Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.electronics.design > #489320 > unrolled thread

OT: Running a pedestal fan in reverse - failed - a rant of sorts.

Back to article view | Back to sci.electronics.design

Contents

  OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-26 17:54 +1100
    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Rheilly Phoull <froggins@iinet.net.au> - 2017-12-26 19:29 +0800
    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. mpm <mpmillard@aol.com> - 2017-12-26 04:49 -0800
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 09:52 +1100
    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. tabbypurr@gmail.com - 2017-12-26 06:07 -0800
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 09:58 +1100
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. mpm <mpmillard@aol.com> - 2017-12-26 18:52 -0800
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 14:57 +1100
    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-26 10:21 -0800
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-12-26 11:48 -0700
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. rickman <gnuarm@gmail.com> - 2017-12-26 14:03 -0500
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John S <Sophi.2@invalid.org> - 2017-12-26 14:31 -0600
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-12-26 15:44 -0500
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John S <Sophi.2@invalid.org> - 2017-12-26 15:06 -0600
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John S <Sophi.2@invalid.org> - 2017-12-26 16:16 -0600
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-26 17:26 -0800
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 14:42 +1100
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. not@telling.you.invalid (Computer Nerd Kev) - 2017-12-26 21:00 +0000
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. rickman <gnuarm@gmail.com> - 2017-12-26 18:37 -0500
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. "David Eather" <eather@tpg.com.au> - 2017-12-27 09:48 +1000
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-27 15:57 +1100
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 09:50 +1100
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. whit3rd <whit3rd@gmail.com> - 2017-12-26 18:55 -0800
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Steve Wilson <no@spam.com> - 2017-12-27 05:40 +0000
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-27 17:24 +1100
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Steve Wilson <no@spam.com> - 2017-12-27 07:12 +0000
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-27 18:40 +1100
              Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Steve Wilson <no@spam.com> - 2017-12-27 12:34 +0000
                Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-28 00:36 +1100
                Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. rickman <gnuarm@gmail.com> - 2017-12-27 17:59 -0500
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. krw@notreal.com - 2017-12-27 09:39 -0500
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. amdx <nojunk@knology.net> - 2017-12-27 10:45 -0600
              Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. tabbypurr@gmail.com - 2017-12-27 09:01 -0800
                Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. amdx <nojunk@knology.net> - 2017-12-27 12:34 -0600
                  Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. rickman <gnuarm@gmail.com> - 2017-12-27 18:03 -0500
                    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. tabbypurr@gmail.com - 2017-12-27 15:18 -0800
                    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. amdx <nojunk@knology.net> - 2017-12-28 09:18 -0600
                  Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-28 12:38 +1100
                  Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. M Philbrook <jamie_ka1lpa@charter.net> - 2017-12-30 09:41 -0500
                    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. makolber@yahoo.com - 2018-01-03 13:48 -0800
                      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. DemonicTubes <tlackie@gmail.com> - 2018-01-03 14:08 -0800
                      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2018-01-04 15:18 +0200
              Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-28 12:36 +1100
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Jasen Betts <jasen@xnet.co.nz> - 2017-12-28 06:36 +0000
              Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Phil Allison <pallison49@gmail.com> - 2017-12-28 00:16 -0800
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Phil Allison <pallison49@gmail.com> - 2017-12-26 22:38 -0800
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. krw@notreal.com - 2017-12-27 09:40 -0500
    Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 15:02 +1100
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 18:11 +1100
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-27 18:42 +1100
        Re: Running a pedestal fan in reverse - failed - a rant of sorts. "P E Schoen" <paul@pstech-inc.com> - 2017-12-27 03:17 -0500
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. tabbypurr@gmail.com - 2017-12-27 01:59 -0800
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-27 21:29 +1100
            Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-12-27 14:24 +0200
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. krw@notreal.com - 2017-12-27 09:43 -0500
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-27 11:25 -0800
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. tabbypurr@gmail.com - 2017-12-27 11:32 -0800
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Jasen Betts <jasen@xnet.co.nz> - 2017-12-28 06:20 +0000
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. amdx <nojunk@knology.net> - 2017-12-27 10:50 -0600
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-28 14:49 +1100
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. FMurtz <haggisz@hotmail.com> - 2017-12-29 11:34 +1100
      Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. bloggs.fredbloggs.fred@gmail.com - 2017-12-27 10:22 -0800
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. Sylvia Else <sylvia@not.at.this.address> - 2017-12-28 09:41 +1100
          Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. bloggs.fredbloggs.fred@gmail.com - 2017-12-27 15:29 -0800
        Re: OT: Running a pedestal fan in reverse - failed - a rant of sorts. rickman <gnuarm@gmail.com> - 2017-12-27 18:40 -0500

Page 3 of 4 — ← Prev page 1 2 [3] 4  Next page →

#490190

On Wednesday, January 3, 2018 at 2:48:35 PM UTC-7, mako...@yahoo.com wrote:
> On Saturday, December 30, 2017 at 9:41:08 AM UTC-5, M Philbrook wrote:
> > In article <p20p2r$48g$1@dont-email.me>, nojunk@knology.net says...
> > > 
> > > On 12/27/2017 11:01 AM, tabbypurr@gmail.com wrote:
> > > > On Wednesday, 27 December 2017 16:46:09 UTC, amdx  wrote:
> > > >> On 12/27/2017 1:12 AM, Steve Wilson wrote:
> > > >>> FMurtz <haggisz@hotmail.com> wrote:
> > > >>>> Steve Wilson wrote:
> > > >>>>> John Larkin <jjlarkin@highlandtechnology.com> wrote:
> > > >>>>>> On Tue, 26 Dec 2017 17:54:51 +1100, Sylvia Else
> > > >>>>>> <sylvia@not.at.this.address> wrote:
> > > >>>      
> > > >>>>>>> For reasons I need not go into, I wanted to make a cheap pedestal fan
> > > >>>>>>> blow backwards, by putting the fan on backwards, and running the
> > > >>>>>>> motor in reverse.
> > > >>>      
> > > >>>>>> Wouldn't those two things cancel?
> > > >>>      
> > > >>>>> Many turbine propeller aircraft can reduce their landing roll by
> > > >>>>> placing the propellers in reverse pitch. The blades are still turning
> > > >>>>> in the same direction, but the thrust vector is reversed. They are not
> > > >>>>> very efficient in this mode, but are still able to slow the aircraft.
> > > >>>    
> > > >>>>> To visualize what would happen in a pedestal fan, imagine turning it
> > > >>>>> around 180 degrees. The motor is still spinning the propeller in the
> > > >>>>> same direction, but the thrust vector is reversed in relation to the
> > > >>>>> floor.
> > > >>>    
> > > >>>>> In order to reverse the thrust vector, either the propeller pitch has
> > > >>>>> to be reversed, or the motor has to be reversed.
> > > >>>    
> > > >>>>> John is right. Doing both would cancel.
> > > >>>    
> > > >>>> Wrong,reversing motor would reverse air flow, reversing the propeller
> > > >>>> would be same air direction but would put the leading edge in the right
> > > >>>> position for efficiency.
> > > >>>
> > > >>> Wrong. Think about it. Reversing the propeller pitch reverses the thrust
> > > >>> vector. This is how turbine aircraft shorten their landing roll.
> > > >>>
> > > >>>
> > > >>    OK I took the cover off a 3 blade fan that turns clockwise. I removed
> > > >> the blade put it on backwards. The fan still blows air in the same
> > > >> direction. It doesn't blow very much air though.
> > > >>    Certainly is some design consideration in the way the blade is curved.
> > > >>                                               Mikek
> > > > 
> > > > so if you then also change the motor direction, you get reverse flow with good efficiency. It's ain't rocket science, it's fan science.
> > > > 
> > > > 
> > > > NT
> > > > 
> > 
> > I am glad you Rocket experts aren't talking about centrifugal 
> > impellers..
> > 
> > ;)
> 
> next topic, why does swapping I and Q cause a spectral inversion?
> 
> :-)
> 
> mark

Or why my '72 Dodge Dart had so many left-hand connections.  According to this thread I must have just had my nuts on backwards!

[toc] | [prev] | [next] | [standalone]

#490224

On 3.1.18 23:48, makolber@yahoo.com wrote:
>> ;)
> 
> next topic, why does swapping I and Q cause a spectral inversion?
> 
> :-)
> 
> mark


Because it effectively changes the sign of the complex
exponential.

For a longer discussion, please start a new thread.

-- 

-TV

[toc] | [prev] | [next] | [standalone]

#489426

On 28/12/2017 3:45 AM, amdx wrote:
> On 12/27/2017 1:12 AM, Steve Wilson wrote:
>> FMurtz <haggisz@hotmail.com> wrote:
>>
>>> Steve Wilson wrote:
>>>> John Larkin <jjlarkin@highlandtechnology.com> wrote:
>>>>> On Tue, 26 Dec 2017 17:54:51 +1100, Sylvia Else
>>>>> <sylvia@not.at.this.address> wrote:
>>>>>> For reasons I need not go into, I wanted to make a cheap pedestal fan
>>>>>> blow backwards, by putting the fan on backwards, and running the
>>>>>> motor in reverse.
>>>>> Wouldn't those two things cancel?
>>>> Many turbine propeller aircraft can reduce their landing roll by
>>>> placing the propellers in reverse pitch. The blades are still turning
>>>> in the same direction, but the thrust vector is reversed. They are not
>>>> very efficient in this mode, but are still able to slow the aircraft.
>>>> To visualize what would happen in a pedestal fan, imagine turning it
>>>> around 180 degrees. The motor is still spinning the propeller in the
>>>> same direction, but the thrust vector is reversed in relation to the
>>>> floor.
>>>> In order to reverse the thrust vector, either the propeller pitch has
>>>> to be reversed, or the motor has to be reversed.
>>>> John is right. Doing both would cancel.
>>> Wrong,reversing motor would reverse air flow, reversing the propeller
>>> would be same air direction but would put the leading edge in the right
>>> position for efficiency.
>>
>> Wrong. Think about it. Reversing the propeller pitch reverses the thrust
>> vector. This is how turbine aircraft shorten their landing roll.
>>
>>
>   OK I took the cover off a 3 blade fan that turns clockwise. I removed 
> the blade put it on backwards. The fan still blows air in the same 
> direction. It doesn't blow very much air though.
>   Certainly is some design consideration in the way the blade is curved.
>                                              Mikek
> 

Ah, the scientific method. I hadn't actually tried it, since I knew the 
efficiency would be reduced and I was starting with a new unassembled 
fan. Interesting that the difference is significant.

Sylvia.

[toc] | [prev] | [next] | [standalone]

#489444

On 2017-12-27, Steve Wilson <no@spam.com> wrote:
> FMurtz <haggisz@hotmail.com> wrote:
>
>> Steve Wilson wrote:
>>> John Larkin <jjlarkin@highlandtechnology.com> wrote:
>  
>>>> On Tue, 26 Dec 2017 17:54:51 +1100, Sylvia Else
>>>> <sylvia@not.at.this.address> wrote: 
>    
>>>>> For reasons I need not go into, I wanted to make a cheap pedestal fan
>>>>> blow backwards, by putting the fan on backwards, and running the
>>>>> motor in reverse. 
>    
>>>> Wouldn't those two things cancel?
>    
>>> Many turbine propeller aircraft can reduce their landing roll by
>>> placing the propellers in reverse pitch. The blades are still turning
>>> in the same direction, but the thrust vector is reversed. They are not
>>> very efficient in this mode, but are still able to slow the aircraft.
>  
>>> To visualize what would happen in a pedestal fan, imagine turning it
>>> around 180 degrees. The motor is still spinning the propeller in the
>>> same direction, but the thrust vector is reversed in relation to the
>>> floor. 
>  
>>> In order to reverse the thrust vector, either the propeller pitch has
>>> to be reversed, or the motor has to be reversed.
>  
>>> John is right. Doing both would cancel.
>  
>> Wrong,reversing motor would reverse air flow, reversing the propeller 
>> would be same air direction but would put the leading edge in the right 
>> position for efficiency.
>
> Wrong. Think about it. Reversing the propeller pitch reverses the thrust 
> vector. This is how turbine aircraft shorten their landing roll.

No, it is not! 

reversesing the proprellor changes the blade pitch by 180 degrees, 

Aircraft make smaller changes to the pitch so that the slope of the
blades reverses,

180 degrees gets you approximately back where you started.

-- 
This email has not been checked by half-arsed antivirus software 

[toc] | [prev] | [next] | [standalone]

#489445

Jasen Bleats wrote:

--------------------

> >
> > Wrong. Think about it. Reversing the propeller pitch reverses the thrust 
> > vector. This is how turbine aircraft shorten their landing roll.
> 
> No, it is not! 
> 

 ** Here we go again ....... 



> reversesing the proprellor changes the blade pitch by 180 degrees, 
> 

**FYI:

The term "pitch" = the distance moved by a prop's tips in one turn. The same term also applies to threads and similar. 

However, "reversing" a prop means moving the blades through neutral to the the opposite pitch  -  used by aircraft and boats to achieve movement in the reverse direction.



....  Phil 

[toc] | [prev] | [next] | [standalone]

#489379

Steve Wilson wrote:

-----------------------
> John Larkin 
> 
>> Sylvia Else
> 
>  
> >>For reasons I need not go into, I wanted to make a cheap pedestal fan 
> >>blow backwards, by putting the fan on backwards, and running the motor 
> >>in reverse. 
>  
> > Wouldn't those two things cancel?
>  
>
> Many turbine propeller aircraft can reduce their landing roll by placing the 
> propellers in reverse pitch. The blades are still turning in the same 
> direction, but the thrust vector is reversed. They are not very efficient in 
> this mode, but are still able to slow the aircraft.
> 
> To visualize what would happen in a pedestal fan, imagine turning it around 
> 180 degrees. The motor is still spinning the propeller in the same direction, 
> but the thrust vector is reversed in relation to the floor.
> 
> In order to reverse the thrust vector, either the propeller pitch has to be 
> reversed, or the motor has to be reversed.
> 
> John is right. Doing both would cancel.
>


** Ouchhh !! He fell at the last fence !!! 

Reversing a moulded fan blade on its drive shaft does NOT reverse the pitch - as pointed out by others here, it simply swaps leading edges for trailing ones.  

FYI:  

The DHC-4 Caribou and the Douglas DC6 series ( piston engine planes )have fully reversing props. 




....  Phil 

[toc] | [prev] | [next] | [standalone]

#489396

On Tue, 26 Dec 2017 22:38:12 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

>Steve Wilson wrote:
>
>-----------------------
>> John Larkin 
>> 
>>> Sylvia Else
>> 
>>  
>> >>For reasons I need not go into, I wanted to make a cheap pedestal fan 
>> >>blow backwards, by putting the fan on backwards, and running the motor 
>> >>in reverse. 
>>  
>> > Wouldn't those two things cancel?
>>  
>>
>> Many turbine propeller aircraft can reduce their landing roll by placing the 
>> propellers in reverse pitch. The blades are still turning in the same 
>> direction, but the thrust vector is reversed. They are not very efficient in 
>> this mode, but are still able to slow the aircraft.
>> 
>> To visualize what would happen in a pedestal fan, imagine turning it around 
>> 180 degrees. The motor is still spinning the propeller in the same direction, 
>> but the thrust vector is reversed in relation to the floor.
>> 
>> In order to reverse the thrust vector, either the propeller pitch has to be 
>> reversed, or the motor has to be reversed.
>> 
>> John is right. Doing both would cancel.
>>
>
>
>** Ouchhh !! He fell at the last fence !!! 
>
>Reversing a moulded fan blade on its drive shaft does NOT reverse the pitch - as pointed out by others here, it simply swaps leading edges for trailing ones.  
>
>FYI:  
>
>The DHC-4 Caribou and the Douglas DC6 series ( piston engine planes )have fully reversing props. 

"Don't try this when airborne"

[toc] | [prev] | [next] | [standalone]

#489371

On 26/12/2017 5:54 PM, Sylvia Else wrote:

I decided I was unwilling to be defeated, and a fair amount of 
soldering, heatshrinking and hot gluing later, I got it to work.

https://www.youtube.com/watch?v=GWB9I33k-Rs

Sylvia.

[toc] | [prev] | [next] | [standalone]

#489380

On 27/12/2017 3:02 PM, Sylvia Else wrote:
> On 26/12/2017 5:54 PM, Sylvia Else wrote:
> 
> I decided I was unwilling to be defeated, and a fair amount of 
> soldering, heatshrinking and hot gluing later, I got it to work.
> 
> https://www.youtube.com/watch?v=GWB9I33k-Rs
> 
> Sylvia.

One issue I haven't addressed is that the fan is held on by a left-hand 
threaded nut, because a right-hand threaded nut will tend to undo itself 
in this application. Since I've reverse the direction, I really need the 
nut to be right-hand threaded, but there's no way I can change the 
threadedness of the shaft.

May need to use some more hot glue - we'll see.

Sylvia.

[toc] | [prev] | [next] | [standalone]

#489383

Sylvia Else wrote:
> On 27/12/2017 3:02 PM, Sylvia Else wrote:
>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>>
>> I decided I was unwilling to be defeated, and a fair amount of 
>> soldering, heatshrinking and hot gluing later, I got it to work.
>>
>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>>
>> Sylvia.
> 
> One issue I haven't addressed is that the fan is held on by a left-hand 
> threaded nut, because a right-hand threaded nut will tend to undo itself 
> in this application. Since I've reverse the direction, I really need the 
> nut to be right-hand threaded, but there's no way I can change the 
> threadedness of the shaft.
> 
> May need to use some more hot glue - we'll see.
> 
> Sylvia.

Thread seal or drill and tap propeller boss for a grub screw.

[toc] | [prev] | [next] | [standalone]

#489384 — Re: Running a pedestal fan in reverse - failed - a rant of sorts.

"Sylvia Else"  wrote in message news:fagvcuFe9alU1@mid.individual.net...

> On 27/12/2017 3:02 PM, Sylvia Else wrote:
>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>
>> I decided I was unwilling to be defeated, and a fair amount of soldering, 
>> heatshrinking and hot gluing later, I got it to work.
>
>> https://www.youtube.com/watch?v=GWB9I33k-Rs

> One issue I haven't addressed is that the fan is held on by a left-hand 
> threaded nut, because a right-hand threaded nut will tend to undo itself 
> in this application. Since I've reverse the direction, I really need the 
> nut to be right-hand threaded, but there's no way I can change the 
> threadedness of the shaft.

> May need to use some more hot glue - we'll see.

I don't think hot glue will be strong enough. It might be possible to cut 
right-hand threads over the left hand threads, but that would probably 
result in severe loss of strength. It might work for a very coarse thread 
with high helix angle, like the level wind mechanism on a fishing reel:

https://www.youtube.com/watch?v=lIfGcMkP408

If there is enough length of thread on the shaft, you might be able to put a 
second nut on it and lock it in position once it's tight. Loc-tite on the 
threads might also work. Another method is to use a lock-nut, or create the 
equivalent by deforming the threads in the nut or on the shaft.

Paul 

[toc] | [prev] | [next] | [standalone]

#489385

On Wednesday, 27 December 2017 07:11:33 UTC, Sylvia Else  wrote:
> On 27/12/2017 3:02 PM, Sylvia Else wrote:
> > On 26/12/2017 5:54 PM, Sylvia Else wrote:
> > 
> > I decided I was unwilling to be defeated, and a fair amount of 
> > soldering, heatshrinking and hot gluing later, I got it to work.
> > 
> > https://www.youtube.com/watch?v=GWB9I33k-Rs
> > 
> > Sylvia.
> 
> One issue I haven't addressed is that the fan is held on by a left-hand 
> threaded nut, because a right-hand threaded nut will tend to undo itself 
> in this application. Since I've reverse the direction, I really need the 
> nut to be right-hand threaded, but there's no way I can change the 
> threadedness of the shaft.
> 
> May need to use some more hot glue - we'll see.
> 
> Sylvia.

threadlock or superglue. I suspect it won't be needed though, it's not as if a pedestal fan applies much torque.


NT

[toc] | [prev] | [next] | [standalone]

#489386

On 27/12/2017 8:59 PM, tabbypurr@gmail.com wrote:
> On Wednesday, 27 December 2017 07:11:33 UTC, Sylvia Else  wrote:
>> On 27/12/2017 3:02 PM, Sylvia Else wrote:
>>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>>>
>>> I decided I was unwilling to be defeated, and a fair amount of
>>> soldering, heatshrinking and hot gluing later, I got it to work.
>>>
>>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>>>
>>> Sylvia.
>>
>> One issue I haven't addressed is that the fan is held on by a left-hand
>> threaded nut, because a right-hand threaded nut will tend to undo itself
>> in this application. Since I've reverse the direction, I really need the
>> nut to be right-hand threaded, but there's no way I can change the
>> threadedness of the shaft.
>>
>> May need to use some more hot glue - we'll see.
>>
>> Sylvia.
> 
> threadlock or superglue. I suspect it won't be needed though, it's not as if a pedestal fan applies much torque.
> 
> 
Yes, I'll just wait and see. No point in fixing it if it's not broken.

Sylvia.

[toc] | [prev] | [next] | [standalone]

#489388

On 27.12.17 12:29, Sylvia Else wrote:
> On 27/12/2017 8:59 PM, tabbypurr@gmail.com wrote:
>> On Wednesday, 27 December 2017 07:11:33 UTC, Sylvia Else  wrote:
>>> On 27/12/2017 3:02 PM, Sylvia Else wrote:
>>>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>>>>
>>>> I decided I was unwilling to be defeated, and a fair amount of
>>>> soldering, heatshrinking and hot gluing later, I got it to work.
>>>>
>>>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>>>>
>>>> Sylvia.
>>>
>>> One issue I haven't addressed is that the fan is held on by a left-hand
>>> threaded nut, because a right-hand threaded nut will tend to undo itself
>>> in this application. Since I've reverse the direction, I really need the
>>> nut to be right-hand threaded, but there's no way I can change the
>>> threadedness of the shaft.
>>>
>>> May need to use some more hot glue - we'll see.
>>>
>>> Sylvia.
>>
>> threadlock or superglue. I suspect it won't be needed though, it's not 
>> as if a pedestal fan applies much torque.
>>
>>
> Yes, I'll just wait and see. No point in fixing it if it's not broken.
> 
> Sylvia.


You might have old sticky nail polish around. Some drops in
the thread at the joint of screw and nut will do.

-- 

-TV

[toc] | [prev] | [next] | [standalone]

#489397

On Wed, 27 Dec 2017 18:11:23 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:

>On 27/12/2017 3:02 PM, Sylvia Else wrote:
>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>> 
>> I decided I was unwilling to be defeated, and a fair amount of 
>> soldering, heatshrinking and hot gluing later, I got it to work.
>> 
>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>> 
>> Sylvia.
>
>One issue I haven't addressed is that the fan is held on by a left-hand 
>threaded nut, because a right-hand threaded nut will tend to undo itself 
>in this application. Since I've reverse the direction, I really need the 
>nut to be right-hand threaded, but there's no way I can change the 
>threadedness of the shaft.
>
>May need to use some more hot glue - we'll see.

Loc-Tite.  If you never want to restore the fan, Epoxe.

[toc] | [prev] | [next] | [standalone]

#489411

On Wed, 27 Dec 2017 18:11:23 +1100, Sylvia Else
<sylvia@not.at.this.address> wrote:

>On 27/12/2017 3:02 PM, Sylvia Else wrote:
>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>> 
>> I decided I was unwilling to be defeated, and a fair amount of 
>> soldering, heatshrinking and hot gluing later, I got it to work.
>> 
>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>> 
>> Sylvia.
>
>One issue I haven't addressed is that the fan is held on by a left-hand 
>threaded nut, because a right-hand threaded nut will tend to undo itself 
>in this application. Since I've reverse the direction, I really need the 
>nut to be right-hand threaded, but there's no way I can change the 
>threadedness of the shaft.
>
>May need to use some more hot glue - we'll see.
>
>Sylvia.

I used nine of the big glue sticks yesterday to fix a really dumb
bathroom light fixture. Hot-melt is interesting; it seems more like an
epoxy reaction than just melting stuff. If it just melted, you
couldn't get anything positioned before it cooled.

I suppose I could look that up.


-- 

John Larkin   Highland Technology, Inc   trk

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

[toc] | [prev] | [next] | [standalone]

#489412

On Wednesday, 27 December 2017 19:26:02 UTC, John Larkin  wrote:
> On Wed, 27 Dec 2017 18:11:23 +1100, Sylvia Else
> <sylvia@not.at.this.address> wrote:
> >On 27/12/2017 3:02 PM, Sylvia Else wrote:
> >> On 26/12/2017 5:54 PM, Sylvia Else wrote:
> >> 
> >> I decided I was unwilling to be defeated, and a fair amount of 
> >> soldering, heatshrinking and hot gluing later, I got it to work.
> >> 
> >> https://www.youtube.com/watch?v=GWB9I33k-Rs
> >> 
> >> Sylvia.
> >
> >One issue I haven't addressed is that the fan is held on by a left-hand 
> >threaded nut, because a right-hand threaded nut will tend to undo itself 
> >in this application. Since I've reverse the direction, I really need the 
> >nut to be right-hand threaded, but there's no way I can change the 
> >threadedness of the shaft.
> >
> >May need to use some more hot glue - we'll see.
> >
> >Sylvia.
> 
> I used nine of the big glue sticks yesterday to fix a really dumb
> bathroom light fixture. Hot-melt is interesting; it seems more like an
> epoxy reaction than just melting stuff. If it just melted, you
> couldn't get anything positioned before it cooled.
> 
> I suppose I could look that up.

Phase change requires a bunch of energy input/output. One common hotmelt glue is PVA.


NT

[toc] | [prev] | [next] | [standalone]

#489443

On 2017-12-27, John Larkin <jjlarkin@highlandtechnology.com> wrote:
>>
>>One issue I haven't addressed is that the fan is held on by a left-hand 
>>threaded nut, because a right-hand threaded nut will tend to undo itself 
>>in this application. Since I've reverse the direction, I really need the 
>>nut to be right-hand threaded, but there's no way I can change the 
>>threadedness of the shaft.
>>
>>May need to use some more hot glue - we'll see.
>>
>>Sylvia.
>
> I used nine of the big glue sticks yesterday to fix a really dumb
> bathroom light fixture. Hot-melt is interesting; it seems more like an
> epoxy reaction than just melting stuff. If it just melted, you
> couldn't get anything positioned before it cooled.

heat-activiated thermoset formulations seem like a good idea, but
wouldn't that clog the gun?

-- 
This email has not been checked by half-arsed antivirus software 

[toc] | [prev] | [next] | [standalone]

#489405

On 12/26/2017 10:02 PM, Sylvia Else wrote:
> On 26/12/2017 5:54 PM, Sylvia Else wrote:
> 
> I decided I was unwilling to be defeated, and a fair amount of 
> soldering, heatshrinking and hot gluing later, I got it to work.
> 
> https://www.youtube.com/watch?v=GWB9I33k-Rs
> 
> Sylvia.

  Is this just to confuse one of your coworkers?
                         Mikek

[toc] | [prev] | [next] | [standalone]

#489434

amdx wrote:
> On 12/26/2017 10:02 PM, Sylvia Else wrote:
>> On 26/12/2017 5:54 PM, Sylvia Else wrote:
>>
>> I decided I was unwilling to be defeated, and a fair amount of 
>> soldering, heatshrinking and hot gluing later, I got it to work.
>>
>> https://www.youtube.com/watch?v=GWB9I33k-Rs
>>
>> Sylvia.
> 
>   Is this just to confuse one of your coworkers?
>                          Mikek


I made this clock for that.
https://imgur.com/a/gwPXM

[toc] | [prev] | [next] | [standalone]

Page 3 of 4 — ← Prev page 1 2 [3] 4  Next page →

Back to top | Article view | sci.electronics.design

csiph-web