Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 63 users online :: 3 registered, 0 hidden and 60 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

DIY Chronograph, am I doing it right?

A place to ask general spud cannon related questions.
Sponsored 
  • Author
    Message

Unread postAuthor: rp181 » Thu Jul 03, 2008 5:18 pm

ahh, i see the way you do it. I dont have a scope, but agilent might give me a 40mhz handheld, that will be usefull.

Ile keep the resistors out, i use NiMH rechargables, so they last awhile, and there rechargable =p. its used for short periods anyway.

Im well aware of the diode needed antiparrallel across thecoil, i have 4 1200v 5500A surge fast recovery diodes.

I clocked a rubberband today, does 30FPS sound about right?
  • 0

User avatar
rp181
Brigadier General
Brigadier General
 
Posts: 1090
Joined: Thu Dec 13, 2007 8:47 pm
Reputation: 0

Unread postAuthor: jimmy101 » Fri Jul 04, 2008 10:18 am

rp181 wrote:I clocked a rubberband today, does 30FPS sound about right?

Maybe.
If you launch the rubber band horizontally and measure the distance it takes to fall to the ground from a known height you can get a rough estimate of the velocity;
v = (horizontal distance) / SQRT(2*height/g)
if g is 32 feet/second^2
v = 4*(horizontal distance) / SQRT(height)
where both distance and height are in feet

So, for a 3 foot drop and a 30 FPS velocity the rubber band should carry about 13 feet.
  • 0

Image

jimmy101
Lieutenant General
Lieutenant General
 
Posts: 3128
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Country: United States (us)
Reputation: 7

Previous

Return to General Spud Cannon Related

Who is online

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot]

Reputation System ©'