Dynamic diving of Bronco type XX111

Hello to all ,you have a nice site here with plenty of intresting stuff.
Being new to submarines,i thought i would try the 1:35 bronco XX111,.My question is if most of the build blogs use 385 type motors would a dynamic diver need a larger motor such as a 540.
Thanks for your time on this
MICKYRUBBLE

Hi,
I see no reason to use a 540,to get the boat to dive it will need to be very low in the water,so it will not take a lot to drive it under,if you where to use a 540 you would shorten the run time and you would need a larger battery,think I would stick with the 385.
Nigele

I agree with Nigele. Mine ran fine with the 385 size motor.

I agree also with Nigele ans Salmon.
Furthermore it is important that your model shall have not much material volume above the waterline when it is surfaced because that volume will displace water when the model shall submerge and this additional water displacement means additional bouyancy that must be overcome by the down force of your diving planes.
For example the SEAWOLF model of my son that is also a dynamic diver has only thin and light material above the waterline when it is surfaced ((in this case thin Aluminium sheet material of 0.5mm thickness).
It is also important that all the air inside the upper deck region and inside the conning tower can escape easyly.

Best regards
Klaus-Dieter

Thanks for your replies.I was under the impression that a dynamic diver needed more power to dive than a static diver.Would a 385 need gearing ( 3:1) to spin a 50mm prop.I have built a lot of surface craft but this is my first attempt at a submarine.I also have a Robbe type VII waiting in the loft .Can any one confirm that Robbe have stopped their boat range,i never see them advertised these days.

Hi Mickyrubble,

yes, I can confim that Robbe has ceased their model submarine program. It seems that this was an economic descision because the number of submarine modellers - also here in Germany - has remained too small. Of course submarine modellers have been surprised. Maybe also the decline of 40MHz radio control sets might have played a role because Robbe wouldn't have been able in the future to continue the delivery of Radio control Systems suitable for model submarines (I suppose). And in general there is a general decline of our hobby since there are only a few young newcomers.

So if you still have a type VII model kit on your loft it can be regarded as an antique collectors item...

Best regards
Klaus-Dieter

It's surprising to hear the hobby is on the decline in Germany. After all the economy appears to be very much industrial based, so I would have thought there'd be a fairly large pool of young people interested in a technically related hobby like this.

Hi Swipe & Hermann,

Hope you don't mind me giving a link to a thread which Klaus-Dieter answered previously and covers this topic: (He may wish to elaborate!)

http://www.theassociationofmodelsubmariners.com/t499-model-boats-sept-issue-intermodellbau-2011-dortmund-article

David

david f wrote:Hi Swipe & Hermann,

Hope you don't mind me giving a link to a thread which Klaus-Dieter answered previously and covers this topic: (He may wish to elaborate!)

http://www.theassociationofmodelsubmariners.com/t499-model-boats-sept-issue-intermodellbau-2011-dortmund-article

David

I read this (and David's recommended thread from 2011) and can only say that the situation is the same over here in the States -- the decline of the Craft is on a very steep slop over here too. The people here are coming out of school stupid, unskilled, and with a mood that demands instant gratification in all pursuits. Not the stuff of model builders.

The Craft, over here, is all but dead -- and will be as old farts like me get to the point where we can't make it into the shop any more.

Last year I attended my last IPMS meeting. In the room were old guys like me -- fat, tired, going through the motions. AND NOT ONE KID IN THE ROOM! When I first attended those meetings, the room was half full of interested kids.

Not any more.

David

Thanks for the replies guys,I read the build blogs here and on other sites and all expect a base level of knowlage on the subject,which unfortunatly i dont have .This isnt a criticism of this site but most sites seem to be this way.I have written articles on Model Boat Mayhem and have done the same thing .
Will i have a viable model if i use the 385 (direct drive or geared) ,6 volt sla battery with a 50mm prop in a dynamic diver.I hope im not pushing your patience asking such basic questions ,but i want to get it right

mickyrubble

Hi Mickyrubble,

don't worry - also basic questions are welcome as nobody can start this Hobby being already supplied with full knowledge.
In your case - if you use a Propeller with 50mm Diameter - I think a gearbox would suit better to the Motor than direct drive. The 50mm Propeller, especially when it has a high pitch, requires a relative high torque and would force the Speed of the 385 Motor too much down resulting in a relative high motor current producing more losses and heat. A gearbox that reduces the rpm at the output shaft and increases the Output torque vice versa let the Motor run more freely.
I must confess that I have no own experience with geared boat drives because I for myself have only direct drives (but with Motors of my own design which that run with less rpm but with higher torques). So I can't predict the best gear ratio for your boat but I suppose a gear ratio approx. 3:1 would do it not too bad.
Perhaps some modeller friends here can give you more advice.

@David and David
I still haven't lost hope for our Hobby yet although we obviously share the same experience in our modern times (and independent of the countries where we live as the People in the US, in the UK and in Germany are not so different). The main Problem is indeed the lack of young people and here is the challenge for old-timers like us. Surely we will not succeed in generating interest for modelling for a very large crowd of Youngsters but it be worth to start the enthusiasm for a few that will Keep on with our Hobby. But we must encourage them, support them and must be Patient. I did it with my son (now 31 years old and still a modeller) and now also with my grandson (only 16 months old but already interested in technical items). At the Moment I can only speculate but I hope he will continue our Hobby one time...

Best regards
Klaus-Dieter

(p.s.: Don't be confused by my writing - my Computer has set sometimes capitals automatically instead of normal letters)

I would agree with your comments about young people entering the hobby.When im sailing models and any person shows interest i offer them a go no matter what age or sex.If i can get one person interested then i have acomplish some thing for the hobby.

385 motors come in different winds, so that will make a degree of difference. It would be helpful if you know where the motor came from and have some specifications.

Also be helpful to know the voltage you want to run at, and the kind of speed you are looking for. Scale speed for a 1/35th Type XXIII would be about 2.5mph submerged. Shouldn't be difficult to get your boat moving at that speed as it's a fairly efficient hull, but perhaps you would like something a little quicker?

SLA's are rather bulky and tend to put the weight up high in the boat, you may want to consider smaller NiMH's which could sit in the figure-of-eight keel, or if you're more adventurous lithium technology.

One option with dynamic divers is to increase the control surface areas to improve response.

MICKYRUBBLE wrote:Hello to all ,you have a nice site here with plenty of intresting stuff.
Being new to submarines,i thought i would try the 1:35 bronco XX111,.My question is if most of the build blogs use 385 type motors would a dynamic diver need a larger motor such as a 540.
Thanks for your time on this
MICKYRUBBLE

The 'standard' SubDriver seen here is used in the Bronco 1/35 Type-23 with success. It's in the Caswell catalog. Comes in both dynamic and static versions.

David

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We are all beginners to quite an extent. You can never predict the performance of a model unless it is an exact copy of something done before. So there is always an element of surprise when you try a new model for the first time.

I would suggest that your model is very likely to be successful based on Salmon' s example. The proof of the pudding (video!)is that it performs well.

If you wish to try a more adventurous (i.e risky) approach, you may a take look at using brushless motors. They must have something going for them with dynamic divers. There is a separate thread on the topic:

http://www.theassociationofmodelsubmariners.com/t1427-going-brushless

No matter which approach you take let us know how you get on.

David