prop and motor advice

Started by Northernflotsam
7 replies 25 likes Last activity: 7 months ago
#8

prop and motor advice

Right folks, you've given me some great options , I think now its a choice between brushless vs brushed...
I appreciate all your guidance on this 😊 so time to roll the dice...
Not and expert but bloody keen
#7

prop and motor advice

It looks as though you have plenty of room, so an MFA 800 brushed motor on direct drive to the shaft. It will control well, be quiet and draw very little current, plus it will add ballast. Use two ujs on the coupling set up so as to mirror each other to eliminate any vibration.
Liked by Northernflotsam
#6

prop and motor advice

I suggest either a high torque 775 or 895 motor, or a geared 3:1 or 4:1 545 size motor, running 12volts through a good 12v Fan-Cooled ESC., with a 60mm 4 blade prop.
Liked by RogerA1 and hermank
#5

prop and motor advice

Hi Northernflotsam, if you decide to fit a brushless motor, I would suggest fitting an out-runner motor in your displacement hull fishing boat.

An in-runner motor would not develop as much torque and turning a large diameter propeller around the 50-60mm size that you suggest would suite an out-runner motor better.

I have run a 50 mm propeller on my restored Rapier using an inexpensive Surpass 1100KV out-runner and it performs really well at low speeds as well as when being driven quickly.

The motor works with a fairly high amps ESC because that is all that I had spare at the time, but with the water cooled SHARK ESC range now being available at such low prices, I would suggest going for the 80A or 100A size for around £30 or less.

With that size of ESC you would have plenty of capacity to run the large propellers with little or no fear of either the motor or the ESC overheating.

From my experience I have found that ESC do not usually get hot when running at high speed, but when they are restricting the power flow to run more slowly they are actually working harder with more chance of getting “warm”.

A larger capacity ESC has more ability to handle any over-loads that one that is only just able to cope with the loads being imposed upon it, and a water cooled ESC is even better IMHO.

Bob.
Never too old to learn
Liked by SimpleSailor and RodC and
#4

prop and motor advice

You could certainly use brushless, especially if you use a prop around 50mm, I think 60mm would be a bit big for a 27" model? As you know, brushless are very powerful for their size and I like their engineering.

I use nearly all brushless, even in slow models, which some would say is overkill and don't perform well at slow speed. But a decent ESC seems to be key and myself and others have found that the Quicrun ESCs I mentioned perform well - I use Overlander motors - and I've found that my models move away very slowly and smoothly.

You want a motor with good torque and I reckon an Overlander 4250/06 800KV Tornado Thumper V3 – Brushless Outrunner RC Motor would do driving a 40mm or 45mm prop at most . It will drive a bigger prop but I think a smaller prop running faster would be better and the motor would be running more efficiently.

A 60amp ESC is recommended.

https://wheelspinmodels.co.uk/i/hobbywing-quicrun-10bl60-60a-brushless-264634/

Actually I was thing more about a tug and so that motor is a bit much, so a
Scratch building 7 Faireys at a scale of 1:12
Liked by SimpleSailor and RodC and
#3

prop and motor advice

brushless was an option but I only ever used that as the option for RC flight (gave up, long story). Could you offer any guidance in regard to using brushless for that size model ?
Not and expert but bloody keen
Liked by hermank
#2

prop and motor advice

I mainly use brushless and so can't really advise on the size of a brushed motor which would probably be the best choice.

But given the size of the prop a motor with a reduction would be a good idea (pulleys and belt), which as well as taking the strain off the motor and less amps draw, would allow you to fit the prop shaft flatter if needs be.

Component Shop do one which is reasonably priced and can be used with the 800/850 motors which are a common choice for bigger models. But maybe as your model is quite small a smaller motor would be better - as I said not my area really. Plenty of other suppliers for belt drive systems.

As regards ESC I'm a fan of HobbyKing Quicrun which are good value for quality v cost. I'm guessing you will need one around 60amp though others can advise better than me on that.
Scratch building 7 Faireys at a scale of 1:12
Liked by RogerA1 and RodC and
#1

prop and motor advice

I'm building a displacement hull fishing boat, 16lbs in weight 27" x 10" beam
single prop, prop needs about 50-60mm ? Anyone have any advice regarding motor and esc choice ?
Not and expert but bloody keen
Liked by hermank

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