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Multicopter => Multi Copter => Topic started by: john888 on May 08, 2013, 09:16:12 PM

Title: Propellers for TriCopter
Post by: john888 on May 08, 2013, 09:16:12 PM
Please don't laugh as I'm about to ask a really stupid question. I am going to build a David Windestål tricopter and have order the parts from Hobbyking. Unfortunately their main warehouse ran out of stock on the propellers so I thought I would order an alternative from their UK warehouse along with two other out of stock items.

Now, to me a propeller is a propeller right? But on Hobbyking's website, some of the props were described as "Right Hand Rotation". I searched the www but not much information there. I am sure this must have been asked here before so please forgive me if it has. So, my question is, what is the difference between a prop whcih has no "Right Hand Rotation" description and one that has?

Thanks
Title: Re: Propellers for TriCopter
Post by: markvanhaze on May 08, 2013, 09:47:42 PM
I also built the same tricopter from david following the hk shopping list.  The difference between the propellers is that assuming both turn the same way,  one will create a upwards lift and the other a downwards lift.  They are basically built as opposite screws.
Title: Re: Propellers for TriCopter
Post by: john888 on May 08, 2013, 09:53:14 PM
Thanks for the reply. If I buy props with "Right Hand Rotation" description, will they work? BTW, how's your TriCopter flying?
Title: Re: Propellers for TriCopter
Post by: markvanhaze on May 08, 2013, 09:56:14 PM
Since it's a tricopter all three props can be identical and it's no matter which type they are.  Right or left will work fine just have 3 identical ones.

My tricopter is in bits after I had a motor fail on me at 15m height. .. I still don't know how it happened but I guess a lose bullet connector.
Title: Re: Propellers for TriCopter
Post by: dirtyharry on May 08, 2013, 09:57:27 PM
Basically you get right hand propellers and left hand ones , normally one pushes the other pulls.

But in a quadcopter you reverse the direction of the  "reverse" pusher propellor so it also pulls. this means you have 2 going clockwise and 2 going CCW , because they induce a turning torque in the frame the 2 sets of props balance each other out so it doesn't spin into a mad frenzy.

As a tricopter controls its "turning frenzy" by tilting one of the props to react against the induced torque you don't need to worry about getting reverse props , just get several sets of your normal CCW props.
Title: Re: Propellers for TriCopter
Post by: john888 on May 08, 2013, 10:00:51 PM
Thanks guys. So I just get the ones without the "Right Hand Rotation" description then.
Title: Re: Propellers for TriCopter
Post by: markvanhaze on May 08, 2013, 10:06:12 PM
Yup.

Sent from my GT-N7100 using Tapatalk 4 Beta

Title: Re: Propellers for TriCopter
Post by: vanmantony on May 09, 2013, 10:06:35 AM
John888, been flying tri's now for a couple of years only ever use standard props
i.e counter clockwise  in fact i always use these    http://r.ebay.com/9tJj2G (http://r.ebay.com/9tJj2G)
well cheap and on 1200kv motors they are perfect once they are balanced up, never had one fail in flight yet (broke loads in trees hedges etc but at 35p a throw who cares LOL,just finished a folding tri to take on me travels heres a pic
(http://s8.postimg.org/hqkmas1bl/tricopter_001.jpg) (http://postimg.org/image/hqkmas1bl/)
cheers Tony
Title: Re: Propellers for TriCopter
Post by: Shikra on May 09, 2013, 11:02:20 AM
I've run both setups - opposing props on front or all the same.
I can tell difference, but its not that great.

In fast power climb you see the effect with a yaw turn. Most evident if open up throttle quick. Thats pretty much it..

APC props are great and popular allround 1047 on 3s with a 7-900kv motor

Title: Re: Propellers for TriCopter
Post by: john888 on May 09, 2013, 08:12:23 PM
@Tony, Never thought to in eBay for my parts. I'll order some definitely! Hey, that tri looks great.

@Shikra, Thanks for the info but I'm a bit lost on "APC props are great and popular allround 1047 on 3s with a 7-900kv motor" as I'm a complete newbee.
Title: Re: Propellers for TriCopter
Post by: electrotor on May 09, 2013, 08:48:00 PM
APC is the name of the manufacturer - it stands for Advanced Precision Composites

1047 means 10" diameter and 4.7" pitch. It is often also written as 10x4.7

This type of APC prop is also called a Slow Flyer prop hence 10x4.7SF. SF props are not designed for use on high speed motors. They are more lightly constructed and have a different blade profile.

http://www.apcprop.com/ProductDetails.asp?ProductCode=LP10047SF (http://www.apcprop.com/ProductDetails.asp?ProductCode=LP10047SF)

7-900kV motor means that for every volt which is applied to the motor it will spin at 700 to 900rpm under no load. It is a way of telling whether a motor is a high speed one or not. High speed could be about 2000kV or more.

3s means a 3 cell Lipo which is around 12.1V

So the above motor would work out at 700 x 12.1 = 8470rpm or 900 x 12.1 = 10890rpm
Title: Propellers for TriCopter
Post by: stevec on May 09, 2013, 10:09:11 PM
Quote from: john888 on May 09, 2013, 08:12:23 PM
@Tony, Never thought to in eBay for my parts. I'll order some definitely! Hey, that tri looks great.

@Shikra, Thanks for the info but I'm a bit lost on "APC props are great and popular allround 1047 on 3s with a 7-900kv motor" as I'm a complete newbee.

Hi John,

I don't normally piss on people's bonfires but you may want to try doing a quad if this is your first venture into rc.

Tri copters tend to need a bit of tuning and can be quite tricky to fly compared to a quad I realise there are the extra expenses of a 4th motor, ESC and prop, but they are really easy to fly.

Maybe my tri was just a poor effort at it but it was a lot less stable than my quad.
I fly helicopters mostly and I'd say a poorly tuned tricopter is harder to fly than a heli.
This may just be me, and not accommodating the different nature of these beasts, but I'd hate to see you pile money into something and watch it crash before you even get a chance to learn how to fly it.

Good luck whatever way you go but I want you to go in with both eyes open.

Cheers
Steve


Sent from my iPad using Tapatalk HD
Title: Re: Propellers for TriCopter
Post by: john888 on May 09, 2013, 11:14:25 PM
Wow! Thanks a lot electrotor. That was very educating to me.

Steve, Thanks for the heads up but I've already gone too deep into the tricopter build. I was inspired by David Windestål at RC Explorer and prior to deciding on thr tricopter, I read in a forum that a tri is more suited for camera work. This piece of info may be complete BS but I like David's simple design so I thought I'll have a go. Well, at least now I know that I have an easier option if my tricopter build ends up in a heap.
Title: Re: Propellers for TriCopter
Post by: vanmantony on May 10, 2013, 09:50:06 AM
john, stick with your tri you won't be disapointed I've built 8 0r 9 now for myself and others some with lights on some folders, all on a similar line to rc explorers. I did make 2 quads for myself and a friend but after a day flying them me broke them up and turned them into tri's.(cannot get on with the handling of quads) I also have planes and ic heli but to be honest I haven,t used then in months to much fun with the tricopter's. If you get stuck with anything give us a shout but following Davids build thread is as good a way to get into it as any cheer's tony

P.S couple of close ups of a build might be of intrest

(http://s16.postimg.org/gzzk5xyc1/tricopter_004.jpg) (http://postimg.org/image/gzzk5xyc1/)

(http://s10.postimg.org/va82fjzp1/tricopter_002.jpg) (http://postimg.org/image/va82fjzp1/)
Title: Re: Propellers for TriCopter
Post by: Shikra on May 10, 2013, 10:32:29 AM
IMHO..

Dont think there is a massive difference really.

Tris are easier to fly LOS with orientation
Quads are easier to build

The only real advantage is a Tri has nicer Yaw characteristics...
NAZA doesnt support Tri

Title: Re: Propellers for TriCopter
Post by: john888 on May 11, 2013, 01:54:02 PM
Quote from: vanmantony on May 10, 2013, 09:50:06 AM
john, stick with your tri you won't be disapointed I've built 8 0r 9 now for myself and others some with lights on some folders, all on a similar line to rc explorers. I did make 2 quads for myself and a friend but after a day flying them me broke them up and turned them into tri's.(cannot get on with the handling of quads) I also have planes and ic heli but to be honest I haven,t used then in months to much fun with the tricopter's. If you get stuck with anything give us a shout but following Davids build thread is as good a way to get into it as any cheer's tony

P.S couple of close ups of a build might be of intrest

(http://s16.postimg.org/gzzk5xyc1/tricopter_004.jpg) (http://postimg.org/image/gzzk5xyc1/)

(http://s10.postimg.org/va82fjzp1/tricopter_002.jpg) (http://postimg.org/image/va82fjzp1/)

Thanks for the encouragement Tony. I do not know much about aerodynamics but I suspect that the long boom in David's design helps in making the tricopter more docile or should I say less twitchy.

Your body plates look like aluminium instead of carbon fibre. Did you make them yourself? I have bought two carbon fibre plates from FlightTest for my first build. I intend to make my own body plates from thin plywood in future. I may lazer cut them at FabLab in Manchester as it is free to use their facilities on Fridays and Saturdays.

Cheers

John





Title: Re: Propellers for TriCopter
Post by: bignose13 on May 11, 2013, 06:46:24 PM
Get these, brill props for the money, not quite APC quality but for your first props you wont go wrong
http://www.giantshark.co.uk/propeller-10x47-black-p-402698.html (http://www.giantshark.co.uk/propeller-10x47-black-p-402698.html)
Title: Re: Propellers for TriCopter
Post by: vanmantony on May 11, 2013, 11:55:23 PM
john, well spotted 1.5mm alloy plates, had a few lengths lying around so used them, also used for yaw mech done 5 or 6 like this always work super smooth and as they are on top of arm totally crash proof
couple of pics might be worth a look

(http://s7.postimg.org/f5325yat3/IMAG0527.jpg) (http://postimg.org/image/f5325yat3/)

(http://s22.postimg.org/csg5we5bx/IMAG0528.jpg) (http://postimg.org/image/csg5we5bx/)
cheers tony