#12 il y a 2 heures 2

Wow ! Il y a toujours tant à apprendre de votre part sur les aspects pratiques des moteurs brushless.
J’apprends toujours énormément d’informations utiles grâce à vous — j’espère juste pouvoir tout retrouver facilement quand j’en aurai besoin !Traduit depuis Anglais.

#11 il y a 1 jour 12

I have a couple of the Surpass 120AMP air cooled ESC that I am not using. One is still in the box and the other has been run in my Kopy Kommander.

The one that I ran in my Kopy Kommander always run OK and never got hot - just nicely warm which I think is good and just about "right".

I could even bung this in my Sprite Plus as it is wired up with XT90 and is ready to go, but I do want to try the SHARK ESC sometime as they look very good and are available at a very competetive price from Ali Express.

The prices for the SHARK ESC vary from day to day, but when I checked this morning (I was actually looking for a small outboard motor to fit the Sea Urchin), the 100AMP ESC was only around £30 with free delivery. Not a bad price!

I have some short LiPo's that are 3C as they were just the right size to fit across the width of my Remora and work very well, but if I could have bought the same size in 2C I am sure that the performance would be very similar, but I would probably get longer run times.

Bob.

Never too old to learn

#10 il y a 1 jour 13

New HobbyWing Quicrun 120amp air-cooled ESC ordered so will be able to do the installation in a few days time. Actually, I had a look at the Seaking water-cooled one and it does have pretty good fins so I reckon it would have been alright. But anyway I needed another ESC and will also need another Seaking for my outboard project. Hate to think how much I've spent over the years! 🤔 😀

Scratch building 7 Faireys at a scale of 1:12 and also have 2 built by Dave Milbourn

Aimé par DJW

#9 il y a 1 jour 14

@zooma Thanks for all that Bob. It could be that it will perform fine on 3S and I have a new battery to try that I bought for the Huntsman 31. Reason for the 4S is that I worked on the rule of thumb that you need around 10k. rpm on these type of models and allowing 80% loss when running loaded in the water means you need around 12k. As the motor is a quite low kV at 800 rather than our more usual 1200 to 1500kV necessitated the 4S, well in theory anyway.

I say this because this is the basis for my other smaller boats which I have run. I get them up onto the plane and then use a bit more throttle to achieve a nice speed, but not manic (as I've said our lake isn't that big and we have these "magnetic" buoys!) but it's nowhere near full throttle. I have thought about getting a device for measuring the rpm to see what the revs actually are and to be a bit more scientific. I suspect they are running well below 10k. rpm.

It's interesting what you say about using 2S. When I bought my first Huntress off DaveM I ran it on 2S but whilst it planed it needed a bit more speed and so changed to 3S which I also use on my other Fairey sports cruisers. They do have smaller, 3 bladed props than you use on your models though.

As I said an easy fix for the Swordsman is to drop down to 36mm diameter but I want to stick with the 42mm and also want to see how it does. Given that this has plenty of power, the prop is a 40mm 3 bladed brass/bronze and the ESC I'm going to get is twice the amps required and has fins/fan I'm confident that it will be fine. Especially as I run my others without the fans attached and they barely get warm.

Scratch building 7 Faireys at a scale of 1:12 and also have 2 built by Dave Milbourn

#8 il y a 1 jour 15

Hi Chris. I am not qualified to advise on any of the technical aspects of electronics, but I do have some experience of running fairly fast and fairly large Classic Model Power Boats with out-runner and in-runner brushless motors most weeks of the year, and hope my observations may be of some interest?

Most of my larger Classic Model Power Boats run with a 50S propeller as this seems to suite them better than other sizes that I have tested, but some have run with a 45X and 50X props reasonably well too.

I have found the Sea King ESC to be totally reliable and they seem to run my boats more smoothly and with more power than any of the alternative ESC that I have used that have the same (or similar) power ratings.

The 120amp and 150amp Sea King ESC that I have used have delivered all the performance that I could ever need, and none of them has ever run HOT. All my Sea King ( and re-badged Turnigy) ESC are water cooled.

My experience with fan cooled 120AMP ESC has not been as good, but they have run well enough without over-heating, but they do not seem to be able to deliver the power as relentlessly.

Water cooling keeps everything running slightly warm and when coupled with inexpensive water-cooled alloy motor mounts the motors run as cool as the ESC. Even the "self-cooling" out-runners benefit from running in an alloy water-cooled motor mount as it helps to keep the main bearing cool.

Strangely I have never found any great benefit from running my in-runner motors with their optional water jackets connected. When I disconnect the water cooling pipes, the large alloy water jacket seems to dissipate the motors heat just as effectively !

I am going to try one of the 100amp water-cooled SHARK ESC in my Sprite plus as I see them working well in some of the local power boats, and I when I have driven them they "feel" like my Sea Kings, so I am keen to try one in my own models.

I also run the 90AMP Sea King (or re-badged Turnigy) ESC in my smaller Remora and that performs superbly with a 40S or 45S propeller.

In real terms I have not found any great advantage on our small lake by running 3S or 4S LiPo batteries instead of 2S.

To benefit from the extra volts, the propeller usually needs to be reduced in size to allow the motor to rev more freely. The increase in speed (in the same hull) is minimal compared to running 2C LiPo packs, but the duration is reduced so I get shorter run times.

For "out and out" racing where speed is the most important factor, then higher voltage's will help, but I no longer compete or race, so I find the higher voltage packs to be of no benefit - .....and they cost more!

Bob.

Water-cooled SHARK 100AMP ESC.

Never too old to learn

#7 il y a 2 jours 23

@AlessandroSPQR I wish it was me taking the notes!

To be honest I've dug myself into a bit of a hole with this one! The Swordsman was I think the second model I started to build some years ago and whilst I'd learned quite a lot by then, not enough or more accurately flawed thinking to some extent.

I say this because I chose not to water-cool (this wasn't the flawed part) and to be on the safe side over-engineer the components which you can do without too much of a cost penalty with a model which you would want to avoid with full-size.

This has worked well with my smaller models upto 31 inches in length where I have chosen a maximum brushless motor diameter of 36mm. The Swordsman is only 2 inches longer but has a bigger beam and is considerably heavier and so I decided to go with a 42mm diameter for more torque. The problem with this is that as you go bigger the choice of kV becomes less and the kV lower with the result that the motor only has 800kV and hence why I've had to go with 4S to get good performance.

My flawed thinking is because I underestimated the power of brushed motors which was reinforced later by getting to know Bob/Zooma and Harry/Canabus who run longer models on no more than 36mm diameter. Bob does water-cool but Harry doesn't. Though Harry does run above 3S on occasions.

But by then I'd already got and fitted the motor and recently bought the 4S battery. They were both relatively expensive and if not used in this model wouldn't be used in another (well maybe the battery could be but not the motor) so I was committed really.

Anyway I've dug myself out of the hole by finding a 120amp HobbyWing Quicrun ESC that does take 4S and has the cooling fins and fan which I will leave in place.

My 120amp water-cooled Seaking ESC won't be wasted as I can use that in my water-jet project which has a water-cooled inrunner brushless motor and I have a 60amp version I can use in another build.

All of this is part of the fun and learning for me!

Chris

Scratch building 7 Faireys at a scale of 1:12 and also have 2 built by Dave Milbourn

Aimé par AlessandroSPQR

#6 il y a 2 jours 24

@ChrisF
Hi Chris, I’ll humbly admit that, rather than trying to answer your question, I’m actually taking notes on your setup and your observations—hahahahaha!

#5 il y a 3 jours 43

As a comparison, I have run a 49in Perkasa on a MFA 850 brushed motor with a Mtronik 50 ESC and a Lipo 3s (11 volts). It went like a demon!

Aimé par ChrisF and oddjob58

#4 il y a 3 jours 45

Hi David, thanks for the thoughts and observations. Mentioning the cooling, or lack thereof, limiting the performance made me think that the max.capacity of 4S also means that the ESC is operating near it's upper limit.

Actually the ESC I bought for this build, same but 120amp takes 2 to 6S so it might be better as has more leeway.

Most of my ESCs are finned with fans at 60amp and above (but fans removed) being the HobbyWing Quicrun range though I have a couple of other makes in boats I've bought which are shrink wrapped and no cooling but only 30amp.

The 120amp Quicrun only takes 3S so no good.

So, I'll revert to using the 120amp Seaking and see how warm it gets in testing.

Scratch building 7 Faireys at a scale of 1:12 and also have 2 built by Dave Milbourn

Aimé par AlessandroSPQR and DJW

#3 il y a 3 jours 46

@ChrisF sorry Chris, i can't offer any advice whatsoever I'm afraid 😞

Will

Far too many projects, nowhere near enough time or skill!

Aimé par ChrisF and AlessandroSPQR

#2 il y a 3 jours 61

Hi Chris, lovely motor as they say..! Like you I prefer the Overlander brand of outrunners, they're very well engineered. I've not used that ESC, I think you said that you don't do water cooling, but that ESC is intended to be water cooled and so I'm not sure how it will behave without. I'd have thought it would rein in the current handling limits. It doesn't really have fins for passive cooling, or a fan, maybe others who know the ESC could comment. Other point about the ESC is it doesn't handle more than 4S, and while it shouldn't be an issue, it leaves just changing the prop if you want to tweak handling and performance. Not really an issue, more of an observation.

Hope to see it on the water..!
David.

Best regards
David.

Aimé par AlessandroSPQR and Madwelshman and

#1 il y a 3 jours 66

Calling Electrical/Electronic Experts

I've just started the RC installation in my Fairey Swordsman 33 and am seeking some advice/thoughts.

This model is using my biggest brushless motor as follows:

Overlander Tornado Thumper V3 4250/06 800KV - Brushless Outrunner RC Motor
• 980 watt motor
• 3-7 LiPo cells
• Shaft Diameter 5mm
• Motor weight 210gm (excluding accessory kit)
• 4mm gold connectors
• Speed Controller Recommended 60A ESC

which having a fairly low kV I'm going to run on 4S to give sufficient planing performance, and which I assume will produce 560w max as 980w is produced from 7s?

I don't water-cool and so always use a "bigger" ESC from the one recommended, so using a 90amp as follows:

The Hobbywing Seaking 90A V4 Speed Control (HW30302362) is a waterproof, brushless, sensorless marine ESC designed for reliable performance on the water. With 90A continuous and 360A peak current handling, 2–4S LiPo support, and a powerful 8A BEC with selectable 6V, 7.4V, or 8.4V output, it provides robust power delivery for a wide range of RC boat setups.
Key Specifications
• Application: Brushless, sensorless; waterproof design
• Continuous/Peak Current: 90A / 360A
• Input Voltage: 2–4S LiPo
• BEC Output: 6V / 7.4V / 8.4V selectable, up to 8A
• Size: 60 x 36.3 x 22.5 mm
• Weight: 115.6 g (including wire and output plug)
Programming & Telemetry
• Supported Tools: LED Program Box, LCD G2 Program Box, LCD PRO, and OTA Programmer
• Data Recording: Extreme value, real-time data, and historical graph supported
• Firmware upgrade supported
• Program Port: Throttle signal wire
Wiring & Connectors
• Input Wires: Red 12AWG 150 mm, Black 12AWG 150 mm
• Output Wires: 3 x Black 12AWG 100 mm
• Input Connectors: None
• Output Connectors: 4.0 mm gold female plug

Battery is an Overlander as follows:

SKU 2971
Barcode 5060470210168
Chemistry Lithium Polymer (LiPo)
Capacity 3700mAh
Voltage 14.8V
Cell Count 4S
Constant Discharge 25C
Burst Discharge 45C
Maximum Constant Current 92.5A
Maximum Burst Current 166.5A
Watt Hours 54.76Wh
Wire Gauge 12AWG (4mm)
Connector Options Deans, EC3 and XT60
Balance Connector Type JST-XH
Brand Overlander Batteries
Range Sport
Dimensions 136 x 43 x 24 (mm)
Weight 308 (g)

Amongst the options for the connector was the XT60 (which I use on a number of my other models) which I chose for fitment.

I was thinking that for the setup in this model I was going to use an XT90 connector but Overlander must feel that the XT60 is fine for this battery with it's fairly low discharge rate? My intended use is going to be pootling around with the odd faster lap as it's quite a small lake - no continuous fast runs. I will change the connector if necessary but don't like to change a "factory" fitted, well soldered on connector unless I have to. They do higher discharge 4S where they do offer the XT90 as an option.

I'm assuming in this scenario that it's the battery max draw is the deciding factor rather than the capacity of the motor and ESC, would that be correct?

What do the members think?

Chris

Scratch building 7 Faireys at a scale of 1:12 and also have 2 built by Dave Milbourn

Aimé par AlessandroSPQR and oddjob58 and

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Calling Electrical/Electronic Experts