right or left prop

[wayne quigleyParticipant @waynequigley28540]

now I am pricing up the moter ect for the fairy huntsman I have bought for a future date and the set up I am looking in to is as follows;

1 grouner 700BB turbo electric motor neodyne 1 16" 5mm prop shaft 1 40mm plastic 2 bladed prop (but westboune model dont do a prop with a 5mm thread)can these be ordered in.and how does this set up sound ok to you guys.I intend to use on 12V but not gell batteries.

Edited By wayne quigley on 21/03/2013 17:15:49

Edited By wayne quigley on 21/03/2013 17:16:21

[wayne quigleyParticipant @waynequigley28540]

[wayne quigleyParticipant @waynequigley28540]

also I would think right hand screw ic the correct one for this set up

[ashley needhamParticipant @ashleyneedham69188]

Wayne. I think that all, or most, anyway, standard X or S pitch props rotate anti-clockwise, when viewed from the rear.

This is, presumably because the thread on the shaft would tend to tighten into the prop when being driven.

What are the likely revs on this setup (which seems ok to me) and so what pitch prop are you going for? As the props are so cheap i would purchase an X and an S pitch one to try out. Or even get a 45mm standard three blade plastic to boot.. you can never tell…

Ashley.

[shipwrightParticipant @shipwright]

Wayne,

Have a look at :

**LINK**

**LINK**

It gives details of motor, batteries and ESC. No mention of prop size.

Ian

[shipwrightParticipant @shipwright]

Wayne,

When I clicked on the links I included it didn't include the following information :

"Alan Bond's Huntsman; a 28" fibreglass hull, fitted with a water cooled Speed 700 Turbo 9.6v motor running on NiMh batteries (12 cells) controlled from a Sea Sprint 35A water cooled ESC."

Note that the motor and ESC are water cooled.

As the no load RPM of the Graupner 700 BB is approximately 15,000 it is essential to use a relatively small prop (assuming that you are going to couple the motor to the propshaft without a gearbox). If you look at threads on other websites (eg Model Boat Mayhem) they mostly suggest a 2 blade prop.

Ian

[wayne quigleyParticipant @waynequigley28540]

Ashley the turbo has a no load speed of 15750rev.

westbournes dont say if they are x or s props,,,what is the differance.I have been looking around and most say 2 blades are best for speed.

Wayne

[Paul TParticipant @pault84577]

Wayne

To achieve maximum thrust from any set up you will need to factor in the propshaft angle, shallow angles require a smaller prop whereas a steep angle requires a much larger one.

The angle can also affect the degree of pitch and number of blades.

Some Huntsman kits have a very steeply angled shaft and I would think that your current 40mm prop is quite close to the mark (but personally I would opt for a 3 bladed version)

Paul

[ashley needhamParticipant @ashleyneedham69188]

Wayne. As paul is indicating, there is no clear cut answer to this.

An "X" pitch prop is of a much courser pitch than an "S" . The props are usually marked on them so Westbouirne should be able to find out. As previously stated, these props are very cheap and a small selection of both pitches in 35mm and 40mm, plus a couple of 40 and 45mm three blade ones will not cost much and enable fine tuning to acheive good performance/max efficiency of the motor. It is not money wasted, as these are very common sizes and they will be used in something later on, if only for comparisons.

i would advise getting an ammeter to measure the current draw of the motor on various props. This is really the only way to go, and will stop dangerous overheating and so on. Again, doesnt have to be an expensive one.

Ashley

[ashley needhamParticipant @ashleyneedham69188]

Wayne. As paul is indicating, there is no clear cut answer to this.

An "X" pitch prop is of a much courser pitch than an "S" . The props are usually marked on them so Westbouirne should be able to find out. As previously stated, these props are very cheap and a small selection of both pitches in 35mm and 40mm, plus a couple of 40 and 45mm three blade ones will not cost much and enable fine tuning to acheive good performance/max efficiency of the motor. It is not money wasted, as these are very common sizes and they will be used in something later on, if only for comparisons.

i would advise getting an ammeter to measure the current draw of the motor on various props. This is really the only way to go, and will stop dangerous overheating and so on. Again, doesnt have to be an expensive one.

Ashley

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