George Worley - 4-Max
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Posts posted by George Worley - 4-Max
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11 hours ago, Nigel Heather said:
Hi,
For Christmas I got a Fun Fly kit (Bills Big Fun). It is an old design originally aimed at a 25-size IC engine (typically one bored out to 32/35/37), has a 47" wingspan, 700 sq in wing area, a flying weight around 3lb.
I want to use an electric setup but the instructions don't cover this. I've spoken to the manufacturer (Bill) and he says many do convert them to electric but he doesn't have any details and he only uses IC.
I've looked at the 4-Max site at their recommended setups - they don't cover this exact kit but they do for the AviCraft Fun 'E' as follows
Motor - 3547-800
ESC - 60A
Battery - 4S
Prop - 13x4
The advice I am seeking is what capacity battery to use - and this is tied in with balancing and thrust to weight ratio.
Firstly is there a rough guide of what Power To Weight ratio I should have for a fun fly aircraft - 3D, prop hanging etc?
Secondly - I've sized up the weight of an IC power system and it comes in around 500-550g, the electric system excluding battery weighs 210g
I have two battery approaches - a smaller capacity (1600mAh) or a larger capacity (3300mAh).
The larger battery weighs 300g so the total weight will be about the same as the IC system it was originally designed for - I also assume that this will make it easier to achieve the correct CoG
The smaller battery weighs 170g so the plane will be lighter and the thrust to weight will be better. It may be more difficult to achieve the CoG though.
Personally, I like the idea of the bigger battery because which ever 4S I go for I will have to buy new and the 3300mAh would be a much more versatile battery that I can use in other models.
These are my thoughts - interested to hear your thoughts.
Cheers,
Nigel
Hi Nigel
For good funfly/3D flying you should be looking at a 1.75 to 2.00 to 1 power to weight ratio
So if your model weighs for example 500g you should be looking for 875-1000g of static thrust
We no longer refere to watts and watts per pound as from experience we find this not a good indication of performance.
If you used our products then the nearest test results we have are as follows
We haven't tested it with a 13x4, the top speed of a 13x4 may be too low at around 36MPH
13x5 JXF High performance Wooden prop
14.8V under load
33.2A at 14.8V
8955RPM
Measured static thrust 2987g/6.59lbs
Estimated top speed 42MPH
To get the best flight performance you need the lightest possible setup.
Funflys generally have short noses so you need to get the motor as far forward as possible,
then work out how much weight you need to get the model to balance.
based upon that weight choose a battery near that weight.
We recommend the smallest battery for a funfly/3d model to be around 15 x max Amps
In this case 33.2/15 = 2.21 so Look at the weight of a 4S 2200mAh LiPo
Cheap LiPo's don't last and they don't perform even if the "specification" is the same.
Try one of our 60C LiPo's you won't be dissapoinrted.
https://www.4-max.co.uk/lipos.htm
George
4-Max
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Hi Simon
Hobbywing timing is set to "low" as defaiult.
Outrunners require high timing for maximum performance.
Change the timing to "High" and see the difference
George
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Hi Tosh, Yes that motor will work, check out this page for more info on that motor combination
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On 02/03/2022 at 17:43, Allan Bennett said:
I've been away for a while, but last week I ordered and received my A10 full kit, and the fuselage is well on its way to being structurally complete, with nacelle framing added today. Motors and ESCs arrived from 4-Max today too.
Having got this far I can see that my earlier suggestion of putting the fans at the front of the nacelles for better efficiency is impractical. But the 50A ESCs supplied by 4-Max seem, in my view, too large to fit comfortably inside the nacelles. I can see in his photos how Colin Low 2 has got them in, but nevertheless I'm going to extend the motor wires and install the ESCs somewhere inside the fuselage instead. This will make them more accessible for my arthritic thumbs, and will also allow me to run the motor wires into the fuselage near the rear of the pylon, where they'll be even less visible.
Hi Allan,
Yes our ESC are not the same as your average ESC.
Firstly they use a 32bit processor, unlike most of our competitors who have the cheaper and slower 16 bit processors.This means our ESC's are more efficient and can deal better with high RPM motors as in EDF applications.
Secondly I have personally tested our ESC's with a battery length of 1M and have had zero problems. Our manufacturer has designed around the old problem buy better design and the use of better/more resilient components.-
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Hi Guys
As per a lot of hobby shops we are still accepting and sending out order to UK customers.
We are not accepting visitors at this time.
We have added a lot of accessories lately to help the budding builders out there.
Please click here for our accessoriesNeed a hand in selecting an electric motor for your latest project? then please drop us an email with as much information as you have and then we can advise the correct motor, ESC, prop, battery and even servos if needed.
Please click here to visit our website
Stay Safe
George -
Hi Guys
Like many on here we are also Peter Miller fans and have started to put together electric power train setups for Peter Miller Designs (with Peter's help and approval), Some are old and some haven't been released yet - Something to wet your appetites.
If you want an electric setup for a design that is not on the list, please get in contact (via our website is best) and we'll be glad to put together a complete system for you.
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Posted by Steve Bell 3 on 20/03/2015 17:15:21:
If like me your building the pusher version beware the recommended motors have been discontinued. Darn itWe do have alternative motors for the pusher version which are slightly less powerful but after chatting to Tony this really should not be a problem as the original motors were very powerful
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Hi Nigel
Looking forward to seeing progress on this thread - Subscribed!
George
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Not quite sure what happened to the picture LOL
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Hi BEB,You may want to re-visit your horizontal stabiliser - Sorry! Tony made a small error in his drawings and drew the elevators wrong. have a look at Trevor Crooks photos, his are correct, you'll see what I mean. Tony blew up this drawing for me and now myself and Colin Low are building 2 off 100" versions, both for electric power. We hope to get them built for around 25lbs and have around 3500W on 12S. So far we have built the tail feathers and have made a plug and cowls, next job is the fuselarge. The plug and cowls must have taken us over 80 hours of work so far. You are doing a very nice job here, keep up the good work.
Edited By George Worley - 4-Max on 17/08/2013 17:49:12
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The Jungmeister and DH-89A Dragon Rapide are both owned by Ian Gear of the Isle of Wight and are powered by Purple Power motors from 4-Max. The Lancaster is owned by Colin Low (Purple Powered), The DC3 belongs to Roy Thompson, the Tigercat is mine (Purple Powered) and the 10S version of the H9 Taylorcraft and the Siamese Funjet belongs to Chris Bradbury. The 6S version of the Tailorcraft belongs to Bob Mahony. Roy, Colin, Chris and myself are all members of the Basingstoke Model Aero Club who are holding their annual Electric Fly-in on the 15th of September. It's generally well attended and we have a great field, so come along and have a fly.
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Posted by George Worley - 4-Max on 17/02/2011 13:38:00:
The latest info from Multiplex is that the Dogfighter is due in June/July 2011 and Web price should be around £80 for the basic airframe and £160 for the RR Version. They are only listing one type so I presume both sets of stickers are included. Until I actually receive my stock I can't confirm this.Just read their blurb and they say there are 2 decal sheets supplied with the model
Edited By George Worley - 4-Max on 17/02/2011 17:34:08
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Yes the white Twister is due out later this year, Web price is expected to be around £80 for the airframe only
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The latest info from Multiplex is that the Dogfighter is due in June/July 2011 and Web price should be around £80 for the basic airframe and £160 for the RR Version. They are only listing one type so I presume both sets of stickers are included. Until I actually receive my stock I can't confirm this.
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Personall I think it will be very popular. I also think it looks like a late mark Spitfire or even a Supermarine Spiteful (see below pic)
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HiI assume you are flying with LiPo batteries. If so then to make your LiPo's last, I suggest you aim for taking out a maximum of 80% of the batteries capacity, less is better.IE with a 2,200mAh battery you want to aim to put back 1760mAh or less.2200 x 0.8 = 1760
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Current age 45Electric ScaleElectric AerobaticElectric SportStarted at 12 years of age with small diesel powered sport and scale free flight modelsCurrently been flying RC for 13 years mainly electric.
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Great event, thanks Mr Mahony!!The event will be on next year. Anyone interested in attending next year please drop me an email via my website and I'll make sure you will receive reminder emails nearer the time.
Some more photos can be found hereCheers n beersGeorgePS it wasn't a Mosquito it was John Ranson with his DH103 Hornet.PPS Hi David, I'll see if I can find out the name of the Sea Fury fan, I had a long chat with him, but didn't catch his name.Edited By George Worley - 4-Max on 29/06/2009 21:37:59
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SebArt Sukhoi 29 50E
I have seen 2 of these models crash and be a total write off. Both were being flown by very experienced and very skilled pilots. Only with the second crash was the problem discovered. The first crash happened when the plane was in low knife edge and the canopy came off. There was no response from the plane and it cart wheeled across the patch, totally destroying the plane.The second crash was similar, this time the plane was doing a knife edge loop and at about 3/4 of the way round, the canopy came off and again the plane did not respond.The first and obvious fault was the canopy comes off way too easily. This is an aerobatic/3D aircraft which should be capable of standard knife edge and knife edge loops.The second fault is far more serious. When the canopy comes off it turns the radio off!!!!!!Both of these models were built as per the instructions and the instructions tell you to install the ON/OFF switch at the front just under the canopy hatch. So when the canopy hatch comes off in flight, it turns the radio off, resulting in total loss of control and in both of these instances total loss of the airframe, motor, ESC and 6S batteries.
If you have one of these and have built it as per the instructions, then I highly recommend that you modify it immediately to put a physical catch so it's impossible for the canopy hatch to come off in flight. Magnets are not good enough for a model of this size.Cheers n beersGeorge -
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4-Max 4S 50mm EDF V2 – What am I doing wrong?
in Electric Ducted Fan
Posted
Not sure why you didn't talk to us as your first port of call.
If we sold them as V2 then they are V2. there is no difference in the markings to distinguish between a V1 and a V2.
You say that the outlet is chocked down 85-90%, is the compaired to the fan diameter or to the FSA?
Any reduction of the exhaust tube will greatly reduce the thrust but it will increase the air speed.
If you want more thrust increase the diameter of the exhaust tube.
Is the inlet ring still fitted?
We recommend a 60C good quality battery, like one of ours
I would also try a 4S 2600mAh if you have the room.
Have you set the ESC to "high" timing?
Is the battery fully charged when conducting these tests?
Battery temperature at this time of the year will affect it's performance.
Is the battery warm, around 20 degrees when conducting the tests?
The figures we quote are in free air with the inlet ring and at nominal voltage.
As soon as you fit it in a model those figures will drop and it will vary from model to model.
Hope this helps