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Author Topic: Propellers  (Read 2476 times)

justboatonic

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Propellers
« on: June 25, 2008, 09:27:00 pm »

OK, daft question I know  ::) there are left and right handed propellers, but, are there left & right handed inward and outward turning propellers?  :-\

I've wired the motors up on Drumbeat and the motors turn outward BUT that puts her astern! I can remedy that by swapping over the motors wires (hold your breath Dave!  O0) which means the props will be inward turning.

Looking at the props, each blade has a straight 'leading' edge and a curved 'trailing' edge. So, which is correctly the advancing edge of the prop (straight or curved) when turning outward \ inward? Will it have a negative impact if I've stuck the wrong sided prop on the shafts?

I cant take them off and swap them over as I dont have the patience to take out the motors and shafts or rudders to get at them! So, the props will have to stay as inward turning but they may really be going backwards when going forwards (if you get my drift!)
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Colin Bishop

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Re: Propellers
« Reply #1 on: June 25, 2008, 09:42:17 pm »

Are you using the white metal ones? If so they are pretty useless and would be better replaced with decent brass ones. The white metal ones are really only fit for static dispal - if that!
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Liverbudgie

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Re: Propellers
« Reply #2 on: June 25, 2008, 09:46:15 pm »

Evening,

There are only left and right handed propellers.

The leading edge will be curved and, the easiest way to solve this problem, is to change the wires to motors from one terminal to the other.

In all probability the props on the real vessel do turn outboard but, on a model such as this, there is little or no difference in the performance.

LB
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justboatonic

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Re: Propellers
« Reply #3 on: June 25, 2008, 10:50:36 pm »

Cheers budgie. So the leading edge is always curved. Must admit I kind of thought it would be the straight edge. But, from what you say, I think with the props turning inward, the leading edge is the curved one so, phew!  O0

Col, not sure if I paid extra with Slipway but the kit came with brass props although there were some white metal ones. Perhaps I did pay extra, I did buy Drumbeat sometime ago (slow builder you see!)  :o
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Robert Davies

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Re: Propellers
« Reply #4 on: June 26, 2008, 10:03:27 am »


It really does depend on the prop design whether or not to run inboard turning props, or outboard turning props.

These are just my findings from a fair few hours of tinkering and on the water testing.

Raboesch props are best if turning outboard, also depending on hull design etc, the difference can be anywhere from: Hmmmm...  Marginal, to Good God! Remarkable.

Raboesch are THE major third party supplier of brass props in the UK ie other people rebrand them as their 'own brand'.

I suggest an on the water test really, but what I will say is this:

You've spent a fair few bob on the kit, and a huge investment in time, why compromise all that for a small investment in time to get it right?

Protip with most boats you can remove the props in situ. If it's a bit marginal for longitudinal room, swing the rudders hard over and that usually gives enough 'wiggle room' to drop the prop out of place.

-Rob
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Martin [Admin]

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Re: Propellers
« Reply #5 on: June 26, 2008, 11:06:09 am »


Getting back to the original problem, Yes you can just reverse the wires on the motors.
Conversely, on my boats where I couldn't remove the props, I've either just removed the
rudders or the the couplings to give me enough room. Make sure to tighten everything up
properly afterwards, a nice prop on the bottom of the lake are most inefficient!!  :P
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DickyD

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Re: Propellers
« Reply #6 on: June 26, 2008, 11:14:01 am »

justboatonic I think I know where you are coming from.
As you know most props will only screw onto the shaft one way. Well if you were to flip the prop over and you were able to screw it on that way, this would give you your "may really be going backwards when going forwards " worry. As long as your shaft doesnt go right through the prop with a nut to hold it on on the rudder side, it cant happen. O0
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Martin [Admin]

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Re: Propellers
« Reply #7 on: June 26, 2008, 11:28:52 am »

Just another thought, if it's an electronic speed controller, you may be able to "program it the wrong way round."
Don't be tempted to swap the battery leads around though!  :D
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SteamboatPhil

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Re: Propellers
« Reply #8 on: June 26, 2008, 12:46:32 pm »

Now I know I'm only a humble striaght running nut (and radio is a bad word) and not being clued up like you lot, but one of my transmiters (yea well I have a couple of springers) has a reverse switch on both throttle and rudder, an easy option methinks.
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DickyD

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Re: Propellers
« Reply #9 on: June 26, 2008, 02:10:53 pm »

justboatonic try this.  O0
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justboatonic

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Re: Propellers
« Reply #10 on: June 26, 2008, 08:03:32 pm »

Cheers all for the advice.

First off, transmitter reverse function. The ESC I've got is the new twin ESC mixer combo from ACTion. I think the instructions say NOT to use Transmitter reverse once its set up (Dave may correct me there!). Anyway even if you could, that would only electronically do the same job as swapping over the motor wires.

As the pic DickyD put up of Drumbeat shows, (those look the same props I have) there isnt a lot of room between the rudders and end of the props. I'd literally have to gut Drumbeat to take the shafts out such that you could unscrew the props.

Next, take off the rudders. Well Drumbeat is a great kit and there's a deck access hatch directly above the rudder tubes. But, there's no a lot of room in there to undo the linkages, take the arms off and the little rubber sealing ring then drop the rudders.

Bottom line is Im not expecting Drumbeat to get up on the plane so I dont really think inward or outward turning props would make that much difference? Anyway, when this weather changes for the better, its down to the lake at Fleetwood to get her bottom wet!
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