Model Boat Mayhem - Forum

Mess Deck: General Section => Tugs and Towing => Topic started by: steamboat66 on September 18, 2016, 04:24:49 PM

Title: TANK STEERING or MIXER?
Post by: steamboat66 on September 18, 2016, 04:24:49 PM
which is more popular? tank steering, or mixer? looking to build a "proper" tug after i've built my springer, and was wondering which way to go for twin screw control.
Title: Re: TANK STEERING or MIXER?
Post by: Martin [Admin] on September 18, 2016, 04:45:12 PM
 
Tank steering is cheapest option.

Rudder or Vtail mixer, next cheapest.

Boat (throttle/rudder) mixer,  most flexible.
Title: Re: TANK STEERING or MIXER?
Post by: dougal99 on September 18, 2016, 05:09:24 PM
Sorry Martin, but I think tank steering is the more flexible option. Takes a bit of practice to get to grips with it but once sorted wunderbar. Using a mixer you're dependent on the set up and that can be a little devil to configure.


Done both prefer tank. :-))
Title: Re: TANK STEERING or MIXER?
Post by: steamboat66 on September 18, 2016, 06:20:32 PM
i think what martin is referring to is the action electronics mixer/ESC, which gives the choice of mixed or tank at the throw of a (DIL) switch, and a quick swap of a servo lead.
Title: Re: TANK STEERING or MIXER?
Post by: kinmel on September 18, 2016, 07:23:45 PM
i think what martin is referring to is the action electronics mixer/ESC, which gives the choice of mixed or tank at the throw of a (DIL) switch, and a quick swap of a servo lead.

My Yorkshireman has the Action mixer, it is plug'n'play and anyone can just sail it with excellent control.

All my other twin motor models have tank steering and after practice I much prefer this method, I hardly use the rudder. 

Of course in the real world, twin screws invariably have tank steering.
Title: Re: TANK STEERING or MIXER?
Post by: Bob K on September 18, 2016, 07:26:21 PM
For me the versatile  Action P94 every time.  With 4 modes to choose from and adjustable rate it covers just about every eventuality.  I have five, in all my multi shaft models.

Example:  A long thin warship is not easy to steer under tank steering, but with a P94 it is a "one finger" straight line yet can turn on a sixpence.
Title: Re: TANK STEERING or MIXER?
Post by: ellisgarth on September 18, 2016, 09:26:09 PM
Go tank, less hassle steering
Title: Re: TANK STEERING or MIXER?
Post by: ballastanksian on September 18, 2016, 10:07:32 PM
I would definitly go tank steering on a model of a 'Popovka' or a Monitor.
Title: Re: TANK STEERING or MIXER?
Post by: NFMike on September 18, 2016, 10:12:28 PM
I'm now using tank steering for my tug with the rudder mixed in. I still have the rudder on a l/r stick but don't really need it.
If I had (e.g.) a warship I probably wouldn't use tank (is that ironic?).
Title: Re: TANK STEERING or MIXER?
Post by: Colin Bishop on September 18, 2016, 10:57:54 PM
I think it is a matter of preference but tank steering does need some practice to work smoothly. For my ongoing fishery cruiser project I have set up the R/C so that I can switch between tank steering for close quarters manouvering and grouping the ESCs together for general sailing by using the undercarriage switch on the TX.

Mixer solutions are also good but cheap and cheerful options using limit switches to cut out or even reverse the inboard props can work effectively too. I used this method on my Isle of Wight Ferry back in the 1980s. The model could turn in its own length.

Colin
Title: Re: TANK STEERING or MIXER?
Post by: meechingman on September 18, 2016, 11:59:05 PM
Having been brought up on the full sized version of my avatar, I was schooled in the art of using engines and rudder movements in harmony. Dad was a good teacher and I learnt this long before owning a model tug! So, not surprisingly I now do the same with both of my twin screw tugs. No mixers, just left and right throttles on ratchet sticks and rudder on the right. My larger tug also has a bow thruster on the left stick. Both tugs can turn on the spot with the same process as the real tug. One engine slow or half ahead, the other slow or half astern. Rudder halfway over in the direction of the spin, easing off in the last 25% of the manouevre, or putting the wheel (stick) amidships and bringing one of the engines to match the other depending of whether I want to end up going ahead, astern or stopped.


Takes a little practice but it's all very do-able, so I would say tank plus rudder. Mind you this is, of course, for conventional twin screw, twin rudder tugs. I'd be a bit lost on a Voith  or twin ASD tug. I know the principles but have never tried it. Perhaps best to try a model before the real thing this time!


That said, I like the idea of being able to swap modes at the flick of a switch, but I'm not sure I personally would benefit.
Title: Re: TANK STEERING or MIXER?
Post by: Captain Povey on September 19, 2016, 11:18:09 AM
Hi There, Well for me its tank steering on the tug, with practice it gives great control and boat can be made to pivot on its axis. Action mixer in Battleship with mixing gives realistic turning control with no real effort. :-)) Graham
Title: Re: TANK STEERING or MIXER?
Post by: Kipper on September 19, 2016, 02:43:14 PM
Tank steer for me, with rudder also on the right stick, the tug is so nimble with this set up, that I have decided not to fit a bow thruster for the time being, which has saved me £40, plus saved me having to buy a mixer.  O0
Title: Re: TANK STEERING or MIXER?
Post by: poll on September 19, 2016, 02:54:15 PM

    Yes tank steering for me.

    John
Title: Re: TANK STEERING or MIXER?
Post by: Bob K on September 19, 2016, 03:46:06 PM
It appears the consensus is that for short wide vessels such as tugs two-stick tank steering is preferred. No doubt for tight manoeuvring where extensive straight line cruising is less called for.

However, for long thin ships such as warships a good mixer system aids scale cruising whilst giving the ability to make tight turns when required.
Title: Re: TANK STEERING or MIXER?
Post by: morley bill 1 on September 19, 2016, 04:40:31 PM
Tank steering every time Bill
Title: Re: TANK STEERING or MIXER?
Post by: steamboat66 on September 19, 2016, 05:36:24 PM
whilst running it all through my head today, i suddenly realized that if one of the remote's gimbals were to be rotated 45 degrees, no mixer would be needed at all. one ESC on each axis, as any straight up/down, or left/right movement would actually run both motors. and set up the right way round, left or right would make the boat pirouette left or right. consensus on here is tank for tugs, so i'll go that way, but maybe with a switch to lock both throttles together should i feel like it.
Title: Re: TANK STEERING or MIXER?
Post by: steamboat66 on September 19, 2016, 10:56:38 PM
my brain is a bit fried now. just spent an hour or so ferreting about in my DX7s. it now has centre sprung throttle channel. so it's ready to go tank steer or "safe" left throttle on single screw.
Title: Re: TANK STEERING or MIXER?
Post by: John W E on September 21, 2016, 06:02:58 PM
Hi there
To truly evaluate the difference between tank steering and mixers we must really study the history or find out where mixers came from.   If we turn back the clocks to say, the early 70s, radio control gear was quite expensive – more than an average weekly wage in those days.   So, to get a multi-channel set they were extremely expensive costing £100s of pounds and Joe Bloggs just couldn’t afford this amount of money.   Along came 2 companies – Hunter Systems and ACTion – and going back I am unsure who came up with the mixer first – it may have been Hunters? But correct me if I am wrong.   Me half tea leaf will come in here maybe 
The idea was on a 2 channel radio set, one with rudder channel and the other was the throttle.  This was great for the average person with a single prop boat.  But, when you come to multi prop boats that is when the problems of a single channel became apparent.   The way round it was you could use a Y lead with 2 speed controllers – obviously one speed controller for each motor – but this did not give you independent control of each motor.  Some of us used to wire up micro switches around the tiller arm of the rudder – so that when you put the rudder hard over to say, port, it came into contact with the micro switch which was wired up to the port motor either switching the motor off – or, if you were really clever there was a resistance wired in so it cut the motor to half speed.  As you can imagine – all of this wiring took up space and was fairly complicated – until, as I say the mixer from ACTion/Hunter which combined your rudder with your throttle channels electronically in a little box. Giving some variable speed.  A lot easier to wire up than the micro switches.
Now, the design of these mixers stayed basically the same for a good few years, but as we move into the 90s Robbe brought out the Robbe F14 super twin stick handset – again this cost some money but also gave independent control of twin motors through a split joystick.
Now we move on to the age of the cheap transmitters which we are in now – where we can do built in mixing on our transmitters.  There are some down sides to this – if we take for instance the mixer a P94 from ACTion it gives you several options built into it – such as tank steering, percentage control of speed and so forth – but, this only takes 2 channels up from your transmitter – if you use a Y tail mixer – you have to use 3 channels on your handset – one for each speed controller and one for your rudder.  This is where the Ytail does its mixing and it’s the same problem if you do the mixing on the handset as well through programming – you use 3 channels so you lose out on one channel all the time. So that is the real main benefit of an on-board mixer. (The likes of either ACTion or Hunter).  Tank steering is where you still have to use 3 channels – the advantage of that is if you are sailing in a straight line, you can adjust each motor slightly to correct any variation off course. 
The best of them all though is what I was taught by a guy called Stan and he had an old tug called Growler and he could thrash us all on any scale sail course we put out on the lake and his words were the best thing to do is to learn how to sail your model – you don’t need any fancy gizmos, such as tank steering bow thrusters or mixers.
Just my thoughts 
John
Title: Re: TANK STEERING or MIXER?
Post by: derekwarner on September 21, 2016, 10:55:45 PM
As this thread is about vessel steering and without getting too far off track, we also need to understand the concept of emergency steering [conventionally] via the rudder

In real vessels [100,000 tonnes] usually one engine & one rudder.....the latter being hydraulically driven and usually with two individual pumps

In many cases, the port pump would be used for route A to B, then the stdb pump used on the return from B to A

However the Underwriters [bean counters of little faith] would not insure such a vessel as if an electrical failure occurred neither pump would be operational

Hence yes even on 100,000 ton vessels steering gear flat [compartment] are a series of large eyebolts secured to the port & stdb hull structure where a 10 tonne hand pulled chain block & tackle can be attached to the rudder yoke and the vessel steered manually

It's all about redundancy or reliability.....many  of todays MEGA liners have diesel driven gen sets driving electric motor powered pods

I am unsure what contingencies these modern day marvels of nautical excellence with drive pods and no rudder would do if each of their multiple engine/gen sets failed <*<

Derek 
Title: Re: TANK STEERING or MIXER?
Post by: Colin Bishop on September 21, 2016, 11:11:44 PM
They drift Derek, they drift......

Colin
Title: Re: TANK STEERING or MIXER?
Post by: derekwarner on September 22, 2016, 01:23:19 AM
Well yes Colin......however some 40 years ago we had the Australian National Line "MV Alnwick Castle" [with 138,000 tons of iron ore] enter the Port of Kembla & she lost her one steering pump [electric motor] that was running.....she drifted until tugs could hold back ...and without damage

This prompted  Lloyds [the underwriters] to revise protocols that any vessel under their books, must have both steering pumps running when entering or leaving port

Prior to this, no vessel under Lloyds insurance could leave port unless both steering pumps were operational as the vessel would have been deemed out of Classification and would hold no insurance

It would be interesting to know or understand what conditions or emergency steering protocols vessels such as QE2 or QM2 have??

Derek
Title: Re: TANK STEERING or MIXER?
Post by: D108 on September 22, 2016, 10:56:27 AM
whilst in the RN certain exercises involved having to hand pump the rudder hydraulics.
I use tank steering,I modified my TX to have twin sticks. I most of my boats are large warships so they don't turn on the spot too well. I just like the set up, both throttles are on ratchets too.


Paul
Title: Re: TANK STEERING or MIXER?
Post by: NFMike on September 22, 2016, 11:29:31 AM
They drift Derek, they drift......

Colin
Yes indeed. For one of these to lose all electrical power, ie failure of multiple generators, would be in the 'act of god' category.
And drifting isn't the end of the world. After all most modern airliners only have two engines and for them drifting is a very limited state.
The fact is that modern machinery and controls are many times more reliable than those of 40 years ago.
Title: Re: TANK STEERING or MIXER?
Post by: Colin Bishop on September 22, 2016, 02:40:30 PM
There have been a number of instances where giant cruise ships have lost all power due to a switchboard malfunction. Some of them for hours or even days. The QM2 has suffered the occasional shutdown itself, fortunately not while docking though.

Colin
Title: Re: TANK STEERING or MIXER?
Post by: T33cno on March 03, 2017, 10:26:49 PM
Mixer  :-)) . The amount of mixer/rudder effect can be very finely adjusted. Notice I drilled a hole in the C of Action so I can adjust without dismantling. This basically adjusts the point at which the inboard prop not only slows or stops but goes into reverse to increase the effect especially in slow manoeuvres.
I have steerable Korts 
(https://photos.smugmug.com/Afon/i-jDLhBPR/0/X3/IMG_0703-X3.jpg)
Title: Re: TANK STEERING or MIXER?
Post by: Stavros on March 03, 2017, 10:45:21 PM
Hope you took the allen key out of the uj before you tried it out O0 {-)




Dave
Title: Re: TANK STEERING or MIXER?
Post by: T33cno on March 03, 2017, 10:48:39 PM
Hope you took the allen key out of the uj before you tried it out O0 {-)




Dave
Not until I put the shaft back in Dave  {-)
Title: Re: TANK STEERING or MIXER?
Post by: T33cno on March 04, 2017, 09:15:58 PM
(https://photos.smugmug.com/Afon/i-BtZTtkj/0/X3/IMG_0720-X3.jpg)
Title: Re: TANK STEERING or MIXER?
Post by: justboatonic on March 04, 2017, 10:27:34 PM
Mixer everyday from me. You'll go in a straight line easier and better plus turns will be more co ordinated.

Some people can manage tank steering but it takes far more practice. Obviously mixers cost as well!
Title: Re: TANK STEERING or MIXER?
Post by: ballastanksian on March 04, 2017, 10:31:40 PM
I agree with using the different methods for different ship types. The Novgorod I am working on was historically tank steered because the rudder recieved little water flow from the bluff hull. Therefore I will tank steer it. Likewise the early monitors suffered very similar control issues because of their hastily designed hull forms and would probably steer better tank style.

Title: Re: TANK STEERING or MIXER?
Post by: T33cno on March 04, 2017, 10:33:28 PM
Mixer everyday from me. You'll go in a straight line easier and better plus turns will be more co ordinated.

Some people can manage tank steering but it takes far more practice. Obviously mixers cost as well!
£79  <:(
Title: Re: TANK STEERING or MIXER?
Post by: Paul2407 on March 11, 2017, 08:58:50 AM
I took T33cno advise and ordered myself a P94 Action it covers all options and for me being (old but new again to boats) I can change things later
I did look at 2 esc's and a separate mixer but these didn't give you the options and they worked out more expensive than the £79 for the action one

be a while until I know how it works yet though
Title: Re: TANK STEERING or MIXER?
Post by: Deadbattery on March 11, 2017, 12:14:34 PM
I did look at 2 esc's and a separate mixer but these didn't give you the options and they worked out more expensive than the £79 for the action one

I have one of those sitiing in a box, waiting to be used as well.
Title: Re: TANK STEERING or MIXER?
Post by: petermun on March 11, 2017, 01:21:31 PM
Have just downloaded Robosizer, so will give it a try to show the tank steering on my USS Powhatan rebuild, Pete