Another newbie commin up!

[crosshare]

Hi guys!
I'm new to this hobby and would like to make a scratch built rc boat out of aluminium cans (cutting the cans into sheets and then shape it up). Am I shooting myself in the foot? Is this a good idea? How should I stick the aluminium together? Iv'e got epxy, silicon, PVC glue. Anything else I should worry about? Its gonna be about 60cm long and 14cm wide..

[_James_]

good idea, but aluminium cans aren't really that friendly to use, im not saying don't try it but using some kind of wood would be suited to a first time builder like you, if you did want to use aluminium, i would think it would be a bit floppy unless you made surports or braces strentchening the hull.

Even before you think about what matiral i recomend you base your design on another boat or draw some kind of plan showing how to install radio gear and stuff...

im pretty sure there have been rc boats constructed out of aloy cans but as i said before, about $15aus of balsa would build you a simple hull that you would follow to waterproof and installed rc equipment


James

[crosshare]

Yeah, I was thinking of supporting the aluminium with 'ribs' made out of wood. I would use balsa if I could get it, but I live in such a remote area its almost impossible. I have made a replica of the boat with cardboard, so that will be my 'plan'.. How do I make my own stuffing tube?

[_James_]

stuffing tubes are just a peice of plastic or something better, like metal tubing wide enough for the propeller shaft, it should have small caps on the ends to stop any vibration of the shaft. all of these peices should be grease up very well with some kind of thick grease like... silicone rubber grease.

could we get a picture of the carboard boat?

James

[crosshare]

Thanks for the info on stuffing tubes. I'm making the 'ribs' now out of thick plywood. Very time consuming coz I'm using the wrong type of saw (got no plywood saw), but I'm satisfied. Haven't got a digicam (gonna get one next month) so can't post da pics right now.. I'm thinking of buying a proper sheet of aluminium instead of using cans. A bit neater that way...

[_James_]

what kind of r/c equipment are you going to use?

James

[crosshare]

I'm using rc equipment entirely from an airplane, 3 channels. 8.4 volt battery. Dunno what size motor... The airplane's some taiwanese brand..

[Knotaddicted]

You might want to check local regulations comcerning frequency of the radio for your location. Generally surface vehicles (cars and boats) require different frequency than planes, for example the U.S. allows 72 Mhz for planes, 75 Mhz for surface, and 27 Mhz for either. There are other frequencies but they generally require an FCC liscence to operate. Good luck on your boat, I can't wait to hear about the aluminum build up and forming.

[crosshare]

I am aware or this, but I'm not sure why this is. Can someone tell me why we need different frequencies? If its because of interference with other rc airplanes, I wouldn't have any problem coz no one here has any.

[Knotaddicted]

The main reason is interferance, and also safety. While you may not know of any, someone could (theoretically) travel to your area and use an RC airplane. That is why the FCC started regulating the frequency. An airplane with interferance can be deadly, and to a lesser degree a surface vehicle also (some cars and boats run 50 mph +). with that said it is illegal to use the incorrect frequency. I'm not saying it isn't done, but please be very careful, and have fun!

[Umi_Ryuzuki]

Lets see here, frequencies.

We were at the pond one summer, and I was sailing my destroyer. After a while, some kids and their dad show up on the other end with a little gas "go fast" boat.
It is common curtesy to check with other RC'ers when you arrive, to verify what channel everyone is sailing on, this group doesn't. As soon as they start up, my boat starts looping in circles, and I have a horrible time getting it back in to the shore. They seem to have trouble keeping the boat running.
"Hmmm", I say, "They must be on my channel." Once I get my boat in, I leave it on, and you can see the boat acting all jittery. So I turn my boat off. The kids in the mean time have gotten their boat running again, and sent it off into the water. It is actually running really well. So I set my two throttles to zero, and when they get to the middle of the pond, I turn on my transmitter.
Boom, their boat stops. "Well fancy that." The pond is only two feet deep, and entirely concrete, and one of the kids has to walk out and get the boat. I demonstrate my godly ablilities to a friends, and we all have a good laugh. They try two more times before they come over and verify whether they are sharing their channel with anyone on our end of the pond. After that, their boat ran fine. ; :rolleyes:

Now if you are on an aircraft frequency, you must realize, that planes do not just stop and float when they get "shot down" by another transmitter. Also imagine what the whirling blades of a plane, or helicopter could do to someone over on the other end of the park. :(

There is a reason it is illegal to cross frequencies.

[CG Bob]

Tower Hobbies (http://www.easyrc.com/radiosystems/radiosystems4.html) has some basic info on radio frequencies. Another thing to remember is that it is illegal to change from 72mHz crystals to 75mhz crystals; the radio must be sent to a factory and FCC approved service center to be retuned to the new frequency band. Most radio manufacturers charge $15-20 to retune the radio system.

From the FCC (http://wireless.fcc.gov/services/personal/radiocontrol/data/bandplan.html) site is the regs regarding R/C models.

Bandplan
FCC rules list 80 channels in the 72.0 - 73.0 MHz and 75.4 -76 MHz VHF ranges for R/C transmissions. You must stop such transmissions, however, if they interfere with authorized radio operations in those VHF ranges or with broadcast TV reception on channels 4 or 5

FCC rules also list HF channels at 26.995, 27.045, 27.095, 27.145, 27.195, and 27.255 MHz that may be used to operate any kind of device including model aircraft and surface craft devices. R/C channels are not afforded any protection from interference due to the operation of fixed and mobile stations in other services assigned to the same or adjacent frequencies.


Channel Allocation


Channels Frequency (MHz) Usage
50 72.0 - 73.0 model aircraft devices
30 75.4 - 76.0 model surface craft devices*


* Any small imitation of a boat, car or vehicle for carrying people or objects, except aircraft.


R/C modeling in the U.S. is a secondary user of the frequencies. If the primary users of the frequencies receive interference from the R/C modelers; the R/C modelers must find a new location to operate.

[crosshare]

Thanks for the info guys. I will certainly take this into account when launching the boat. You see, in my area, ther isn't anywhere condusive to flying or landing. The wind's too strong, trees everywhere, rough terrain.. I would'nt think why anyone here would want to fly anything, and haven't seen anyone doing that. That said, I will still be very careful.

[afc]

Crosshare,
Even though you can take all the care as you think possible and have no cause to think anyone flies in the area, the simple fact is that if your actions cause injury or damage to someone, you will be legally liable. I would even venture to state that you would be held 'strictly liable' for the damage/injury you caused as the FCC regulations specifically sought to guard against this kind of injury/damage.
If you own any assets, e.g. home, retirement savings, etc., you would be putting youself, your assets and your family's peace of mind at risk. In the grand scheme of life, it would just be cheaper to buy a surface channel radio (seen some 2nd hand radios listed for sale at $25 on this site). The new two channel sets are relatively cheap for the peace of mind (at any rate cheaper that the risk you run or the regret you will live with if you injure or kill someone -- the latter will get you jail time).
Just my 2 cents worth...
regards,
Albert

[crosshare]

Albert,
thanks for your 2 cents.. I'll see if I can get a surface channel radio.. But really the chances of someone flying here are pretty remote.. Its like timbuktu over here..
Crosshare

[Tony Oliver]

I suggest you read up on the penalties for infringing the regulations. I know that here in the UK it's cheaper by far to buy new gear than to run the risk.

You will already have some idea of the bad feeling that doing your own thing causes. Any visiting modeller who sees you operate is likely to report it - one phone call is all it takes.

The frequencies were only made available in the first place due to much hard work internationally to set aside freqs for surface vessels and aircraft on separate bands. We really don't need to give regulatory authorities any reason to remove them again.

Tony
Moderator

Anyone do any park flying, indoor flying or slope soaring in your area?

[CG Bob]

But really the chances of someone flying here are pretty remote.. There is always the chance that someone IS flying a model out there. Could be a government contractor testing a new UAV for the military. Could be someone flying a r/c rocket plane; or using a tethered balloon to do some aerial photography via r/c.


Its like timbuktu over here.. How close to Mali, West Africa are you? :)

[Ken-Ohki]

I would not use aluminum cans for making a boat from scratch. I would also not use sheet aluminum, but I see it as a better materiel to use. Personaly, I would probably make a foam body and then fiberglass or polyurithain it ( probably the pollyurithain ).

Just to recomend alternate building materiels, Plastic from a 2 liter bottle, PLexiglass sheets, Xactobard, Blocks of paking foam, and even the sides off of one of those big 3 dollar walmart toats will provide some suitable building materiel.

I wont comment on the "proper" freq to use discusion. Seing as how last time I participated in a conversation like that, The other side resorted to name calling and belitting comments. But I have made several old R/C toys into variouse new R/C toys with great sugsess, So go for it, Nothin like making things do what ya want them to. Where would our tecnologicaly advanced civilazation be without people saying. "Hmm,,, I can make that do this".

Ken-Ohki
"I make things do what I want them too, The Hell with what they are designed to do."

[OhioMike]

Building out of metal is very prolific in the UK. A material used for many years across the pond was known as tin plate constuction. I have a book at home with an entire chapter devoted to it. Basically its as you indicated in your first post. Frames layed out per the plan, even going as far as useing builders plans with frameing location as on the real ship. Then with curved sheets of tin layed in place and soldered to each following plate of tin. Dont recall the process for attaching to frames. This technique was used mainly from what i have read to simulate the riveted type constuction of earlier shipbuilding. A fella named Bud Lederer, here in the states built an incredible aircraft carrier of the Enterprise, CV-6 years ago. He used a technique of normal planked construction then after fiberglassing, he attached scale size aluminum sheets butted to each other and fastened to the hull with contact cement. This was to simulate welded steel plates. I believe he sealed overall afterwards with either polyurethane or a laquer clear coat. It looked Fantastic. it was also RC and he sailed her often. There have been many other examples of this technique over the years. I would not recommend it for a first scratchbuild effort though. Learn the art of obtaining the compound curves associated with hull construction with a planked job first. Or if your inclined to, a kit or even a Fiberglass hull from one of many vendors can give you a sort of jump start on whatever project you have your eye on. loyalhanna has a vast selection from many manufacturers. you'll pay overall more though going that route. Good luck.

[Tony Oliver]

I agree with OhioMIke, but if you are comfortable with the idea of using aluminium then go for it. It may be something you give up on, but it may also be a real achievement. Someone has to make the breakthrough, so why not you?

At least you can say you tried and if it's successful - Wow! - and we want pics please!

Tony

[3nero]

making models from alluminium is very possible
here is a pic of the normandie made from tin but made about 60 or 70 years ago and still sailing today
pic (http://groups.msn.com/_Secure/0VwAeA94Z91!qBPY*Ryy0xfgh2DWe!46fP3xmKIUxS7IgwjQbe uXfaHSsvm1kZkelt0Eszw50iVrKpouq3R7nDJTnqMjjF3pqYC2 fhGqtAHOAnGvKR5!4vYVzB7139q92/IMAG00054.JPG?dc=4675389078291508015)

the model is about 6 1/2 foot long the tug in the backround is mine and was later sunk by the normandie and will never sail again :(

[crosshare]

Wow, you guys talk about construction with aluminium like it’s very difficult.. As I’m new to this scene, I didn’t really know what material to use and thought of aluminium coz it’s easier to get. Thanks Ken-Ohki for your recommendations on materials. Can I ask what why using aluminium isn’t that easy? Is it shaping the aluminium? Coz the difficult thing for me now is shaping the hull. I have to cut the aluminium into strips at the front side to get the shape I want.. Then place them on the frames I made.
I’ll take you guys’ advice and try another material if this is too tricky..
Thanks guys for the encouragements (and the link)..

[afc]

3nero,
What happen to the tug?
~Albert

[CG Bob]

Can I ask what why using aluminium isn’t that easy? Is it shaping the aluminium? If you're an expereinced sheet metal mechanic, working with the aluminum won't be hard. If not, you'll learn a whole new set of skills. I did 27 years in the USCG as a Damage Controlman (http://www.gocoastguard.com/Rates/DCrate.htm) . one of my skills was welding both steel and aluminum. Aluminum comes in many different alloys for many different purposes. Structural aluminum for flagpoles, doors and hobby use is generally known as a 6000 series aluminum. Marine grade aluminum for ships is generally a 5000 series aluminum. Within each series are many different sub-series and grades of hardness. A common structural aluminum is 6061-T6. I realize that welding aluminum is a skill most modelers don't have, but some of the prinicples do apply to using it in model making. You can get some electrolysis or galvanic reactions if you use two dis-similar types of aluminum. The electrolysis can cause can cause weakness in the joints between the plates. You must clean the aluminum oxide off the surface before gluing the surfaces togther, fine sandpaper works well, followed by wiping the surface with some alcohol. Welding suppliers usually stock aluminum cleaning solutions. The various hardnesses (T#) of aluminum affect its ability to be worked with handtools like tin snips and hacksaws.

When I was stationed in Milwaukee, WI., a man came to the pond with a nice aluminum tug boat model about 4 feet long. He was awelder by trade, and the model was all welded aluminum. The model was powered by a 12 volt gel cell. The model got about 6 feet from shore, and it hit the wake of one of the r/c PT boats. The tug started rolling, and then smoke started billowing from the cabin portholes. The rolling had caused the unsecured battery to fall over. The battery terminals shorted out against the bare metal of the hull.

[3nero]

3nero,
What happen to the tug?
~Albert
long story short
she was having trouble and heading straight for the side of the pond (brick wall) i tried to nudge her side ways to aviod a head on collision with the wall. but i misjudged her speed and got in front of her bow. my tug was planked with 2mm balsa she is made from 3mm alluminium and more than twice the size of the tug. the phrase "like a hot knife through butter" was used a lot that day :D
after the collision all that was left on the surface of the pond of my tug was the lifeboat which was just sitting on the deck and not yet tied to the davitts.so at least the crew had a chance :p
if anyone is interested i can take pics of the tug which was recovered a while later.
Btw the normandie stoped dead in the water just after the collision so the rescue kind of worked :rolleyes:

[ropanach]

I'd like to see some of the action shots, please.

[crosshare]

CG Bob,
Looks like I'm learning a new trade altogether.. BTW, will there be a difference in quality if I solder it instead of weld it? Or is soldering not possible?
Regards,
Crosshare

[3nero]

I'd like to see some of the action shots, please.

sorry no cameras around that day. :(

[CG Bob]

BTW, will there be a difference in quality if I solder it instead of weld it? Or is soldering not possible? Welding and soldering are two similar, BUT DIFFERENT processes. During welding, heat is applied to each piece, melting and fusing them to form a permanent bond. Welding does not necessarily require a filler metal or rod; spot welding relies on the heat generated by two electrodes, one on each side of the seam. Most welding does use a filler metal, usually in the form of a rod or wire.

Soldering also uses molten metal to join two pieces of metal. But the solder has a melting point lower than that of the workpieces. Soldering typically uses metals with melting points below 800 degrees Fahrenheit (about 450 degrees C).

Welding produces a stronger bond between the metals, because they are fused together. Soldering uses a lower temperature. Both methods will burn the wood frames you indicated you already have cut out for the model.

There are aluminum alloys that can be soldered, you'll have to do some internet research for "aluminum solder and flux". I did a quick search and found one supplier of aluminum solder and flux, 1 pound (2.2 kg) is $35.00 US. Other suppliers have comparable prices. All of the suppliers I found recommend using a torch to apply the heat, most with a neutral flame.

You might want to consider using CA or a slow setting epoxy to attach aluminum sheets to your frames. An alternative is to plank the frames with wood or styrene; and then apply aluminum to the wood or styrene with epoxy or CA.

[crosshare]

Thanks CG Bob for the info. I think $35 for just soldering is a bit off budget for me.. I'll stick to my original idea of using adhesive..

[afc]

Thanks 3nero. That must have been some event to see .. but sorry about the loss.

Crosshare,
Might want to try this:
http://durafix.com/
I have not used it but if you do and it works well let us know.

regards,
Albert

[Umi_Ryuzuki]

I have never been very successful at bonding aluminum with CA.
It works at first, but the slightest shock will cause the glue to let go.
Most of the work I have done is with aluminum tubing. And the connections are tenious at best.

Most likely I am not quick enough to apply adhesives after sanding or cleaning the oxidation off of the aluminum part. But if you can work around the immediate oxidation of aluminium I would recommend trying epoxy adhesives.

I prefer brass, and soldering when it comes to metal work.

3nero,
It was a metal boat, what could have happened if it hit the side of the pond? :rolleyes: Sorry to hear yours got cut in half. :(

[3nero]

3nero,
It was a metal boat, what could have happened if it hit the side of the pond? :rolleyes: Sorry to hear yours got cut in half. :(

yeah its metal but its an antique and the wall was probably going to win.
mine wasn't quite cut in half. the sharp bow of the normandie sliced into my hull cracking it right down to the keel and lifted the rear deck up.the deck got stuck on her bow forcing the tug to capsize and sink in mere seconds.
when it was recovered i was surprized that the damage wasn't more, but on closer inspection the crack runs the full lenght of the keel stern to bow.so it would be quicker to build a new hull than to repair the original. :(

but i have to admit the crash was one of the coolest things i ever saw :D

[klangooooo]

Hello there; I new to this group and have an interest in boats and also into r/cplanes but at the moment I would like to know if anybody has any clue if there is any body in the Reno/CarsonCity/Sparks/Fallon Nevada area that likes to go R/c boating? I finaly got My R/c boat up and running about a month ago and would like to meet with some people that have the same interests. I know it is December but would like to get things together and make plans for spring and summer. thanks. klangooooo@yahoo.com

[3nero]

i found this on
ebay (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=1431&item=6137130848&rd=1)

its a model of the titanic made from aluminium soda cans
just taught it belonged here :)

BTW its not mine just in case anyone thinks its me that is selling it. :D

also it looks like the guy made it himself you could ask him how he did it

[Tony Oliver]

I think that particular model is best described as 'stand-off' scale.

Back to the original question, The most useful adhesive for sheet alumin(i)um that I've found is contact glue - the slightly rubbery type you coat onto each surface, wait up to 15 mins then touch them together. Called EvoStick in the UK, is that the same as the Durafix mentioned above?. It's permanent, and allows slight flexing with temperature changes.

Because it's so messy to apply (it can be thinned with chloroform) it is worth ,asking off edges with tape to keep the job neat and give a working edge.

The only metal skinned models I have had anything to do with was many years ago when I, as an early teenager, was allowed to help an old modeller who built tinplate models using tin cans. He soldered them up and it was he who taught me to solder properly. Even then, the sheets were riveted to the frames and the whole thing caulked inside with what he called 'Rubberoid' which I think was a type of vehicle underseal. These weren't small models - the one I worked on was a 9ft King George V battleship.

Soldering is cheap on tinplate, prohibitively expensive on aluminium on that scale.