Re: Latest Aeromodeller magazine

[Slowmatch]

Out of interest Pete, I don’t suppose you know the weight of Richard Crossleys Short Shetland do you? Or anyone else for that matter?
The only reason I ask is I googled the motors he’s using on the model, and they provide 25g of static thrust. I’m trying to understand motor sizes needed for outdoor scale electric, so it is of interest to me purely from that perspective...

Richard aims for static thrust equal to half the weight of the model.

There's a nice simple(ish) way of looking at it. In steady flight you are probably familiar with the vector diagram showing that Lift = Weight and Thrust = Drag.

We can work out the Lift to Drag ratio by glide testing. For example if a model flies 6 metres forward for every metre of height lost then it's L/D ratio is 6:1. By happy coincidence Weight to Thrust ratio needed for level flight is exactly the same (it's balanced) ie 6:1 or thrust is equal to one sixth of the weight.

Of course static thrust is reduced by forward speed (maybe as much as a third or a half) and you need excess thrust to climb. So Richard's aiming point of 50% gives you the needed margin for scalelike performance indoors. You might want a bit more thrust for outdoor flying, climbing in turbulent air etc.

Jon

Re: Latest Aeromodeller magazine

[MarkM]

Out of interest Pete, I don’t suppose you know the weight of Richard Crossleys Short Shetland do you? Or anyone else for that matter?
The only reason I ask is I googled the motors he’s using on the model, and they provide 25g of static thrust. I’m trying to understand motor sizes needed for outdoor scale electric, so it is of interest to me purely from that perspective...

Richard aims for static thrust equal to half the weight of the model.

There's a nice simple(ish) way of looking at it. In steady flight you are probably familiar with the vector diagram showing that Lift = Weight and Thrust = Drag.

We can work out the Lift to Drag ratio by glide testing. For example if a model flies 6 metres forward for every metre of height lost then it's L/D ratio is 6:1. By happy coincidence Weight to Thrust ratio needed for level flight is exactly the same (it's balanced) ie 6:1 or thrust is equal to one sixth of the weight.

Of course static thrust is reduced by forward speed (maybe as much as a third or a half) and you need excess thrust to climb. So Richard's aiming point of 50% gives you the needed margin for scalelike performance indoors. You might want a bit more thrust for outdoor flying, climbing in turbulent air etc.

Jon

Absolutely brilliant! Thanks for that information. I don’t suppose you have any information on the GWS gearboxes do you? I’ve seen you can get them in different ratios, but I’m unsure if they would even be suitable for outdoor models.

Re: Latest Aeromodeller magazine

[Slowmatch]

Mark,

GWS published a lot of details including performance and specs on their website:
https://www.gwsus.com/english/product/powersystem/ips.htm
Click on the picture thumbnail of the particular motor to see the data.

I've not personally used geared GWS (only direct drive on E20s) but they were very sought after for E30. Pete Tolhurst would be able to tell you more (I think he wrote it up at the time.) Maybe start a new thread with more details of your model and I'll try to help?

Further to the above post, there is a formula to estimate climb rate from excess thrust but it need a few more specific model details.


Jon

[MarkM]

Mark,

GWS published a lot of details including performance and specs on their website:
https://www.gwsus.com/english/product/powersystem/ips.htm
Click on the picture thumbnail of the particular motor to see the data.

I've not personally used geared GWS (only direct drive on E20s) but they were very sought after for E30. Pete Tolhurst would be able to tell you more (I think he wrote it up at the time.) Maybe start a new thread with more details of your model and I'll try to help?

Further to the above post, there is a formula to estimate climb rate from excess thrust but it need a few more specific model details.


Jon

Thanks for the link Jon. I’ll start a new thread to save clogging this one.

[DavidJP]

Hmmm…… A generation thing again by the look of it and that I grew up in a harder world than we have today, in some respects.  True we don’t know both sides of the story - an possibly it is all down to communication.  Often the cause of things that go wrong today.  I would like to know the efforts  made by the printer to find a source elsewhere - or was he given virtually no advance warning?  And when did Aeromodeller know there would be a delay.  Yes what about the ball bearing factories - that is the point - take out a necessary ingredient and you can find it has wide reaching effects.  Not a new idea at all.  Anyway it matters not really - I am largely unaffected now by this casual attitude we have today.  And we have far worse things looming on the horizon than Aeromodeller being delayed!

[Arnold S]

Hmmm…… A generation thing again by the look of it and that I grew up in a harder world than we have today, in some respects.  True we don’t know both sides of the story - an possibly it is all down to communication.  Often the cause of things that go wrong today.  I would like to know the efforts  made by the printer to find a source elsewhere - or was he given virtually no advance warning?  And when did Aeromodeller know there would be a delay.  Yes what about the ball bearing factories - that is the point - take out a necessary ingredient and you can find it has wide reaching effects.  Not a new idea at all.  Anyway it matters not really - I am largely unaffected now by this casual attitude we have today.  And we have far worse things looming on the horizon than Aeromodeller being delayed!

David, you are incredibly patronising.  I am well over 50 and have worked as a professional engineer for over 30 of those years and I have not seen supply problems as bad as they are at the moment.  Things are very difficult in all area’s of manufacturing and see it daily, thus my sympathy for problems people may have.

Heard of the Azovstal steel works?  That caused a huge delay in our production schedules as they had the plate for one of our loco’s in process.  Of course the poor sods of mine and my lad’s generation defending it to the death didn’t have it as bad as your generation, how could they?  We thought we might put a call through and tell them to stiffen their upper lip and get on with it, but we decided it might not have the desired effect.

BTW your generation sold our steel and heavy engineering capability down the Swanny, I suppose we can thank you for that…

The world is still hard, but just in a different way…

Andrew

[TheLurker]

Me?  I blame the bean-counters.

There was a time when companies held enough stock in stores to be able to continue working through a short term disruption of supplies.  Then someone said, "Transport links are incredibly reliable these days, we can save money by not having all this stuff in stores and have it delivered just as we need it.  Nor do we need to maintain our warehouses nor yet employ men in brown coats to disburse these stocks on production of the correct chitty."  The engineers and makers of all manner of goods said? "Are you quite bonkers!?  What happens if there are transport problems?"  "Ah, it'll never happen. These are modern times and nothing can go wrong.", quoth the bean-counters; they being ignorant of the dictum that any enterprise wrought by mankind will, sooner or later, be unmade and usually without much warning at that.  And it came to pass that many people became poorly and this reduced the number available to make and transport the raw materials with which to make goods and lo also did many people take up arms one against another and that threw a socking great spanner in the works as well.  Yet more peoples, in previous times famed* for their nous as traders and merchants, discarded really quite efficient trading arrangements in favour of those that were, quite frankly, barking mad and the engineers and technicians and all those who wrought and sold all manner of things looked at the bean-counters and said, "Told you so." 


*Well some people given to wearing their hats sideways were a bit dismissive about the mercantile aspect of these peoples.


It's done and dusted chaps; let's hope normal service has been resumed and we see no more problems like this.

Cheers,
Lurk

[DavidJP]

I am indeed sorry Andrew as I certainly never meant to be patronising - something I studiously avoid as it is truly disgustingly insulting habit!  Something (to my surprise) that was explained to me by friends who could be considered as part of a minority groups! Yes indeed my generation did wreck the heavy engineering capability down the swanny as you say and more stupid decisions besides.  I recall at the time many people from all walks being puzzled at such a decision but there was another side however……..That said I do find a tendency now that people are inclined to look for excuses now rather than solutions.  Blaming circumstances means things largely make no progress.  The Germans were pretty battered towards the end of the war particularly but like us found ways of improving and thereby overcoming problems.  Maybe my mood is coloured today by this soft society.  I have learnt that parents are relieved of yet another responsibility they should automatically embrace  - seeing their children brush their teeth.  Let us not deal with the problem at source but find a solution by spending money and passing the burden to others.   Avoid making the parent(s) feel inadequate at all costs.

Hmmm… posted somewhat mischievously so I can see the number who ignore me move further upwards! Already in double figures.  Childish I know but indulge me.

[DavidJP]

Words of wisdom indeed Lurk.  All part of the tendency to employ people who have no real experience of the job.  Ofsted and the management of the NHS are prime examples.  So long as they have a university degree which preferably is irrelevant for the job in hand.

I will now retire whilst I can still walk!

[billdennis747]

Beano was late last week.

[Pete Fardell]

David, I thought your snippy comment, “and when did Aeromodeller know there would be a delay” was particularly unfair after Colin went to some trouble to keep us informed, and I doubt anyone here was anywhere near as badly affected by the delay as he was as editor.
And it’s not a “generation thing”. I know plenty of people your age and older who accept that things go a bit awry sometimes, and always have done.

[DavidJP]

Ahhh...... your prejudices are showing methinks!  I was not criticising Colin who as I see it has done nothing wrong.  He is a victim. And presumably has communicated what he knew, when it came to his notice. So the question remains - when did the printer know there would be a delay due to the shortage of paper. and how quickly did he tell Aeromodeller.  And why did he not have a plan "B"?

I am not surprised you can tell me your know plenty of people of my generation (pre - war) who hold contrary views to myself. Thank goodness for diversity.  Indeed I accept things can go awry - but my course is to find out why and then to try and procure a solution to prevent occurrences; no harm in that surely? Or should one just shrug ones shoulders and say "C'est la vie".

But really I must leave this game now.

[Pete Fardell]

David, I may have misinterpreted your comment re AeroModeller. In which case, my apologies. I still think we shouldn’t judge the printers without knowing the facts though.

Probably time to put this one to bed now and look forward to the upcoming Feb issue!

[DavidJP]

Accepted most willingly.  I am pretty sure by the way that your contribution to the mag. will be much appreciated.  I was inspired today to return to the Aerographics (VMC) Gladiator.

[Horten 229]

Wow !  I can't  imagine the furore if the Feb one is late (er) or printed on lesser quality paper.
  Cheers Phil.

[DavidJP]

Actually Phil I think if both events - or either them were to occur it would pass unnoticed - I for one would have nothing to say. No point in saying it all again.

[Arnold S]

.

[Arnold S]

Strange double post things are occurring.

Any clues anyone?

[Gary Dickens]

Digital February issue is out. Good read.

Gary

[Pete Fardell]

Non-digital copy just landed on my doormat! (I expect the printers had too much paper so got it out nice and early to declutter their warehouse. Hope that’s not a problem for anyone?)

George, you made the cover!

[Slowmatch]

Strange double post things are occurring.

Any clues anyone?

Some strange glitches in the matrix! I'm seeing Pete's last post as #44 on page 2 of this thread.... but also as #54 on page 3!

Wow !  I can't  imagine the furore if the Feb one is late (er) or printed on lesser quality paper.
  Cheers Phil.

Mine is still on my cracked phone screen sadly...

George, you made the cover!

And a more beautiful cover model would be hard to find!

[TheLurker]

Non-digital copy ...

That would be the paper version then? 

PF > George, you made the cover!
He's good, isn't he?

While I'm here.  It looks like a couple of bits got lost down the back of a cabinet when the Willow Wren material was filed.  The suggested fitting order for tissue panels and the hint for fitting the stringer supports.  Attached.

Oh, by the way.  I'm not "Chris".  Nothing wrong with being called Chris, why some of my best friends are called Chris and a jolly fine name it is too, but I'm not one.

Cheers,
Lurk

[Squirrelnet]

Great to see George's AVRO on the front cover

Another great issue.... more like this please :-)

...from an actual Chris

[g_kandylakis]

Jon, Lurk, Chris, thanks...

George, you made the cover!

Hi Pete, yes, it does seem so! Very glad about it... Aeromodeller and Model Builder were the magazines I grew up with and learned all I could from them, so to see the Avro on the cover certainly makes me proud...

A great report too, both in terms of content and also of page number. Together with Scale Matters, definetely a "Scale" issue...

Needless to say, I would like a hard copy as well, if you can pick one for me for April...


Weird times at the moment for me, as I am in the process of moving back to Greece after nearly 8 years in Germany... That will put a pause on modelling for a while, so If I do make it in April, you can expect the same as in Nimegen... i.e. questionable flying quality, my trademark...

At least I can concentrate and finally finish my long promised article to Colin for the Avro and dual FF/RC flying...

George

[billdennis747]

Hi George,
I've never seen workmanship and detailing like that. It's incredible (although I know about the blemish in the rudder!)
Bill