Adding a few internal bits while waiting for a decent day for a sea trial. Stereo is working well and spaghetti tied down,- runs off 2 separate 1s 3000mah LiPo cells (good cells recycled from old batteries) Also added a thermostatic fan control for the ESC in case it gets hot. A 30 deg C thermo switch has been screwed to the heat sink on the ESC along with a 6v fan with a voltage regulator (uses a 2s LiPo for a supply). If the ESC gets above 30C the fan will come on, then switch off at around 25C. All self contained and automatic.

A buzzer can be connected as well for an audible warning. Cheap insurance, as these switches can be strapped to motors, batteries or whatever. Different temperature switches are available from Ali Expr very cheaply. They are rated 220V AC 1A (work on DC -plenty for small fans or buzzers) or can be used to switch relays for higher power requirements.

Makes an interesting feature if the fan comes on while you are running the boat, you come in, turn the RC off, then a few mins later the fan switches off by itself.

Still some small fittings to put on, but 98% done now. Will probably think of something else to add later. Have also ordered a GT Power sound module for more noise, which should arrive in a few weeks.

JB

Testing the 890kv motor,- runs well albeit a bit noisy at a transition frequency (motor hard mounted) Moved the stereo setup (BT board with amp) to under the cabin roof with the speakers under the hatches which works much better. Still have some wiring to tidy for it.

Motor is very economical and ran for 30 mins continuous at cruising speed, but still had 15 mins left at least. Much softer starting than the bigger inrunner. The 4000mah 3s LiPo was only down to 3.9v/cell after 30 mins continuous, (got tired of waiting so stopped at that.) Should have around a 3km endurance as battery was only at 90% at the start.

JB

Finally got it's butt wet. Motor is too powerful (knew it would be but had to try as I only have 2 suitable motors with 5mm shafts to fit the cable collet) I have lots of outrunners but the shafts are on the wrong end and would require re working, (motors can be front or back mounted and to change them requires the shaft pressed out the other end). Motor was a 1400kv inrunner with an internal fan, for 4s LiPo, I've changed it to an 890kv on a 3s as the original was far to touchy.

Motor adjustments in the vid of the original motor are just using a few click of trim,- totally unmanageable in reality. Changed the ESC as well to see if that gets rid of some electrical noise, but the motor is solid mounted to the hull so makes a racket, ( not so bad with the top on)

I'd like to change it to brushed HV motor and ESC, so it can have reverse, but the collets to suit the smaller shafts on the brushless motors to go with the cable, aren't available, so may have to try bushing down the 5mm collet at some stage. One thing which is amusing is that the boat sits with the chines 1/2" above the water, due to the light balsa /glass construction (originals in ply) with the deep V. Had an idea that might happen (probably needed to scale up the weight as well). When going from 26" to 1m and re designing the whole boat from a blown up plan, - everything changes.

The water and air pumps (previously described) are switched by 2 servo operated micro switches (seen in my usual spaghetti) and can be individually operated ( can be seen in the tank video) for cooling (if needed) and exhaust effect (and just for fun😊)

If things check out reliably, a pond test might be the next effort.

This boat's a bit of a tribute to Peter Gargan (Red PMG) in SA who kindly sent me a copy the original plan he had reworked for laser cutting. Sadly he passed away in 2022 so didn't get to see it done.

JB

Almost there ! finished the swim platform on the transom and tested the water/air injected exhaust. I need to order a few finishing bits from CMB (cleats to go with the fairleads) which are too fiddly to resin cast like I did with the fairleads and bow anchor guide.

The video shows the air/water exhaust with and without air injection. The amount of splatter can be adjusted by moving the small plastic tube insert in the end of the exhaust pipe, in or out. The tube acts as a dam, letting the water completely fill the exhaust as a particular water pump speed (adjusted by a small voltage regulator under the pump tray). Air is also adjustable if necessary.

For a bit of fun and a bit more realism, I'm going to experiment with a proper wet exhaust design (ie 'waterlock muffler' ) which has chambers which fill with the expelled cooling water from the engine, along with the exhaust. The water is then pushed out in a spurt by the exhaust pressure,- more pronounced at idle. (pic of a vetus system). If I can get one working nicely, I'll fit it to the Stiletto.

Thinking of fitting an engine sound module as well, but the prices have increased a lot lately on Ali Expr

Should be filling the test tank shortly, as the weather is improving.

My son has moved back home for a while, so I have had to vacate my modelling room 😔🤔 BUT,- all is not lost ! I have managed to reconfigure my larger garden/storage shed as an emergency modelling area and added lights and radio.😊 Can even have TV if I add a splitter box to the LNB on the dish😀

JB

Got round to making the 'exhaust' and water systems yesterday. Fitted the air pump and plumbing for that and the water pump, and installed a pick-up behind the prop.. The Exhaust is the same type as smoke and water system myself and Graham 93 developed, and uses a large diameter tube with a smaller tube inside, and another small tube which enters the side of the large tube near the front. With the smoke system, the water runs through the center tube, and the air and smoke enter through the side tube, and mix near the outlet.

I won't be using the smoker side of it, just the air and water to simulate a water cooled exhaust (hopefully)- works on the bench so should be ok. I can easily add a smoker later if I change my mind. We came up with the idea to add an essential part to any inboard engined launch or runabout, as it's the thing most people leave out. Most boats have water outlets but no exhaust, so where does the exhaust go? (someone's going to say "but they're electric" ?🤔)

'Chromed' the front rails and ladder and added the mahogany treads as well last night. Drilled all the mounting holes for the rails and ladder, but haven't glued them in yet. Swim platform to make and a few other bits to add like switches for the pumps so they can be controlled by the TX, and it will almost be test tank time. Waiting for the weather to improve, but it's slowly warming up now.

JB

Sound system is working better now with the addition of an amplifier board (from Ali Expr) Good part is that any sounds can be recorded and played using the IR remote, (as long as it's not too sunny) or sent to the boat via BT from a phone. Small sample vid of sound recording from the board and the small multi player BTing radio to the board. Can be left on board or used from the shore (only about 25ft range, so works best left in the boat)

I have added tinted hatches to the front and rear cabin tops Rear one can open and close but the front one is fixed, - only thought of a way of making them openable after gluing the front one 🤔 Rear one has a plastic (1mm PETG like the hatch) z shaped 'hinge' with a slot, which is held underneath the roof loosely forward with a screw, and a 2mm wide plastic strut at the rear with a z catch bent into it.

Started on a stern ladder tonight,- will have mahogany treads and a small platform.
Next- a dance floor 😂

JB

More work done over the last few days,- Cable housing glued in and rudder fitted, water pump fitted, and yesterday my favourite bit of 'bling' the BT player with IR remote. This uses a cheap bluetooth player/board and 2 speakers. It can be used with a phone, watch or just the remote. I've added a small IR sensor on an extension lead from the board and installed it under the radar, making is more visible to the remote. The speakers are hotmelted to the top of some plastic honey jars, with cutouts for the sound, as an experiment to get more bass. Works quite well and increases the volume by 50%

I have a small multi function Ruizu BT player with FM radio, (about matchbox size) which can also be used through the board via BT, as a radio or music player (needs an aerial in the headphone socket for radio use). The board also has inputs for an external plug in player or pre recorded micro SD cards. A lot of fun playing with these gadgets, and very cheap and simple to set up. You can pre record sounds on an MSD card and play them via the remote, just by selecting a number, (ie comms sounds, sirens etc). Almost unlimited fun, and a hell of a lot cheaper than buying specialized units with one or two sounds.

This is the third model I've fitted one to now. Graham (93) has fitted a similar unit (with amp) to his rowboat, (with Bill and Ben) which works really well, and is audible from a reasonable distance on the pond.

Probably more shiny bits to come yet,- hopefully an engine sound unit as well with remote key fob start 🤓.

JB

Almost finished the lights now, having added a stern light and dash light. Also started on some bow rails and fitted the grab rails.

JB

Using the aforementioned method of using the actual background as the decal background, you can see the difference. I cropped the rear pillar pic and pasted it in 'paint', then did the same with the decal pic, sized it played with the colour a bit with Wind 11 photo ed to try and get the tone right, and overlaid that on the pillar pic using the transparent selection tool. Printed it as described previously, clear coated it when dry, trimmed it as close as possible and applied it.

The first effort was just trying to match colours with 'paint' which is usually not the best due to lack of options.

JB

Started with printing some decals today but not happy with the stiletto decal. If you want colours to stand out better or need white, you have to use white decal paper. The problem with this is having to try and trim round the picture so you don't have any white showing.
I found a way round this by trying to match the background to the surface the decal's going on.

You can do this in paint, or in windows 11 in the photo editing section (remove/replace background) It's sometimes hard to match colours, even using custom colours, but there is another way I came up with, and that is to take a clear pic of the surface you want to match, then use that as a background and then add text or subject over that. This can work well on certain designs, as long as you are not too critical.

I managed to almost exactly match Chrysler Charger orange to that paint on one of my planes using that method. With the runabout decal. I managed to match the woodgrain on the decal to the boat. Using white decal paper is easy on white, and it stops the colours looking opaque. There are limitations with colours, but as printers can't print white yet, it can be a useful method.

Make the background large enough so it can be easily trimmed as close as possible to the subject, as this will make it less noticeable.

Another idea I came up with was how to save expensive decal paper. If you finalize your image, (center it if possible) then print it on plain paper (A4) to check the size, (adjust as necessary) then sellotape a piece of decal paper over that image, (make sure it covers the edges and is smoothed down flat, or it might catch in the printer) leaving about 4-5mm round the image so no sellotape overlaps it, (hold it up to the light to make sure), then place the paper in the printer tray so it comes out the same way as before on the same settings as before, and the printer should print pretty much exactly over the image. (rough example pic5)

Leave the image on the paper and leave the ink to dry (I put them in the oven at 50c till dry) then spray a few coats of clear over it (still taped to the paper), then let that dry (oven's good for this as well (as long as the boss is ok with it😉). When dry, trim the decal to suit and
apply. My reason for using this method to save decal paper is, if you use a whole sheet for a small decal, and spray the clear over the image, you can't print on any surrounding paper with spray on it.

Clear decal paper works best with dark on light (pic 4) as the other way round the decal can look opaque.

I have even managed to print on silk using the tape/overlay method. (pic 6)

JB

short video of the overlaid printing