Results 1 to 7 of 7

Thread: Help with rudder placement

  1. #1
    Join Date
    Apr 2017
    Location
    NZ
    Posts
    4

    Default Help with rudder placement

    I need some help with setting up this mono with a speedmaster stinger strut and rudder that I bought from ose. I have only ever had tunnels and monos with outboards on them so dont know how long the rudder needs to be and how far offset

    The boat is 33" long, I was given a turnigy 3974 220kv motor and 120A esc to run in it and have 3s batteries




  2. #2
    Join Date
    Aug 2008
    Location
    CO
    Posts
    7,080

    Default

    Without any knowledge of how you intend to run your boat,
    i would suggest a length of 100-130 mm unless going for speed then 60-80mm
    My standard for off set is leading edge even with drive dog and as close without hitting the prop.

    Mount the stinger first (5-10ish mm above keel), run in the flex with prop (if you are meaning 2200kv, then pretty small) and set up rudder just to the starboard by about a half a prop diameter, but main thing is that it doesn’t hit at full left.

    If you want more left turn as in sport running, put the rudder farther in front of the prop.

    Just my thoughts based on the no context question.
    "Look good doin' it"
    See the fleet

  3. #3
    Join Date
    Apr 2017
    Location
    NZ
    Posts
    4

    Default

    Quote Originally Posted by Jesse J View Post
    Without any knowledge of how you intend to run your boat,
    i would suggest a length of 100-130 mm unless going for speed then 60-80mm
    My standard for off set is leading edge even with drive dog and as close without hitting the prop.

    Mount the stinger first (5-10ish mm above keel), run in the flex with prop (if you are meaning 2200kv, then pretty small) and set up rudder just to the starboard by about a half a prop diameter, but main thing is that it doesn’t hit at full left.

    If you want more left turn as in sport running, put the rudder farther in front of the prop.

    Just my thoughts based on the no context question.
    It will just be used for a bit of fun, no racing.

    Yes motor is 2200kv.

    Any recommendations on prop size to start off with

  4. #4
    Join Date
    Aug 2008
    Location
    CO
    Posts
    7,080

    Default

    Well to keep using your 120amp esc (which is way low, really need 150-180) and not blow it up, I’d start with a 40-42mm prop. If you went to180amp, you might be able to get away with a 45, maybe 48mm, depending on ho loose you set things up. That was all assuming 4s, which would be max I’d ever run on that high of kv. I would strongly recommend against trying 6s, unless you ran a 28mm prop and only did one pass. I prefer lower kv motors.

    Recall that amp draw is high with high kv motors, so you need a bigger esc; this will be your limiting factor when you want more speed. Small prop increases will produce greater amp draw increases than with a low kv motor.

    All that said, if you are determined to run the stated setup, I recommend running your 3s in parallel and not going above a 45mm prop. Even still keep checking on temps.
    "Look good doin' it"
    See the fleet

  5. #5
    Join Date
    Jan 2019
    Location
    WI
    Posts
    29

    Default

    Quote Originally Posted by 00quattro00 View Post
    I need some help with setting up this mono with a speedmaster stinger strut and rudder that I bought from ose. I have only ever had tunnels and monos with outboards on them so dont know how long the rudder needs to be and how far offset

    The boat is 33" long, I was given a turnigy 3974 220kv motor and 120A esc to run in it and have 3s batteries
    If your going to put a (Outboard on it ) No need for Rudder ,, Just Trim Plates and Turn Fins ,, The outboard is the Rudder
    I got the pic off a different Tread ( By ,, MadProps ) that is a Twin but do the same with a single Outboard

    650EP.jpg
    HE WHO DIES WITH THE MOST TOYS WINS

    Russ

  6. #6
    Join Date
    Apr 2017
    Location
    NZ
    Posts
    4

    Default

    Quote Originally Posted by Jesse J View Post
    Well to keep using your 120amp esc (which is way low, really need 150-180) and not blow it up, I’d start with a 40-42mm prop. If you went to180amp, you might be able to get away with a 45, maybe 48mm, depending on ho loose you set things up. That was all assuming 4s, which would be max I’d ever run on that high of kv. I would strongly recommend against trying 6s, unless you ran a 28mm prop and only did one pass. I prefer lower kv motors.

    Recall that amp draw is high with high kv motors, so you need a bigger esc; this will be your limiting factor when you want more speed. Small prop increases will produce greater amp draw increases than with a low kv motor.

    All that said, if you are determined to run the stated setup, I recommend running your 3s in parallel and not going above a 45mm prop. Even still keep checking on temps.
    What motor/esc/battery combo would you run in it?

  7. #7
    Join Date
    Nov 2008
    Location
    Ql
    Posts
    3,169

    Default

    This may be of help.
    It is for Leo's JetChopper 30", but it will proportion out to a 33" hull. Especially if your hull is around 230mm wide.

    00002760 (1).jpg

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •