Can you make a floating model out of styrene?

[polar_explorer]

I've built a few ship kits now, just static ones, and am thinking of starting my first big, floating, moving scratchbuild. I'm looking at making the Antarctic research vessel Hesperides, found it on http://www.freeshipplans.com/. I'm going to make it in 1/72ish scale (maybe 1/76 to fit the plan on the paper better), so it will be over a meter long. I am good at building stuff out of plasticard/styrene so am wanting to use this. Do you think it will be able to stand up to being a working model? I would build the hull by making the frames from thickest stuff i can find, or multiple sheets laminated, putting thick ribs between them of square section, or maybe I beams, and then plating in thick (1-2mm) styrene. Make the whole lot with plastic weld and i thing that should be a strong, water tight model. Has anyone built one using this method? All the blogs I've seen have been using plywood and fibre glass, something i am trying to avoid as i only have a small flat, no garage to work from.

Then second question, what is the most complex radio system you can get. I am looking for one that will do prop, rudder(s) and bow thruster, plus have functions to turn on lights, stream sonar cables, spin helicopter blades, turn radars, that sort of thing. And maybe a horn too. Is there some sort of digital system that can do that. In model railways we use a system called digital command control that can do all that, but requires two wires (or rails) to connect.

Thanks for any help
Tom

[tweety777]

The problem with styrene is it's lifetime.
A sailing model made of styrene might last about 10 years, maybe a little more, but you will live longer then the model.
I would advise to use thin wood planks and add polyester on it.
That way it will last a lifetime.
Building with wooden planks is different but not hard to do.
It will take more time then plates, but on straight parts you can perfectly use plates of wood.

For the radio the Robbe F14 is perfect.
Use 3 channels for proportionel control of the rudders (one channel), bowthruster and engine's.
The other channels can be used to control 16-channel decoders which turns 1 channel into 16 channels.
All you need to do is push the switch on the transmitter up as many times as the number of the function.
That will be hard enough to start with.
Right now i'm working on a system to control an almost unlimited amount of functions using serial codes and a PIC, but i'm getting help for that from som-one who knows how to make such electronics.
I will try to find some ways to make your functions work soon.

Greetings Josse

[doog_k]

I still have 20 year old styrene vac-formed hulls, there is no visible degradation that I have noticed.
I guess the oldest hulls I built that have been built from Styrene sheet are about 15 years, these have no leaks that I've noticed, even along the joints.

I'm presently building a 1/144th scale I-400 submarine from 100% styrene and don't anticipate any problems.

However, when I build my surface ships I generally use balsa, dope and card to complete the hulls, the deck is then plated in plastic and the superstructure is completed in plastic sheet.

As for the multi-function radio, the DCC used in railways hasn't been adopted in RC, possibly because of the aero basis of most kit, I'm not sure if the safety aspect of controlling a model airplane in flight via only 2 wires and DCC would be risked. There are a whole range of multifunction systems to give all sorts of functions, I'd suggest a local club is the best place to get practical advice on this.

[Admhawk]

The biggest issue with using styrene for RC models is thickness. Most try and use stuff that is too thin and it's doesn't last. Using 2 or 3 mil stuff will be fine. Lot's of old revell/matchbox Flower class corvettes still working out there. Not many build the hull out of styrene, but no reason it won't work.

Getting a 7-8 channel radio is easy and the 16 channel decoder/switcher is the way to go for lot's of functions. The newer 2.4ghz radios are easy to program for multiple functions as well. Look into Spektrum radios.

[polar_explorer]

Thanks for all the advice guys. I will make the hull from styrene then, good thick stuff. I'm also planning to reinforce the bow with metal of some sort as this ship is an ice breaker. It will be really cool if it can carve a way through a pond on a cold winters day. So my next question is, how big a motor will i need. The ship scales to 1.15m long or so, and has one large 5 blade propeller. It also scales to about 7kg so i'll guess that that is how heavy it will end up to float at the right level. It's top speed is only 16 knots, so what sort of size motor will it need to do a scale 16 knot? When i've got time i will go and browse the local model shop and pester them, but need an idea of what i'm looking for.

[tweety777]

How large is the propeller?
The diameter of the prop should be about the diameter of the engine, unless you use a reduction gearbox.
If i hear the size of the model i would say Speed 500 to 700-size engine's would be good for getting scale speed (means that it looks like the real ship), but if the prop is too big a reduction gearbox might be useful.

Greetings Josse

[doog_k]

I too use a strip of brass down the stem, it reinforces the balsa hulls I mentioned earlier, however have a care if you're using styrene, bonding will be tricky.

As for props, I ALWAYS use a belt drive, it allows more flexibility in terms of speed, minimises vibration & noise. It also minimises strain on the motor and thus battery drain.

[tweety777]

I would in any case use polyester or epoxy to make sure it really is watertight.

Greetings Josse

[doog_k]

I've found a great filler to help eliminate leaks are some of the off cuts of the plastic, dissolved in liquid polystyrene cement and carefully brushed along seams and allowed to set. You're then left with the same material as the structure as a filler and easily sanded to match.

If there are still leaks I pour Johnsons Clear/ Future floor polish into the hull, if it runs through any gaps (it has a similar viscosity to water), catch it in a container and pour it back in. After a few cycles the polish, which is actually an acrylic varnish, builds up and eventually seals the gaps.

[polar_explorer]

According to the plans the propeller needs to be 41mm, so i'll get a 44mm one as that's the size you can get. So do i need a 45mm diameter motor then?

[tweety777]

That's correct.
500-size can be used in direct-drive i think, though it might be on the end of it's limits.

Greetings Josse

[commodore4]

Hi- I,m new here,but, I have used plastics exclusively for my last four R.C. boats. The oldest is a tug that is styrene planks on lucite frames and keel.That boat is now over thirty years old and has NEVER developed a leak. I see you want to break ice? Well being as how it,s a model the ice needs to be thin or it won,t work .You can sheath the bow for about an inch back on the sides and about two and a half inches below the waterline!You can use just about any newer radio I,ve seen. I looked at one not long age that makes my 4 channel radios look old fashioned! It had, I think ,12 channels and all kinds of switching for additional gear. You will find on your build that you need ballasting tanks just for the ability to float at the designed waterline.It,s easy on tugs because I use 12 volts so I use a corvette gell cell battery and that takes care of ballast.I hope this helps you. commodore4

[polar_explorer]

Yes i will obviously be trying to go through scale ice. I'll also put a lot of weight right up in the bow to give it smashing power, like a real ice breaker. My current plan is to make a watertight floating hull out of plastic. Then once its driving around and flaoting well i'll epoxy brass or something like that to the bow for strength, and protection from pointy bits of ice. I've been looking at electic bits and plan to use an action electronics controller with a 6 channel Rx system, that will give me 6 switched channels, should be enough i think. Thanks for all the help guys, i'm getting there now. In the new year i will be having the keel laying ceremony.

[commodore4]

HI,I gave more thought to your idea of breaking the ice with this model.I tried this on a civil war ram and it worked! After building the hull and frames as stout as I could,To many parts here will actually weaken the hull! You will have to take the weight into consideration though.I put bb,s and patching cement in a slurry and poured it into the bow.It never has developed a leak ,but,I had to add about three inches more freeboard than would,ve been required ,because you have to balance the weight forward with weight aft and for gosh sakes make sure you have built the keel to take this strain!!I took the keel and built it like an upside down railroad bridge,you know,wider in the middle and thinner on the ends! I hope this helps! Oh! don,t forget to install two, yes two,double thickness w/t bulkheads just aft of this point.They must go ALL the way from the bottom to the deck or they won,t work commodore4