Dumas MISS UNLIMITED KIT #1305
Specifications
- Boat Length
- 26" (66.04 cm)
- Motor Type
- Brushed
- Drive Type
- Direct
- Props
- Single
- Battery Type
- LiFe
- Run Time
- 353 min
- Model Speed
- 377 km/h (234.3mph)
Photos
About this boat
Not sure about the motor. looking at 600 - 800 brush type motors. that is what i have experience with as of now,. Not sure how brushless motors are rated. yes i have read the how and what the numbers mean, but i'm not sure how i can convert that to a 600 type motor.. any help would be of great h... i'm not going to race this, no clubs around here. I just want it to go up on plane, not 60 MPH. I'm thinking that a 600 type will do the job, also have batteries and a ESC for brush type. but i have been looking into burshless and trying to get educated on what all the numbers mean...
that are no charts to convert over so i'm asking if anyone have a good working knowledge on how you pick out an burshless motor... thank you.⚡
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For a hydro you should go brushless, as more efficient, more powerful, than similar size brushed motors.
Generally avoid sensor controlled, go for sensorless as they will run on many more brushless speed controllers.
(Quick note brushless motors can only run via a speed controller do not connect directly to a battery, another way to kill a brushless motor, is to run it with no load, so connect it to a prop shaft).
Generally there are two variations on brushless motors, in-runner which look like a brushed motor but you have 3 wires, and an out-runner which has the outer casing moving.
Physical dimensions are as follows:
In-runner 3650 = 36mm diameter and 50mm long similar size of a 550 brushed motor.
examples 2860, 3660, 4290 getting bigger.
can add water cooling via jackets or copper tube.
Out-runners generally have more torque, but can only be water cooled via a special engine mount.
https://www.ebay.co.uk/itm/MOTOR-MOUNT-WATERCOOLED-BRUSHLESS-brushed-28mm-to-36-540-600-rc-boat/390949237673?hash=item5b0663f3a9:g:TYcAAOSwDM5e405d
physical dimensions are as follows:
2212 is 22mm wide and 12mm long
6384 is 63mm wide and 84mm long
ok now a bit technical Torque of brushless motors is shown by KV
example 1500kv this mean it will spin at 1500 rpm per 1volt applied so on a 7.4v lipo it would like to run at, 11,100 rpm, but will not under load.
The lower the number the greater the torque assuming same power motor.
In practice I have found you can get good results from a wide range of KV from 1000 to 4000.
If you run on 7.4v assuming prop fully submersed I have used a
RCECHO LEOPARD Model 3536 KV1520 RC Outrunner with good results with a 36mm prop. on a 24in/60cm boat retail at around £25.
https://www.amazon.co.uk/LEOPARD-Outrunner-Brushless-Propeller-RCECHO/dp/B00EQTTJI0/ref=sxts_sxwds-bia-wc-p13n1_0?cv_ct_cx=outrunner&dchild=1&keywords=outrunner&pd_rd_i=B00EQTTJI0&pd_rd_r=bf3b322c-b81f-4810-bf27-d5c603344fe8&pd_rd_w=IwqPF&pd_rd_wg=N0xcy&pf_rd_p=9b1a9511-9af9-4d06-8643-d54ebec511ef&pf_rd_r=30MVDB33NBVDPXSQTW45&psc=1&qid=1597159924&sr=1-1-fdbae751-0fa5-4c0f-900b-865654896618
Your speed controller (ESC) need to be over spec at least double the motor current rating especially ones from china.
This one should be OK.
https://www.amazon.co.uk/gp/product/B082SSKWQK/ref=ox_sc_saved_title_10?smid=A3VARKKFF1JJQO&psc=1
Final note I hope these note are useful to you, It is a complex subject and can get technical.
I am sure some one will have a differing opinion, If your unsure run the boat on what you have, and upgrade later, a lively boat takes a lot of concentration to drive and patience to set up correctly.
It turned out a good boat but some parts and directions were not that good.
Your build will also turn out well I'm sure.
Rick