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>> Home > Tags > coupling

Billings Sea King by AllenA Fleet Admiral!   Posted: 2 days ago
[Score: 8/10] 27"/900g Billings Sea King Capable of 10mph and a runtime of 25mins Twin Propellors (3 Blade 40mm) Direct Drive to a 2 x Como Drill (3 Blade) Powered by NiMH (7.2v) 2Amp/h Batteries Controlled Through Chinese 320a Fan cooled (10Amps) ESC - Comments: Found at a Boot Sale in a sorry state. Retained the 2 Como motors but replaced ESC with Chinese Fan Cooled 320a. Acoms AR-201 Rx, Futaba servo all linked to new old stock Acoms Techniplus Alpha 27mhz Tx. New rudder, original propshaft with new couplings. Hull painted in Hammerite Gold and Plastikote white. Retained orignal Billings decals. New stanchions and rails. Re-veneered deck and added some fancy balsa work. Plains well after contra-rotating the props.

Too Powerful Brushless ? by Traiderman Sub-Lieutenant   Posted: 8 days ago
Hi, i have searched for a 500 watt 500kv motor and just can't find any, what company do you use for motors? at last i think i found a suitable Motor, i hope, it's a keda 36-42m 500 watt 950 kv, with a 5mm shaft and fits my new 5mm to 5mm coupling, so don't need any other parts for the power train! will need to change the hole to hole distance to fit the 16mm spacing of the new motor.Then gluing the new 5mm Shaft in, i think thats a good setup. The new 500 watt motor should have a long running time i guess on 10000 mah Lipo's? Anyway thanks again for helping me, very much appreciated! Graham

Too Powerful Brushless ? by BOATSHED Admiral   Posted: 15 days ago
Great bit of information , Many thanks pmdevlin. I have only ever used 5mm shaft's and gone out with a variation of small to medium nylon prop's and played on the pond bank with them until I got one suitable. Then I would go for a cast alloy or bronze to that size. But this has been on IC engines, up until about 3 years ago. I have used the same way on brushless since. I have seen others using thinner 4 mm shafts and having problems. I have also always used a prop shaft support under the boat and if I have any type of gap between the coupling and where the shaft goes through the hull I would always add a wedge of wood epoxied in. Once again no backlash on the shaft to make it come loose. The only time I have damaged shafts has been through sheer stupidity racing round a pond with others and misjudging the distance and the bank jumps out and collides with the boat. Whoops broadsides with a nice hard concrete bank and, Yep new shaft needed. But as you say the throttle stick will take you from as slow as you want to flat out. Except when it's IC slow isn't always possible if you do not have a clutch fitted.

Too Powerful Brushless ? by reilly4 Commander   Posted: 16 days ago
Graham, I have attached the same table that Doug sent me. This has the relevant information you seek. According to the table attached the Graupner 500 kV ECO has a specified output of 1440 watts and 80Amps. Strangely the 400 kV ECO has a specified output of 2010 Watts. So the 1440Watt output is questionable and may be a typo based on the other entries in the table. more likely to be 2440Watts In any case you need a 5mm diameter propeller shaft. For shaft alignment i use a brass tube that slides snugly on the propeller shaft and then on the motor shaft. When the tube rotates/slides well on both then the shafts are aligned. I then fit the motor mounts, check and tweak the alignment if necessary, remove the tube and replace with a universal coupling. If the motor or propeller shafts are a different diameter then I insert the relevant size smaller tube inside the larger of the tubes. This method is simple and has served me well, including for larger IC engine powered boats belonging to friends. Haig

Too Powerful Brushless ? by Dave M Fleet Admiral!   Posted: 17 days ago
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 vibration. 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.

Too Powerful Brushless ? by Traiderman Sub-Lieutenant   Posted: 17 days ago
Hi Mark, i have a 4mm shaft fitted and the boat was out of the water at the time, it happened when i just touched the throttle! i thinking maybe a 5mm shaft would be good (less whipping)with a racing propeller and a 1100kv motor with a rubber heavy duty coupling, i think that would be a good setup and will be suitable for a 3ft boat. i think the brass propeller is just not built for high revs, or was it a 1 off badly made propeller? anyway would that setup be good? thanks Graham

Too Powerful Brushless ? by Traiderman Sub-Lieutenant   Posted: 19 days ago
hi Richard, Thanks for the info, i have decided to remove the Prop and check it for straitness, before i start again with rebuilding using a heavy duty coupling and a slower motor, as i think the existing motor is just too fast at 47000 rpm for the propshaft and coupling and if the propellor is slightly out of balance then the prop will come off again! Thank you Richard and all other contributors that have helped! Graham

Too Powerful Brushless ? by Dave M Fleet Admiral!   Posted: 20 days ago
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 thrust washer then at the inboard end a thrust washer locknut and coupling. There should be a gap between the thrust washer 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

Too Powerful Brushless ? by Traiderman Sub-Lieutenant   Posted: 20 days ago
hi all, i have a problem with my prop shaft, every time i start the Hobbyking Brushless 3660SL (3180 KV ) the prop shaft comes adrift from the boat hull. it's powered by a 14.7V Poly Lipo battery. is it too powerful for an Aeronault Queen 36"? or is the prop shaft vibrating because of out of balance propellor or the coupling? i have used Heavy Duty Araldite to glue the prop shaft on to the boat. it has come adrift 2 times now. Thanks for any help i may receive - Graham

Al KHUBAR 2 by Dave M Fleet Admiral!   Posted: 2 months ago
Yes but the centre part of back deck on the Al Khubar is removable so you can get to the rudders and motor couplings. The instructions suggest a close fitting sheet of plasticard will suffice. Didn't for me as the deck get very wet even in calm waters. Hope you have better luck than me.

Skiff update by RNinMunich Fleet Admiral!   Posted: 2 months ago
Hi Granpa, There are 3 dealers in Canada (see first pic). Aero-naut has 7 model outboards. The pics show the 2 smallest, with part numbers. Please note: They are sold without props or motors but with coupling for 4mm shafts. Here you can see the specs / dimensions of all variants The 'Retro' versions on this page come complete with in-runner motor and water cooling. The Aqua Race mini complete with motor and prop is probably the one for your skiff! Happy hunting, cheers Doug 😎

Prop Shaft Grease by boaty Commander   Posted: 3 months ago
Hi Bryan Best way to remove the propshaft is to undo the universal joint at the top then slide the shaft out through the stern tube . Sometimes this may be difficult if the rudder gets in the way. If you remove the prop there is a good chance you can extract the shaft without too much difficulty but be careful not to bend the shaft. Referring to the latter it is advisable to remove the rudder but on some occasions I have bent the rudder slightly though there is an element of risk in this as the rudder has to be realigned. When reassembling the shaft and universal coupling check that after fitting the prop there is adequate clearance between the prop hub and the stern tube and the same with the coupling so the assembly can rotate freely without rubbing against the tube . Regards Boaty😊

Sea Queen Prop shaft by Dave M Fleet Admiral!   Posted: 3 months ago
Hi AndyG Not sure what type of coupling was supplied but I use a common Universal coupling on my 48" Sea Queen and use a brushless 42 size 850Kv water cooled motor of 700 watts and it is happy driving a Prop Shop prop of 42mm at 45 amp on full throttle. Power is from an 11.1v Lipo of at least 2200 mA but Nimhs would work, just not as fast and less duration. My motor is mounted in the main cabin and I have no problem with the prop shaft. Originally designed for IC power so perhaps you have heard of problems when we used such powerful and not so well controlled devices. My model goes on the plane very easily and any more power would make it unstable. Pics attached to show my set up. You can just see the coupling in front of the motor.

Sea Queen Prop shaft by AndyG009 Lieutenant   Posted: 3 months ago
Hi all Have purchased a Sea Queen kit, and after getting info from this site plan to fit a brushless motor and Lipo's. Have been advised to change coupling from supplied, for one that will take the power - comments please. Also is there likely to be problems with more power going through the long M4 prop shaft ? I would rathersolve problems now before boat is built, so any help would be useful.

Motor problem by RichardSReade Sub-Lieutenant   Posted: 4 months ago
Fair enough pmdevlin I accept what you are saying, however it started as a motor not being big enough for the size of the propeller and then went on further as the shaft was 4BA not 4mm and I could not locate a smaller prop, a plain brass tube and stainless shaft has been fitted,way back in the 60's when it was first started and as I knew nothing about boats in 2015 when I finished the basic structure, I did not know that it would have been the smart thing to fit a shaft with bearings. So this is the way I am going to go, I have ordered the 850 brush motor and the adapter to fit the motor shaft to my red coupling,this I have been assured will be more than big enough to drive the prop without getting hot or needing a water jacket, if this is the case when I fit it and sail it, then result, if not I will then have to go down the path that you suggest, I have nothing to lose trying the larger motor and everything to gain if it works. By the way the batteries are all new