Model Boat Mayhem - Forum

Please login or register.

Login with username, password and session length.
Pages: 1 [2] 3   Go Down

Author Topic: Rudders and Bowden cables????  (Read 11056 times)

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #25 on: January 26, 2014, 07:43:24 PM »

given the length of the boat
seen that Bowden is blocked at each pair

this is just fine

Bowden would one meter and would not be blocked it would be different!
but who would do that?

Thanks Gazou ........... I think the single cable is now the way forward ......... It is well supported at each former, hardly anything in the way of a curve, and no movement in the outer.
Logged
Cheers
Peter

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,220
  • You bark - I will bite!!!
  • Location: Fareham
Re: Rudders and Bowden cables????
« Reply #26 on: January 26, 2014, 07:46:12 PM »

Dave,
My main concern isn't the use of a bowden cable but the length from the last bulkhead to the tiller arm as in the pic of the installation.
This looks long enough to allow the inner cable to flex when under tension.


Thanks Circlip under compression, Doh!!


Bob
Logged
Officially a GOG.

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,737
  • Location: North of Watford, South of Hadrians wall
Re: Rudders and Bowden cables????
« Reply #27 on: January 26, 2014, 07:58:21 PM »

What you have to remember Peter is that the "Norm" before snakes was a Balsa or spruce stick, with bits of bent wire spliced on each ends, a throwback from bang-bang escapements. and yes Bob +1 
Quote
This looks long enough to allow the inner cable to flex when under tension.
    Compression. 
 
  Regards   Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,909
  • Location: Wollongong Australia
Re: Rudders and Bowden cables????
« Reply #28 on: January 26, 2014, 08:24:55 PM »

From the alternate thread.....

Peter....just a thought........why not keep the Q&A to this build all in the one thread?...it will be simpler for you & will make more sense for others reading it in the future.........Derek
__________________________________________________________________________________________________________

Hullo Peter.........many kits are understandably made to a price  O0

However many builders see certain attributes that could be installed or modified to provide a more reliable or better design build

Bowden cables is such rudder applications may be an improvement.......however even running in a nylon cased tube.....if it is a true cable construction is subjected to PUSH-PULL forces which by consideration is not really conducive to long term life <*< [stranded wire is designed to be used in tension..........not in compression]

However two Bowden cables....one on either side of the balanced rudder attachment>>>>>>to the servo arm balanced attachment ...when adjusted is a balanced mechanical element  :-)) .....Derek   

 
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #29 on: January 26, 2014, 08:29:02 PM »

From the alternate thread.....

Peter....just a thought........why not keep the Q&A to this build all in the one thread?...it will be simpler for you & will make more sense for others reading it in the future.........Derek
__________________________________________________________________________________________________________

Hullo Peter.........many kits are understandably made to a price  O0

However many builders see certain attributes that could be installed or modified to provide a more reliable or better design build

Bowden cables is such rudder applications may be an improvement.......however even running in a nylon cased tube.....if it is a true cable construction is subjected to PUSH-PULL forces which by consideration is not really conducive to long term life <*< [stranded wire is designed to be used in tension..........not in compression]

However two Bowden cables....one on either side of the balanced rudder attachment>>>>>>to the servo arm balanced attachment ...when adjusted is a balanced mechanical element  :-)) .....Derek

Thanks Derek......... I'll make sure I keep it all in one place in future.  {:-{
Logged
Cheers
Peter

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #30 on: January 26, 2014, 08:33:44 PM »

What you have to remember Peter is that the "Norm" before snakes was a Balsa or spruce stick, with bits of bent wire spliced on each ends, a throwback from bang-bang escapements. and yes Bob +1      Compression. 
 
  Regards   Ian.

I've taken a couple of measurements on that .......... It's difficult to be precise as it's a "dry fit" ..... But I reckon, with the tiller arm at the mid point the inner cable is out of the outer about 30mm and at full extension about 50mm. I guess that'll be the same at the servo end as well. as both arms are the same length.
Logged
Cheers
Peter

Shipmate60

  • Global Moderator
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 5,220
  • You bark - I will bite!!!
  • Location: Fareham
Re: Rudders and Bowden cables????
« Reply #31 on: January 26, 2014, 10:19:17 PM »

Peter,
On your measurements that only leaves about 10mm free.
That is not enough to fit the connector to the cable and tiller arm.
Assuming the connector is 20mm long that will leave at least 30mm, at present dimensions, exposed.
This should be fine initially but will be subject to bending on compression so might need changing in the future.
It is of course your choice just pointing out any possible problems.


Bob
Logged
Officially a GOG.

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,909
  • Location: Wollongong Australia
Re: Rudders and Bowden cables????
« Reply #32 on: January 26, 2014, 11:00:08 PM »

Peter....... to your comment..... "I figured we are looking at a low speed tug here and not a high performance race boat"

The following is rather simplistic O0............but clearly confirms an understanding of actual comparative rudder loadings between two differing vessels you mention ok2

NB..... I have used imperial dimensions in the description .....them metricated by approximation  %%

Example 1 
4 inch square tug boat rudder = 100 x 100 mm, speed 5 km, mass 30 kg

100x100x5
         30 = 1666 units of load on the rudder surface

Example 2
1 inch square speed boat rudder = 25mm x 25mm, speed 20 km, mass 7 kg

25x25x20
        7   = 1785 units of load on the rudder surface

As you can see...... first thoughts can sometimes be a little  :embarrassed:.......Derek
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #33 on: January 26, 2014, 11:06:40 PM »

........and there I was, thinking this cable thing was a really clever idea  {:-{
Logged
Cheers
Peter

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,909
  • Location: Wollongong Australia
Re: Rudders and Bowden cables????
« Reply #34 on: January 26, 2014, 11:31:39 PM »

Don't despair Peter  ;)......I still think adequately considered Bowden type cables for rudder control are an excellent choice  :-)).......

Digressing a little........over the past months...I have been trying to understand how I can use a 1:20 scale link chain for rudder control & have just taken delivery from the USA....two 1.0 mm diameter wire size Grade 316L stainless steel fusion welded 9 hoops per inch chains O0 for my intended rudder steerage....however it by necessity will be Pull>Pull.........

By the same guestimation method as below....... %) I concluded some 1200 units of loading on my intended rudder

So hence the need for actual fusion welded chain construction.......Derek
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #35 on: January 26, 2014, 11:40:09 PM »

Don't despair Peter  ;) ......I still think adequately considered Bowden type cables for rudder control are an excellent choice  :-)) .......

Digressing a little........over the past months...I have been trying to understand how I can use a 1:20 scale link chain for rudder control & have just taken delivery from the USA....two 1.0 mm diameter wire size Grade 316L stainless steel fusion welded 9 hoops per inch chains O0 for my intended rudder steerage....however it by necessity will be Pull>Pull.........Derek
Derek....there is a fella in France building the same boat as I am. He is using a chain setup for rudder control. Really quite clever. Tomorrow I will pot the link to his build thread.
Logged
Cheers
Peter

NFMike

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,062
  • Location: Hythe, Hants, UK
    • Plague Marine Services
Re: Rudders and Bowden cables????
« Reply #36 on: January 27, 2014, 12:39:55 AM »

From the Bowden cable article in Wikipedia:
The linear movement of the inner cable is most often used to transmit a pulling force, although push/pull cables have gained popularity in recent years e.g. as gear shift cables. Many light aircraft use a push/pull bowden cable for the throttle control, and here it is normal for the inner element to be solid wire, rather than a multi-strand cable.

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,909
  • Location: Wollongong Australia
Re: Rudders and Bowden cables????
« Reply #37 on: January 27, 2014, 01:22:49 AM »

You have been very selective in the text you offer here Plague  :o.........

Certain Bowden cables also have a contra wound inner cable core to the outside wound casing O0 which naturally offers greater anti buckle characteristics over conventionally same handed wound inner core & outer casing......

Perhaps another member may offer a more accurate calculation method  :-)) for the rudder loading than my simplistic comparison  {-)..... Derek
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #38 on: January 27, 2014, 12:41:36 PM »

Peter,
On your measurements that only leaves about 10mm free.
That is not enough to fit the connector to the cable and tiller arm.
Assuming the connector is 20mm long that will leave at least 30mm, at present dimensions, exposed.
This should be fine initially but will be subject to bending on compression so might need changing in the future.
It is of course your choice just pointing out any possible problems.


Bob

Thanks Bob...... It is much appreciated ........... How about I use something like this...... and connect the end of the wire direct to the tiller....???... Bearing in mind that I am now sold on the idea of a second cable for a closed loop.
Logged
Cheers
Peter

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,737
  • Location: North of Watford, South of Hadrians wall
Re: Rudders and Bowden cables????
« Reply #39 on: January 27, 2014, 12:47:53 PM »

And just to add, Goggle "Morse Controls"  O0
 
  Existing outer will be in wrong place if you're going for double lines Peter.
 
  Regards   Ian.
 
  (bet yer keep yer gob shut next time  {-)   )
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

boatmadman

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 2,721
  • Location: South Cumbria
Re: Rudders and Bowden cables????
« Reply #40 on: January 27, 2014, 12:57:35 PM »

This is all getting far too in depth for the original question, to which the answer is... yes a single cable will be fine provided the sheath is properly supported, which it is.


I have use single set ups like this in a few boats, fast, slow, little & large all with no problems.
Logged
if at first you dont succeed.....have a beer.....

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #41 on: January 27, 2014, 01:01:58 PM »

And just to add, Goggle "Morse Controls"  O0
 
  Existing outer will be in wrong place if you're going for double lines Peter.
 
  Regards   Ian.
 
  (bet yer keep yer gob shut next time  {-)   )

Existing outer will be in wrong place ??? How so. I was going to run it from below the exisitng outer onto a double servo horn.........and across and up to the port side stern ???? ......... Now you are going to tell me "both cables have to be the same length ........ {-)
 
Logged
Cheers
Peter

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #42 on: January 27, 2014, 01:05:21 PM »

This is all getting far too in depth for the original question, to which the answer is... yes a single cable will be fine provided the sheath is properly supported, which it is.


I have use single set ups like this in a few boats, fast, slow, little & large all with no problems.

Thanks........ The voice of reason at last  O0 O0 O0 ........ I knew I was right all along. :-))
Logged
Cheers
Peter

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,737
  • Location: North of Watford, South of Hadrians wall
Re: Rudders and Bowden cables????
« Reply #43 on: January 27, 2014, 01:19:49 PM »

Naaa, a few of us have already said you'll probably be OK with your existing set up. We just like to offer alternatives for others to think about. Sadly for future use, many seem not to be able to locate or understand the word "Search"  O0   >>:-(
 
  Regards   Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #44 on: January 27, 2014, 01:27:02 PM »

Naaa, a few of us have already said you'll probably be OK with your existing set up. We just like to offer alternatives for others to think about. Sadly for future use, many seem not to be able to locate or understand the word "Search"  O0   >>:-(
 
  Regards   Ian.

Ian ......... Your and everyones input to my question is greatly appreciated......... I'm learning a great deal here as I go along.  :-)
Logged
Cheers
Peter

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 3,737
  • Location: North of Watford, South of Hadrians wall
Re: Rudders and Bowden cables????
« Reply #45 on: January 27, 2014, 03:58:45 PM »

Just had a look at the KG V  battleship, even HE's used closed loop on the rudder. {-)
 
   Regards  Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #46 on: January 28, 2014, 09:34:47 PM »

I have bitten the proverbial bullet and run a second cable for the rudder. So we now have the "Holy Grail" of rudder systems in the form of a closed loop ........ Second cable takes a bit of a detour around the formers in a curve. But I've tried the inner cable in it and it runs freely. It's all clamped up at the moment waiting on the expoxy to dry ............ I'll post up some photos tomorrow.
Logged
Cheers
Peter

NFMike

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 1,062
  • Location: Hythe, Hants, UK
    • Plague Marine Services
Re: Rudders and Bowden cables????
« Reply #47 on: January 29, 2014, 12:13:33 AM »

Probably too late (the epoxy is done) but you need to make sure both sides have exactly equal geometry or it may bind.
That means that the position of the rudder in every position of the servo is the same on each side.

derekwarner

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,909
  • Location: Wollongong Australia
Re: Rudders and Bowden cables????
« Reply #48 on: January 29, 2014, 01:22:23 AM »

Probably not too late to cut/grind the epoxied cable out Peter...........I do agree with Plague that the cable geometry should be identical or just mirror reversed  O0.....Derek
Logged
Derek Warner

Honorary Secretary [Retired]
Illawarra Live Steamers Co-op
Australia
www.ils.org.au

peter61_uk

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 208
  • Permanently Bewildered
  • Location: Farnborough, UK
Re: Rudders and Bowden cables????
« Reply #49 on: January 29, 2014, 09:56:41 AM »

 {-) {-) {-) {-)  You guys have absolutely no idea how much I laughed when I read this "geometry" thing.......... and I so wish I'd never posted this thing about "Rudders and Bowden Cables" in the first place  {-) {-) {-) {-) .
 
Still ......... Given the fact that it all started with me mounting the bl**dy servo on it's side (and there weren't much in the way of choices) ........ and again there aren't much in the way of choices where to have run the second cable (I did measure it before I fitted it and it's 50mm longer than the first one .........
 
So we are where we are as they say....... I can leave it in place and once the top deck is on then it wont be visible...... Give the twin cable system a try and if it does "bind" then I'll just take the second inner cable out, and run it with "one" which is what I'd planned (right or wrong) in the first place.
 
 
 
 
Logged
Cheers
Peter
Pages: 1 [2] 3   Go Up