Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
December 15, 2019, 09:30:58 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 [2] 3 4 5   Go Down
Print
Author Topic: Consolidated PB2Y-2 Coronado  (Read 6978 times)
0 Members and 1 Guest are viewing this topic.
ZK-AUD
Platinum Member
******

Kudos: 50
Offline Offline

New Zealand New Zealand

Posts: 1,152



Ignore
« Reply #25 on: March 26, 2018, 02:05:28 PM »

Lovely work Richard.  I was looking at your rear fairings and thinking that would be exactly how I would do it too.  There's a lot to be said for the judicious use of soft block for those key features on the model that give it its character.  Following this with interest.
Logged
DavidJP
Titanium Member
*******

Kudos: 46
Offline Offline

United Kingdom United Kingdom

Posts: 2,908




Ignore
« Reply #26 on: March 27, 2018, 04:33:25 AM »

Still looking very light Richard.  The balsa fairing has happened well .  Amazing stuff really.  I can't remember if it was Pelly Fry or the Col. who recalled that in the 30s there was a model shop in Oxford Street (London) - Jones I think and he had received a bit of balsa from the US - handed it over to one of them with the remark - "this will never catch on....but you can have it".

Yes we would still be making and flying model aeroplanes without it but somehow not as we do so successfully. 

Oulton Broad for flight testing?



Logged
Rich Adams
Silver Member
****

Kudos: 105
Offline Offline

United States United States

Posts: 108



Ignore
« Reply #27 on: March 27, 2018, 08:37:13 AM »

Beautiful woodwork. This is making me think about my fascination for the old Pan Am China Clippers.
Logged
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #28 on: March 27, 2018, 11:35:13 AM »

Lovely work Richard.  I was looking at your rear fairings and thinking that would be exactly how I would do it too.  There's a lot to be said for the judicious use of soft block for those key features on the model that give it its character.  Following this with interest.

Thanks ZK.
I did contemplate cutting curved 'stringers' for that section but decided it would look a bit of a mess when covered.
Logged

Richard Crossley
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #29 on: March 27, 2018, 11:37:55 AM »



Oulton Broad for flight testing?





Sheringham model boat pond would be a calmer option!
Logged

Richard Crossley
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #30 on: March 27, 2018, 11:40:54 AM »

Beautiful woodwork. This is making me think about my fascination for the old Pan Am China Clippers.

Thanks Rich. Once you start looking there are some super flying boats. Most can be simplified to a large extent but will still capture the character. I like the Boeing 314, looks like pretty good proportions, and lots of dihedral. Martin M-130 Clipper is super-nice too.
Logged

Richard Crossley
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #31 on: March 28, 2018, 03:55:53 AM »

The two fins were completed last night. They look very similar to the fins on a B-24 Liberator. Both fins will be hinged with thin litho plate strips. The dihedral tailplane gives a distinctive look to the model.

So thats all of the structure built now, current total weight is 19.45g. My target weight for completed, covered and sprayed airframe is 35g.

The weight of the 4 motors, cell, wire and Zombie will be about 25g, for a projected flying weight of 60g, giving a wing loading 0f 7.3g/dm2.

I do have the nacelles, and some detailing to ad, but this will be minimal. and most of the paint is silver, which is a light colour to spray, so fingers crossed!
Attached files Thumbnail(s):
Re: Consolidated PB2Y-2 Coronado
Logged

Richard Crossley
DavidJP
Titanium Member
*******

Kudos: 46
Offline Offline

United Kingdom United Kingdom

Posts: 2,908




Ignore
« Reply #32 on: March 28, 2018, 07:22:13 AM »

I wonder if flying boats have a slight advantage by having no undercarriage which can be a bit weighty? Even the suggestion above of the dolly wheel and whiskas has to be lighter than most undercarriages? A seaplane not so so I guess.

Sherringham pond?  Be a bit difficult landing back on the water I suggest Richard?  Hence the Broad?  But I know of a couple of other lakes you could try.  You seem rather into this model, which is nice. 
Logged
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #33 on: April 05, 2018, 05:48:01 AM »

Latest progress report on the PB2Y-2:
I now have all of the tricky engine nacelles finished. These are a 1/32" balsa wrapped around a simple structure. Using 1/32" balsa sheet like this is not perfect as it always 'starves' when I use it. I guess an alternative would have been to stringer them. Paper or thin card card weighed just too heavy compared with balsa, so they are a compromise. The tapered fairings that go behind the cowls are soft block, hollowed with a drill/sanding drum. The wings are detachable using thin 1mm carbon tube and alum tube. These were nice and light, and only added 0.8g total to the weight. I may need a couple of little neo-magnets though to keep them in place. Rudders will be adjustable, hinged with litho plate strips. Atomic Workshop are currently wiring up my engines with the correct lead lengths etc, and once ready the running gear will be installed before covering the rest of the model. She looks a little like one of those Russian 'Ekranoplanes' with the outer wing sections off?
Attached files Thumbnail(s):
Re: Consolidated PB2Y-2 Coronado
Re: Consolidated PB2Y-2 Coronado
Re: Consolidated PB2Y-2 Coronado
Logged

Richard Crossley
meatbomber
Bronze Member
***

Kudos: 2
Offline Offline

Czech Republic Czech Republic

Posts: 53




Ignore
« Reply #34 on: April 06, 2018, 09:08:00 AM »

What a fantastic model ! I`ve been day dreaming about building a 1:12 scale Coronado, in a similar fashion (just a bot more sturdy wood Wink)  Ivan Pettigrew style for RC but alas not yet. Looking forward to seeing your rendition fly!
Cheers
Phillip
Logged
Rudder flutter
Silver Member
****

Kudos: 126
Offline Offline

United Kingdom United Kingdom

Posts: 192

Topic starter


Ignore
« Reply #35 on: April 07, 2018, 07:04:19 AM »

Whilst working on the Coronado lately I have noticed that I have become sensitive to Cyano. I think this can happen after repeated exposure to the fumes. At first I thought it was a cough that kept coming back, but now I realise it only happens after working with cyano adhesive. Symptoms consist of a dry cough, that lasts well into the following day and can be bad overnight after using the glue. It also affects my sinuses and gives cold-like symptoms. I've not had this before, although have been using Cyano for most of my modelling life. When building last night I used a face mask with filters, which helped, but still had mild affects. I think I need to avoid these glues now. Anyone else have similar problems?
Logged

Richard Crossley
SP250
Gold Member
*****

Kudos: 10
Offline Offline

United Kingdom United Kingdom

Posts: 445



Ignore
« Reply #36 on: April 07, 2018, 07:13:28 AM »

Yes Richard

I've been sensitive to cyano ever since it came out - I get the same as you, additionally I feel like I have clingfilm on my eyeballs and vision gets cloudy & deteriorates.
The only cyano I can use is the odourless stuff, even then only in short bursts. 
So I tend to use white pva for most wood to wood joints & POR on foam, just have to accept the longer drying times.

John M
Logged
DavidJP
Titanium Member
*******

Kudos: 46
Offline Offline

United Kingdom United Kingdom

Posts: 2,908




Ignore
« Reply #37 on: April 07, 2018, 08:17:30 AM »

Hmmm.... could be - had not occurred to me that it might be a cause.  Have not used cyno in any "quantities" for a few days and not suffered so will take note when using it again.  However I do find using it in small quantities as suggested by David Collis, with the "eye" end as the applicator results in the fumes/odour are much less noticeable.  It is logical though that it could be an irritant.  Will ask some medics I know who can access things on the 'net we cannot.  But as it has been used to repair wounds for years i guess it is not harmful.

Must admit always wondered how some kids can stick their heads in carrier bag of  a "glue" for fun!

Richard I was wondering how you were getting on with this magnificent beast because of late we have some shallow "lakes" in a number of the fields which would be excellent for launching an RoW flying boat model - guess same over there?     
Logged
billdennis747
Titanium Member
*******

Kudos: 54
Offline Offline

United Kingdom United Kingdom

Posts: 3,719



Ignore
« Reply #38 on: April 07, 2018, 11:01:13 AM »

Paul Briggs told me he keeled over after an extended cyano session. He said it doesn´t have ´cyano´in the name for nothing
Logged
LASTWOODSMAN
Platinum Member
******

Kudos: 26
Offline Offline

Canada Canada

Posts: 1,036


REAL PLANES HAD ROUND ENGINES AND TWO WINGS



Ignore
« Reply #39 on: April 07, 2018, 01:07:34 PM »

Cyano Acrylate glues are insidiously dangerous - they always emit a toxic vapour pressure.   The toxicity of CA glues cause  flu-like symptoms,  may trigger asthma, and  irritate sensitive membranes in the eyes, nose, and throat.   I have read that the damage is permanent.   Those  "sensitive membranes in the eyes, nose, and throat  are immediately polymerized by the moisture in the membranes, and become inert."  ie permanent damage.   And the damage keeps building up.
https://en.wikipedia.org/wiki/Cyanoacrylate#Toxicity

     Aliphatic straight chain carbon "White Glues" are non-toxic.  I only use white glues.

LASTWOODSMAN
« Last Edit: April 07, 2018, 01:27:12 PM by LASTWOODSMAN » Logged

OH, I HAVE SLIPPED THE SURLY BONDS OF EARTH ... UP, UP THE LONG DELIRIOUS BURNING BLUE ... SUNWARD I'VE CLIMBED AND JOINED THE TUMBLING MIRTH OF SUN-SPLIT CLOUDS ...
Graham Banham
Gold Member
*****

Kudos: 24
Offline Offline

United Kingdom United Kingdom

Posts: 697




Ignore
« Reply #40 on: April 07, 2018, 01:56:26 PM »

No doubt that CA’s are nasty in terms of their fumes. However, i read the same wikipedia entry, and i read it that it’s the CA fumes that are immediately polymerised by contact with the moisture in the eye, nose and throat membranes, not the membranes themselves. So the damage to membranes would not appear permanent, but repeated exposure to any kind of irritant can’t be good.

 This ties in with the fact that the CA curing reaction is speeded up in the presence of water (i.e. moisture), and the use of more than a thin layer of CA does not cure or stick at all, as only the outer surface of a thicker layer is in contact with air/ moisture, so it sets immediately forming a skin over the remaining uncured CA preventing or dramatically slowing its reaction.
Logged
LASTWOODSMAN
Platinum Member
******

Kudos: 26
Offline Offline

Canada Canada

Posts: 1,036


REAL PLANES HAD ROUND ENGINES AND TWO WINGS



Ignore
« Reply #41 on: April 07, 2018, 03:23:35 PM »

This is an important conversation about CA glues, that we really should have, and I don't mind talking about it.
     Cyano is short for Cyanide which consists of a carbon atom triple-bonded to a nitrogen atom.  Many cyanides are highly toxic. The cyanide anion is an inhibitor of the enzyme cytochrome c oxidase (also known as aa3) in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells which make up the tissue in all animals). It attaches to the iron within this protein. The binding of cyanide to this enzyme prevents transport of electrons from cytochrome c to oxygen. As a result, the electron transport chain is disrupted, meaning that the cell can no longer aerobically produce ATP for energy. Tissues that depend highly on aerobic respiration, such as the central nervous system and the heart, are particularly affected. This is an example of histotoxic hypoxia.
Minimum risk levels (MRLs) MAY NOT PROTECT AGAINST delayed health effects or health effects acquired following repeated sublethal exposure, such as hypersensitivity, asthma, or bronchitis. MRLs may be revised after sufficient data accumulates.

Here is Cyanide in wiki https://en.wikipedia.org/wiki/Cyanide#Toxicity

Maybe this New Jersey Hazardous Substance Fact Sheet might shed some light on Methyl 2-Cyanoacrylate, which is CA glue. http://nj.gov/health/eoh/rtkweb/documents/fs/1241.pdf

LASTWOODSMAN
« Last Edit: April 07, 2018, 03:43:51 PM by LASTWOODSMAN » Logged

OH, I HAVE SLIPPED THE SURLY BONDS OF EARTH ... UP, UP THE LONG DELIRIOUS BURNING BLUE ... SUNWARD I'VE CLIMBED AND JOINED THE TUMBLING MIRTH OF SUN-SPLIT CLOUDS ...
Ex Member
Guest

« Reply #42 on: April 07, 2018, 05:23:55 PM »

I use high grade CA quite a lot at work to attach strain gauges.  I have never really felt any ill effects from it.  However in this process I use a catalyst to make the glue go off quicker, and of course I only use a tiny amount.

At home and on models I again only use tiny amounts at a time putting a few drops into a pistachio nut shell held firm in blu tak.  I then apply the glue with a pin or a cocktail stick.

I think the key thing is to use it sparingly and only when required, it’s definitely a case of less being more.

I generally use PVA for most joints only really using CA for quick repairs, holding dissimilar materials, locally hardening balsa and using it on the ends of rubber motors to stop the knots undoing...

Andrew

Logged
Pete Fardell
Palladium Member
********

Kudos: 123
Offline Offline

United Kingdom United Kingdom

Posts: 5,016




Ignore
« Reply #43 on: April 07, 2018, 05:43:52 PM »

Although I used to have periodic bouts of seasonal asthma, I have never had so much as a wheeze triggered by CA even when I've split a bottle of the stuff. In accidental large quantities, or when I've occasionally (and probably unwisely) spread it over a large area, it  certainly makes my eyes water though, and my throat sting for a few moments. I don't suffer from asthma much at all these days, but I will certainly be a lot more careful with CA from now on. Thanks for all the warnings!

(Still loving the build, Richard!)
Logged
dputt7
Platinum Member
******

Kudos: 90
Offline Offline

Australia Australia

Posts: 1,991




Ignore
« Reply #44 on: April 07, 2018, 07:38:23 PM »

  Only last week I was thinking about weather I needed to wear a Dusk Mask while building because of that cough. Still not sure If it's the CA or Balsa Dust!
Logged
ffadict
Bronze Member
***

Kudos: 0
Offline Offline

United States United States

Posts: 52



Ignore
« Reply #45 on: April 07, 2018, 08:32:51 PM »

The main thing about these modeling chemicals seems to be the need for ventilation, a little at odds with trying to keep light pieces held down, but better than health problems later.
Logged
DavidJP
Titanium Member
*******

Kudos: 46
Offline Offline

United Kingdom United Kingdom

Posts: 2,908




Ignore
« Reply #46 on: April 08, 2018, 05:35:52 AM »

Isn’t the bottom line here a matter of common sense.   There are many things over the that are proven to be toxic one way or another and to varying degrees.  And we are all affected differently. In the end it is an individual choice.  Some wish to cocoon themselves others not.  No different from those who choose to abuse their bodies with drugs, tobacco, alchohol or bad diets and become obese. Their call,

I will continue to use cyno. Dope drink alcohol and enjoy food.  In amounts and to the extent  with which I feel comfortable and, take reasonable precautions.  As I have nearly always done.  But then being on the threshold of becoming an octogenarian perhaps it matters not?
Logged
Ex Member
Guest

« Reply #47 on: April 08, 2018, 06:08:36 AM »

All substances are poisons to the human body, even water! It’s all about the amount required to have the effect...  it is surprising what comes up in lists of LD50 rating for various things.  As David eluded to, check out caffeine!

Anyhow nice model Richard see you next week!

Andrew
Logged
PB_guy
Gold Member
*****

Kudos: 13
Offline Offline

Canada Canada

Posts: 516


Just a kid at heart.



Ignore
« Reply #48 on: April 08, 2018, 09:51:19 AM »

Boy Andrew, that brought back memories. I haven't done LD50's for more than 30 years! (lethal dose for 50% of the population treated).
ian
Logged
LASTWOODSMAN
Platinum Member
******

Kudos: 26
Offline Offline

Canada Canada

Posts: 1,036


REAL PLANES HAD ROUND ENGINES AND TWO WINGS



Ignore
« Reply #49 on: April 08, 2018, 11:16:58 AM »

     Thank you Richard for your first hand, honest testimony, regarding the ill effects of CA glue expposure, and bringing up the topic for discussion.  
     I am also really enjoying your meticulous build of that magnificent PB2Y Coronado flying boat patrol bomber,  with that twin tail of marked dihedral.   I will be watching this one closely.
     PS     I have done a lot of toxic gas testing for the huge, cavernous,  "vessel" entry permits in a Pulp and Paper Mill in Northern Ontario, before anyone could enter, and throughout the Mill.    Depending on the toxicity results, men were only allowed very short periods of time of exposure to do their maintenance work.   Yes, LD 50  and a lot of other ones ...

LASTWOODSMAN
Logged

OH, I HAVE SLIPPED THE SURLY BONDS OF EARTH ... UP, UP THE LONG DELIRIOUS BURNING BLUE ... SUNWARD I'VE CLIMBED AND JOINED THE TUMBLING MIRTH OF SUN-SPLIT CLOUDS ...
Pages: 1 [2] 3 4 5   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!