win a ball from Bowling.com

Author Topic: Verifying the CG on a bowling ball - video  (Read 7462 times)

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Verifying the CG on a bowling ball - video
« on: March 22, 2014, 05:55:47 PM »
First video I've made with my new video camera, wanted to do a short one just to try it out.  Took several hours to upload and render, and I'm rather disappointed at the quality of the upload.  Just playing it through the camera's hdmi cable to a tv, it's crystal clear, but youtube's compression must really suck.  The videos I was taking on my iphone look almost as good and take just a couple minutes to upload.  Anyway, it's about how to verify the location of the CG on a bowling ball, and how to find it if it's mismarked.  Just a short simple video, let me know what you think, thanks. 

http://www.youtube.com/watch?v=fObpICb_R8g
« Last Edit: March 24, 2014, 09:48:23 AM by Gizmo823 »
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

 

TheGom

  • Hero Member
  • *****
  • Posts: 577
Re: Locating the CG on a bowling ball - video
« Reply #1 on: March 22, 2014, 06:11:02 PM »
Giz, nice job!

Question for you. Doing before drilling allows you to properly layout the ball correct?Can this also be done "after" the ball has been drilled and if so, what does one learn from it?

Thanks

kidlost2000

  • Hero Member
  • *****
  • Posts: 5789
Re: Locating the CG on a bowling ball - video
« Reply #2 on: March 22, 2014, 06:14:45 PM »
Double check on youtube the settings when playing a video. Often times it does something and adjust the video playback to the lowest quality. Ive had it happen mid video before.
…… you can't  add a physics term to a bowling term and expect it to mean something.

kidlost2000

  • Hero Member
  • *****
  • Posts: 5789
Re: Locating the CG on a bowling ball - video
« Reply #3 on: March 22, 2014, 06:24:46 PM »
I enjoyed the video and the quality looks good.

I never check the cg. After I layout the ball i go through and check the statics prior to drilling and if something is out of the norm then I go back to locate the proper cg.
…… you can't  add a physics term to a bowling term and expect it to mean something.

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Locating the CG on a bowling ball - video
« Reply #4 on: March 22, 2014, 06:27:03 PM »
When you do it before drilling, the grip center will be where you want to weigh it from, not on the CG.  Doing it before drilling is a good idea because it will give you a good estimate what your post-drilling static weights will be.  This is important for keeping the ball within legal limits if you aren't using a weighthole, and if you are, it will let you know how much weight you will have and where it will be at so if you have to, you can manipulate where the weight ends up with hole depth.  It's also useful because if you use a layout that won't utilize a weighthole, you could find out that you could need a weighthole before you drill it so you can adjust your layout before the fact, rather than having to add one that you don't want or hadn't factored in after drilling.  You will always want to weigh it again after drilling to find out exactly what your weights are before you take any further action also. 

Giz, nice job!

Question for you. Doing before drilling allows you to properly layout the ball correct?Can this also be done "after" the ball has been drilled and if so, what does one learn from it?

Thanks
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Locating the CG on a bowling ball - video
« Reply #5 on: March 22, 2014, 06:28:20 PM »
I checked the settings, but it's playing at 1080p the whole video . . oh well.

And yeah that's a good point about when you weigh it.  Should be able to tell if something's up when you weigh it after you lay it out. 
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

itsallaboutme

  • Hero Member
  • *****
  • Posts: 2017
Re: Locating the CG on a bowling ball - video
« Reply #6 on: March 22, 2014, 07:04:22 PM »
Appears to me somebody needs to learn the way you find the cg not using the trial and error method.

MI 2 AZ

  • Hero Member
  • *****
  • Posts: 8159
Re: Locating the CG on a bowling ball - video
« Reply #7 on: March 22, 2014, 08:25:47 PM »
Gizmo,  is the old Lane #1 method still valid?

http://www.lane1bowling.com/pdf/find-the-center-of-gravity.pdf


_________________________________________
Six decades of league bowling and still learning.

ABC/USBC Lifetime Member since Aug 1995.

JohnP

  • Hero Member
  • *****
  • Posts: 5819
Re: Locating the CG on a bowling ball - video
« Reply #8 on: March 23, 2014, 09:37:19 PM »
Yes, the procedure on the Lane 1 site is valid, and no guess work is required.  --  JohnP

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Locating the CG on a bowling ball - video
« Reply #9 on: March 24, 2014, 07:54:40 AM »
I do remember seeing that several years ago . . I might go back and redo it then.  I'll confess to not having to chase down many, and if I do, it's never been far off.  Haha I basically do the same thing without realizing it, but it really doesn't take that long to chase it down either way.  Maybe I'll just put that link in the description, or should I just refilm the video? 
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

itsallaboutme

  • Hero Member
  • *****
  • Posts: 2017
Re: Locating the CG on a bowling ball - video
« Reply #10 on: March 24, 2014, 08:09:01 AM »
Either redo or rename yours "verifying the cg of a bowling ball".

When you do it the proper way you don't need any manufacturer markings to start.

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Locating the CG on a bowling ball - video
« Reply #11 on: March 24, 2014, 09:18:25 AM »
True.  The "locating" part was a last minute add on too . . was just going to originally do the first half, should have just left it off. 

Either redo or rename yours "verifying the cg of a bowling ball".

When you do it the proper way you don't need any manufacturer markings to start.
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Verifying the CG on a bowling ball - video
« Reply #12 on: March 24, 2014, 09:49:26 AM »
Video has been edited.  I'll make a new video on location. 
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?

JohnP

  • Hero Member
  • *****
  • Posts: 5819
Re: Verifying the CG on a bowling ball - video
« Reply #13 on: March 24, 2014, 03:48:00 PM »
When I want to verify if a cg mark is correct I put the cg mark at top dead center of the scale using my ProSect, balance it, then spin it to different positions, resetting it to top dead center each time.  If the mark is correct the scale will stay balanced each time.  The problem with this is that it takes almost as much time as using the Lane 1 method.  --  JohnP

Gizmo823

  • Hero Member
  • *****
  • Posts: 2167
Re: Verifying the CG on a bowling ball - video
« Reply #14 on: March 25, 2014, 08:06:05 AM »
Yeah I can check/find a cg pretty quickly, but as far as teaching it or explaining how to find it in a video, the Lane 1 method is the best way to show somebody.  I've just always chased the line in the direction of the weight, just flipping it a few times until I got it right, then I chased the other direction.  I'm sure people have several different ways to do it, but the Lane 1 way is probably the way to teach it if you're going to. 

When I want to verify if a cg mark is correct I put the cg mark at top dead center of the scale using my ProSect, balance it, then spin it to different positions, resetting it to top dead center each time.  If the mark is correct the scale will stay balanced each time.  The problem with this is that it takes almost as much time as using the Lane 1 method.  --  JohnP
What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?