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[bobgrimward]

Hi Guys,
Could you help with a speedline severn class lifeboat.
I am coming to the end of the build and have ordered two MBA 850 motors too drive it. When they arrived they looked quite big too me and was wondering if they will be O.K. to use.
I intend to to drive them both from a 12v battery and they would drive two 50mm five blade props.
What do you think or shall I order some 60 motors.
Many thanks

[BFSMP]

I think that the modern look on these big speedline boats is to put larger kv brushless motors into them, rather than brushed.


once saw an Arun lifeboat with 2 x 850's installed and it barely moved.


Jim.

[boat captain]

look under the forum Lifeboats and SARs plenty of combinations depending on the scale of your boat.

[nemesis]

 it possibly had to big props on, hence the slowness, nemesis

[nemesis]

sorry, just read the posting, 850s take amps and in my opinion 50mm props are too big. Try smaller ones and let the motors rev. I fell into the same situation with 850s on my Trent until I put smaller props on, then I got the performance that I was happy with, good luck, nemesis

[bobgrimward]

Thanks guys,
Forgot to mention it is a 16th scale.
I was thinking about going brushless could anyone recommend what motors and controllers would be suitable and the best place too buy them from. Never fitted brushless before buy it seems the way to go.
Thanks

[boat captain]

As I said before look under Lifeboats and SARS on this forum.

[Flundle (Speedline Models)]

I used the scale props provided in the kit and two Turnigy D3530/14 11kVA running on three cell lipos.  This gives around 12,000 rpm under no load. I don't know whats happening with the Volt/Amp/Watt situation but it goes nice and slowly and quite quick too as is it's more usual mode.
Good planning shots are around somewhere with this arrangement.

Just for interest, I put these motors in my Landing Craft, with much smaller props and just 2cells.
It can make it go just too fast, shipping water under the door but it gives enough poke to be able to go against a reasonable breeze and overcome windage on the high sides and loading ramp.

I think what I'm saying is that these are very flexible motors and respond well to Voltage changes and prop sizes.
Adrian

[bobgrimward]

Many thanks Flundle. Could I ask what speed controllers you used as this is the way I will go.

[flack]

Hi,


I have a Speedline 1/16th scale Severn to build and in line with several other boats of a similar size I will fit Overlander Thumper 4260/06 500kv brushless motors controlled with Fusion Hawk 60 amp electronic speed controllers. Power is provided by two 11.1v 5000Ma Lipo's. Very good all round performance without the need for any kind of cooling.

https://wheelspinmodels.co.uk/i/85116/
https://wheelspinmodels.co.uk/i/262234/?gclid=EAIaIQobChMIiOTUuqmV1QIVCrcbCh1WLwIMEAYYASABEgLFBPD_BwE


Shaun

[Mobile wizard]

Hi Flack,

I'm waiting for my Speedline Severn 16th scale to be delivered, just seen your post on motor's and ESC recommendation and was thinking of going the same way and was wondering did you use the prop shafts provided and what size props did you use.

Thanks in advance.
Mark.

[flack]

Hi Mark,


I tend to use Raboesch waterproof propshafts in my boats, not the cheapest but they are certainly expertly machined. In relation to propellers I tend to use Prop Shop ones and seek advice from the owner as to the best match for the boat size, type and size of motors.


Hope this is of some help.


Shaun

[17-21]

Having built a Severn a few years ago, and now just about to start a new build in the new year some info for your ref.


First go brushless more power and more battery friendly. 850 will eat battery power and your running time will be 10 Min's tops on a 12 volt Led acid battery.


You should be running 75mm 5 blade props if you want scale size props,


The boat should weigh in when finished at around 25Kg.
I will be using 850 rpm per volt brushless motors via 50 Amp ESc on 14.4 Lipo batteries x 2.

[Mobile wizard]

Having built a Severn a few years ago, and now just about to start a new build in the new year some info for your ref.


First go brushless more power and more battery friendly. 850 will eat battery power and your running time will be 10 Min's tops on a 12 volt Led acid battery.


You should be running 75mm 5 blade props if you want scale size props,


The boat should weigh in when finished at around 25Kg.
I will be using 850 rpm per volt brushless motors via 50 Amp ESc on 14.4 Lipo batteries x 2.

Hi 17-21,


Is that 16th or 12th scale?


Thanks.

[17-21]

sorry its 12th scale so my if is wrong for 16th


Phil

[Mobile wizard]

sorry its 12th scale so my if is wrong for 16th


Phil

Hi Phil,


Thought 75mm props were a bit too big for 16th scale.
I will be going brushless with lipo's.


Regards.
Mark.