Model Boat Mayhem
Mess Deck: General Section => Tugs and Towing => Topic started by: toesupwa on January 22, 2010, 09:36:10 pm
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This is the latest addition to the Toesup fleet.. A modern harbour tug.. 24" x 11"
I have made up my own plug / mold / hull from a few sketches over the last 18 months or so..
I've also produced my own 'Z' drives... O0
The tug has a working winch and will have working keel coolers, cooling the motors and ESC's
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Thats a good looking boat Toes, have you any pics from the start of the build, nice one
Bosun
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Yeah... just a few.. O0
The plug..
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Still the plug...
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.. still the plug...
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Plug and mold..
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Plug, mold and hull..
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The build...
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.. still the build..
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any chance of seeing how you built the Z drives :-))
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The original sketch..
The keel coolers...
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any chance of seeing how you built the Z drives :-))
Of course...
The Z drives...
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thanks it has given some thought to something
in the future :-))
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An absolute work of art Toes and a great build thread. Lovely engineering throughout and a very unusual and interesting subject.
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Great job on it Toes! I just love the Z-drives.
George
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Very interesting model, built in the style of a tractor tug but is actually an ASD! I think that you will have a very interesting time when you tow over aft with her as the towing point is actually aft of the pivot point of the units..........will be very interesting to see the outcome! A good looking model none the less.
TugChief.
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I think that you will have a very interesting time when you tow over aft with her as the towing point is actually aft of the pivot point of the units..........will be very interesting to see the outcome!
The winch unit is about 2" (50mm) in front of the Z drive units... and the 'staple' is only just behind the CL of the drive units..
"will be very interesting to see the outcome"... can you elaborate please?... {:-{
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Looks very impressive, can't say much more! Keep us posted on progress, Dave :-))
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Hi Toesupwa,
The pivot point must be counted as the last point the the tow rope is in contact with the tugs structure and as you correctly point our your towing point (Staple) is aft of the units. If you look at the configuration of any single, twin or ASD propelled tug you will find that the towing point is just aft of midships, mush further forward that on your vessel.
The easiest way to explain i feel is in terms of vessel rudders. These have developed over the years and there are three basic types which have been used over the past century or so;
Fully Balanced. This is when the rudder stock is almost in the centre of the rudder blade allowing equal forces to act on the area ahead of the pivot point and equally on the area aft of the pivot point. The advantage of this is that you require a very small torque to turn the rudder, but the disadvantage is directional instability as the rudder will have a tendency to wander due to the equal forces being appled as it passes through the water. In tug terms this would be great for a harbour tug with her towing point midships as she would be very maneuverable and would be able to pivot on her tow line with minimum rudder appled. This direction instability always gives the danger or turning the tug over (where the tow rope comes across the beam at right angles almost midships at the towing point) and this is why a gog or gob rope is sometimes used to transfer the towing point further aft.
Semi Balanced. This is where the rudder stock is approximately 1/3 back from the leading edge of the rudder blade. This increases the turning torque required but gives much better direction stability. This is the type of rudder used in all merchant vessels with a conventional propulsion package built today. In tug terms this is what most single/twin/ASD tugs have. This gives good maneuverability for use in harbours but still excellent direction stability for towing at sea (i.e. in a straight line).
Non Balanced. This is where the rudder stock is located right on the leading edge of the rudder, whilst giving the best directional stability it gives the worst turning performance and requires the most torque to turn the rudder blade. This is the category that your tug falls into. When you are towing over aft your tug will not pivot around the towing point at all. The entire tug will have to force the complete length of her hull through the water to change direction which will lead to using all engine power to position your tug and not the tow, this will lead to total loss of control of the tow.
You have made such a nice job of her top sides and she looks like she will be a cracking model, i would just suggest that you think about the option of placing the towing winch on the bow and towing through the lead on the bow as most ASD tugs to to avoid disappointment with the performance of your finished model.
Cheers.
Tugchief.
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The pivot point must be counted as the last point the the tow rope is in contact with the tugs structure and as you correctly point our your towing point (Staple) is aft of the units. If you look at the configuration of any single, twin or ASD propelled tug you will find that the towing point is just aft of midships, mush further forward that on your vessel.
You have made such a nice job of her top sides and she looks like she will be a cracking model, i would just suggest that you think about the option of placing the towing winch on the bow and towing through the lead on the bow as most ASD tugs to to avoid disappointment with the performance of your finished model.
Thanks Tugchief...
That goes some way to explaining what to expect with a tow... though with the two Z drives under the stern, I'm still tempted to try it 'as is' and see what effect it has.. I can always cut off the rear staple at a later stage and tow direct from the winch and 'H' frame...
I cant move the winch to the bow, there is not enough room either within the depth of the hull or across the width of the hull to fit it in... {:-{
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Great tug, that is one brilliant job you are doing Toesupwa.
One IMPRESSED John b
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Fantastic work so far! i am in the throws of making a plug up for my next project only wish it turns out at 1 10th as good as yours and i will be over the moon.
i was thinking of adding the plate detail to the plug do you think it will work as i have yet to get my sticky hand all over a mold!
cant wait to see your model as you do further work.
are the Korts turned from ply wood laminated into a block? what angle did you set the top slide over to on the turning?
regards
Martin
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i was thinking of adding the plate detail to the plug do you think it will work as i have yet to get my sticky hand all over a mold!
cant wait to see your model as you do further work.
are the Korts turned from ply wood laminated into a block? what angle did you set the top slide over to on the turning?
You could try adding detail to your plug / mold / hull.. but if its your first attempt, I wouldnt advise it.. Get a decent hull out of the mold first and then do a second mold from the plug with detail when you have some experience..
Yes, the kort's are wrapped ply around a 'plug' i turned to the specific dia. of the props...
The full 'story' on making the kort's is here..
http://www.rcgroups.com/forums/showthread.php?t=1025555
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Thanks for the tips! your other posting the other web site is great. last time i made some i did is by casting resin in a yogurt pot then bored it out in the lathe thinking back it i put one pot in another i could have use less resin.
my cardboard plugs are ready for final sanding and then laying up the GRP mold
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I've made up the window frames with some railway line.. and the wheelhouse roof and lower superstructure handrails...
%)
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Nice neat looking work.
John
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Nice work there Toes!
I don't know why mine always look 'beaten' - as if someone dropped the wheelhouse when mounting it!
Do you build each section on a template - I could use a short course on building a window frame/wheelhouse.
Think I'll print these photos off.
Thanks for posting,
Mike
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Do you build each section on a template - I could use a short course on building a window frame/wheelhouse.
No Mike, no template...
Once the holes are cut in the wheelhouse, i fit each individual piece of frame to fit the 'hole'.. When all 4 sides are a good fit, then just solder each corner while they are in place in the ply.
Pull out the finished frame and clean up the join...
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I've produced a set of stairs / ladders and handrails..
While the weather has not been cooperative for painting.. raining and cold... I've been spending some time on the lathe making the cap's for the towing bollards and 'H' frames, also a pair of life raft canisters and the winch capstans.
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MHT (AKA 'The other WW') has changed color..
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The MHT has had a light rubbing down, another coat of primer, a light coat of sealer over the primer below the waterline... and some color above the waterline. I still have to do the paintwork inside the bulwarks and the deck yet.. and the black 'waterline'
The Bow Thruster has gone back in after painting...
.. and the keel coolers have been attached to the hull...
The next job is to re-install the drives so I can float test WW...
I guess the pic's give away what WW's 'livery' is to be.. ok2
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I noticed your bow thruster. I like the look of the blades close to the outside edge and wondered how they are driven.
Could you describe the connections and what motor system you have please.
ken
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Its the Raboesch 108 - 30 bow thruster, 33mm dia.. :-))
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Smashing. Thank you for that. I have found them at Model Dockyard.
Just the thing for my Severn, meethinks. :-))
ken
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Ken, just fitted one in the Tamar, pricey but good :-))
Russ
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I have researched it and found it runs on a 7.2 volt ?? motor. How odd that someone should design this voltage. I am looking into the possibility of fitting a 12 volt motor.
Could anyone see the connections please and advise if another motor could be fitted to the gear arrangement as I don't have a close up of the connections here. (before I ask the shop and look simple !)
This does look just the job to shift the Severn and I shall be getting one anyway but don't want the wrong motor in my spares box. ( can't get over such a stupid voltage)
Forgive me for stealing your thread, Toes. :embarrassed:
Cheers
Ken
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Its not such a stupid voltage Ken, 5 of my boats run on 7.2 Volts.
A product of the modern world I'm afraid. ok2
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Deans Marine also do them: http://www.deansmarine.co.uk/
http://www.modelboatmayhem.co.uk/forum/index.php?topic=19334.msg188888#msg188888 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=19334.msg188888#msg188888)
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Why not go for the marx ludder thruster without the motor , i have ordered one from them to replace the one in my tug .
You can fit whatever voltage motor you like then , i run mine with a 540 5 poll motor on 12v.
daz
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http://www.modelboatmayhem.co.uk/forum/index.php?topic=19334.msg188888#msg188888 (http://www.modelboatmayhem.co.uk/forum/index.php?topic=19334.msg188888#msg188888)
I had read this thread previously but had not digested it. It's a good read of the subject, and covers a lot of angles on 'Bow thrusters'.
Could all the above references to Bow thrusters be moved over to this thread as the subject deserves it's own columns, and we won't be disturbing 'Toes' thread.
This is certainly a great looking thruster. Thanks for the picture Martin.
ken
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Oops sorry Toes.
daz
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Just discovered this thread. Toes, you've built a great and very cute looking tug. Can't wait to see it finished and sailing.
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super work :D
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Just discovered this thread.
It's coming along... little by little..
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The electricians will arrive within the week for Pilot house outfitting...
:-)
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.. and I'm about ready to start on the insides of the wheelhouse Umi.. :-))
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Oh... and I've started to work out the electrical panel.. %%
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Hi toes........ ...I have been watching this thread since first presented....& it is :-)) ....but today I am stumped %%
"Oh... and I've started to work out the electrical panel.."
So what do I see?
a. a receiver in the middle
b. two ESC outboard?
c. one mixer in the near middle?
d. but what is that aluminium finned fan assisted water cooled box module with the 3/8"NPT brass plug on the perspex lid?........
I have seen that you have made provision for water cooling the twin engines...but did not realise such a thermal gradient requirement would occur ...... Derek :o :embarrassed:
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Hi toes........ ...I have been watching this thread since first presented....& it is :-)) ....but today I am stumped %%
d. but what is that aluminium finned fan assisted water cooled box module with the 3/8"NPT brass plug on the perspex lid?........
I have seen that you have made provision for water cooling the twin engines...but did not realise such a thermal gradient requirement would occur ...... Derek :o :embarrassed:
Look UNDER the boat in post #30... :o
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Looks interesting Tows!
Tough little tug there.
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So what do I see?
a. a receiver in the middle
b. two ESC outboard?
c. one mixer in the near middle?
d. but what is that aluminium finned fan assisted water cooled box module with the 3/8"NPT brass plug on the perspex lid?........
a/ Correct
b/ Correct
c/ No, it's another ESC... and the 4th is soon to be added..
d/ It's the header tank for the keel cooling system... ok2
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While I'm waiting for some other bits to arrive (I have the second pump) I've been making up some small detail pieces.. O0
The Captains chair.. I have a seated Captain, but he needs a re-paint
The rear staple lamp... and it works!
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Superbly thought out, designed, and put together :-)) :-)) :-))
Keep the pictures coming mate!!!
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I have received a 'goody package' from Umi.... Thanks Umi!..
The bumper strips have started to be added... but I'm thinking i need more...
The radar has been added and has started to be painted... and yes, it works!..
.. and I've started on the wheelhouse interior 'panels' and screens...
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Looking pretty sharp there!
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Toes
Looking good there, one question how did you make the light on the staple? It looks really effective. :-)) :-)) :-))
Brian
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one question how did you make the light on the staple? It looks really effective. :-)) :-)) :-))
It's one of Umi's floodlights cast in acrylic (I think?) painted white to reflect the light and then painted black as a case finish. The wiring is fed down in to the hull inside the staple...
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Seriously impressed with this! The attention to detail is fantastic. Please keep the pics coming!
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I've been doing some 'interior' wheelhouse work and have finished (except the screens) the control panels.... and yes, they do illuminate.. O0
and I have a Captain with a 'grotty' red cap...
... and I'm still working on the .. ahem... wiring / rat's nest / electrical panel i have created... :o
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Looking good! :-))
What's that little water tank for?
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I think it is mentioned in reply#50.
Thats a great piece of workmanship, hopefully oneday I will get to those levels.
Jim.
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... oh yes! :embarrassed:
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Looking good! :-))
What's that little water tank for?
WW lives!....
It's been back in to the DTF for a motor / steering test run.
It seems to have plenty of power.. there may be a need for more steering, though it does seem to turn readily enough.
.. and i also now have a working keel cooling system... (that's what the little water tank is for Martin O0 )
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Today has been LED's... lots of them!..
4 Deck floods, 8 deck lights, 2 in the wheelhouse under the control panels... and I'm halfway up the mast...
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Superb build, Toes.
I had never heard of "keel coolers" before and wondered why the keel needed cooling, duh! How efficient is that system?
Looking foward to seeing her perform.
Roger in France
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:-))....without a pun...Toes....but brilliant illumination O0 in the bridge house ....regards Derek
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That is brilliant toes, that is the best wheel house i have seen O0 O0 O0.
regards John B
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That is brilliant toes, that is the best wheel house i have seen O0 O0 O0.
regards John B
DITTO....THAT'S ONE UBBER WHEELHOUSE!!!!
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I had never heard of "keel coolers" before and wondered why the keel needed cooling, duh! How efficient is that system?
I've had two bowls of water, one hot from the tap (too hot to put your hand in) and the other one with ice in it. Putting a keel cooler in the one with the ice and pumping water through the system on 6v , it took 8 minutes to get the water in the hot bowl to the same temperature as the one with the ice in it.
The experiment proves it works... but I'll have to see in practice how efficient it is at cooling the on board equipment when i have a heavy barge attached to the tug.
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I also now have mast lights and the wheelhouse deck lights...
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Way cool. 8)
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Externally the MHT is finished... except for maybe a few bit's of 'deck dross'.
The electronics board needs finishing off and I'm going to pull the port drive as it seems tighter than the starboard drive.
Ladies and Gentlemen... The TBW gives you...
'William Wallace'
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10.5 / 10! :-))
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Def the canine gonads, your best yet Toes. Interior illumination :-))is just perfect
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Absolutely Superb Toes :-)) :-)) :-)) :-)) :-)) :-))
Brian
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Truly excellent Toes :-)) :-))
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Hi Toes
This has certainly been an interesting thread - learned a lot here - right from watching out for a piece of foam through how to build your own nozzles - amazing stuff, thanks for having the camera beside you.
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That's it, I'm off to do aeromodelling, what a brilliant piece of workmanship.
Retrotug
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Hello Toes,
Just looked through your build... truely amazing and awesome build, love the small details on the bridge and the lights. :-)) Was this the new build you told me about whilst at Pompey. I've got lots to look forward to on my build and lots to learn.
Cheers
CP
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That is brilliant very neet build O0 O0.
TOP marks for your tug :-))Cant wait to see her working
Best regards John B
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Wow. that is amazing :)
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Hi Toes you have some very cool skills this is just amazing... :-))