Biggles' Elder Brother - Moderator
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Posts posted by Biggles' Elder Brother - Moderator
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Yes Bruce - three cheers for George. There is just one small catch, George is a businessman, his interest is not in just selling you a "balanced setup" - his interest is in selling you a 4Max balanced set up. Nowt wrong with that, as long as you fully understand where he is coming from. Checking out his site he has a recommended set up for the Super Sixy -it costs £48 more than the exactly equivalent set up I have proposed! Oh, and yes - you still have the problem that you know nothing about why this is a "balanced set up" - you are just sticking in there whatever someone else says.
BEB
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 18:12:03
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Ah, missed that! OK, so, Stan your homework is to redo those calculations but for the lighter weight of the mini. Share them with us and we can "check you out" and confirm you are buying the right things.
Its much better to do it this way where you understand why these are the "right" elements, rather than to just "put in what someone else says". This way you learn how to do it for yourself - otherwise you are always just dependent on someone else!
BEB
PS If you can't find the weight of the mini SS look at the power output of the recommended IC - they say 0.1 to 0.15. An OS 0.15 claims 0.4hp, that is about 300W. In practice I would work on 250W
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 18:24:51
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Hi Stan,
well first of all there is jargon with everything - even IC!
Forget about capacitors and heavy gauge wiring, its all much much simpler than that!
First thing is how much is the Super Sixty going to weigh and so how much power will it require? That determines the motor you choose, and the battery. Those in turn will tell us what speed controller we need and what prop is likely to work well. All of these (motor, speed controller and battery) already come with all the wires you need. No problem.
So what sort of stuff to buy?
Well the SS60 will weight in around 4-5lbs. We don't want too much power - its a gentle aeroplane! So let's look at a target of around 80W/lb, that should be plenty. So at say 5lbs we would need 5x80W that's 400W.
If we use a 3 cell battery (also called a 3s) which is a nice size and can be bought fairly cheaply. Its voltage is nominally 11.1v - so to get 400W we would need 400W/11.1v = 36A. So allowing some "headroom" we can use a speed controller rated at 60A - it will be well within spec.
Also say you want to be able to fly for 10mins - 36A is the max, you won't fly at full throttle all the time, so let's say your average current is 20A, that means for 10mins you need about 20/6 Ah = 3.3 - or 3300mAh. A bit bigger would be good - that's a bottom line.
We can now move on to the motor, it must fit two requirements:
1. It needs to be able to handle over 36A - quite a bit over 36A preferably!
2. We want it to rotate at a max speed of about 10,000rpm - more or less. So with a 3s battery (11.1v) we need a motor that has a "volts to revs ratio" (which we call the kV) of about 10,000/11.1 = 900.
OK lets go shopping! Going to the HK website and based on the figures above;
and a suitable speed controller
All that for just £74.
Hope this is helpful, any questions just ask.
BEB
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 17:29:41
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Oh look, a duplicate post I have to delete - see Phil I do need to look in, its my job.
Percy you realy must try to read the posts more carefully, I'm fully aware of who the OP was and I never said I believed it was your personal thread, even though you may well be the originator of the largest number of posts in it. My comment was in a PS, a separate paragraph, (new subject) and I was using the plural form of "your" meaning all of those who wish to continue this thread.
BEB
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 16:31:45
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Posted by Percy Verance on 12/10/2018 14:39:12:
If they found it boring and repetative, why on earth did they bother to read it?
And they read it all, then ask for it to be closed? Unbelievable. If they don't like this thread there are plenty of others.
Isn't that what Mary Whitehouse used to do? "I'm not interested in it/ don't like it, so nobody else should see it either".
As I havd said Percy, we don't accept such requests, which is why the thread is still here! But IIRC someone asked what made me think people found it boring - well that does! Just answering the question really.
BEB
PS I suggest you just get on with your thread now and I will look in from time to time (when I feel I have the stength) to check all is well, there are no duplicate posts and you haven't strangled each other yet!
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 15:10:17
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1. I haven't said it shouldn't be here in the chit-chat section. (Although a 900+ post thread on an issue not related to the topic of the forum does, personally, make me wonder if it souldn't be somewhere else - like on a nother forum).
2. A significant number of members PMed me when the thread was active before (far more than have ever connected me on the topic of any other single thread), stating they think the thread is boring and repetative - even asking for it to be closed. I have always declined such requests as: firstly, you're right they don't have to read it, secondly we only close threads for either structural reasons (repetition of an existing thread) or because they breech the CoC. Sadly there is nothing in the CoC about endlessly going round in circles!
3. As a moderator sadly I do have to look at it to ensure it needs no maintainance or other action - even when I don't want to.
BEB
Edited By Biggles' Elder Brother - Moderator on 12/10/2018 14:38:04
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If the manufacturer and retailler tells you that about his product that's fine. Follow the advice. As you say he will have to stand by it and he's probably right!
However, my advice would be to not generalise this advice - or at least to only do so with caution. George is an expert with respect to his own products yes, but for the rest he's just "knowledgable and well informed" as indeed a lot of people are - including many on this forum.
BEB
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I have moved the posts placed in a new thread on this into this old thread - you obviously didn't look carefully enough Percy!
I don't think we need two threads on what many see as an utterly tedious topic of very little relevance to model aeroplanes!
BEB
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Posted by Geoff Sleath on 11/10/2018 21:37:07
So that's nearly 2 days work and all I've done is get a motor fitted! Am I the only person who takes 2 days to do a job which should take 2 hours?
Most emphatically not Geoff - I'm a member of that club too! I start with what should be something simple and then it all just magnifies beyond my control! Think back to my WOT4XL thread - that was supposed to be just tidying up a winter hack! Three weeks it took!
Anyway interesting thread, I will be following.
BEB
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The weight question has filled me with curiousity now! It's perfectly possible my memory is at fault - it was some time ago when I put this together.
I'll try to nip out to the shed this afternoon and quickly weigh the WOTTY. I'll report back.
BEB
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Yes Alan is right - that is the way you solve this problem.
I have just completed a BlackHorse 20cc Sea Fury (66" wing span). I don't know if you have already selected retract units if not you could take a look at these which I used.
If it would help I could take some pictures of the Seafury U/C retracted - you could possibly get an estimate of the angle off that? Let me know if you want them.
BEB
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Mmmm, that's a tricky one! It's obviously going to be a stressed joint so its has to be good and TBH I wouldn't be 100% confident in any bond because the underlying EPO isn't that strong!
If there was no alternative and I had to do it I'd probably think in terms of well keying the plastic with some sandpaper then using perhaps epoxy or maybe Gorilla glue. But its a joint I'd want to keep a very careful eye on for some time once in use.
BEB
PS How big a motor are we talking about?
Edited By Biggles' Elder Brother - Moderator on 10/10/2018 11:27:09
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Nice one Geoff.
It's a long time ago now but, to the best of my memory, mine came out at 4.5lb with a 4s on board.
I did my own conversion as well - very straight forward as the most difficult part of any conversion tends to be making a hatch and that's already done for you!
BEB
PS Mine balanced fine with the battery right forward in the fuel tank bay - I found no need to break into the cowl area - which is very small anyway - though I have mounted the ESC in there.
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I had this problem Michael, it was stuck on my work email address and of course I'm retired now. Contact the nice ladies in the office on [email protected] and they can sort it out for you!
BEB
Edited By Biggles' Elder Brother - Moderator on 09/10/2018 16:12:40
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Looking smart Erf - a real credit to you.
BEB
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Nice work Ken.
I'd definately say £20 notes would work out cheaper! It would give an interesting invidual look as well!
BEB
PS There is always baco-foil and Pritt stick?
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The motor I use is rated at 60A, 800kV. The recommended prop was 12x8, but as Geoff says the Watt meter is the judge. With a 12x8 I was only pulling about 40A+ - I wanted more than that. A 13x8 takes me to about 50A max about 700W (on a model weighing only 4.5lb or so!)
Don't get too close to the motor max current - you need some headoom for both the motor and the ESC (both rated at 60A in my case). You have a little bit of a safety margin because whatever the Wattmeter shows static on the ground, it will be slightky less in the air. So, by pushing 50A on the ground, I'm comfortably within limits in the air.
BEB
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I don't think that set up will dissapoinbt you Jonathan. I usually use a 13x8 on mine, that seems to give good balance between thrust/power and endurance.
BEB
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Welcome to the forum Dave!
BEB
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If you have technical questions about using the system can you first of all refer to the documentation that Andy Simmons mentioned earlier in this thread. It's in the Documents section of your membership area - the answer you are looking for is possibly there! If not, then by all means ask Andy on here, but let's not drive the poor lad mad by making him answer the same half dozen basic questions, that are covered in the document, over and over again!
Thanks
BEB
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There is already a thread on this! Please check before starting new threads as to whether something is already there.
The other thread is here. I will close this one and, when I can, I move the posts from here to that thread.
BEB
Edited By Biggles' Elder Brother - Moderator on 08/10/2018 15:22:08
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So sorry to hear that onetenor. I will keep you of both in my prayers.
Remember, you have friends on here and if you feel the need for some respite time and a chat, we're here 24/7.
BEBEdited By Biggles' Elder Brother - Moderator on 08/10/2018 09:36:14
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Yes I thought it was OK, quite enjoyable. But not as good as Model Squadron I felt. There was less sense of excitement and fun and less spirit of fellowship. But the OP is right any programme featuring modelling at peak time is welcome.
I also totally agree with David; too may people judge these programmes by what they would want as specialists, but no one is ever going to make that programme - there simply are not enough of us to make it worthwhile. These are programmes to give the general public an entertaining, off beat, look at the hobby - they are not made to be RCM&E on TV!
BEB
PS We have new members on here saying they were attracted by Model Squadron, we have reports on here of clubs getting new members inspired by Model Squadron - so next time you decide to "have a go at it" because it wasn't a serious technical exposition of aeromodelling, comprehensible by a few thousand modellers only, just stop and reflect - maybe it hit the mark after all?
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I use 4s 5000mAh in my 53" WOTTY - goes very well on them, no question of any lack of power!
BEB
Margaret's health
in Chit-chat
Posted
My am so sorry to hear that onetenor. Please accept my condolences. I'll be thinking of you and holding you and your family in my prayers.
BEB