Response

Re: SEAPLANE TENDER STAND ADDITION

Hi All. Interesting debate😉 All I can say is that my experience with lithium grease, whatever the colour, is that it will over time cake and stick to the walls of the tube. Had similar experience using it in car wheel bearings ☹️ Seems to be due to the nature of lithium, i.e. plates, which slide over each other to provide the 'lubrication effect'. But it don't last. Eventually the stuff dries out and the plates stick together. Coagulation 😭 I now use Gear-Flon, a PTFE/TEFLON grease from Dupont. Bought mine from Krick here in Germany. I squish it in under pressure with an oversize syringe.😉 You can also find it on Amazon etc. https://www.amazon.de/GEAR-FLON-Hochleistungsfett-mit-Teflon/dp/B00UI0AS40?language=en_GB Cheers, Doug 😎 PS To JB: I also inject some into ball races, until it extrudes from the other side, before fitting them!😉 PPS: Almost forgot😮 I also fit a dished oil saver washer between the shaft tube and the . A habit I got into while still using oils for shaft lubricants.

5 years ago by RNinMunich

Blog

New drive Train and Oiler

Most of this actually took place last August / July! Regular readers may have seen that when Dad built this boat in the 60s he put a Taycol Target field motor in it. About 25 years ago I put a Decaperm and 'modern' transistor ESC in her to provide forward and reverse. Performance was sedate to say the least. I have since modified the Taycol (see below) so it can be run forward and reverse and decided to put it in an ancient Billings Boats Danish fish cutter (Gina) that I inherited from an Aunt. The cutter is badly in need of renovation (see pic 1) and the Taycol will be more suited to her performance requirement! On advice from Canabus in Hobart I obtained a Propdrive 2830 1000kV brushless motor, appropriate ESC and a 35mm 3 blade prop from Raboesch. Pic 2 shows the old and new motors. Next step was to trial fit new motor mount, coupling and prop. Pics 3 &4. While doing this it became obvious that a new shaft was in order, as mentioned in last update. Soooo, - appropriate stainless steel rod, s and set ring were acquired and back to the workshop. After cutting to length to accommodate the new coupling type a 3mm thread was cut a the prop end. At the inboard end I milled recesses for the grub screws in the set ring and the coupling, pics 5 - 7. I don't like to just file(or even mill) flats for the screws cos they have a tendency to slip and work loose😡 Trial fitted the new shaft and found I'd boobed a bit with the measurements and need extra s to make up the difference. 😲 Pic 8. No sweat, they came in a pack of 50 anyway😊 You can also see in this pic that I decided to fit an oiler pipe while everything was in bits anyway.😉 To solder it on in a cramped space without setting the boat on fire 😡 I packed a wet rag underneath and used a gas Kitchen Torch! Known as a 'Gas Gourmet Burner'. Yep, those handy little gas torches like your Missus uses to melt the brown sugar on her Crème Brûlée!! So do I, delicious 😜😉 The torches are not expensive, small, very handy, refillable with lighter gas and can be adjusted to a very small hot flame. ideal for this job. See pics 9 & 10. Pic 11 shows the new motor & mount, shaft and coupling all trial fitted after using a brass alignment tool I quickly made up on the lathe. Pic also shows the trial electrical installation after cleaning up the 'machinery compartment' a little and painting with silver Hammerite. A Quickrun BL ESC is sitting in the bottom in one of the trays my Dad originally fitted for the 2 wet cell (very wet!) 6V lead acid batteries. The home made board on the left carries the battery and ESC connectors, main ON/OFF switch with LED, blade fuse holder with a 20A fuse and a green LED which tells me if the fuse is blown! Stuck on the walls (OK Bulkheads!) with so called Servo Tape are a 6 ch Turnigy iA6 2.4Gig RX and the arming switch for the ESC. Battery compartment is sized to fit 2S and 3S hard case LiPos. For trials I can fit my Wattmeter forward of the switchboard and splice it into the battery supply using Tamiya connectors. Might change these to XT60s later if current drain is more than 12 to 15A. All for now, all this was pulled out again preparatory to cosmetics on the hull, decks, cabin roof and walls inside and out. But that's another chapter so, 'Tune in next week, same time same channel when once again it's time for 'WHAT DO YOU MEAN BUCK RODGERS IS APPROACHING!? 😁 Or 'The Saga of the Cabin Roof' 😉 Cheers Doug 😎 BTW: After drilling the shaft tube for the oiler pipe I flushed it out with light machine oil (pumped in from a big syringe) and shoved a few pipe cleaners through (rotating them on the way) to remove any remaining drill swarf!!

6 years ago by RNinMunich

Forum

Prop size and speed

Agreed Martin, one thing at a time! BUT: Stuart; I believe we are discussing your 24" Commander here. In which case your results mirror mine with my 24" Sea Scout. Except that my prop shaft did not bind!!😉 It was also reluctant to plane with a 2S LiPo (7.4V nominal) but went very well and planed easily with a 3S (11.1V nominal). I also was using 4000mAH batteries. I published my results using various batteries here in the Media - Video section. Go to the Media Gallery and search for Sea Scout. So, I would leave the motor and prop alone and (after fixing the prop shaft!!!) try a 3S battery. I'm sure you will be satisfied 👍 Prop technology is complex as Martin said, our old friend Bernoulli raises his head for instance🤔 But, essentially bigger is better for more speed or same speed with lower shaft revolutions when applied to real size ships. BUT 2: with our electric powered models bigger props often simply increase the load on the motor causing it to draw more current for a fractional increase in boat speed if any. In essence props with fewer blades are inherently more efficient as you hinted. Minimum being 2 of course 🙄 Two bladers are popular with the Fast Electric guys for that reason. I don't do speedboats, I'm a scale guy and my maxim is; If the real vessel had an XYZ screw then so will my model! Summary; first fix the propshaft; lubrication, alignment with motor shaft, ensure a few thou of clearance between prop hub / locknut and the end of the shaft tube. Preferably with a in between. Second, fit a 3S battery preferably crosswise above the C of G of the boat. As you can see in the pic of my Sea Scout 'engine room' in your Commander thread. For those with a mathematical mind, undying curiosity and an afternoon to spare I attach a paper on the Principles of Ship Propulsion from MAN, the supplier of small to huge diesels to probably a majority of ships (commercial and naval) built today. You should find Chapter 2: Propeller Propulsion particularly illuminating! Happy reading 😉 Just remember the paper deals with real ships and real water, we have scale ships but not scale water🤔 Basic dynamics still apply though. Cheers, Doug 😎

5 years ago by RNinMunich

Forum

Cheap motor for a quick fit, but what prop gents?...

OK, found one, 'discontinued product' 🤔 Seems Tower pro only make gas engines these days. https://hobbyking.com/en_us/towerpro-brushless-outrunner-2408-21.html Specs "TP 2408-21 The most widely used towerpro motor available today. the 2408-21T is often used in GWS (means Grand Wing System, USA apparently!) upgrades. Paired with just an 18A besc, this motor is an excellent and cheap way to upgrade small planes to brushless. An RD1047, RD9070 or 8040 size propeller are the best choice, with the RD9070 and 8040 giving the best thrust and amp draw balance. For 2-3 Li-Poly Cells (7.2-12.6V) 31 mm diameter x 62 mm length Maximum current: 13A Weight: 50.2 grams / 1.77 oz Comes with stick mount plastic frame Firewall mount capable Comes with two prop nuts and one washer 3mm shaft diameter 10mm x 10mm stick mount Kv: 1750 9 Stator Poles, 12 Magnets" So it's OK for a 3S LiPo, which will give about 19.400rpm OFF LOAD. Max current 13A ON LOAD. No way of finding the other little one without at least a hint🤔 Looks like an Outrunner plane motor as well. Suck it and see! Probably similar specs to the Tower motor. The two brushed ESCs should be good for your Taycols as none of them should take much more than 10A or so. Use 15A fuses, as I have already fitted to your converter boards.😉 Bon chance mon ami, Cheers, Doug 😎 Re GWS; https://www.google.com/search?q=GWS+models&client=firefox-b&tbm=isch&source=iu&ictx=1&fir=Yy9FOffyN9znOM%253A%252Cm55UYJTjtHfuaM%252C_&usg=AFrqEzdcX_L57leaM37UXLA9kg6sVLbSag&sa=X&ved=2ahUKEwiyo8mUnO_cAhUkB8AKHc_UDNEQ9QEwAnoECAYQBA#imgrc=Yy9FOffyN9znOM: Pic is a typical GWS small plane, called 'Slow Stick'. if I had one I would name it 'Spindle-shanks' 😁

6 years ago by RNinMunich

Blog

Make shift Washer!

It's said necessity is the mother of invention. Well, I looked at the top of zap-a-gap bottle top. Saw it was shaped like a 1/6" nylon washer. Drilled through the center and presto! One nylon , made up! As soon as I have a chance. I'll go to the local Hardware store. And I will get some stainless steal washers! Thank you, all for your valuable in put. It is well appreciated!

6 years ago by figtree7nts

Response

Test fit the Rudder!

Evenin' Ed, No! you need some kind of between the prop / locknut and the end of the tube! Otherwise when full ahead the prop or nut will grind against the tube 😡 I would swap the thick nylon washer for a thin stainless steel washer. A good DIY store should have some. Should win you a mm or so. if the shaft moves back and forth more than that then something else is wrong. The movement on my Sea Scout shaft is about 20 thou max. Or as RH suggests you could use Loctite to secure the prop instead of the locknut. I would prefer the stainless washer. Cheers Doug 😎 BTW: I also fit washers at the inboard end, between a collet and the tube. As shown in pic attached of my new Sea Scout installation. New propshaft was milled to lock the collet in place (Pic 2). Cocked it up slightly so I needed extra spacing washers! 😁 no one's perfect 😉

6 years ago by RNinMunich

Response

Test fit the Rudder!

Looks a bit close for comfort to me 😲 As Colin says forward thrust will help keep it clear, but going astern might be tight??? Is that really a bush, or just a nylon washer? If it is bushed into the tube to hold the shaft then I would be tempted to shave half a mil off the end of the tube. And/or file a slight dip into the leading edge of the rudder. If there is a bearing in the tube end and this is just washer I might reduce it's thickness on some wet n dry, or replace it with a thinner stainless washer. Cheers Doug 😎

6 years ago by RNinMunich

Forum

Too Powerful Brushless ?

Hi, Thanks for the info Peter and Dave, very much appreciated! The hull is all wood. I will order an 1100kv motor and make sure there is 's on the Propsharft. Thanks again Graham

6 years ago by Traiderman

Forum

Too Powerful Brushless ?

I have to agree with Peter's comments. I would also suggest that you look at the coupling and fitment of your prop shaft. it could be that the whole unit is seizing together. You also need to check it is true and free running. You need a prop and locknut followed by a then at the inboard end a locknut and coupling. There should be a gap between the and bearing of a few thou', we used to use a Rizla paper, Make sure all joint are tight and that the shaft turns freely and smoothly. The motor need to be securely mounted to a good solid base and 100% aligned with the coupling and prop shaft. Personal experience tells me you don't get a second chance with brushless, you have been fortunate if it is only the prop tube has suffered. Is your hull wood, plastic, fibreglass? Whilst Araldite is a fine adhesive you may need to use Stabliz Express or UHU Acrylit Plus which provide an exceptionally strong joint. E-bay have sellers of UHU in the UK. Good luck and please keep us posted

6 years ago by Dave M

Forum

Prop Shaft Grease

I would add that it is important that you also have a at each end of the propshaft. We used to use Rizla cigarette papers to gauge the clearance.

6 years ago by Dave M

Forum

Motor problem

Hi Richard, Good morning, Prop first, if the blade to hub is 30mm, it is a 60mm diameter prop, think of the circle of sweep, twice the size that your 550 motor can take. As the shaft is free running, we can discount drag, simply the motor working to extreme, so we need to prop down considerably, If you are staying with the 540 motor in the pics, a 35mm 3 blade prop is the maximum, a rough guide is no bigger than the motor diameter. I would save myself a lot of problems in the future and fit a larger motor, Canabus is right a watt meter will save its readings so you can get a proper idea what the motor is doing. I would swing towards the 850, or the 700. Not expensive but safe to run with a smaller prop. The 700 might fit your mounting but the 850 will need a new one, usually supplied in the box. The Sea Commander will serve you well as a great sailing model, once you are past the teething problems. Just looked back, your first post said the hull was built in the 60's, it might have a 4ba thread, not many ba props available these days, a 4mm prop will fit but it will be tight, don't forget the locking nut (to many props at the bottom of the lake) also a to protect the motor bearings. Mark

7 years ago by jarvo

Forum

Crash Tender Shaft Tube Poistion

Hi Neil, (Old (Sea) Dogs can learn😉). My pleasure, happy to help. Today (quite coincidentally!) I ran across a mathematical dissertation on the relationships between prop, rudder and hull (Yawn!) done by Marin Corp. for a symposium on 'Fast Mono-hulls'. Primarily naval. Full of Froude numbers and Lord knows what. But the upshot was that the optimum distance between prop and rudder should be 0.47 x radius of prop. So with my 30mm prop and 17mm distance I'm a 'bit' off🤔 15x0.47=7.05. Shucks; where are my s? Need a couple more 😉 Never mind, I wanted to make a new shaft anyway, to fit the brushless upgrade mounting. Ho hum! Whatever - Have fun, Doug 😎

7 years ago by RNinMunich

Blog

The electrics, drive & radio

The switch panel and wiring loom was made, tested and dry fitted a while ago and so it only needs securing to the bulkhead with four fixing screws, the two NiMh batteries were strapped down to the bearers with cable ties as close to the chines as possible and the XT60 connectors mated. I have read that placing the heavy batteries as far away from the keel as possible improves the handling, all other heavy items are centered along the keel for symmetry and should help the boat to sit evenly in the water. I’m not sure if I will need to do any ballasting, hopefully the maiden voyages should give me an indication. The prop shaft was greased and fitted, and with the prop, s and lock nuts in place, the clearance was adjusted and locked with some Loctite so the motor could then be installed. The initial motor alignment was made with a solid coupler which was then replaced with the universal joint, I took the precaution to grind a flat on the motor shaft so that the locking grub screw has better grip on the shaft. The grease tube was then fitted to the shaft clamp and secured to the side of the switch panel. The ESC was fixed to the back of the bulkhead with another couple of cable ties and the input cables, again XT60 types, and the three pole XT60 motor connectors mated. I have also fitted a Turnigy in-line volt, amp and watt meter in the circuit before the ESC so that I can log readings in case of spurious fuse blowing issues or unexpected battery life problems. The water cooling tubes were then run from the water pickup, through the ESC and then back to the transom ‘exhaust’ outlet, all water connections are fitted with spring clips to ensure water tight connections. I have used quite a large bore silicone tubing to ensure maximum water flow and made sure that all bends are kink and compression free. The R/C receiver is fixed to the rear cabin wall with some Velcro pads for easy removal, the two aerials were fitted in some plastic tubing at 90 degrees to each other as recommended for 2.4 gig systems and as high above the waterline as possible. The receiver is connected to a separate 4.8 volt NiMh battery via a changeover switch that also has a charging connection and LED power indicator, and I have also fitted a battery voltage indicator, just because they are cheap and convenient although the R/C system that I have has telemetry that reports RX voltage as standard. The battery charger I have chosen can handle the 16 cell series configuration of the drive batteries and so they can be charged in-situ when the main power switch is toggled over to the charge position. The RX and lighting batteries are charged separately. All of the servo and lighting switch cables are routed through the hull to the receiver through pre drilled holes in the bulkheads at high level for neatness and to retain the integrity of each compartment just in case 😲!!. The servo and cables and the water cooling tubes are strapped to a supporting bar between the bulkheads for neatness and security. With the TX switched on first, the RX is then powered up and the main power switch toggled to the ‘operate’ position, the ESC then gives a reassuring series of bleeps that confirm that all is well. The ESC was set up using a Turnigy programming card specifically for that model of controller and if required I can tweak the settings once the boat has had a few sailings. The last things to do now are to fit some strong magnets to hold the hatches and roofs down securely and then finally raise the RAF ensigns 😁

7 years ago by robbob

Response

propellers specilly made

Hi Dave theres a grub screw on the prop so i filed a small flat area on the shaft to take the grub screw and little bit of thread lock on the grub screw and yes theres is . cliff

7 years ago by Mataroa

Response

propellers specilly made

Hi cliff How are you going to attach the props to the shaft? Normally if the prop shaft has a plain and threaded end, the threaded end goes to the prop with a locknut and , The other end inside the boat has a and a collett with grub screw(s). Dave

7 years ago by Dave M

Response

The Taycol Target Renovation

Flippin' 'eck! Which of the 17 million Royal Blues did you mean??? I assume you mean the original darker version with a hint of red/purple? Might start with primary blue and add a dollop or two of maroon or burgundy! Yep, you're right navy blue knickers were rather boring, but the contents generally not so 😉 Don't know when you were last in Munich but Conrad now has two stores here, a small overcrowded one in Tal in the city and a newer huge superstore opposite the Olympia Einkauf Zentrum in the north of the city. That's right, where that nutter started shooting at people last year! if they ain't got it it probably ain't made😉 'Qual der Wahl' as they say round here. Wanted to see what the Target was going to look like, so here a couple of impressions. I'm rather pleased with it and myself 😁 Can't wait for the PB to arrive. Just discovered another use for it - s😲 Cheers 😎

7 years ago by RNinMunich

Forum

Battery problems

Hi Patto I agree with what has already been posted, but it would help if we knew the size and type of prop you are running with your brushless motor. Fast large racing props do not work well with brushless unless your battery can provide the very heavy sustained current required. As Haverlock suggests a Wattmeter will allow you to select the best prop for your set up. LiPo power will give you all the speed you need but at an initial high cost as they require special chargers and correct management. You could use NiMh batteries which are lighter than SLA and are more suited to high discharge currents. You can get these in 12v packs and 5000mAhr would be a good starting point. If your motor is cutting out it is more likely the ESC is the culprit due to too high current draw. Another possibility is that the propshaft is too tight, it should turn freely with no tight spots and have s at both ends. Dave

7 years ago by Dave M

Forum

Richards 48'' Swordsman

Hi Richard Whilst the delamination appears local chance are the fuel has penetrated well into the laminates together with water. Use whatever you want to patch the damage but a fresh piece of ply will probably be cheaper and more resilient. Cascamite will not work well with cyano. I would, after sorting the damage, use a thin resin poured and swilled around the hull insides to seal, followed by a covering of glass fibre or cloth over the outside impregnated with polyester lay up resin. You can fill any resulting blemishes with car body filler. As the model had an ic engine chances are the prop shaft will be showing signs of its age. Even if the bearings appear ok'ish the shaft is most likely bent or twisted. I suggest whilst you are sorting out the delamination you purchase a new unit of the same size. Most modern kit is metric so your shaft should fit any props and couplings you purchase. Some use an allen key to secure the coupling so this may not apply. Don't forget to fix a locknut and at either end of the prop tube. If you look at the blogs on this site there are several example of how others have completed similar tasks Hope this helps Please keep asking if you need any further help Dave

7 years ago by Dave M

Forum

Skeg on King Fisher

Hi Grandpa Looking at the latest photos suggests the shaft and keel will be secure and if the prop is clearing the hull then the shaft may be long enough. You may need to add an extended coupling to allow for the motor. As I mentioned it would be a good idea to fit the motor, coupling shaft and prop now to make sure it all fits nice and square and runs freely. Don't forget you must have s at either end of the propshaft together with a locknut for both the coupling and prop.😁 I am in the Crewe club and Mark I believe sails with Etherow. We are both North West clubs so a few hundred miles from Canterbury. Good to hear you have a local modellers Club. Good building Dave

7 years ago by Dave M

Forum

Propshaft Alignment

Hi cormorant Can't actually see the washer between the coupling and the proptube which appears to have a nylon bearing. It would benefit from a slightly more balanced fit on the motor shaft and propshaft with the coupling having equal gaps at either end. Most motors will move on their bearings in their case when running and it is important to make sure that the prop assembly does not exert any force on the motor. That's the function of the thrust bearings. Correctly fitted there should be a small gap between the prop tube and the washer. Rixla cigarete paper was popular as a guide to set the gap in the days of IC and is still a good indicator. Hope this helps Dave

8 years ago by Dave M

Forum

Propshaft Alignment

Hi Cormorant I believe you should have selected the jigs to match the length of your chosen coupling. Once you glue the shaft in place and the adhesive has hardened you disconnect the shaft and motor from your jig and rebuild with your chosen coupling. Do make sure you include a lock nut and between the coupling and shaft. There should be a similar washer and lock nut at the prop end. Dave

8 years ago by Dave M

Forum

Blowing fuses

HI Georgio I have an Aerokits Solent (pics attached). Some pics show the model in an earler guise. I have recently upgraded the electrics and corrected the number. its a model of the Douglas Currie 48-016 This type of lifeboat had a top speed of about 9/10 knots so was not as fast as the later fast afloat boats. Two 850 motors would be much to powerful for this model. Regarding the waterline most models I see are usually ballasted far to low in the water, the real boat had a draught of 4'8" and in service it was usually possible to see the white bottom paint just above the waterline. I use two Bhuler 12v motors with two electronize ESCs and a 12v 12 amp SLA. Sails at scale speed and I can usually get a good hour if I use fast speed sparingly. The fact that you have lost a prop suggests that you may not have s and locknuts at either end of your prop tubes. As you have found without a locknut the props can and do become detached. Another symptom is that without lock nuts the whole shaft can tighten up and seize, especially if you do not have a locknut at the drive end. The s take the load when going ahead or astern and you should adjust so that there is minimal play between the washer and bearing. We used to use cigarret paper to set the clearance. Glad to hear you are managing to sail, I used to sail on the original lake when I lived on the Wirral, and I do hope you can sort out all the niggling little problems. Cheers Dave

9 years ago by Dave M

Forum

How do I fit a propellor shaft ?

HI Dave Could you explain more about the maybe a picture not to sure if I have this on my boat maybe a picture of whole thing Ie prop, nut, sharft bearing, washer and prop shaft any help is appreciated I cant wait to get this running right so I can enjoy this boat. Regards George

9 years ago by georgeo5664

Forum

How do I fit a propellor shaft ?

HI George Yes you do need to lock the prop to the shaft with the lock nut. I have made special thin spanners to hold the nut so I can adjust in situ. You also need a between the nut and the shaft bearing, preferably brass. The play between the washer and the bearing is minimal, at one time we used to use a cigarette paper like a feeler gauge but unless you are running at high revs you can set this by eye and feel. As long as there are no tight spots you should be OK. At the other end of the prop shaft you should have another washer and nut again locked to the drive joint. This will protect the bearings in your motor as they are not designed to take longitudinal force. Failure to lock the connections will either result in the prop or drive becoming detached or the drive and shaft seizing resulting in damage to the motor or ESC. For this reason you should also have a fuse fitted between the battery and ESC rated at less than the mtor stall current or the max amps for the ESC, whichever is the lower. Hope this helps Dave

9 years ago by Dave M

Response

Vosper 1/16th scale crash tender

I would check the rudder shaft. At full speed the model is sitting well down in the water and if you have the shaft low to allow for the well deck the water pressure will be considerable. I try to use close fitting shafts and tube and place an 'o' ring above and below the tube with a brass washer holding the ring against the tube top and bottom. You should have a at either end of your prop tube with minimal clearance (a cigarette paper used to be used in the past). I agree with Alan, the prop shaft bearing should be a close fit. if you can feel any play at either end they probably need replacing. Hope you can solve the problem

9 years ago by Dave M

Forum

Motors overheating

HI Thom The question over shaft alignment, it does cause a lot of extra drag if not in line, but as you say your stuck with it. Replace the bent shaft, but test the motor out of the hull against the good one, possible it needs "running in" before you splash the cash. What I meant with the lock nuts and s, there needs to be slight end float on the shaft, the washers act as a bearing against the end of the shaft tube. Did you use oil to lubricate the shafts or did you use grease? Grease can cause a lot of drag with high speed motors Mark

10 years ago by jarvo

Forum

Motors overheating

HI Mark, Think I found one motor which is a bit faulty (doesn't turn as freely as the other) and possibly a very slight bend in the shaft. I'm also using raboesch couplers from motor to shaft so they seem to be fine regardless of the angle. They aren't perfectly aligned but as close as I can get considering the hull design and motor size. I'll try a new shaft and a new motor and see how it handles. As for locknuts - everything is tight so there is no movement at all. No s in place on either side. Would that make a huge difference? Thanks again for your help! Thom

10 years ago by Thom

Forum

Motors overheating

HI Thom I was thinking you had something like 60mm props, with small props there is something wrong with the driveline. Are the motors and shafts in line both vertically and horizontally? If you remove the couplings the shafts should be very free to spin if not remove the shaft from the tube and role it across a piece of glass, (the glass is very smooth) there should be no wobble or twitching anywhere along the shaft, if there is the shaft is bent and will need replacing. The amp test will show which one is the worst and go from there. Just had a brainwave!!!! (don't happen very often these days.) The locknuts on the props and couplings, is there a little end float, IE. the shaft can move back and forth slightly, possible the shaft is locking up. Also are the s in place on both ends???? Mark

10 years ago by jarvo

Forum

prop shaft

You should be able to tighten the nuts / washers so that the shaft is a nice sliding fit on the bearings in the prop shaft. 3mm is too much. I would check that there is indeed a bearing at each end of the shaft as they can sometimes push out and 3 to 4mm is about the thickness of a bearing outside the shaft. If you do not have the correct clearance water will run up the shaft, but worse the shaft will not have the benefit of a thrust bearing at each end allowing it to move away from the motor / coupling. Won't do either any good. If this is a commercial item I would speak with the vendor and ask for their help. Could be that the washers supplied are too thin. Good luck 😀

11 years ago by Dave M

Forum

NewBe Help Needed - Noisy Motor Arrangement

HI Neil Just to clarify. The bearings should ideally be a sliding fit to the shaft Ie slide freely without any binding. in your other post you refer to the end play between the shaft and tube - this should be minimal ( Rizla cigarette papers used to be used) and a needs to be fitted at both ends, This takes up the pressure from the prop as it rotates. Without this the motor bearings will suffer from the pressure. Regarding the wear in the bearings, this sloppiness will create an Imbalance and a smooth drive will be difficult or even Impossible to achieve, additionally the extra gap will allow water to work up the shaft by capillary action, this is another reason to fit a close fitting washer as it will help seal small misalignments. If it were me I would be attempting to replace the bearing before removing the shaft. if you are already resigned to this course you may as well try this easier option first as you can be no worse off. But do try just adjusting the motor first as this may save you any further effort. 😀

12 years ago by Dave M

Forum

Jotika Sea Queen

HI Ianed57 Robert has correctly identified some of your possible problems. However have you checked for free running of your prop shaft, and is there a at the prop end. The motor combination has worked for many others so it should for you. As a brushless motor user, albeit in a 34" fireboat, I would advise you to have no fear of the motors or the batteries. Yes special chargers and controllers are required and running gear and alignment need to be of a high standard to handle the power. I buy motors / ESC's direct from China (Compass Store http://stores.shop.ebay.co.uk/Compass-Store__W0QQ_armrsZ1) at a fraction of the cost of uk suppliers, and LiPo batteries / chargers can be obtained at reasonable cost from the Component Shop in the UK. (http://www.component-shop.co.uk/) Good luck with Improving your boat's performance. Dave

15 years ago by Dave M

Forum

fireboat cof g

Reading this thread it occured to me that you may have a bearing problem. Your last post seems to suggest that you do have some concerns. Was this model originally powered by an IC engine? My 34" certainly had been and the shaft and bearings were to put it mildly - worn. I took out both and refitted with new to the same size - bit of a pain I know but well worth the effort. I use locknuts at both ends of the shaft and make sure I have s at each shaft end. Hope this helps. Dave

15 years ago by Dave M