Response

Cooling coil

I cannot see how you can mount the water cooling coil safely onto a out runner motor. Near impossible I would have thought. if there is too much then I would think that it would rub on the motor and wear a hole in it and flood the boat or just jam up the motor. I would go for an in runner. Much more practical in a boat in my thoughts.

5 years ago by BOATSHED

Blog

Day Three

Hi, Using 3mm Baltic birch plywood, I skinned the hull. Used Titebond III wood glue, bent by hand, drilled and tacked in place with small brads. I cut the bottom oversized so it was easier to position, after drying 16 hours I cut the edges flush with the sides using a Japanese pull saw. Built the core for my rudder, see photos, solder my own arm as I did not have one. Used a 3/16" set collar, filed the surface to expose brass and solder a piece brass. Will drill the second hole later. Attached brass plate that will be inside the actual rudder, will build from either plastic or wood. Next, laid out the placement of the stuffing tube, then drilled the hull then I built a motor mount from wood and added some green foam to limit mount and sound transfer. Set the rudder post and block. Time to let everything overnight. Joe

5 years ago by Joe727

Forum

My other hobby

Hi. Mi private pilots license also does not include night flying. But interesting is to consider when they define what is included. When having a certain number of instructed night flights you are entitled to fly in the vicinity of an airport. Vicinity of an airport German definition is that you have to be able to see the traffic in the pattern of an airport. When I did my flight from San Jose, CA to Phoenix SkyHarbour, I was able to see the traffic being about 1.5 hours from the airport. The night definition is that the night begins 30 minutes after sunset. So was entitled to do this night approaches as you can see the traffic in the pattern, on a large airport like Sky Harbour, and in the Southwest of the USA from very far. But when doing these landing operations at a large international airport, shortly before touch-down you are flying into a black hole. Due to this on my first landing in Sky Harbour, I made an awful 3-point-landing making the plane jump 2 or 3 times. Fortunately, I was aware of how to react properly when this happens. The second special experience is when you are taxiing on the runway to get to its exit and report "runway vacated" in a small plane like a Cessna Cutlass the lights lose their structure. So I went to search for the yellow line on the left side of the runway until it curved into the exit. But this yellow line and the blue runway lights are hugely distant from each other so I had to focus my efforts to stay to the right of the blue lights but still being able to see the yellow line. Once I crossed the lines that mark that you are leaving the runway I could report back to the tower "runway vacated". My second-night landing was when I did try to fly to an airport next to the "Grand Canyon". As the report of the airport said expect gain or lose 40 knots of speed on final I decided not to land and flew back To Phoenix. What a wonderful experience. The landscape was already impressive on my flight to the Grand Canyon, but it was topped when I flew by night. First I was in contact with one center in charge while being above a certain altitude. Then this center passes you to one in charge below that altitude. Makes you feel like a professional pilot. Finally, this center did pass me to the tower of Sky Harbor. I was approaching from the north. Then, what controllers of large airports like they make you cross the airport midfield what ensures you stay away from the other traffic of the airport. You cannot imagine what a sight it is when you approach a large city like Phoenix by night. After he gave me its clear to land I was remembering my awful night landing earlier. When I did have the feeling that I was about to touch-down I did control the airplane so that all you felt on touch-down was the of the wheels turning. A Geman friend of mine that was on the plane with me was so impressed that he said he would fly again with me at any time. One other fact I want to share is the importance to really dominate the phraseology of radio communication and what Americans call to know the system. On my first approach by night to Phoenix, I did confuse the last VOR with the ILS beacon. So when switching to what I thought to be the last VOR the needle got full to the right and stayed there. So I did a report I was not able to tune in the VOR and so tower did give me instructions for the further approach. When you fly in from the west you fly over a mountain full of antennas and the red lights on top of it. I felt very good being routed by the tower. Those of you familiar with night-flight and how to find the location of the airport know the rule of the black spot within the lights of the city is where the airport is. Well, Sky Harbor has the terminal building between its 2 runways and so Sky Harbor does not look like a black spot. So when the tower asked me if I had field in sight I did respond negative a couple of times until he reported that I was on the 45 for the runway. Then I finally saw the airport. Here is something that is the consequence of good radio training. My instructor always said to report negative until you are really enabled to say affirm. So Tower knows when you are really able to report affirm. Do not be shy, it is your and others life! The second time on that approach was when tower gave me the instruction: 3-60 to the right until further advice! My teacher played the role of the tower and one of the things he said to teach us the right behavior was to stay silent and fly as instructed until tower contacts you again. I do confess I had never done 3-60s neither by night nor during the day! So I put the plane into a standard curve, kept it there, watched my altitude and speed. Being so familiar with this instruction from the tower I felt "at home" and this being relaxed was very useful!

5 years ago by Hellmut1956

Forum

Boat shaft connectors (which stuffs to use and which is good)

Thank you dodgy!! I needed this. I was always telling myself that a slight misalignment is okay bcz I'm going to use flexible coupler, so it's okay. There I might have done something wrong! Can you please give me the link,of that silicone tube that your using? Or I mean what kind of tube they are, where they are used😊 And yes I ment a lot s by earthquake. Sorry for that. At first I used some thin silicone tubes also, they weren't great.🤐

5 years ago by Sakibian

Forum

Boat shaft connectors (which stuffs to use and which is good)

I'm not sure what you mean by 'earthquakes' - do you mean there was lots of ? The prop-shaft and the motor shaft should be aligned as precisely as you can manage. Though a universal joint will accept some misalignment, you should aim to get things so precise that there is no need for a joint! That tube looks rather thin. I use tube which is 10-12mm in OD, with about 3-4 mm thick walls. You are correct that I 'make the shafts larger' by putting little knurled knobs made from aluminium bar on them. if you do not have a lathe, you can buy similar couplings like this: https://www.cornwallmodelboats.co.uk/acatalog/Robbe-Flexible-Coupling-3.2-4mm-R1445.html#SID=1586

5 years ago by DodgyGeezer

Forum

Allen Screw Removal

If there is nothing left to grip in the holes I would next try a left handed drill. The , heat and left hand direction may unscrew the bolt. Which ever direction drill you use the hole in the bolt head will keep it centred. Start with a smaller size and drill deep enough to be just below the head. Go up a size and drill again but don't get to close to the bolt thread diameter. Your ideal situation will be that as you get close the head will snap off. You could drill close then drive a screwdriver bit in and use that to snap the head off. Steve

6 years ago by steve-d

Forum

Aldi excellent service

Just had excellent service from Aldi. The rotary multi tool I bought packed up. I contacted a lovely sounding lass who has arranged for a replacement and told me to keep the faulty one. Now have a project. I think was the cause from a bent mandrel. Might be a soldered joint needs fixing or the speed control gone u/s. Wish me luck John O/T👍👍👍

6 years ago by onetenor

Forum

Exciters/transducers

Im not on here that much, so a little late picking this up. Are you talking about TT25 transducers like the ones Mrrcsound sell/ I suppose they all work the same, I've used these a lot, in planes mostly, and experimented with boats, so can offer some hands on advice. Firstly, you don't cut any holes to let sound out, as this isn't how they work. its all about the s. The centre ring is epoxied (that's the best way, they have to be permanent, but with some teasing they can be removed it required, rather than cyno) to the surface, which obviously needs to be flat. The thinner the material, the more sound, but its marginal, as the thinner you go, the less bass, or deeper tones. With planes, the best material by far is the epo foam, so when mounting into a ply or balsa plane they work best going to foam, then the ply, and the same will apply for a boat. 2-3mm is generally the optimum thickness. Remember, the area is going to vibrate, so use an area that can do this, the sides of a hull are ideal. The back of the transducers get hot, so don't cover the back, the heat has to dissipate and once secure, make sure the unit can move in and out, its easy to drip glue in the wrong place and the whole thing gets stuck, it wont vibrate now, so won't do the job. Also, its worth epoxying the transducer to 2mm foam, epo that the ready to fly planes works best, its close density, the stuff that packs white goods is poor as its a more open density and falls apart. Once you have this, you can move it around by just holding it against the hull to see where the best sound is. All this is relevant to the Mrrcsound transducers, I use a number of his sound units, so cant really comment on what you are using as I cant find that info on this thread (did a man read!) Here are a couple of my models to give you an idea👍 https://www.youtube.com/watch?v=jXFvrkDl7ow&t=207s https://www.youtube.com/watch?v=_OITvPabFHY&t=165s so these are all Mrrcsound units, and both have two tt25 transducers either side ogf the hull and fuselage. With the Mrrcsound systems, you can use two tt25, if you want an additional two, then an aux amp is required hope that helps! Paul

6 years ago by pmdevlin

Forum

54'' long Cervia tug.

My Cervia was ready built. I have replaced the Electric motor with a large servo motor (Brushed) .Direct drive and being heavy helps with ballasting. lead acid gel cells are power source. Motor rated voltage24 v but run it on 12v . low rev high torque no load current 1 amp. Shaft diameter 0.5 in. Gives some idea of power out. Being servo motor (ex computer drive 30 years old) well balanced no . Photo near shore shows power of motor.

6 years ago by tysonyoung

Blog

BRAVE BORDERER

Blog 4 update – Adjustable transom flap using metallic tape did not work. Think the caused flexing and fatigue, so it finally split. Fortunately had established the correct angle, so reproduced the flap arrangement with a fixed thin alloy plate. Much more robust. Have installed the new brushless motors and ESCs. The current layout is brushless motors on the outer propellers and brushed on the centre, all powered by a single 3S Li-Po battery and Rx. Am hoping to commence water trails this week, but have found an issue which was also present with the original brushless motors. When either brushless motor is powered up it operates nicely, however, as soon as the second motor is started either motor “stutters” and a pronounced “squeal” can be heard. The brushed motor is unaffected. Have now tried several ESCs but to no avail, the issue remains. It can be cured though by powering each brushless motor with it's own battery. When this is done everything powers up cleanly and quietly. The obvious solution is to use two Li-Po batteries and abandon the single battery approach. Am reluctant to do this as the model weight will increase yet again. Has anybody experienced this when using twin brushless motors and, if so, how was it resolved?

6 years ago by Rowen

Forum

Exciters/transducers

I would have thought you need the thinnest part of the hull for best ?👍

6 years ago by onetenor

Response

Hull Pt2: Motorisation - Come What May!!

Hi again Mike, forgot to mention the false floor bit! Sorry, no pics - shipyard design secret! 😁 No, haven't got that far yet. Still have to make the gear end plates so I can get the shaft spacing / gear meshing right, i.e. height of the motor above the prop shaft. Plan is to fix an ally plate into the hull with captive 4mm domed nyloc nuts fixed in it. The Taycol has right angled brass mounting brackets for vertical fixing so I shall mount it using 4mm bolts with compression springs between the brackets and the ally plate. The nyloc nuts SHOULD hold things in position! That way I should be able to adjust the motor height and tilt in any direction (well, pitch and roll anyway!) to get the two shafts parallel in the vertical plane and optimum meshing of the gears and minimum . That's the theory anyway 😉 Then I only have to worry about getting the shafts aligned in the horizontal plane, the 'Yaw'. Which should be relatively easy with careful fitting of the ally plate. Minor yaw adjustment could be accommodated by opening out the bracket holes to curved slots with a diamond file. Objective is max power transfer with minimum noise and friction. Not to mention easier mounting than fiddling about with shims! And I don't have to worry about not getting the angle of the ally plate in the hull dead right 😊 Accurate measurements inside this sloppily built hull are virtually impossible! There are no right angles or straight lines or even symmetry where you would normally expect them 😲 So no true reference points or datum lines. We'll see. Cheers, Doug 😎 Ooops! Somehow my response to the motor conversion 'secrets' slipped into the previous Update!? See below in 'A Messy Business'.

6 years ago by RNinMunich

Forum

Sea Queen prop shaft

Heartily agree Rex 👍 Two such couplings in series is a guarantee for misalignment and high potential 🤔 which wouldn't do the 'posh' bearings much good! 😡 I would move the motor. Bon chance, Doug 😎

6 years ago by RNinMunich

Forum

Sea Queen prop shaft

What is the KV of your motor and how many volts do you intend to use? The theory is that this is how it should be done and in practice I Have done this setup with Huco type couplings which turned over very smoothly but they could not handle the high revs ie14.000 The Radio Active couplings are first class but again I have experienced some balance issues and with them. I worry slightly that the length of 2 couplings together is somewhat long but I may be totally wrong. All you can do is to try it I shall follow with interest

6 years ago by Rex3644

Forum

Too Powerful Brushless ?

That sound better with a 5 mm shaft. But still be sure to support the shaft under the boat and if possible also under the shaft inside the boat. This way you shouldn't have any trouble with though the shaft to loosen it.

6 years ago by BOATSHED

Forum

Too Powerful Brushless ?

Hi Graham Now we can see the actual prop shaft and motor it is clear that the shaft is not supported inside the hull close to the coupling. At the high revs your motor achieves I am not surprised you have had problems. I do agree with all the comments and help you have been offered and agree a 5mm shaft would help as well as a different motor. I use 3 blade brass props with brushless and have no problems but do keep the prop size to a diameter no greater than the motor diameter, as Mark advises. It's difficult to see how much space is in the hull to allow the motor coupling and shaft to be closer, but if you are replacing the shaft it may be a good time to reposition the motor and the shaft with the prop attached to a slightly different angle. This will mean opening the slot and perhaps enlarging the outside skeg but you can easily repair any damage with plastic padding to make good. Even if you keep the existing arrangement I suggest you provide support for the prop shaft close to the bearing as I suspect this is where you have experienced the problem with the . A simple 2" block of wood attached to the keel and shaft would suffice. Model looks very good and I look forward to seeing some on water shots.

6 years ago by Dave M

Forum

Too Powerful Brushless ?

HI Graham. Every picture tells a story!!! The motor is definitely wrong, its designed for racing, low torque, mega revs, not for scale boats. What diameter is the shaft tube??? looks thin??? did the prop shear in the water?? would explain the and damage to the shaft mountings, try a Raboesch shaft, with a ballrace at the motor end, great quality, also they do a huge range of props, google the name there site will come up. Mark

6 years ago by jarvo

Forum

Too Powerful Brushless ?

By the way the Araldite is very good glue but is brittle and as you have found cracks off with . The other glues mentioned all have flexibility so will absorb any .

6 years ago by onetenor

Forum

Too Powerful Brushless ?

Hi traiderman I am no expert. dont forget, as pmdent highlights, you you multiply the KV by the volts of the supply to get the RPM of the prop. so you can play with the volts supplied or the Kv of the motor or both. regarding the , have you supported the outer end of the shaft? if the shaft leaves the hull and has a good amount of unsupported shaft the end of the shaft effectively will scribe a circle. At the speed the shaft is turning and with the pressure on the prop this may cause your . Richard

6 years ago by rmwall107

Forum

Too Powerful Brushless ?

Traderman - whilst I am not an expert ( I am currently trying to decide what brushless combo to fit to a 34" RAF Crash tender) - clearly your motor is turing your prop shaft way to fast. With your motor spec of 3180 kV and a 14.7 V Lipo - your motor will be trying to turn your shaft at a speed of somewhere in the order of 45,000 RPM !! Firstly your prop shaft may not be rated for anything like this speed and secondly any slight mis alignment will likely be generating significant - enough to cause your problem- have you noticed any? As to motor power - the motor may not be too powerful - but certainly dropping to a lower kV motor say 1100 and reducing the Lipo voltage to a 11 or even 7 volt system might be the right answer......but as I am finding its all a bit suck it and see... Peter

6 years ago by pmdent

Forum

RE ads90's Vosper Firefloat

Many thanks Dave and all. The reason I think it was a kit is because of the superstructure and deck detailing which you cannot see on my photos. All of the window frames have raised rivets around them and the deck has deck raised deck strips. As a modeller I know that these can be recreated but they look too perfectly spaced, etc. Many thanks for looking through your back catalogues Dave. Terry was very helpful and sent me quite a bit of information - he is a font of knowledge. My boat is well used at our pond at Eastrop, Basingstoke where I am the Secretary and Treasurer of the model boat club. Every couple of years I do have to give the hull a rub down and re-spray as being made from balsa and when running fast, the does tend to crack the hull along the panel joint lines, but it is an easy fix and I try not to abuse it as it is precious to me.

6 years ago by ads90

Forum

Rudder Strut Assemblies

I am building from scratch a 35" Mini Momo and looking at the hardware required for the stern. Is there any great advantage to having a Z Type Rudder / Strut Assembly rather than simply having a Stinger and the separate rudder? To me they look like they could be a source of or potential problems as they do not appear to be fixed to the stern at the location of the rudder. Thanks

6 years ago by peterd

Forum

Seabreacher

Just spent a few hours fitting brushless motor to seabreacher....and 150amp esc ...problem working at these high motor speeds is and motor has actually bent the driveshaft which is brass 6 mm ...next step is new shaft of steel....

7 years ago by Captain-Steve

Forum

Motor problem

Hi all I have located an 850 motor and mount at Howes Models in Kiddlington not too far from where I live in Malmesbury, for £22.50 however the prop shaft is 4BA, the coupling is not a problem as I can get the insert for the larger motor to fit the existing red coupling, but I can only seem to find 4mm 40 or 45mm propellers which are a fraction bigger than the 4BA which I know will screw on but they would have a bit of a wobble on the threads and could give me an out of balance , apart from drilling out the old propshaft assy and fitting a new 4mm one what else can I do? or does anyone have a old 4BA prop they can let me have?

7 years ago by RichardSReade

Directory

(Pleasure Craft) Aero kits Sea Queen

I felt the need to build something large from scratch having built Sea Nymph Sea Rover aero kits Swordsman kit. Many GRP based I/C powered before converting many of them to Brushless power. in Feb 2017 I bought plans from ebay in readiness for a family trip to Wales. My brother in law has a well kitted workshop in which he produced Sailing dingy kits before retiring. The aim was to produce this boat for the least possible cost. Thankfully there are lots of ply off cuts in Wales plus an 8x5 sheet of 1.5mm so I set about making my own kit during the time I was there. The motor was to be a Marx Decaperm selected from my bits box which I chose to set up using the geared drive. On the first launch performance was lacking to say the least so the motor mount was adjusted to direct drive but alas performance was not much better then everything stopped. The wires on the commutator had become unsolder end a common problem apparently I've now fitted a 3650 brushless stolen from an early attempt of a Huntsman 31 built for my Grand daughter which had replaced the Graupner 600, she is now 19 and interested in other things beginning with B. Having fitted the brushless a lot of was experienced his was traced to a misaligned coupling,next outing will be with a huco type of fitting just to check it out roll on Thursday. (Motor: 3650 watercooled) (ESC: Hobby wing 100 amp w/c) (8/10)

7 years ago by Rex3644

Forum

Crash Tender Shaft Tube Poistion

Paul - luckily I have a new shaft as purchased one the other as Dave said about about making sure it true before fitting due to issues later on if it wasn't true. Doug - I'm going to go for your's and Dave suggestion of fitting a fillet as to be honest it sounds easier and like Paul says its underwater so wont be seen and if it ever gets in the water wouldn't want to lose it on first trip out😁😁😁

7 years ago by neilmc

Forum

Crash Tender Shaft Tube Poistion

Neil, the suggestions about prop support are all valid, just different takes on things. I would (if you intend to repaint the hull) sand off to key, or prime the old paint prior to installing the shaft, as it will be easier to repaint and prep. Question, sorry if I missed this, is that a new shaft with new bearings? if not get new from shg marine (they are at the Blackpool, show, and the midlands engineering show if you can get to either, I'm not sure where you are?) they are dirt cheap, called aceteal or something similar, they water lubricate, and cost about £2 each. Roll the inner shaft on a piece of glass or a mirror, this will tell you if its bent, any sign of this, get a new one, or you might have alignment and issues. (glass is totally flat! there's a free tip to test you prop shafts ha ha !!👍) same can be bought from shg, and get stainless. Back to the support, the thing Dave mentions is a piece of wood that fits between the hull, and the shaft. The shaft is then epoxied to this, giving support, but it wont be true to original. You have the original support, so remodel this to fit your new angle. if you use any bolts etc to secure, use stainless so they don't rust. Once painted, it will be hidden, and its underneath anyway so cant be seen. it will need to be tight to the outershaft, once positioned, you could solder, as they are both brass, and either feed into the hull bend over and epoxy, or screw as per original. Here is my big fireboat, its twin, but the concept is the same, the support came into the hull, and on this example, I put a brass pin through, and epoxied it all

7 years ago by pmdevlin

Forum

Crash Tender Shaft Tube Poistion

Thanks both Doug and Dave I do have a couple of different mounts which were purchased to try and get round my sticky motor which initially proved to the glue holding the shaft had failed causing and the old diesel mount causing misalignment. I have just recently even purchased a plastic type mount like the one you have Doug😉 Should have removed the mount when you suggested it a year ago Dave but a little scared now I can start a fresh. Now thats done and new lease of life should see me busy at the weekend. Little concerned on the hungry and smelly motor but like the idea of a Lipo with Tamiya connector will have a look for those later. Was a little worried about drilling through but like the idea of dowel and sand paper nice and easy I think until I get bored and then probably resort to the drill lol. Thanks for all the advice and the confidence you guys give. Ill update my year old blog with progress over the next couple of weeks.😁😁

7 years ago by neilmc

Response

Decks

Some info. on radar, armament and wartime mods! 'Ya pays ya money and yer takes yer choice'! 😎 "Armament, electronics and protection The main armament of the Illustrious class consisted of sixteen quick-firing (QF) 4.5-inch (110 mm) dual-purpose guns in eight twin-gun turrets, four in sponsons on each side of the hull. The roofs of the gun turrets protruded above the level of the flight deck to allow them to fire across the deck at high elevations.[11] The gun had a maximum range of 20,760 yards (18,980 m).[12] Her light anti-aircraft defences included six octuple mounts for QF 2-pounder ("pom-pom") anti-aircraft (AA) guns, two each fore and aft of the island and two in sponsons on the port side of the hull.[11] The 2-pounder gun had a maximum range of 6,800 yards (6,200 m).[13] The completion of Illustrious was delayed two months to fit her with a Type 79Z early-warning radar; she was the first aircraft carrier in the world to be fitted with radar before completion.[11] This version of the radar had separate transmitting and receiving antennas which required a new mainmast to be added to the aft end of the island to mount the transmitter.[14] The Illustrious-class ships had a flight deck protected by 3 inches (76 mm) of armour and the internal sides and ends of the hangars were 4.5 inches (114 mm) thick. The hangar deck itself was 2.5 inches (64 mm) thick and extended the full width of the ship to meet the top of the 4.5-inch waterline armour belt. The belt was closed by 2.5-inch transverse bulkheads fore and aft. The underwater defence system was a layered system of liquid- and air-filled compartments backed by a 1.5-inch (38 mm) splinter bulkhead.[15] Wartime modifications While under repair in 1941, Illustrious's rear "round-down" was flattened to increase the usable length of the flight deck to 670 feet (204.2 m).[16] This increased her aircraft complement to 41 aircraft by use of a permanent deck park.[17] Her light AA armament was also augmented by the addition of 10 Oerlikon 20 mm autocannon in single mounts with a maximum range of 4,800 yards (4,400 m).[18] in addition the two steel fire curtains in the hangar were replaced by asbestos ones.[19] After her return to the UK later that year, her Type 79Z radar was replaced by a Type 281 system and a Type 285 gunnery radar was mounted on one of the main fire-control directors.[16] The additional crewmen, maintenance personnel and facilities needed to support these aircraft, weapons and sensors increased her complement to 1,326.[7] During her 1943 refits, the flight deck was modified to extend its usable length to 740 feet (225.6 m), and "outriggers" were probably added at this time. These were 'U'-shaped beams that extended from the side of the flight deck into which aircraft tailwheels were placed. The aircraft were pushed back until the main wheels were near the edge of the flight deck to allow more aircraft to be stored on the deck. Twin Oerlikon mounts replaced most of the single mounts. Other twin mounts were added so that by May she had a total of eighteen twin and two single mounts. The Type 281 radar was replaced by an upgraded Type 281M, and a single-antenna Type 79M was added. Type 282 gunnery radars were added for each of the "pom-pom" directors, and the rest of the main directors were fitted with Type 285 radars. A Type 272 target-indicator radar was mounted above her bridge.[16] These changes increased her aircraft capacity to 57[20] and caused her crew to grow to 1,831.[7] A year later, in preparation for her service against the Japanese in the Pacific, one starboard octuple "pom-pom" mount, directly abaft the island, was replaced by two 40 mm Bofors AA guns;[21] which had a maximum range of 10,750 yards (9,830 m).[22] Two more twin Oerlikon mounts were added, and her boilers were retubed.[21] At this time her complement was 1,997 officers and enlisted men.[7] By 1945, accumulated wear-and-tear as well as undiagnosed shock damage to Illustrious's machinery caused severe s in her centre propeller shaft at high speeds. in an effort to cure the problem, the propeller was removed, and the shaft was locked in place in February; these radical measures succeeded in reducing, but not eliminating, the s and reduced the ship's speed to about 24 knots (44 km/h; 28 mph).["

7 years ago by RNinMunich

Forum

Best way to mount brushed motor

Trying to replace the motor mount in an existing model is difficult. Especially when there is structure above the motor. The former arrangement was geared and I am changing it to direct drive. Getting the alignment and motor to allow for the smoothest operation is a lot of trial fits. This motor has lots of torque.

7 years ago by Ronald

Forum

a very noisy fireboat

its early on with this project, I was going to wait until its completed, but not sure when that will be, so Ill give you a sneak peak. I've been using a sound system in one of my model planes, and over time have become friendly with the guy who makes them, helping him with various things. I got thinking about the 4 foot fireboat I have, and how cool it would be to have a sound unit. So, to cut a long story short, I knew he had a plane sound with twin Merlin's for a bomber, and I use a merlin for my P51 Mustang model. After a serious amount of pestering, I got him to modify one of the 5 stock sounds on his Boat sound unit, using the twin Merlin sound from the planes. It took some work, getting rid of the propeller sound on the start up and shut down sequence. I ran it for the first time last night, but forgot to take spare batteries, and a small screwdriver to adjust the settings, so couldnt change the settings, in particular, the volume was set way too loud, losing some of the clarity of sound. This is pretty close to the real engines, which where v8 meteor, this sound is an actual recording of the v12 Merlin, its doubled up, and staggered, so you can hear the two engines running. It has start up and shut down sequence, it isn't clever enough to read reverse unfortunately. Its a speakerless system, using transducers instead of speakers, which are much louder, smaller and lighter. They rely on s, they are epoxied to the hull, and the whole boat becomes the speaker! Its the first time I've done this, and its pretty new on the market for boats, planes have been going for a few years. I've realised that whilst I put them above the waterline, I didn't account for the roll of the hull, when one (there is one on either side) goes below the waterline it muffles the s, and causes a funny sort of gurgling noise, ah well, like I say, its early days! Still a bit of tweaking to do, but you get the idea. Stock sounds are Turbo cat diesel, Johnson outboard, evenrude outboard, mercule v8, steam. They also have aux sounds, such as ships bell, steam whistle, horn, seagulls etc. I think on my system the Johnson is dropped in lieu of the twin merlin sound. Have a look at www.mrrcsound.com https://www.youtube.com/watch?v=EkJUHe1tR_w

7 years ago by pmdevlin

Forum

a very noisy fireboat

Hi Paul As I already have the Action sound unit (Whitby lifeboat engine sound, my model) and a 20w amp I sourced some resonators from Holland www.soundimports.eu/. They were out of stock for the initial order so I bought two lower power exciters to see what they were like. Attached to the back deck of my Trent and plenty of volume but the was very visible. I have now received some 24Watt (Dayton Audio DAEX25FHE-4 Framed High Efficiency 25mm Exciter 24W 4 Ohm) similar to yours and they are attached to the hull sides above the waterline and sound great on the bench. Will be trying on our lake as soon as the weather improves but should be as good as the big 8" speaker I was using and several pounds lighter so the model will sit correctly on the waterline. Thanks for sharing this sound medium Mine are attached by 3M VHB (Very High Bond) adhesive so I am hoping if I need to move or replace I can buy some glue to re-attach Dave

7 years ago by Dave M

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a very noisy fireboat

Hi Doug, they are from mrrcsound, available on the website, they are called tt25 transducers. Having played with these at length with model planes, I now know the hull thickness isn't enough. The thicker the material, the deeper the sound, but you lose volume. Unfortunately once epoxied on, they don't come off, until the epoxy goes brittle, which does happen as the s cause this. if I try to pull them off now, they will break. I have too much volume, and not enough depth. With a plane, due to distance away from operator, you need the volume, with the boat, they don't go anywhere near as far away from the operator, so I messed up here😭 Ill turn it down a lot, see how that works out

7 years ago by pmdevlin

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Propshaft Bearings

Hi Rolfman, I don't have a link, never looked for one!, but the the following observations - 1) it helps enormously if you own a small lathe, which I admit I do, and also admit not everyone does. 😉 Dremeling is OK - as far as it goes! BUT - a little offline (in the original mechanical engineering sense!😉) creates friction and which negates the expense and effort to fit ball races in the first place 🤔 A lathe with a dead centre eliminates this source of error. 2) The ball race should NEVER be soldered or brazed. (When did you last see a car wheel bearing soldered or welded in?) Any process which includes applying heat to both tube and ball race can, and most probably will, damage the ball race, especially if it is one of the 'packed for life' types. You will boil the grease packing out of the race and possibly distort the rings. Correct technique would be to machine the tube (on a lathe for accuracy) to a few thou less than the OD of the ball race. The machining creates a step inside the tube, with depth to accommodate the thickness of the ball race. The end of the tube is then GENTLY heated and the ball race pressed in. This should preferably be done on the lathe using the dead centre to ensure concentricity. When everything cools down you have a tight 'shrink fit'. No other 'glue' needed😉 BTW: I have been pedantic using the term 'ball race' because that is what Allen has bought and shown in his pic. A 'bearing' can also be a simple bush, which can be soldered or brazed with less problem than ball races BUT - needs even more care with alignment as it has no 'give' like a ball race! I am faced with exactly this problem with corrections to my Graupner Graf Spee where one shaft and it's bushes are out of alignment 🤔 I will most likely replace the bushes with ball races. Hope I haven't discouraged you but I wondered why you went this way! Good luck, Doug 😎

7 years ago by RNinMunich

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Wiring in a rx, an ESC and a battery (pack)

Hi Doug It's a tinny type noise, no s or anything I can see/feel.... I'm using the Tamco Tx and Rx along with an Mtroniks Viper 20 ESC....once it's all switched on the green rx light is on and the red/green light is on on the ESC....the Tx is also switched on and all is quiet...once the throttle moves the sound starts...possibly the motor, could be a normal sound one should expect....the coupling appears ok

7 years ago by NickW

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Wiring in a rx, an ESC and a battery (pack)

Hearty Congrats 👍 What sort of noise? Can you feel any s from the motor and/or coupling - prop shaft? Carefully test motor / shaft with your finger tips!! Dry bearing somewhere perhaps? cheers Doug 😎

7 years ago by RNinMunich

Forum

Glue guns

I have a lot of experience with Glue Guns having taught Technology in schools for 30 years +. There are two main types of glue stick-Hot melt and Low melt (for safer use). The hot glue will stick skin with often devastating results!!. I also build theatrical props and it is very useful for building all sorts of things and will stick most things well. ie wood, metal, plastics (which it can effect) glass, clothing, felt, straw, string, rubber and many many more, but they are all quick fixes and can come apart with constant use and especially on shiny surfaces. In models I tend to use the stuff to hold cables in place and tack things in position quickly to align them before finally gluing with Epoxy. Motors can be be held in place with Hot Glue and the advantages are it makes a good sound insulator and can be repositioned for a few minutes before it goes cool. Also it can be prised off again if you need to change the motor. I would not not recommend it as a permanent fix on many model things and certainly not as a structural adhesive, fittings etc. will almost certainly fall off eventually. if you regard it as a third hand you'll find it a useful addition to your gluing arsenal. Happy boating......Ron.

7 years ago by ronrees

Forum

Kingfisher Plans

Hi Gramps.What you propose is known as a skeg and will reduce shaft too.To protect the prop you could fit a cage mounted between the skeg and the hull or just a curved rod/bar mounted the same way curling round the prop.Good luck John

7 years ago by onetenor

Forum

Scudder

Hi I have refurbished this 'Scudder' hydroplane designed by Vic Smeed in the 50/60,s. I think it looks a bit like a marine Douglas Dakota! In place of a an OS MAX 3 15 glow diesel, I fitted a A2212/13T, 1000KV brushless motor and propeller and an HW H30A controller. It goes well but will not quite plane. It current uses a NiCad 7.2v. I have adjusted the angle of the prop/motor to push the nose up a bit, but will the motor/controller set up take a higher voltage so it will have more power? Hi Gents Update on the Scudder...I fitted an 11v Lipo, and relaunched. Loads of power; the hydro immediately went onto the plane and ran very fast....then the trouble started! The roof flew off, passed through the prop, and was chopped up...this in turn damaged the prop blades and possibly through , the motor mount then broke up! Maldon never had so much entertainment!

8 years ago by frankburgess

Blog

Motor mount and propshaft

Now that the side skins are fitted it's possible to get the motor mount in position so that the prop shaft can be set into the keel properly. The kit includes a very clever mounting system for the motor that once fixed in place will still allow for minor adjustment to get the prop shaft lined up as straight and true as possible. The motor mount is carefully marked and drilled to accept the motors mounting plate and is then bolted in place with cap head bolts and self-locking nuts, the mounting cheeks are the bolted to the mount with wing nuts and spring washers which will provide the motor adjustment. All of the mounting hardware I have used is stainless steel and is not included in the VMW kit so these were sourced from eBay suppliers. I also found on eBay a 5mm to 5mm rigid coupling and used this temporarily in place of the flexible coupling to hold the motor, coupling and shaft in perfect alignment while the motor mount is glued and pinned to the hull side skins. Once I was happy with the alignment I could epoxy the prop shaft into the keel, the rigid coupling can then be replaced with the flexible coupling. Spinning the outrunner motor case with the shaft attached proved very smooth without any tight spots or noise, at this stage the shaft is un-lubricated and I will be fitting an oiler sytem for this. I also fixed a brass angle plate between the bottom of the motor mount and the keel to further locate and support the motor mount. it should also (hopefully) prevent any twisting or deflection when the motor is under load and reduce any .

8 years ago by robbob

Forum

Propshaft Alignment

I use the bonded rubber type from "model boat bits". Made to suit and dampers. They will also make new shafts s for existing tubes if worn.

8 years ago by Derek

Blog

Perkasa Fittings

the Perkasa fittings arrived today from Battlecraft so lots to get on with but before they get attached I have to varnish the hull and make and epoxy some wedges onto the prop shafts to stop any its all good fun 💭

9 years ago by Northumbrian

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M, Tronics

If you are getting a lot of from starting the motor, try looking at the U/J. if its one of the plastic one's they have been known in the past to be out of ballance, turn the plastic part end to end, this may help, or change the U/J completley

9 years ago by jarvo

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M, Tronics

Under normal usages you shouldn't need to put rubber mounts on an electric motor. By their nature they are balanced and produce thrust with more than one impulse per revolution. if an electric motor setup is giving a lot of start looking for the cause!

9 years ago by Haverlock

Forum

M, Tronics

HI Saltysnogbad The use of rubber grommets when mounting your servos was a requirement for models using IC engines where the could interfere with the control especially in a model aircraft. Unless you are running a very fast race boat it is probably not necessary but many do use the grommets as they allow slight movement if the push rods become tight at full travel. That said they won't do any harm if you do choose to make use. Dave

9 years ago by Dave M

Forum

fire boat Identification

I have several original Aerokits models and all follow the same design principle developed by Les Rowell in the late 1950s and 1960s. IC engined boats were very popular at the time and electric motors were very chunky and heavy and required large batteries for power. The construction had of necessity to be robust to carry the weight and also strong enough to withstand the power and from the IC engine. Weight was not a particular concern so the hulls were made to last. As Shaun has stated the parts were all supplied pre-cut and the plan and building guides were aids to help the average modeller. Modern Laser cutting techniques have enabled the designs to be re-engineered to reproduce the original outlines but using more current construction techniques now possible. The result is a model that weighs less without losing the original concept. There will always be those who prefer to have an original but the current copies will help to introduce present modellers to this classic range of wooden boats. Dave Wiggins has an article in Februarys MMI (Issue335) about the Sea Scout and shows pictures of an actual un-built kit plus an exploded view of the plan.

9 years ago by Dave M

Blog

Completed

Perkasa now finished and maiden voyage completed, build time a bit over five months. Radar rotates and lights work, and Bofors rotates under radio control. initial trials showed that the prop shaft inner had been made out of some bent stainless and it whirled alarmingly at speed, making a horrendous noise. The shaft is quite long and with bearings around 18 inches apart it is very flexible, and the bend when it was stationary just got worse as revs increased. Straightening was found to be Impossible but some Improvement was obtained with a mid-position, pressed in, Teflon bearing, and the terrible rattling/ noise was reduced by replacing the rear brass bearing with Teflon. A new inner shaft has however been ordered. With the same motor and batteries as my 46 inch Fireboat and no extra ballast, the Perkasa weighs about 600g more, but its performance seemed to be slightly faster. This boat does have a 5mm larger propeller but still it only drew around 55A maximum. At high speed it lifted noticeably at the front so after the first run I have added some 300g of leaded vinyl - taken from an old X-ray gown - placed under the Bofors. The hull shape at the front is much more successful than the fireboat in keeping water off the deck at slower speeds, but the hull becomes dead flat at the rear making this a real planing boat capable of high speed. With a single motor and a fairly big prop I found considerable torque reaction, and on the first run I couldn't trim the boat to run straight, it just wanted to turn right. The rudder was adjusted quite a bit to overcome this, but I suppose that's not much of a price to pay if the alternative was contra-rotating motors and props, or three props like the original! 😎

10 years ago by Lauriem

Forum

Aerokits sea scout hull skins

HI Alan The only problem with 5 min or 10 min epoxy is that it is brittle, compared with long set 1hour / 24 hour, the longer it takes to set the stronger the molecular bond. (what words for a saturday!!!!!) That said so long as the epoxy is not subject to , motor mount etc its good to go. Just as an add-on, if you wand your epoxy to be runny, add a small amount of meths, it also slows the setting time, while the meths evaporates. Mark

10 years ago by jarvo

Blog

Prop shaft and rudder stock

Today I have affixed the motor mount, propshaft and rudder stock to the hull of the model, The rudder stock I decided was to long so I have cut it down and to prevent undue stress on the thin hull I have placed a piece of wood across it to prevent any bending stress. I have created some more cardboard templates for wood to be cut, but I can't cut anymore wood as all I have used so far is a hacksaw and a rotary tool with its horrible cutting bits which is just burning the wood, therefore I have placed an order for some new cutting bits that are designed for wood. I was going to buy a coping saw but to get straight lines especially for the main deck I decided for the new cutting bits. The hull itself has been sanded down to get rid of all the bumpy edges and I have been in contact with a paint shop to see what paint I should use for the fibreglass and hull itself. I have decided that the propshaft needs some support to reduce s.Therefore it has been supported with some scrap wood it looks terrible but it won't be seen once the mount for the servo has been placed over it. All in all its going slow but once the cutting bits arrive and the bloody transmitter / receiver gets delivered I will have the underwater bits ready for water testing, before I start on the superstructure and details. Lessons learnt so far. 1) Always use high grit (320 ) wet sandpaper to fibreglass as the dust is horrible and gets everywhere 2) Always use cardboard of the same thickness of wood to be used for templates otherwise they give the wrong dimensions. :@

10 years ago by ubay93

Blog

Aerokits 46'' Fireboat twin screw brushless conversion

ok time to fit all the runing gear back into the boat, this is now becoming second nature, I can do it with my eyes closed! Batts charged, time for a bench test, horror!! at half stick, there is a bad resonate , flippin heck!!!> 😟 we decide to fit centre bearings in the prop tubes, maybe the shafts are "whipping" as they are quite long, so everything out again, bearing fitted, all back in, still the same! By pure fluke, I put my hand on the top of the shafts, with motors running, and the goes away, so we need extra support, the bulkhead is not enough. HS93 knocks up a pair of mount/motor supports, that go between motor and mount, fits two locating plates in the hull using captive nuts, hey presto, its perfect, silky smooth, at last we can get wet!

11 years ago by pmdevlin