Model Boat Mayhem
Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: Riyadh69 on June 24, 2014, 04:10:52 pm
-
Greetings from the Garden of England,
Just starting to plan a new build of the Vic Smeed version of Huntsman 28. The plans indicate a Tapplin Twin, which I believe was about 7.5 cc diesel with an output of 0.29Bhp? I want to use twin props contra-rotating but the cost of a pair of glow motors of suitable size with rear induction is beyond budget. What size electric do I need, there seems such a choice I am totally confused?
Regards
Riyadh69
-
Hi, Greetings from the Land Downunder ok2
What size props do you intend to use?
the power of the Taplin is about 220 watts so is quite modest which is easily covered by a lot of motors, the rev range is around 9000 at full power going by the sales info i found.
On those numbers a 900 to 1100 KV motor on 3 cell Lipo or Kv to suit different voltage so about 1500 Kv on 2 cell or 700 Kv at on 4 cell
This motor has the same spec as the taplin, it will look ridiculously small,
http://www.hobbyking.com/hobbyking/store/__25082__NTM_Prop_Drive_28_26_1000KV_235W_short_shaft_version_.html
I would go for a higher rated one, this will probably negate the need for cooling then so would suggest maybe
http://www.hobbyking.com/hobbyking/store/__16233__NTM_Prop_Drive_35_42_Series_1000KV_700W.html
Its around the same diameter as a 500-600 can motor with 6 X the rated power, and 4X the taplin, It wont go much faster but it will be verymuch under its current rating and will probably not require any cooling whatsoever.
Depending on the prop size a 30-50 amp ESC is all thats required
Willcopy this over to RC groups where you asked the same Q
-
Hi Nick,
Thanks for the information and will go for twin motor installation with the larger of the motors and scale 3 blade props 40mm diameter as the drawing.
Started to build one of these in 1971 or maybe 72 but never got finished due to children and work, plus working in Iraq and Saudi. I also forgot the full size dingy building, last one for the 1978 Fireball UK Nationals, but just as we were tuning it, got set to Iraq!
Regards
Riyadh69 AKA Mike Allen
-
If they are 40 MM props the smaller motor will be adequate, the larger motor will handle 50-55 mm props
http://www.hobbyking.com/hobbyking/store/__18158__Turnigy_Aerodrive_SK3_2836_1040kv_Brushless_Outrunner_Motor.html
same diameter as the smaller one but a better motor I think, I have used a very similar motor on 3 cell Lipo and 40 mm brass props goes pretty good. the setup will give adequate scale speed, if you wanted to push the hull you could increase the KV to about 1200 or so, or use 4 cell, but I would run a 3 call and 1000 Kv to start out with, its has proven to be a safe setup.
Cheers
Nick