Date: Thu Oct 29 15:52:42 2009 ** **Back to Contents ** ------------------------------------------------------------------------ **

Author: cbettis@unlserve.unl.edu** **Received: from wm-imp-3.unl.edu (wm-imp-3.unl.edu [129.93.88.31]) by uni00ml.unity.ncsu.edu (8.13.7/8.13.8/Nv5.2008.0610.1) with ESMTP id n9TJjDg5030911 for ; Thu, 29 Oct 2009 15:45:13 -0400 Received: from localhost (localhost [127.0.0.1]) by wm-imp-3.unl.edu (8.13.8/8.13.8) with ESMTP id n9TJjCUm017221 for ; Thu, 29 Oct 2009 14:45:12 -0500 Received: from lecturdemo.unl.edu (lecturdemo.unl.edu [129.93.36.196]) by wm-imp-3.unl.edu (Horde MIME library) with HTTP; Thu, 29 Oct 2009 14:45:12 -0500 Message-ID:

Subject: Re: Vacuum Bazooka and clear PVC

Post:

David,

The idea is that the three fold point cuts the tape into flaps that
fold in instead of rupturing. I have also used the hammer and stopper
technique but thought I would give this a go with the new version.

Cliff

Quoting David Tam :

> Looks great, Cliff! I never did get the tape residuals not to stick
> inside the cannon, so on mine I replaced that end with a rubber
> stopper that I knock off with a hammer. It didn't occur to me that a
> sharper point might do the trick - any ideas why this works?
>
> David
>
>
>
> On Thu, Oct 29, 2009 at 2:25 PM, Thomas Senior wrote:
>> Very neat Cliff.
>> Could you explain the benefit of the the arrow head for puncturing the
>> tape?
>> Tom
>> ________________________________
>> From: David Kardelis
>> To: "tap-l@lists.ncsu.edu"
>> Sent: Thu, October 29, 2009 12:58:13 PM
>> Subject: Re: [tap-l] Vacuum Bazooka and clear PVC
>>
>> Thanks, Cliff. Arrow heads I got. Thought it was funny that you were using
>> a Broadhead to puncture the tape.
>>
>> I'll have to see if can find some pvc rod.
>>
>> dave
>>
>>
>>
>> -----Original Message-----
>> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
>> Behalf Of cbettis@unlserve.unl.edu
>> Sent: Thursday, October 29, 2009 11:47 AM
>> To: tap-l@lists.ncsu.edu
>> Subject: Re: [tap-l] Vacuum Bazooka and clear PVC
>>
>> David,
>>
>> The pipe was McMaster-Carr 49035K87. The pipe unions used to make the
>> end flanges 4881K65. The valve was a Nibco mss sp-110. The feet and
>> valve brace were made of 1/2 inch Delrin sheet. The collar was made
>> from 3.5 inch PVC rod. The can holder was mde of particle board and
>> steel rods. The arrow point was bought from Cabela's XK-416364.
>>
>> Cliff
>>
>> Quoting David Kardelis :
>>
>>> Was just planning on making this. Do you have a parts list for the
>>> PVC/Vacuum valves etc.
>>>
>>> Thanks dave
>>>
>>> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu]
>>> On Behalf Of Wayne Easterling
>>> Sent: Thursday, October 29, 2009 10:03 AM
>>> To: tap-l@lists.ncsu.edu
>>> Subject: Re: [tap-l] Vacuum Bazooka and clear PVC
>>>
>>> Hi Cliff,
>>> Very nice setup! What was used for the collar that the
>>> vacuum line threads into? It looks to be ABS that you needed to
>>> machine some.
>>> Wayne
>>>
>>> ________________________________
>>> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu]
>>> On Behalf Of cbettis@unlserve.unl.edu
>>> Sent: Thursday, October 29, 2009 8:33 AM
>>> To: tap-l
>>> Subject: [tap-l] Vacuum Bazooka and clear PVC
>>>
>>>
>>> I wanted to let you all know that McMaster-Carr is now selling the
>>> clear PVC pipe in 8 foot lengths so you can make a bazooka with just
>>> a single length of it. Here is a picture of my implementaion:
>>>
>>> https://physicslearning2.colorado.edu/image/displayimage.php?album=4&pos=1
>>>
>>> This is the vacuum valve:
>>>
>>> https://physicslearning2.colorado.edu/image/displayimage.php?album=4&pos=2
>>>
>>> This is the arrow point I use to puncture the tape:
>>>
>>> https://physicslearning2.colorado.edu/image/displayimage.php?album=4&pos=0
>>>
>>> This the container I use for safe storage of the arrow point:
>>>
>>> https://physicslearning2.colorado.edu/image/displayimage.php?album=4&pos=3
>>>
>>> Using photogates, I measured the ping pong ball's exit velocity.
>>> With just a puff of breath propelling it, it was 6 m/s; using the
>>> vacuum pump and the pressure of the inrushing atmosphere when the
>>> tape is punctured, it was 300 m/s.
>>>
>>> Cliff
>>>
>>
>>
>>
>>
>>
>>
>>
>





From tap-l-owner@lists.ncsu.edu Thu Oct 29 15:52:42 2009
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