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Mar 12, 2018, 07:04 AM
1 revolution and throw!
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somekind of golden weight


hello ,

i would like to hear what people think about dlg weight.

frequently i read people like to have a little bit of ballast in there when they have a lighter airframe then let's say 225gram .
i read about the same conclusion in every specific dedicated thread for a certain model . golden weight 230-240gram...
and it seems like wing area doens't change this wich sounds different then what most would have expect i think .
some have bigger wings , thicker foils , others have smaller wings with thinner foils yet it all seems to come down to 230-240gr as optimal flying weight for anything else then dead air

The xxlite is a perfect exemple , for me it didn't worked well at lower weight and others all came to this same conclusion , it's capabilitys where in it's huge ability to cover ground , when trying to make it a floater by reducing weight it seems like the legs where cut of and it would never become a king floater anyway that was not where it was good at .

is this a correct statement that 230-240gr is gold , why is this?
Last edited by krikkens; Mar 12, 2018 at 07:19 AM.
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Mar 12, 2018, 07:59 AM
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I am not sure me posting will help or hurt your thread.....LOL, LOL

I have found the same thing even with the smaller planes I build. There is definitely a point of getting to light.
Mar 12, 2018, 08:04 AM
french team pilote
I agree kristof ! it s a good weight
Mar 12, 2018, 08:10 AM
1 revolution and throw!
Quote:
Originally Posted by The_Builder
I am not sure me posting will help or hurt your thread.....LOL, LOL

I have found the same thing even with the smaller planes I build. There is definitely a point of getting to light.
it all contributes to this discussion Paul , are you talking about 1m planes? what weight was it for 1M and do other came to this same conclusion?

the thing that strikes me is how pilots like to fly they're planes in normal conditions , this means not deadly calm but not windy so they need ballast .

it seems like 230-240 gr seems the optimum for active conditions witouth being windy .

One would expect that a smaller wing with thin airfoils has a diffrent optimal weight for these conditions compared to a bigger wing with thicker airfoils (not talking about older designs with huge wings, just comparing the models that came out last few years ) but they all seem to shine at about the same weight
Mar 12, 2018, 08:24 AM
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Quote:
Originally Posted by krikkens
it all contributes to this discussion Paul , are you talking about 1m planes? what weight was it for 1M and do other came to this same conclusion?

the thing that strikes me is how pilots like to fly they're planes in normal conditions , this means not deadly calm but not windy so they need ballast .

it seems like 230-240 gr seems the optimum for active conditions witouth being windy .

One would expect that a smaller wing with thin airfoils has a diffrent optimal weight for these conditions compared to a bigger wing with thicker airfoils (not talking about older designs with huge wings, just comparing the models that came out last few years ) but they all seem to shine at about the same weight
I have built two sizes recently, 1M and 1.3M and they both seem to behave just the way you are suggesting. On a 1M it seems to be in the 120g to 130g range for normal conditions. On my 1.3 it seems to be in the 185g to 200g range. It seems that with the smaller planes the range is more narrow. Around the world there are around 200 Epee's flying and that seems to be the weight most people like. I have a new wing with a much thinner airfoil and narrower chord and it too seems to fly great at 120grams.
Mar 12, 2018, 10:15 AM
Registered User

This should be interesting


Yes there seems to be a magic number for all, small to large. Now I have not looked into it, but I know even in my larger planes 2.6 to 4m the same seems to apply. Light is only good to a certain point. We found this also in real gliders with the same attributes being what is acceptable as far as L/D and flyability.
My best 1.5m flyers are 231 and 236g. I know there is a lot more to it then wing loading, but it would be interesting to scale the numbers to see what if any the correlation is. I'm no math wiz so this is out of my realm.
Cary
Mar 12, 2018, 10:53 AM
Registered User
I have 2 CX4s, 265/263 grams, and I canít argue with the performance. I changed a CX4 from TD to 4-in-pod and reduced the weight by 15 grams. When I got the CG right, there wasnít significant difference in how it flew.

Iím not qualified to discuss the aspects of design that go into making DLGs . Each designer/manufacturer makes a decision as to airfoil, aspect ratio, etc for the results they want to achieve. Finding a design that flies how you like, with the proper setup IMHO is more important than that last 5-10 grams.
Mar 12, 2018, 02:00 PM
New at this whole life thing
Cfiimei's Avatar
I know my 1.3M flies much better at 190g than at 170, and my 1M’s prefer to be around 130. The exception is the 1.3 in dead calm evening sessions, where I’ll pull out the 20g of ballast and enjoy flying around ridiculously slow and flat as the sun sets. Even then I’d get better times with the ballast in, but it’s fun.
Mar 12, 2018, 02:05 PM
Registered User
clintc's Avatar
I think where the weight is matters as much or more than the final weight. Love my light snipe @ 205 even in some wind. Add an once and it’s great in light winds. But it does fly slower and is more active in the air because the weight is near the cg and not out in wings or tail
Mar 12, 2018, 02:12 PM
Closed Account
Quote:
Originally Posted by clintc
I think where the weight is matters as much or more than the final weight. Love my light snipe @ 205 even in some wind. Add an once and itís great in light winds. But it does fly slower and is more active in the air because the weight is near the cg and not out in wings or tail
I think you hit on a good point, where the weight is in the plane.
Mar 12, 2018, 02:32 PM
1 revolution and throw!
Quote:
Originally Posted by clintc
I think where the weight is matters as much or more than the final weight. Love my light snipe @ 205 even in some wind. Add an once and itís great in light winds. But it does fly slower and is more active in the air because the weight is near the cg and not out in wings or tail
i didn't followed the snipe thread up close but that's about contrary to my point , a lot of gliders seem to do much better when put at around 240gr if it was build out lighter so just by adding ballast an not by a hevier airframe
Mar 12, 2018, 02:59 PM
ThomasLee's Avatar
For launching, 240-250g is best for me. For flying, I much prefer empty and only moving CG until absolutely necessary even though I launch a little lower with it at 215g. I believe a lot of people prefer the 240g range because it's a comfort zone, and going between models feel relatively similar. Once you go to lower weights, you need to spend quite a bit of time to understand how it works and feels before you fully attach to it.

https://www.rcgroups.com/forums/show...&postcount=890
Mar 12, 2018, 03:40 PM
stefan
I‘d say the lower you go with wing loading, the lower is your speed for minimum descent rate, which i assume is a bit more noticeable than glide ratio (as in „boy, i got 3min of glide time out of this bird!“ instead of „boy, with my 50m launch height I covered 750m of ground while circling!“). At some point, this optimum speed is just so low that you lose too much height getting from one bubble to the next. If there are only a few, if any bubbles around, the glide time is what counts. Thats why one chooses the lightest plane in the quiver on those rounds with (completely) dead air at 8.00 in the morning.

So depending on where you are or what the average magnitude of wind speed is at your location, you might consider another weight to be „the“ golden weight, which works for a wide variety of wind conditions.

Taking into account thermal strength, aircraft performance etc, it is actually possible to compute „the“ golden weight. As the real ones do.
Mar 12, 2018, 03:40 PM
Registered User
clintc's Avatar
Quote:
Originally Posted by krikkens
i didn't followed the snipe thread up close but that's about contrary to my point , a lot of gliders seem to do much better when put at around 240gr if it was build out lighter so just by adding ballast an not by a hevier airframe
I guess what I was saying was Iím fine with a lighter than Ďgoldení range airframe without ballast in a lot of conditions people say they are too light for. I think the 230g range is more about flying style than performance. Iím sure there is a limit to how light. But Iíd say itís less than where people say they like to fly
Mar 12, 2018, 03:53 PM
Rising F3X Star
Quote:
Originally Posted by The_Builder
...Around the world there are around 200 Epee's flying...
Is this true? There have been 35 posts in the for sale and wanted sailplanes section re: the epee since may 2016. That's less than 2 years of production. Assuming the other 170 were sold by PM contact or by Facebook page, that's roughly 2 per week sold. That's a lot of eppes. And you are confident that these are all still "flying"?


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