Author Topic: Flights of Fancy  (Read 20110 times)

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #200 on: July 30, 2020, 09:26:33 pm »
Here we go, a short flight.  This is a rarity, most flights, if there's any sort of a breeze, are a nice LH circuit.

https:// vimeo.com/ 443164836  <-- Stitch the URL together*.

Eleven or twelve paces on the line.  Still needs a bit of fettling, but it's good enough (by my lights) to share.  Ignore the ugly great lump of blu-tack, that'll be converted to a sliver of lead glued to the back of the NB when I've got trim properly sorted.

AUW is about 33.5g

As I expected the only way you'll get any endurance from this is if you catch a thermal, but as it flies I'm chalking this one up as a win it being only my second blank sheet project.

Best flight this evening was about 12s, nice LH circuit.


*Can anyone shed on any light on why the forum sw chokes on vimeo URLs?  I'd be interested to know, cos it's irritating.
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Re: Flights of Fancy
« Reply #201 on: July 30, 2020, 09:57:01 pm »
If I put the URL
Code: [Select]
https://vimeo.com/443164836 in a post then the preview automatically converts it to an iframe containing the URL
Code: [Select]
https://player.vimeo.com/video/443164836 The SMF sofware is automatically embedding the video.

I'll put the first URL here:

Re: Flights of Fancy
« Reply #202 on: July 30, 2020, 09:59:01 pm »
The posted version looks much like the preview. Is it broken for you?

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #203 on: July 31, 2020, 09:51:23 am »
RIGHT, more newbie questions.

Instructions (1970's vintage I think) refer to use of tissue paste, dope, thinners etc.

Quick review of t'interwebz suggests that
1- Glue - UHU, watered down PVA ... basically anything that will stick the tissue
b - water or diluted ipa for initial shrinking (not the beer kind!)
iii) Ambivalent on additional shrinking dopes and laquers

I have some tissue past in the kit box, which is now >20 years old, what's the voice of experience here?
“Procrastination is the thief of time, collar him.” –Charles Dickens

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #204 on: July 31, 2020, 10:07:41 am »
At work ATM.  Will reply properly later outlining what I do.   Bear in mind nearly everyone has a, "Works for me." approach and no two modellers use identical techniques.
Τα πιο όμορφα ταξίδια γίνονται με τις δικές μας δυνάμεις - Φίλοι του Ποδήλατου

andytheflyer

  • Andytheex-flyer.....
Re: Flights of Fancy
« Reply #205 on: July 31, 2020, 11:46:17 am »
RIGHT, more newbie questions.

Instructions (1970's vintage I think) refer to use of tissue paste, dope, thinners etc.

Quick review of t'interwebz suggests that
1- Glue - UHU, watered down PVA ... basically anything that will stick the tissue
b - water or diluted ipa for initial shrinking (not the beer kind!)
iii) Ambivalent on additional shrinking dopes and laquers

I have some tissue past in the kit box, which is now >20 years old, what's the voice of experience here?
1) watery IPA, applied with a brush
b) water, misted from a spray bottle
iii) DeLuxe Materials Eze Dope - it's water based.

20 years ago it was tissue paste and dope.  We've gone all touchy-feely since then.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #206 on: July 31, 2020, 01:59:31 pm »
I assume you mean
1 - watered down PVA, not IPA
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Flights of Fancy
« Reply #207 on: July 31, 2020, 02:12:40 pm »
I assume you mean
1 - watered down PVA, not IPA

If you water down IPA make sure you don't sell it or you'll have weights and measures after you. Also it will taste rubbish.
I think you'll find it's a bit more complicated than that.

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #208 on: July 31, 2020, 02:56:01 pm »
Speaking of IPA, I have some Whitstable Bay which I shall be drinking later, but first this, while I can still type...

Choice of tissue.
a) Domestic.  Relatively heavy, no wet strength.
b) "Esaki".   Dearer than domestic.  Good wet strength.  Rumour is that it's not being made any more.  There *are* comparable tissues so ask around.

Choice of Doping compounds.
a) Solvent based.  Shrinking and non-shrinking.  Various compositions available.
b) Non solvent based.  Only know of one ATM.  EzeDope by Deluxe Materials.  Of which more later.

Tissue Fixative
a) Tissue paste. Various mfrs.  As far as the tube that came with the kit goes, ask yourself if you'd trust the glue that came with a 20 YO tube repair kit.
b) Dope
c) PVA.  Thinned
d) Glue stick and PVA.

What follows is *not* prescriptive.  Others will have their preferred way of working and will swear blind that it is the one true way.  Bollocks.  Whatever works best for you is the way to go.

I haven't used dope to fix tissue to an airframe since 1973.  It was straight-forward and some of the (even) older builders still use it. Especially for under-cambered ribs.

My preferred technique is to use glue stick, UHU for pref. - consistency is good, to put a thin bead around the edge of the piece being covered and then fix the tissue in place, teasing out the worst of the wrinkles and bags.  When the glue has cured properly (min. of a couple of hours) I then go over this with water thinned PVA (50% by volume) using a fine, 00, paint brush gently rubbing the glue in with the dampened end of the brush.

Working this way means you can use domestic tissue without too much stress.  Thinned PVA and domestic tissue under tension is not a good combination.

Doping.
I use two approaches.

For a single colour domestic tissue finish with very small areas of tissue decoration Deluxe Materials EzeDope.  The first coat, 5% by volume with water,  is misted on.  You can buy small pump sprays in the travel section of Boots and the like.  The second and subsequent coats, 30% by vol, can be brushed or sprayed on.  You have to be v. careful with EzeDope & domestic tissue, see the earlier point about wet strength.  Deluxe recommend using "Esaki" or similar for obvious reasons. It can be used in the house without choking everyone else and it can be sent through the post.   I've used it for models up to 36" span.


If I'm doing a two or three colour tissue finish, the Ju87's splinter camouflage is a good example, I'll use thinned non shrinking dope (30% by volume with cellulose thinners or more dilute depending on size of model) after steam shrinking the tissue.  You can buy dope by electronic mail order, but it has to be shipped by courier so can work out very expensive if that's all you're buying.

Companies.
Vintage Model Company
SLEC
Balsa Cabin
Free Flight Supplies - A one man band, but good.

And I strongly suggest that you sign up at the Hip Pocket Aeronautics forum where you will get some *real* expert help rather than my idiotic ramblings.
Τα πιο όμορφα ταξίδια γίνονται με τις δικές μας δυνάμεις - Φίλοι του Ποδήλατου

andytheflyer

  • Andytheex-flyer.....
Re: Flights of Fancy
« Reply #209 on: August 01, 2020, 10:43:15 am »
I assume you mean
1 - watered down PVA, not IPA
er, yes...........

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #210 on: August 01, 2020, 08:57:20 pm »
Oh dear!

EzeDope - Check
New model kit - Check

“Procrastination is the thief of time, collar him.” –Charles Dickens

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #211 on: August 02, 2020, 09:03:06 am »
Quote from: ElyDave
...New model kit - Check
My work here is done. *evil cackle*.

Sounds like someone visited the VMC site.  C'mon Dave, don't tease.  Which one is it?
Τα πιο όμορφα ταξίδια γίνονται με τις δικές μας δυνάμεις - Φίλοι του Ποδήλατου

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #212 on: August 02, 2020, 09:10:53 am »
In my defence, I only went there 'cos I couldn't find the EzeDope elsewhere.

I was torn between the Cessna 140 and Bird Dog, went with the Bird Dog in the end.   If they had a Cessna 150 I would have had that as that's wjhat I did my Air Cadet Flying Scholarship in
“Procrastination is the thief of time, collar him.” –Charles Dickens

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #213 on: August 02, 2020, 09:25:51 am »
Well, cor, blimey strike a light!  Guess what I've just started on?  Yup.  The Bird Dog.  It had been sitting in my kit hoard for a couple of years and was looking all forlorn.  Only got the wing centre section so far.  Mine'll be a USAF grey tissue finish O1-E and if I'm feeling adventurous it'll be a shark-mouth scheme, tail No. 5-62534. If. :)

You've chosen a good one.  Andrew Darby's designs fly pretty much off the board and I know that models built from that kit have a reputation for flying like they're on rails. 

The only thing I'd suggest at the moment is that you make two dihedral guides for the centre section (3 deg. off vertical).  The kit parts are cut to give that angle, but it's a bit of a three-handed job to get the centre section put together and having a couple of guides to prop. up the ribs makes it a tad easier.

Fin Mods
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ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #214 on: August 05, 2020, 09:58:18 am »
OH appears scrolling through credit card entries on the phone
"Is this yours? The Vintage Model Company?"

[quick thinks]

"yes, it's the bits to finish this" says I pointing at said model [not mentioning new kit at all, nothing to see here]
“Procrastination is the thief of time, collar him.” –Charles Dickens

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #215 on: August 06, 2020, 09:45:29 pm »
Slowly, slowly starting the covering, tail plane and fin done so far with no dramas.  Manged to snap the single, very thin piece connecting the two wings whilst trying to shape and do the initial gluing of the tissue.  I've pared the remains out of them, luckily there is a spare in the kit so my plan is to cover the wings as much as possible then rejoin them and cover the final gap before shrinking.

Any tips of stopping a gull-wing from warping? I was thinking of doing one side at a time and building some props to go underneath to maintain the line whilst I weight it or pin it down from above.

I think it might be very tight on tissue to cover the fuselage.
“Procrastination is the thief of time, collar him.” –Charles Dickens

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #216 on: August 07, 2020, 06:44:30 am »
Quote from: ElyDave
I was thinking of doing one side at a time and building some props to go underneath to maintain the line whilst I weight it or pin it down from above.

Warping.  Yup, you've more or less got it sussed.  With kinked wings (Ju87, Minimoa, Walthew MKII) I wrap cling film or some other covering around the part that isn't being shrunk, apply the shrinking agent (steam / 5% EzeDope / water) to the uncovered part and pin it to the board.  Pin it to the building board using spacers at intervals under the LE & TE.  If you're using EzeDope use 1/8" min thickness spacers, 1/4" is better, use the scrap sheet from the kit, because the tissue can bag quite a lot and stick to the board when it's wet.  With an anhedral wing like your kit you'll need a block that raises the wing section being treated far enough off the board that the "tip" of the untreated section is clear of the board.  I generally use a stack of Model Board glued together (see HobbyCraft) because it will take pins and is easy to cut to the appropriate size  / shape and it's cheap enough that I don't feel dreadful about the single use.

It will take longer to dry out completely than you might expect.  I often leave even small wings pinned down for 12+ hours.

Quote from: ElyDave
I think it might be very tight on tissue to cover the fuselage.

*Cough*
Quote from: TheLurker
There'll probably be only just enough tissue in the kit.  Buy some more, it's dirt cheap,....
:)

What colour tissue is it?  If it's white I have some spare domestic and it'll be far cheaper for me to stick a couple of sheets in the post than it will be for you to ring up VMC/{some other company} just for that and get stung for postage.  It also give you a bit of spare for patching.  If you'd like some let me know where to send it.  It'll be sent flat so you'll have to iron it to get the worst of the creases out.
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ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Flights of Fancy
« Reply #217 on: August 07, 2020, 09:16:51 am »
I'll let you know, thanks - looking at it I might have enough by flipping the fuselage sections 180-deg alternating fat end to thin end.  I'm keeping scraps for repairs and small sections as necessary.

I've worked out that three cassette tapes is the height of the wing tip angle, and three erasers is the point of the gull wing angle change. 

Tailplane and fin now fully dry, and I'm happy enough with the results. Could probably be better, but first attempt and all that
“Procrastination is the thief of time, collar him.” –Charles Dickens

TheLurker

  • Goes well with magnolia.
Re: Flights of Fancy
« Reply #218 on: Yesterday at 09:19:51 am »
Quote from: ElyDave
...I'm happy enough with the results. Could probably be better, but first attempt and all that
Don't worry about it.  I think there's only one or two stick and tissue models in thousands that have wrinkle free covering.  Other people looking at it don't see the flaws or if they do they discount them.  As long as the flying surfaces aren't warped and are true WRT each other it'll fly and that is the primary objective.

I put my VMC Osprey through some post refit, ballasting changes, test flights last night. The pilot requires a bit more tutelage, but for something that many would dismiss as a "toy" it's pretty good indeed and suggests that with a longer tow (40-50m rather than the 20m line I use) some fairly long flights ought to be achievable.

Endurance is a gnat's north of 15s, 16s if one is really optimistic, on a 20m line in very, very light winds.   

https://vimeo.com/ 445680677  <-- stitch it together.

It's not the best flight, see the stall when the tow drops, which is the result of a hurried reballasting after total loss of ballast on a previous flight*. This leads me to today's top tip, "When you've established the base trim, glue the ballast in place. Clot."


*When you hear an odd rattling noise** in the steepest part of the climb and the flight is very, very, very, stally do investigate immediately.  Don't assume it was a rubbish launch, carry on and then stand there looking like a lemon on the subsequent equally stally flight wondering what's gone wrong.

**The fishing weights bouncing off the canopy I expect.
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