronograph based (but not exclusively). But if that doesn't float your boat, I'm working on increasing the actual accuracy of the program's output, by working in a feature based on bullet drag models, as well as giving the main algorithm a bit of a shakedown to improve accuracy and efficiency

Should I succeed in getting my act together, I could probably have it finished in a few days.
Does that thing kinda look like a big cat to you?
User avatar
Jared Haehnel
Corporal 2
Corporal 2
Posts: 611
Joined: Tue Feb 19, 2008 4:15 pm
Location: White River Jct, Vermont

Thu Mar 06, 2008 8:38 am

That would be a very helpful tool Rag...

In my small corner of the spudding world it is bright and sunny and a balmy 20 degrees outside. The snow banks are pretty near 10ft tall.

I just ordered the 4 inch tees for my next cannon and am looking forward to getting all the parts together to begin construction. :)
My current projects....

Currently buying part for...
http://www.spudfiles.com/forums/my-new- ... rt,15.html
Still on the drawing board...
C02 tank hybrid
Screen doors for submarines...
User avatar
Fnord
First Sergeant 2
First Sergeant 2
Posts: 2239
Joined: Tue Feb 13, 2007 9:20 pm
Location: Pripyat
Been thanked: 1 time
Contact:

Thu Mar 06, 2008 10:18 am

Back off topic...
Edit: just realized you're also in ohio Fnord. where do you live? i'm in cincinnati

In short, a LONG way away. Basically, I live at the highest point of the WV panhandle for physical/geographical reference.

Edit: Hey! Everyone! Do an image search of "cleveland ohio" without quotes.

Haha. gotcha.
Image
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Thu Mar 06, 2008 12:56 pm

_Fnord wrote:Back off topic...
Curses, in spite of my attempt, it's gone off the rails again.
Last edited by Ragnarok on Thu Mar 06, 2008 1:32 pm, edited 2 times in total.
Does that thing kinda look like a big cat to you?
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Thu Mar 06, 2008 1:20 pm

Ragnarok wrote:...off the rails
I'm going <A HREF=" the rails</a> on a crazy train...


Anyone here read that book? Supposed to be really good if you're an RR fan.
User avatar
Jared Haehnel
Corporal 2
Corporal 2
Posts: 611
Joined: Tue Feb 19, 2008 4:15 pm
Location: White River Jct, Vermont

Thu Mar 06, 2008 1:25 pm

How fitting.....
My current projects....

Currently buying part for...
http://www.spudfiles.com/forums/my-new- ... rt,15.html
Still on the drawing board...
C02 tank hybrid
Screen doors for submarines...
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Thu Mar 06, 2008 1:34 pm

MrCrowley wrote:I'm going <A HREF=" the rails</a> on a crazy train...
No fair!... :D

Still I'm battling an appalling cold, and trying to pass the time with this coding, but it gets harder when you have to blow your nose every 20 seconds.

Anyway, as I haven't got anything better to do, the drag feature is now mostly hardwired in, all the conventional bullet models, and a few others I spent ages trying to find:
G1, G2, G5, G6, G7, G8, Gi, Gs, Gl, Gc, as well as the old fixed Cd version as well.
From that list, G1, Gs, Gl and Gc are most likely to be useful - although the others might find occasional use. G7 for example should be good for low drag darts.

There are also two features for the less technically minded, one of which selects a model based on the similarity of form factors, and the other of which (once I have fine tuned it, at least) blends other curves to make a reasonable guestimate for drag curves over the Mach range. Not 100% on of course, that needs actual measurements, but it should be decent.
Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Captain
Captain
Posts: 5401
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK

Fri Mar 07, 2008 10:11 am

Yes, double post I know.

I'm still coding this lot. Just cracked the principles behind one of the chrono-tools.
This one can take a velocity (or ideally, an average of several velocities) measured at one distance from the muzzle, and another (further) distance, and from those velocities - and this is the clever bit - work out the drag co-efficent of the projectile from that data. It will also convert that to an appropriate zero figure using the available drag models for that velocity as well.

There's a version of this for both lightgate chronies, and for the poorman's sound rec chrony. I'm also wondering if I can fit in a feature that will actually automatically match it to a drag model if you add a third reading point to allow it to gain a curve of data.
Quite useful, even if I do say so myself.

The other main chrono tool should be a Drag reverser. This takes a drag coefficient, a velocity reading, and a distance to the chrony, then works back to find the muzzle velocity - this is mainly intended for people firing either very light projectiles, or very fast projectiles.

The point is that if a chrony is too near to the muzzle, the muzzle blast may affect the reading. Too far away, then you've already lost some velocity. Many supersonic claims are snubbed because of the positioning of the chrony - the user wants minimal drag losses, so places it close - but that then creates a risk of muzzle blast error, which is the main complaint.

This tool allows the chrony to be placed well out of the way of the muzzle blast (possibly without the diffusers to avoid hitting them by mistake), but you can then put the drag losses back on.

Again, designed for the sound rec chrony as well, which helps sort out one of the main problems with it - the drag losses.

So, I'm working hard here. Anyway, if you have any more ideas for this, you can either get them to me now (below please, not via PM, or I'll no doubt get some repeats), which means they'll be ready for the first beta version (thus meaning they can get ironed out quickly), or you could tell me after the beta release, but that means I'll take longer to get them working perfectly smoothly.
Does that thing kinda look like a big cat to you?
Post Reply