Confederation Marine Modellers
Elevon control - an explanation by Rowen
Doug has acquired a kit from the Billings range of the Smit Nederland. The instructions are not that good. The model is 1:32 scale and will be 33 inches long with a 11 inch beam. This kit was made back in the 70's and was not lazer cut so every piece of wood has to be cut by hand. It is twin screw with Kort nozzles, Becker rudders made from brass, and brass props. Winches and some other fittings are plastic. It has been a slow build but is coming along.
The area is open for passive recreation only, such as hiking, biking and bird-watching. All on-site facilities (including washroom buildings, pavilions, Trail Centre and gatehouses, etc.) will remain closed. Gatherings, groups and and use of picnic tables are not allowed. The parking and dock area used for model boating is closed off. One person per car is also requested.
Most of us are delighted when our model just responds to radio signals and performs properly. Typically, we use a “lever” style transmitter (Tx) and on a twin motor vessel, if seeking individual motor control, one motor is controlled by the up/down movement of each lever. This works well but has some limitations. Both hands need to be used and rudder effect is easily masked by inadvertent motor operation. This is particularly apparent on faster models with a brushless motor installation.
There was an article published in “Model Boats” magazine in March 2019 suggesting another approach. All of our RC equipment was generally developed for model aircraft, for that is where the volume market is. However, sometimes features are offered that boaters would not usually use. On some of the more sophisticated Transmitters (Tx) both “Elevon” and “V-tail” mixing are available. These link two radio functions together so one control lever can operate both features. I will describe the “Elevon” as it is the one I use on my Flysky Tx, although both functions are offered.
"Elevons" are control surfaces on delta wing aircraft where the functions of elevator and aileron are combined. My Tx is the “Mode 2” style where elevator and aileron controls are on the RH lever. In aircraft with separate wings and tail, the Forward/Back stick movements operate the 2 elevators and cause the aircraft to pitch up or down, and side/side movements operate the 2 ailerons and cause the aircraft to roll. When the 'elevon' control method is used, the same stick movements cause the same aircraft motions but operate only 2 elevons.
On a model boat, elevon control puts both ESCs on the RH control lever. Moving the lever up operates both screws in the forward direction and down into reverse. Going from side to side speeds up or slows down either motor, so the boat goes in the direction the lever dictates. Rather more intuitive than before. After setting this function up and then testing it, I decided it works well. This was accomplished by:
Your Radio instructions should give detailed information on setting up the radio.
I was running out of things to do and thought I would buy a kit of some sort as I thought that would reduce the want to run out and get something as I might do if I were building from scratch. I called Steve to ask about which kit manufacturers are the best and he gave me a kit for a Brixham sailing trawler so I am making my way through that.
Thanks to Rowen, Peter, Garth, Paul, Bruce, Doug, Rick and Andris we are able to give you updates on their activities during the present restrictions. We'd like to hear from our other members what you are doing to fill your time. It may not be boat modelling, but maybe you have something going that would inspire another member to have a go. Or just drop a line to let us know how you are. Please send an email, with photos if possible, to Roy. You'll find my email address in the membership list.
An update from Bruce.
May's substitute meeting
Rowen writes: I have often tried to heat relieve strains in plywood, once glued and clamped in place, by gentle heating with a heat gun. I have never been sure just how well it works, but as no parts have sprung apart I have assumed it is fine. I am building a pilot boat model that has a pronounced rounded bow to support a substantial rubber buffer. I was wondering how to do this as I was reluctant to try the usual wood block sanded to shape approach.
I decided to cut a length of thin plywood (1/16") to the same depth as the inwale and held this in a steel tube bender and applied gentle heat. Lo and behold the ply gradually relaxed and took up the shape of the bender.
When cooled the wood was released and most of the shape is retained. It was then cut to length and glued to the frames and bow support, where it fits nicely.
Rowen has used this technique on his models to control brushless motors. He found that using differential motor control for steering could be difficult. The brushless motor response is so rapid it is impossible to do anything gently. For steering he tends to use rudder control on the LH stick when running at slow speed or when in confined waters, and turns using Elevon differential motor control on the RH lever at speed or on open water. Differential control will probably be smoother when using brushed motors.
Rick's steam launch 'Miranda'.
Hints and tips - bending plywood.
After the shafts were correctly located, the motor mount position was established. I made up a mount using wood and aluminium plate. The motor shaft spacing is determined using the shaft centre lines. The longitudinal location can be measured from the shaft slope and height.
Two brushed, 550 type motors were then fitted to the mount, followed by the shaft couplings. The mount location can be fine tuned by slightly sliding the mount around until the motor and shafts could be rotated with the minimum force. The mount was then glued into place.
The shaft couplings used are steel, which tend to be noisy. I find that if a rubber or plastic sleeve is pushed over the coupling it quietens considerably. The inner coupling cavity/sleeve can also be filled with grease to ensure the joint is lubricated. I had earlier installed “oiler” fittings to the shafts for periodic lubrication.
I decided to try the Quicrun 1060 series ESC on this model, one per motor, to improve control. So far they work well, although the installation would be eased if the wires were longer.
I made up rudders by wrapping styrene sheet around a flattened brass rod and gluing together. The doubled over sheet was then cut to the rudder side profile and the section sanded to shape. Once compete the shafts were lubricated and inserted into the tubes. The rudder servo was fitted with a control linkage made up using old bicycle spokes and tested. I set the radio up to the “elevon” control sequence and tested the systems. Nice thing about brushed motors is everything usually works right the first time! No programming of ESCs etc needed either!
The hull was now watertight with the powertrain fitted; time for trial tests on the local pool. This may appear awry chronologically as I wanted to get the hull sailing properly before adding the superstructure etc as a winter project. I am using 3 S Li-Po batteries and I found the performance adequate. Nice bow and wave patterns, similar to the actual vessel photographs.
For his project for next winter, Doug has obtained a Trumpeter 1:200 kit of the Titanic. The kit has over 1200 pieces along with a set of photo etch parts. Doug will be making it radio-controlled and has ordered the upgrade for it. It also came with an LED light package. Doug has joined a Titanic forum an found a lot of information on the build.
Paul has a great maxim for these unusual times: "I am determined NOT to have to say, when this is all over, “I should have done (fill in the blank) when I had all that time on my hands”."
Late last month I called Dundas Valley Hobby's get a few things I made the rudder made & rudder shaft, installed the planked cabin floor & moved on to the deck opening. It took a while to figure out how to hold cabin down and went the simple way using nuts & bolts. I tried a little brown paint on the hull. By this time I was thinking, " Must keep busy or I may go crazy" .
Finally, I just thought I'd add a few more things to my build .The motor I finally put in was a motor I got off of Bob Farrant. I think my wife will not let me leave it on the table even though it's starting to look like furniture. Just a little silver soldering on the rudder stay well & follow the arrows .
I showed the plans to the club membership at the Jan 2020 meeting of this boat I designed and named the Warlock. This boat will be powered by a 3 hp brushless motor and a 22.2v lipo battery. Construction of the frame work is 1/8'' birch plywood, hull bottom and sides are 1/16'' birch plywood. The deck is light 1/32'' birch plywood. Outboard tunnel hull radio box retrofit. I built a separate speed control box on top of the existing radio box like a 2nd floor on as bungalow making sure the cowl will still fit on top of the box. The reasons for this modification is to be able to move the lipo battery further back towards the stern for proper center of gravity. THis helps the hull to fly at speed and also eliminates 12'' of motor wire from the speed control and shortens the water lines. The radio receiver was moved to the bow area of the radio box . Warlock 6S mono hull . I had to design a cowl for the deck because of the speed control protruding above the deck . Templates for side and top profile of the cowl were cut from 1/8'' melamine which was traced on to 1'' thick pink Dow foam. This was sanded to shape then I applied 6 layers of 2 oz fiberglass cloth using Pacers epoxy finishing resin. When the cowl was fully cured i carved the foam away and fiber glassed the cowl to the deck with 2 oz cloth. The hull is now ready for painting.
Owner Robin says that she has ordered a Plexiglass shield for the counter and as soon as she has that she will be open for business. Only 2 people will be allowed into the store at a time.
She has been getting regular deliveries so the store is well stocked with wood, metal, paints etc.
Roy's 3 projects: Empress, smoke unit, bumper beeper.
50 Point Conservation area.
Rowen's Her Majesty's Air Force Vessel "Seal" - Part 2.
These are pictures of my recently completed 1937 14 foot RC runabout - now called "Thunder Mite" - like a drug - you just add water!. KInda looks like a classy "Balloon Buster".
Rick has been doing some testing on the steam engine which has been run on air. The servos are set up, and the radio connected. Rick is using a 2 channel radio that he won in a raffle. The prop is fitted. The boat has been tested in the tub, the next step is to get outdoors on the water.
Andris' tunnel hull speedboat.
Garth's Chris Craft "Contstellation" - Part 2.
Doug's 2 projects: 'Smit Nederland' and 'Titanic'
Dundas Valley Hobbies.
Peter's new runabout 'Thunder Mite' - Conclusion.
Work is proceeding slowly on the Empress of Canada. Painting of the lower hull is almost finished, just waiting for a suitable day to give it a coat of matt varnish.
The wrap-around walls at the front and rear of the superstructure on the upper hull are almost complete and then the hull will get an exterior coat of white.
I have completed a water-based smoke unit to fit into the Empress. The box has been made from styrene, the nebuliser & water pump purchased from eBay, the voltage increaser from Amazon and the fan loaned from Peter. I'm awaiting delivery of some components to control the speed of the fan from the radio throttle channel.
The third project is a gadget to use on the bumper boats. When a bumper hits the wall, or is hit, it will flash LED's and sound a buzzer. I have completed one prototype to check that it's feasible. The final version will get rid of all the spaghetti wiring and be much smaller.
The forward / aft trim looks OK, although I was surprised by the draft. The model weights about 6 lbs and is already close to the waterline. I added ballast weights to see what would be needed to bring the model down to waterline. This shows that rather less that 3 lbs was available for the deck, superstructure and detail. I'm going to have to watch my weight again!
I decided to increase the top speed by overpowering the ESCs using a 4S battery. The ESCs must have a high voltage limiter as they cut out. From a box of bits I found a voltage reducer and installed it. Providing the voltage is adjusted to below about 14 volts, the ESCs operate fine. I settled on using 13.25 v to give a slight margin. The increase in voltage gave a marked increase in performance, and I decided to use this set-up permanently. I think the model is slightly overpowered, but at least it can be quickly moved out of conflict situations!
Bruce writes: I regret to say that I've done absolutely nothing model boat wise. No I haven't lost interest in the club, only in the building aspect of my own boats. As a result of this I'll be looking around for help in finishing up what I had planned. I'm working more on my music, I play piano at home both by ear and I also read music and I recently took on a project whereby I found an intro to a song I'm learning, However the intro was a video, so I'm studying the video and writing the music for it to be added when complete. Also working around the house like most of us homeowners.
Despite this covid issue I'm cautiously optimistic that my larger boat will see water this summer. The cushions were redone over the winter, but no I didn't do them, I got a referral for that. Also, you've heard the phrase "if it's going to happen, it'll happen to me", well , the story of my life. Usually when I start prepping the boat for the season I tend to run into "road blocks", and it's usually something stupid I've missed. Well I did some prep for this season not knowing when it will start, well lo and behold everything went smooth as silk, and I'm guessing it would be inappropriate to continue with what came out of my mouth after that.
As a result of my lack of building interest I will be selling off some tools I haven't used in some time, but at a later date. Hope I have not bored anyone, but this is basically what I've been up to. Well I hope everyone is staying safe, I hope to see you all soon.
- or what you might have seen if we'd had an April meeting.