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Author Topic: Washer-Nut-Prop or can I do Washer-Prop-Nut?  (Read 12946 times)

DickyD

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #25 on: January 10, 2012, 11:58:01 pm »

You obviously have no imagination Colin.  {-) {-)
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Patternmaker

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #26 on: January 11, 2012, 08:25:29 am »

Hummmmmmm that indicates a lack of for-thought on behaif of the designer and modeller if you have to go to so much truble to remove all the rudder linkages to get the rudder off   %) %) {-) {-) {-)




Bluebird perhaps you could enlighten me how you would have fitted the rudder and its related components and still keep the models authenticity.


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HS93 (RIP)

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #27 on: January 11, 2012, 08:56:34 am »

I want to know how you change prop will you have to change shaft as well or do all your props have the hole in exactly the same place,

Peter
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John W E

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #28 on: January 11, 2012, 11:46:34 am »

Hi all

 

First of all I wish some people would read and understand the question and replies given properly before jumping in with both feet!!! I did say in my original reply to AlisterL that this is one method of doing the job and it will be more than likely a permanentfix .. not that it was the only way nor that it was the right way.

 

The next thing we should all remember is - that not all modellers have the same knowledge or a well equipped workshop with all the tools such as a surface plate and grinding compound as some of us ... May I suggest the next time you answer aquestion on a ‘How do I do this subject’  try and imagine yourself on a desert island with only the basic tools such as a file, hand drill and a pair of pliers to do the job with - then see what reply you come up with REMEMBER some of us on this forum may not know what tools or knowledge the person asking the question has at his disposal!

 

My replies to  Patternmaker were meant to be a tongue in cheek and not taken to heart!

 

He has asked me how I would have gone about making a removable rudder.  I have put a couple of scribbles / ideas on :


 

First one is the top half of the rudder post is permanently fixed to the hull  with its related components and the bottom half blade is removable

 

The second idea is to use say a10 or 12 BA bolt through the tiller stock which locates into a tube which in turn is fixed to the servo linkage.

 

Aye

John

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Patternmaker

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #29 on: January 11, 2012, 02:08:15 pm »

My replies to  Patternmaker were meant to be a tongue in cheek and not taken to heart!
He has asked me how I would have gone about making a removable rudder.  I have put a couple of scribbles / ideas on :
First one is the top half of the rudder post is permanently fixed to the hull  with its related components and the bottom half blade is removable
The second idea is to use say a10 or 12 BA bolt through the tiller stock which locates into a tube which in turn is fixed to the servo linkage.


Yes your ideas would work, as I can remove my propeller easily without disturbing the shaft or rudder with the tried and tested way a locknut, there is no need for the extra work on the rudder, your second idea which I considered when building would have meant a larger slot in the transom. I certainly would not use a 10 or 12BA screw to take the thrust of a 12 sq in Rudder blade with a high torque servo, 5BA minimum, the head would have shown on rudder, from the onset I have tried to keep this model as original as possible to the 25ft boat.

All I said was I am not keen on the idea of a pin which has how been changed to a taper pin.

If its tongue in cheek not to be taken to heart why say it.
Its not what you say it's the way you say it.

I like others I feel sorry for Alister who asked for advice on this subject to be caught up in all this sniping, end of
as far as I am concerned.

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Shipmate60

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #30 on: January 11, 2012, 08:47:22 pm »

Off topic posts removed, please play nicely!!

Bob
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CF-FZG

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #31 on: January 11, 2012, 10:36:51 pm »

Mark Mark Mark,

Are you trying to confuse us?.
Not wanting to get into a slanging match but,
Reread post 3 as you suggest and did not come to the same conclusions you did.
As a layman, may I suggest to all, KISS is always appropriate in any commentary, my understanding of what the enumerated points in post 3 are referring to is "Tension" namely stretching between the two points which will then try to regain their original positons by eliminating that tension by compressing back to normal. I don't read that as meaning the forces applied being torsional/rotational.
However to be fair, there is a comment much later, of "tension/torsion".
This as far as I see it doesn't alter the tension, stretching applied to the nut and propeller connection referred to by all.
So in KISS terms why is post three and similar statements wrong and to be ignored?????

Not trying to confuse anyone, (unfortunately it tends to come unasked for {:-{ )
I'm not interested in a slanging match, but I will try and explain my to reasoning.

My main argument against Derek's postings is with his incorrect use of terminology, confusing the different forces involved in the 'locking nut technique' to the extent he picks one 'out of the hat'.

Now the following may appear as picky/pedantic/whatever - but it can confuse those who don't fully understand the terminology and then start repeating the mistakes 'as gospel' to others >>:-(

While the forces "compression" and "tension" are not mutually exclusive, to describe the nut and prop, (I'm using the same 'components' as the thread), as being in tension is wrong.  The nut and prop are in compression, so the shaft between the two parts must in tension.
The only 'torsional force' involved is, (basically), how hard you turn the nut against the prop to obtain the 'locking' effect.

Now take post #8 - I'll reply 'inline' in red as it's easier that trying to quote/reply every point

Quote
mmmmmm... this is an interesting subject

1. the anti rotational torque [acting] on the propeller blade surface is the resultant of the applied input power - this applies equally to FWD or ASTERN rotation Very confusing >>:-( torque can't apply to a blade surface - it applies to the prop-boss to shaft interface, but does apply to either rotation
2. these are complex calculations.......
3. if the resultant applied power [torque] exceeds the induced mechanical tension [torque] applied between the two components .....then yes something else will fail in the drive line Just a very confusing statement due to incorrect use of power/torque/tension.
4. however this does not include the loss of induced tension/torque between the propeller & the lock nut Again, incorrect use of the same terms - it's loss of 'compression' between the prop and nut
5. if you have experienced...  'the odd prop come off (usually only in the middle of the pond though)' ...please re-read & consider the points offered Easy to read and consider - not so easy to understand!

Please don't mistake me saying that Derek doesn't know what he's talking about - from 'reading between the lines' he knows exactly what he wants to say, but just tries too hard to use big and technical words and finally makes a right pig's ear out of it.


Mark.
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HS93 (RIP)

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #32 on: January 11, 2012, 10:56:14 pm »

If you stand on your head Derek's posts make perfect sense  {-)

keep it up, or is it down under, Derek.  %%

Peter

PS Now this IS supposed to be a joke post in case anybody takes offence.
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Colin Bishop

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #33 on: January 11, 2012, 11:07:49 pm »

Well, this topic certainly demonstrates just how many nuts there are on Mayhem.

Never have I seen something so simple made so complicated.

Colin
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Peter Fitness

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #34 on: January 11, 2012, 11:41:24 pm »

When I fitted the prop to my first ever boat, using the thrust washer and lock nut principle, I had absolutely no idea of the physics involved. I just put it all together and tightened it up, and to this day, I have never had a problem. If I'd known the possible technical complications I may never have attempted it without first doing an engineering degree.

Having read some of the preceding posts with great interest, I now have a much better grasp of the underlying principles of the seemingly basic job of fitting a washer and lock nut. However, I can't help but wonder if my early successful effort was just sheer blind luck, or, as Colin suggests, it really is a very simple exercise after all. %)

Peter.
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derekwarner

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #35 on: January 11, 2012, 11:43:00 pm »

Folks.......I must admit the following quotation from CF-FZG whilst a little simplified ...does seem to cover the answer to original question :P .......

"While the forces "compression" and "tension" are not mutually exclusive, to describe the nut and prop, (I'm using the same 'components' as the thread), as being in tension is wrong.  The nut and prop are in compression, so the shaft between the two parts must in tension.
The only 'torsional force' involved is, (basically), how hard you turn the nut against the prop to obtain the 'locking' effect".


One point that we have not considered yet is the material selection between the three elements ..... :o & hence the relative material yield points...will a shaft fail by shear at the root diameter of the thread form or the nut thread start to strip as the compressive load applied to the shorter length as opposed the the longer threaded propeller hub?

I would be more than happy  %% to make a few brief assumptions if the majority of members are interested  >>:-( please don't hesitate to respond  :kiss:

I also appreciate the concern displayed by HS93 in the difficuility of reading & understanding all of this cods wollop whilst standing on your head in OZ ...... {-) .....Derek

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HS93 (RIP)

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #36 on: January 12, 2012, 04:45:53 am »

Off topic posts removed, please play nicely!!

Bob


shipmate60, can I ask why MY post was removed I dont think it was of topic it was how we do it on a powerfull electric boat where we change props four or five times a day .?

Peter
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DickyD

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #37 on: January 12, 2012, 05:24:32 am »

shipmate60, can I ask why MY post was removed I dont think it was of topic it was how we do it on a powerfull electric boat where we change props four or five times a day .?

Peter
Its called censorship, nice to see it doesn't just happen to me.

Send the PM Bob.
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derekwarner

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #38 on: January 12, 2012, 05:51:37 am »

I think I read it earlier in daylight hours in OZ HS93...... :o ....or before most of UK was awake  {-)

From memory it related to shear pins in model outboard drives and also in Z drives ...I found it interesting  O0 as I have ZERO experience in these drive formats.............thankyou.....Derek
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DickyD

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #39 on: January 12, 2012, 05:58:14 am »

Thankyou Derek I'm glad my comments were not wasted, they were also not off topic. >>:-( Still got removed though.
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HS93 (RIP)

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #40 on: January 12, 2012, 06:07:10 am »

Yep that was one Of Dickeys, mine was about a high powered boat that has a out runner that will run at 2700 watts Continuous plus a Continuous  90 amps murders batteries, and how we Just silver solder the nuts on.  some days testing we may have 5 prop changes and a few gear changes trying to get a bit more speed out of the boat , of and we haven't lost a prop through falling off.

Peter
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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #41 on: January 12, 2012, 07:42:44 am »

DickyD & HS93.....Gents...in OZ during my daily lunch break [30 minutes] I usually log on to both Mayhem & Paddleducks....... O0 to catch the latest postings from Europe ...  %% from the previous evening

Today I read briefly about ......

"and how we Just silver solder the nuts on.  some days testing we may have 5 prop changes and a few gear changes"....
.and
"shear pins in model outboard drives and also in Z drives"

This evening on return to home ....I find both communications deleted  <*< ...by a Mayhem Administrator  <:(

I may be 20,200 km from UK..........but do not remember reading any comment in the above two postings that warranted the RED pen of moderation...........Derek
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RaaArtyGunner

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #42 on: January 12, 2012, 07:44:06 am »

Guys,

That is interesting looks like mine was also removed but here is the strange bit, have a look at reply 31 where my post is quoted verbatim.
So it seems it is OK to use my post in reply 31 after the deletions but not stand alone?
Would appear mistakes have been made.
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Tug-Kenny RIP

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #43 on: January 12, 2012, 10:32:01 am »


Did we answer your questions AlisterL  ?

What a wealth of information for such a simple question.

I think this subject has been thrashed to the ultimate end, considering all we want to do is make a model boat.

Thank you all for contributing

The end



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pettyofficernick

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #44 on: January 12, 2012, 10:37:37 am »

Hear Hear! :-)) :-))
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John W E

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #45 on: January 12, 2012, 11:01:18 am »

and the next topic to be flogged to deeth is...............................do we really need a fuse?

only joking mind ya {-) {-) {-) {-) {-)
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CF-FZG

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #46 on: January 12, 2012, 07:09:09 pm »

Guys,

That is interesting looks like mine was also removed but here is the strange bit, have a look at reply 31 where my post is quoted verbatim.
So it seems it is OK to use my post in reply 31 after the deletions but not stand alone?
Would appear mistakes have been made.

What's really strange is that I quoted your post after the 'thread cleaned up' post, methinks there's some very strange censorship moderation going on here <*<


Mark.
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AlisterL

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #47 on: January 12, 2012, 08:31:32 pm »

Hi Kenny,

yes thank you I think the question is answered.

My thanks again, to all those who contributed potential solutions to the questions I posed - it is much appreciated.
I have not built many boats and those that I have have all been relatively simple, and this was something where I thought there was a good reason not to do it, but couldn't remember what it was (everything coming undone). However, as I expected, the experience of others on the forum shows that it is possible, by several means.

FWIW, I will be using loctite to make sure nothing comes off as I don't think I will be able to get the prop more than finger-tight, but I will be using the lock-nut too.

John (Bluebird) - thanks for the thought about the fuses, but I discounted them as not being useful in locking the prop on :) :) :)
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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #48 on: January 12, 2012, 09:23:33 pm »

Hi there Alistair
To make tightening props a little easier for yourself you can make yourself a small prop spanner quiet easily from a piece of flat steel bar – say 1/8” thick by say 1” wide x 3” long and at one end drill a hole slightly larger than the boss of your propeller.  Then, drill 3 equally spaced holes of roughly 1/8” diameter to take the dreaded steel 1/8” steel pins set into them.  This makes up a form of ‘claw’ spanner.   The pins locate over the blades of the prop and hold it securely thus enabling you to tighten the propeller and the lock nut fairly tight.   I have attached a scribble to show you what I mean.

Aye
John
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Tug-Kenny RIP

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Re: Washer-Nut-Prop or can I do Washer-Prop-Nut?
« Reply #49 on: January 12, 2012, 09:31:03 pm »


That's a good idea John.   :-)) 

ken

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