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Oct 13, 2018, 10:09 PM
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davereap's Avatar
Thats about a 170W motor, possibly a bit small for a 40".... although the Q's dont need a lot of power to fly...
A 30" size might be better

I am running a 160W QX motor on a 26"
the 26 is a mismatch of V1 wing plus a V2 body.... an all V2 or V3 will fly better.
26inch quasar 9 may 2018 1 (6 min 17 sec)
Last edited by davereap; Oct 13, 2018 at 10:16 PM.
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Oct 14, 2018, 04:12 AM
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davereap's Avatar
duh!
I just realised my 26 inch quasar has a KFm4 wing not a KFm2..
I am chopping the wing to make it into the better V2 shape ..
Last edited by davereap; Oct 14, 2018 at 08:17 AM.
Oct 16, 2018, 05:17 AM
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Just printing ouit the plans just now. ended up going for 160%. Can i make a suggestion that maybe make your plans outlines only. Saves on ink
Oct 16, 2018, 08:28 AM
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OK just got the wing half plan stuck together..


Yikes.. This is going to be big. A1 foamboasrd isn't even big enough for 1 half of a wing. I'll need to make the elevons an d tail section of the wing from a separate piece of foamboard. Not even sure 4 sheets is enough...

I've joined foamboasrd before. Hot glue seems to give a pretty strong. join but I'll probably need a spar.

Now to leave the the paper on or not.


Damn I forgot about the kfm step will need a few more boards. Have never made a kfm step. That will ad strength and I guess is could go withjoiut paper
Last edited by bazsound; Oct 16, 2018 at 01:48 PM.
Oct 17, 2018, 01:04 AM
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davereap's Avatar
Quote:
Originally Posted by bazsound
Just printing ouit the plans just now. ended up going for 160%. Can i make a suggestion that maybe make your plans outlines only. Saves on ink
Yes I will do..on the pdf's... I use a cheap black and white laser printer.. so I didnt think about the coloured faces on the posted pdf plans..
here are the plans again with faces removed so its just the outlines
Last edited by davereap; Nov 04, 2018 at 03:58 AM.
Oct 17, 2018, 01:34 AM
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davereap's Avatar
what foamboard are you using? all the uk stuff is well too heavy with paper on , and our boards are a S** to remove the paper from..
Easy foams to use are the hobbyking 5mm or the B&Q Diall 5mm boards

hobbyking is all out of stock so the B&Q foam is the best bet... 15 for a pack... sheets are 24" x 30"
https://www.diy.com/departments/dial...1570772_BQ.prd
Last edited by davereap; Nov 04, 2018 at 03:59 AM.
Oct 17, 2018, 03:26 AM
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Quote:
Originally Posted by davereap
what foamboard are you using? all the uk stuff is well too heavy with paper on , and our boards are a S** to remove the paper from..
Easy foam to use is the hobbyking 5mm or the B&Q boards

hobbyking is all out of stock so the B&Q foam is the best bet... 15 for a pack...
https://www.diy.com/departments/dial...1570772_BQ.prd
It's the west stuff from hobbycraft. Yeah the stuffs heavy. I built my first plane using it (yak 54 3d plane) it flew but was heavy. I used a 3s 800 on it with a powerful motor. Really should have ran on 2s and a blue wonder.

I've removed the paper and found it not to hard. Just spray the paper and let it soak. If you're lucky u can get it to come of in olne go.

Can't buy the b&q foam I'll get a n ear full. So I'll just cut out all the pieces and remove the paper then laminate it with packing tape. I already have 4 boards.

Now I wlknder though.. When size goes up doesn't wing loading start coming down?

The paper does add slot of strength. Without the paper even with kfm doublerds I'll need a spar and might even need some support on the fuselage
Oct 17, 2018, 05:36 AM
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Good progress so far. Really liking the size!

Wing is coming in at 300g with paper on. Kinda seems light when I compare it to the ft mini arrow I built which was 300g flying weight. But mind u I've not added fuselage and components... So fuselage another 200? Oh doubles.

I've used gorrilia glue to try keep weight down. Using hot glue to just pin it in place
Oct 17, 2018, 07:06 AM
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OK fuselage cut out and it isn't as heavy as I thought. 100g. So that comes to 400g. 30a esc 30g. Say 50g for motor. Round it up to 200g brings us to 500g. 30g for servos.

So I'm going tl need at least 200w for 3d thrust. If I aim for 1200g thrust. I'm thinking I could leave the paper on for strength but still run a couple of carbon tubes for wing support to stop it flexing unless the steps add enough strength.

Looks line I may be able to run this on 1000may batteries at a push
Oct 17, 2018, 09:42 AM
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davereap's Avatar
Yes remove all the paper and glue from the hobbycraft boards... and recover with tape where its most needed..
Tape over the KF area top and bottom of the wing..tape the trailing edge, tape the elevons, fin and rudder

Been there and done that in the early days..lol..had art boards soaking in the bath for ages..
then I found depron .. and that was a real time saver.. now depron is getting harder to get.. so its hobbyking aerofoam when its in stock... and B&Q for XPS and robotbirds for EPP..

A foam of last resort is the light crumbly EPS , its used for packing and building work insulation.. this can be cut to an airfoil shape, using a hot wire or even a carving knife,, the foam is covered with glue soaked news paper layers and /or laminating film or tape.. the results are not bad...
https://www.rcgroups.com/forums/show...e-flying-wings
Last edited by davereap; Oct 17, 2018 at 09:55 AM.
Oct 17, 2018, 01:20 PM
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Ended up putting it together. With the paper on it's actually quite strong it flexes a lot less than my pizza box flier which is depron with tape. It probably would still have been fairly strong with packing tape. But I really couldn't be bothered spending half hour removing paper another hour taping etc. From what I remember the weight saving although noticeable It wasn't much. On my ft mini arrow I think I saved 50g.

Hard to get on the scale but looks to be about 430g. Thinking of retireikng my pizza box flyer. It's got a turnigy 2836/8 1100kv motor on it and was powered by a 40amp speed controller with 22003s. Completely outrages for a piece of hk foam sheet covered in tape.

Can't just the servos from it though. Tower pro 9g servos. Not getting enough throw from them.



OK looking up my motor. It's more than capable. With a 11x4 it will produce a whooping 1300g thrust pulling 25amps. My 1000may batteries are only 20c and although that's only at full throttle it might be pushing it for them. A slightly larger higher c battery may be needed.
Last edited by bazsound; Oct 17, 2018 at 01:37 PM.
Oct 17, 2018, 03:51 PM
Jim
Quote:
Originally Posted by bazsound
OK fuselage cut out and it isn't as heavy as I thought. 100g. So that comes to 400g. 30a esc 30g. Say 50g for motor. Round it up to 200g brings us to 500g. 30g for servos.

So I'm going tl need at least 200w for 3d thrust. If I aim for 1200g thrust. I'm thinking I could leave the paper on for strength but still run a couple of carbon tubes for wing support to stop it flexing unless the steps add enough strength.

Looks line I may be able to run this on 1000may batteries at a push
Awaiting maiden video! Looks like it will be majestic!
Oct 18, 2018, 12:43 AM
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davereap's Avatar
At 16oz or so, its not overweight at all..
Some of my bigger foamies have been at 20-30oz...560-840 gms and they flew nicely..

But that sort of weight needs some metal geared servos with a bit more power... something 12-15gm size.

For wing stiffening I now use laminating film strips..I use the A3 pouches ..a 150micron pouch has two 75micron sides .. this is strong stuff.. Most often I put 2"strips across the wing , above and below to make a foam sandwich at the thickest part of the wing.. On a KF this is will go on the top of the wing and mirrored below at the step lines.. where needed joints are made, overlapped by about 1".. they dont show up ..
Previously I used pallet strapping glued along the thickest part of the wing, again one strip above and mirrored below..
You can see the strapping on the big V wing above..

https://www.rcgroups.com/forums/show...-reinforcement
the laminating film is used the same as the pallet strapping... but being able to iron it on its a cleaner job..
See the pic for laminating film on the KF layers ... Strapping would have gone along the step lines crossing at the centre and going over as far as the leading edges...
Last edited by davereap; Oct 18, 2018 at 01:12 AM.
Oct 18, 2018, 01:19 AM
flyin' fool
goldguy's Avatar
On my last foam board built the paper removed weighed more than 70% of my total RTF weight and tape weight was just a fraction.

I just gave 10 sheets away as I found a new better non papered 6mm foam as good as Depron at 10th the price.
Oct 18, 2018, 04:32 AM
Registered User
Quote:
Originally Posted by goldguy
On my last foam board built the paper removed weighed more than 70% of my total RTF weight and tape weight was just a fraction.

I just gave 10 sheets away as I found a new better non papered 6mm foam as good as Depron at 10th the price.
Yeah hk foam u get 20 sheets for 10. But I didn't want 20 sheets plus there's 5 delivery and haven't to be in. I was an hobby craft for other stuff and though I'll make something and picked up 4 sheets.

If need be I can remove the paper between the fibre tape. But I think it will fly fine as is. I know a lot of people always batter on about light is might... But try flying a feather weight foamie in 10+MPH plus they just don't fly like a plane.


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