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[Plastic - RIP]

Hi - I'm building another Blue Devil and have a question - the space to connect to the rudders is very small and is a major source of leaks as the back end sits very low in the water and the decks are awash in tight turns.

Has anyone tried abandoning the rudders and doing differential steering using just throttles?

Did it work? Was the turning circle enormous?

Also, I fitted 2 brass rudders to my last one and they acted to counteract the normal leaning out in turns - mine leant into turns like a motorbike.

Will the ommision of rudders make it more likely to capsize?

I'm looking to seal the deck down in the bow & stern so there will be no access to change my mind later.

Cheers

[TailUK]

My limited experience with to so called "tank" steering is that's it's indistinct and tricky to use. Try reducing to a single rudder which'll give you a little more room and limit the movement to make the turns less violent.

[derekwarner]

Hey plastic....a Lindberg Blue Devil.....a very light and finely structured/designed vessel with little freeboard

1. the change to a brass [over plastic] pair of rudders will have [marginally] altered/lowered the vessels draft by the stern
2. this [lower centre of gravity - metre centric point of balance] in itself would appear to have created the difference in lean during a turn ...[like understeer and oversteer in a car..........I think the oversteer - leaning into the water curve would also assist with minimising the vessel turning circle]

3. the lowered stern could contribute to greater water entry via the rudder posts. I would be worth considering improving the water tightness of the rudder post  shafts.......
4. tank steering without using a proportional mixer can have very robotic results with very un seaman like steerage 
5. yes, removing the two brass rudders lifts that same metre centric point of balance to a higher level.....so it would also increase the instability or the balance of the hull....= 

Derek 

[Plastic - RIP]

Hey plastic....a Lindberg Blue Devil.....a very light and finely structured/designed vessel with little freeboard

1. the change to a brass [over plastic] pair of rudders will have [marginally] altered/lowered the vessels draft by the stern
2. this [lower centre of gravity - metre centric point of balance] in itself would appear to have created the difference in lean during a turn ...[like understeer and oversteer in a car..........I think the oversteer - leaning into the water curve would also assist with minimising the vessel turning circle]

3. the lowered stern could contribute to greater water entry via the rudder posts. I would be worth considering improving the water tightness of the rudder post  shafts.......
4. tank steering without using a proportional mixer can have very robotic results with very un seaman like steerage 
5. yes, removing the two brass rudders lifts that same metre centric point of balance to a higher level.....so it would also increase the instability or the balance of the hull....= 

Derek

Cheers for that.

I was thinking that the rudders, being way below the centres, were acting like aeroplane ailerons and causing a 'roll' effect - the 2 slightly oversized brass ones creating so much force that they overcame the tendancy of the opposite force (the mass of the superstructure wanting to lean outwards) in turns - or am I way off with my thinking?

[Stan]

Hi plastic I have the Deans Fletcher a much bigger model.My model is fitted with a single scale rudder and scale props 42mm in diameter during a full power turn it also heals over a lot but never had any water in my model. Can you glue down the deck and make parts of the superstructure removable to gain access to the internals.I had this kit many years ago but never converted to rc operation hope all goes well with your build.Have tried tank steering with out much success.


Stan

[Plastic - RIP]

Hi plastic I have the Deans Fletcher a much bigger model.My model is fitted with a single scale rudder and scale props 42mm in diameter during a full power turn it also heals over a lot but never had any water in my model. Can you glue down the deck and make parts of the superstructure removable to gain access to the internals.I had this kit many years ago but never converted to rc operation hope all goes well with your build.Have tried tank steering with out much success.


Stan

Hi Stan - The Blue Devil is notoriously top-heavy. The freeboard at the stern is only about 15mm so when at a decent speed, the props blow all the water out from under the stern so it drops into the hole left behind leaving the deck almost level with the water. When turning, the edges of the deck go under. If I seal that portion of the deck it means I cannot access the rudders.
I was thinking about using the mechanism that moves the turrets & radar but that requires all of the superstructure fixed in position - it's a bit of a no-win situation.
If I want the turrets to move, I might have to hide servos high up in the superstructure - which causes more intability problems.
I'm concerned that a long, narrow hull will be useless with tank steering - probably more suited to something short & fat.

My last one had 2 brass rudders and fixed turrets so was super-stable. pic shows stern during construction.

[Stan]

Hi plastic my deans model is fitted with just one rudder set in between the two props yes the turning circle is large but the full size vessel had a large turning circle.On my Deans model I tend to powerback during a turn this cuts down on the heal .Will send you some pics of the stern of my model.




Stan.

[RAAArtyGunner]

Stan,

Could you also please post them on the forum.

This is a popular model with at least a couple of build threads on here.

[Stan]

Will do.


Stan

[Stan]

HI Plastic my model is a lot bigger than the Blue Devil and it only uses  385 size motors driving 42mm props. Have look at the MFA  280 OR 140/1 motors both have similar spec. Have sent you a pm also.

Stan.

[Stan]

HI Derek pictures of the rear of the Deans Marine Fletcher. Scale props  42 mm diameter and scale rudder. This model is bigger the Blue Devil and it is powered using two 385 motors on 6 volts. Plastic if you could fit brass props and smaller motors I do not think performance would suffer. Look on the MFA web site full spec for smaller motors than 385 hope this helps. I have enclosed a picture of my Fletcher and its stable mate U S S Gambier Bay.

Stan.

[Martin (Admin)]

Also see:

http://www.modelboatmayhem.co.uk/forum/index.php/topic,39106.msg390817.html#msg390817

https://www.rcgroups.com/forums/showthread.php?1073283-Lindberg-Blue-Devil-conversion

http://www.modelboatmayhem.co.uk/forum/index.php/topic,37890.msg545005.html#msg545005

[RAAArtyGunner]

HI Derek pictures of the rear of the Deans Marine Fletcher. Scale props  42 mm diameter and scale rudder. This model is bigger the Blue Devil and it is powered using two 385 motors on 6 volts. Plastic if you could fit brass props and smaller motors I do not think performance would suffer. Look on the MFA web site full spec for smaller motors than 385 hope this helps. I have enclosed a picture of my Fletcher and its stable mate U S S Gambier Bay.

Stan.

Stan,

Thank you