Dave Hopkin
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Posts posted by Dave Hopkin
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Why not just have the club officials have an on-line spreadsheet (google docs for instance) where you record the Owner, the model and the engine, test date and results
Update it with each test and it can be accessed at the field via a smart phone and not a tree needs to die
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Dont encourage them!!!!
Someone in Crab Air will see this and try it with a full load of "Self Loading Freight"
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Changes by the hour but.....
Lets Dance - Bowie
Rockin the Casbah - Clash
Theres a lot of clever ********** - Ian Dury
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An "800watt 790kv" motor will draw X current depending on the prop load you fit, bigger the prop the higher the current
What you need to do is set the motor and prop up on a test rig and measure the current it draws turning your chosen prop
Once you know the current draw from the bench test you can divide the battery mAH capacity by the current draw to give you a decent idea of the duration
If you find you are drawing 20Amps at cruising speed then
A 4000 mAH will give 4 Amps for an Hour, 20/4 = 5, 1 Hour /. 5 = 12 mins
Estimated Current Draw / Battery Capacity = X
1 Hour / X = Duraction
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I think you might be confusing EXPO and RATES....
Rates limits the total movement of the Servo from end to end, which limits the control surface movement
Expo alters the sensitivity of the servo in the centre stick area but does not alter the total movement
Rates are highly suitable for learners who tend to over control - setting rates reduced the violence of a full stick movement (though do try to treat the stick like a womans t.. not a Gorilla's throat)
Expo can land learners in trouble as it tends to encourage over control as "nothing seems to happen when i move the stick a bit"
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Posted by Jon Laughton on 26/06/2018 06:01:15:
Dave is this another of your Depron wonders or is it mixed media?
Hi Jon
No its all old fashioned Balsa!!!!
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Posted by SIMON CRAGG on 27/06/2018 17:45:54:Its a BH3720A-KV500 shich means nothing to me!. Do I just make sure I do not exceed the 40amps, or do I have to worry about amps and volts etc? Many thanks for your help so far!
If this is the correct motor (its BM not BH) **LINK**
Then its rated for 3 to 4 Cell Lipos
With a max current of 35a continious 49a burst
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Posted by john stones 1 on 27/06/2018 18:27:27:
Willie Messerschmitt, Kaiser Wilhelm, Irving Berlin
Your boys took a hell of a beating. 
How will I ever get over the mighty boche being knocked out........
Oh wait, I have,............. Fritz your plane leaves in 20 mins gate 4 see ya.....
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Posted by Chris Walby on 25/06/2018 21:19:40:
DH, Nice photo
Could you post details of the model please
Its from the "Flying Scale Models" plan by Paul Tupker
44" Semi-Scale Gloster Meteor IV
2 x 70mm EDF running on a 4S 5000mah Lipo
Seems to be fully aerobatic (though I am nervous of the wing joiners between the inner and out wing panels where the fan ducts are!)
Aileron, throttle and Elevator controls only
I deviated from the plan in a couple of ways...
1) Elevator Servo is a thin wing servo embedded in the horizontal stabiliser
2) I had two or three goes at the wing - the plan says to build a centre section and two outer panels then join them with the Fan formers as dihedral braces - of course this means you cant set the wing up on a flat surface as the lower portion of the fan former hold it up in the air!
In the end I gave up that idea and just built the wing in two halves (ignoring the fan formers) - set the wing up, then added the formers afterwards and cut away the portion of the wing structure afterwards
Edited By Dave Hopkin on 25/06/2018 21:43:09
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Finally got it trimmed and a decent flying shot.....
Edited By Dave Hopkin on 25/06/2018 20:40:15
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Do you mean these RDS Adaptors?
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I work in the Finance Industry and NO UK Bank will EVER send you a link to click on to enter your on line bank application - Any text or email you may receive that includes a clickable link is a SCAM Never ever open it
What it will do in 99% of the cases is collect your security details and transmit them to a (criminal) 3rd Party
If you get an email that makes you want to check your accounts go to google and enter the on-line baking system from google NEVER from an email
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Not sure why you felt livid - the law is clear you may use reasonable force to defend yourself
But there is a dead body that certainly didnt die from natural causes so the police are duty bound to investigate the circumstances and make a recommendation to the CPS who will make the decision to prosecute or not
If the police and the CPS believe "reasonable force" was used no charges should be brought against him
So getting livid at the moment is a little premature - wait until the CPS make a decision
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Cheap screwdrivers with moulded plastic handles
Either the blade just deforms and twists or the plastic handles shatters...
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Nice to see an almost lost art alive and well
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Posted by John Lee on 30/03/2018 12:12:39:
Fancy an anti-gravity machine?
Does it come with a free tin foil hat?
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Its not so much the crashing that gets to me, its the way time seems to stand still while its in the process of transitioning from "fully controlled flight" to "making a hole in the ground" and you are utterly helpless
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You can tell a lot by the kind of paper people buy...
If they buy the Mail they are right wing reactionaries
If they buy the Guardian they are left wing liberals
If they buy sandpaper they are Australian Cricketers......
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Posted by Paul Marsh on 26/03/2018 20:30:10:
Tip: Never reply to suspected emails, even for fun, do not reply at all and delete/block!
Sound advice, working in a financial institution we have to go through mandatory training in this (even though I dint deal with the public or accounts but the regulator cant be refused!) these courses show how the scams work but also the value to the scammer of a reply from a potential victim (even if its an invitation to "go away"
They buy/share lists of email addressed that may or may not be real people so they cost about $0.01 per name, if they get any sort of reply the resale value of the email name jumps to about $0.5 - they then sell these one to other scammers and the cycle continues
Resist the temptation to play with them or invite them to depart - you are just indirectly giving them money
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To help turn the watt meter into something less cabbage like.....
In simple terms there are two variable components affecting how an electric set up works
Voltage - Your Lipo , for safety's sake lets take a fully charged 3S lipo as 13v volts
Loading - Your prop the bigger/more pitcher the more the load
Now a brushless motor will TRY and reach its maximum RPM no matter what the loading is, so as voltage in a set up is fixed the only other thing that can change is current
So as you load up a motor the more current it will draw (eventually reaching magic smoke) Wattage is simply found by multiplying Volts by Amps
Hence Matty's instructions to open the throttle gradually watching the Wattage (hence current rise) backing off if the current reaches close to the ESC rating
If you can switch your meter to display Amps its actually more useful for this secnario
1) At full throttle if the Amps you are pulling is greater than the ESC current rating you need to change the prop for less load OR put a bigger sized ESC in the system OR use a lower voltage battery
2) If at full throttle the current plus 15% is less than the ESC rating its a green light
3) If the current draw is close to the ESC play safe and treat it as (1)
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The legal position is that the Bank of England will exchange them for ever as there are a promisary note for £10, but retail banks/building societies are not legally bound to accept them after the 1st March,
From our internal web site the XXXXXXX bank will continue to accept them and that position will be reviewed on the 1st September
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Posted by Don Fry on 13/03/2018 18:44:49:
But being serious, the ultra light aircraft shrink fabrics like Ceconite, work well. There are on line application instructions which are good. They sell a glue. Don't bother, balsaloc, or equivalents are good for us. Ceconite cone by the yard, off a ( I assume, six foot) width. Cheap.
Edited By Don Fry on 13/03/2018 18:45:18
!0/10 for the tip Don!!!
The Ceconite arrived in tube format about 7ft long! which sent SHMBO's eyebrow somewhere near the ceiling however after the Balsaloc was slapped on and hammered in place with a iron at 100 degrees and shrunk at 120 it goes on a treat.............. will finish off with some non shrinking dope.....
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Posted by oldgit on 16/03/2018 17:03:32:
what exactly do you get with a short kit, do you need to buy any other wood, do you need to cut out and shape wood - eg ribs ???
Edited By oldgit on 16/03/2018 17:04:07
Short Kits (usually) have a plan, the wing ribs, fuselage formers, and any other complex shape pre cut for you, the builder will have to add sheet and strip wood as required
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Posted by John Lee on 13/03/2018 19:42:20:Posted by Dave Hopkin on 13/03/2018 18:32:46:
As a kid I used Nylon and Dope, is there any fabric on sale that heat shrinks that's not aimed at the modelling market, is there a specfic "breed" of polyester that will shrink under an iron??
As Don says there is Lightweight Ceconite, 66inch wide £6.26 a yard. Link
Well ordered 3m of the Ultralight Ceconite - hefty postage charges so we will see.....
Dual Ailerons
in All Things Model Flying
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By the position of the servos - have the servos facing in opposite directions
Left hand wing with the output arm facing the tip and the right hand wing one also facing the tip
Use the Y lead and they will work as an opposed pair