Model Boat Mayhem

Mess Deck: General Section => Chit-Chat => Topic started by: Sparrow on January 20, 2020, 01:32:21 pm

Title: Motor size
Post by: Sparrow on January 20, 2020, 01:32:21 pm
Could someone help me with brushless size motor I need to fit in Farley huntress 23 inch size, I did think of taking a Turnigy D3542/6  1000KV and 60A speed controller and water-cooled motor housing from a 48 inch fibreglass  Moonraker I built 8 years ago but think it will be far to powerfull as it would push that up on a plane with no problem, I see the plan info used 380 / 400 brushed motor but would like equivalent at least if not better in brushless and  LiPo also size speed controller size please. Many thanks peter.
Title: Re: Motor size
Post by: Subculture on January 20, 2020, 03:50:26 pm
Any 28mm outrunner of around 2200-3000kv for 2s system, or 1700-2000kv for 3s will be fine.

e.g. https://www.ebay.co.uk/itm/A2212-930-1000-1400-2200-2700KV-Brushless-Drone-Outrunner-Motor-For-Helicopter/283571017671?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Dd47e10b6b4134fe2bebec94b65b31163%26pid%3D100005%26rk%3D6%26rkt%3D12%26mehot%3Dpf%26sd%3D401783197687%26itm%3D283571017671%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851 (https://www.ebay.co.uk/itm/A2212-930-1000-1400-2200-2700KV-Brushless-Drone-Outrunner-Motor-For-Helicopter/283571017671?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Dd47e10b6b4134fe2bebec94b65b31163%26pid%3D100005%26rk%3D6%26rkt%3D12%26mehot%3Dpf%26sd%3D401783197687%26itm%3D283571017671%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851)

A suitable esc? I like Blheli_s and BLheli_32 controllers, super smooth, reversible, and tiny footprint. They're designed for multicopters, but work fine in boats too.  You configure them in a free app.

e.g. https://www.ebay.co.uk/itm/Turnigy-Multistar-BLheli-32-ARM-33A-3g-Race-Spec-ESC-2-5S-NEW/274199554897?hash=item3fd7912b51:g:gycAAOSwjONeGzTG (https://www.ebay.co.uk/itm/Turnigy-Multistar-BLheli-32-ARM-33A-3g-Race-Spec-ESC-2-5S-NEW/274199554897?hash=item3fd7912b51:g:gycAAOSwjONeGzTG)
You need a separate BEC with most blheli esc's. I use these.

https://www.ebay.co.uk/itm/DC-DC-Converter-Step-Down-Module-3A-5V-Mini-BEC-For-RC-Plane-FPV-ZL/143459030500?epid=877153637&hash=item2166d315e4:g:1McAAOSwlPFd5JVi

Title: Re: Motor size
Post by: DaveM on January 20, 2020, 04:40:03 pm
I see the plan info used 380 / 400 brushed motor   
Which plan are you looking at? The plan and article I sent you shows a Turnigy 2836/11 750kv brushless motor - clearly labelled as such. It's the MOUNT which is 380/400 sized - again clearly labelled. The motor you propose is similar to the one I used in a 36" version of the same boat and would vastly overpower this model. The article also explains that I used this speed controller with a 2200maH 3S LiPo; no seperate BEC is required with it. https://www.componentshop.co.uk/30a-waterproof-brushless-motor-speed-controller-esc.html (https://www.componentshop.co.uk/30a-waterproof-brushless-motor-speed-controller-esc.html)

DM
Title: Re: Motor size
Post by: Subculture on January 20, 2020, 05:52:09 pm
I based my motor recommendations on brushless replacement for a speed 400 (which tend to wind around 2200-2300RPM pre volt), clearly the prop size is somewhat larger than speed 400 could swing direct if a 750kv motor is specified.

Regarding ESC, quite a price difference and the onboard BEC looks considerably lower specced although no doubt adequate to power a single servo.
Title: Re: Motor size
Post by: john44 on January 20, 2020, 06:48:02 pm
Hi sparrow, follow DM,s advice and you won't be disappointed, unless you want very fast
uncontrollable boats that is.


John
Title: Re: Motor size
Post by: DaveM on January 20, 2020, 06:54:06 pm
https://www.youtube.com/watch?reload=9&v=JzHGhfT45wo&feature=youtu.be (https://www.youtube.com/watch?reload=9&v=JzHGhfT45wo&feature=youtu.be)

See at about 7.20. Motor/ESC/battery exactly as per previous posts. Judge the performance for yourself.

I would suggest that when reading a plan - especially one which was supplied by the designer for no charge - it often pays to take note of the text. At the very least it avoids uninformed speculation. BTW the suggested marine ESC has reverse and a 1A output - quite sufficient for an HS 81 servo.


DM
Title: Re: Motor size
Post by: Sparrow on January 20, 2020, 07:48:35 pm
Sorry Dave I read the motor mount being 380/ 400 but misted the motor detail above I will now order your suggestions, by the way model now covered in all hull finished today very pleased with progress so far, rubbing down tomorrow then glass fibre mat. Once again sorry for missed details  <*< <*< <*< <*<  peter
Title: Re: Motor size
Post by: Sparrow on January 27, 2020, 09:39:39 pm
Dave  I have now tried to on four occasions over several hours on line to find Turnigy brushless 750 KV from
Hobby King when I click to bye it come up you must buy 10 for some reason I have tried several times same thing every time so have given up. I have found a Leopard Hobby from Component Shop 730kv 28/30 would that be a suitable alternative to the Turnigy please sorry to be asking again for same advice.
Many thanks Peter.
Title: Re: Motor size
Post by: coch y bonddu on January 27, 2020, 10:03:10 pm
I would have said so as on 12v you are only dropping 300 rpm




Dave
Title: Re: Motor size
Post by: Taranis on January 27, 2020, 10:30:54 pm

Your suggested alternative is not just fewer KV but a shorter motor
I would stick to DaveM  :-))

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F132661558808 (https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F132661558808)


Hobbyking is out of stock
Title: Re: Motor size
Post by: Taranis on January 27, 2020, 11:43:04 pm
The same motor drives my 30" Lobster boat on the plane with 7.2volt stick and 45mm 3 blade prop.
https://www.modelboatmayhem.co.uk/forum/index.php/topic,62915.msg666677.html#msg666677 (https://www.modelboatmayhem.co.uk/forum/index.php/topic,62915.msg666677.html#msg666677)
(https://photos.smugmug.com/Midwest-Booth-Bay-Lobster-boat/i-R6PdXT3/0/4f42feef/X3/728E9079-72F9-432D-A12B-D20A22C32F24-X3.jpg)
(https://photos.smugmug.com/Midwest-Booth-Bay-Lobster-boat/i-7g7KPXP/0/5447b80f/XL/E4481FE9-936C-4AA5-A605-26AA3E1CB879-XL.jpg)
Title: Re: Motor size
Post by: Sparrow on January 28, 2020, 12:25:32 am
Thanks Andy at last ordered  O0 O0 l looked on ebay but did not find one will order esc now to Dave M suggestion things at last coming together thanks again. Peter