Jump to content

A4 Skyhawk - Building tips and Plan queries


Recommended Posts

  • 2 weeks later...

My drop tanks are 27mm inboard of rib R5, which is a bit further out than the tailplane tips. I worked it out using the wingspan from scale drawing; I suspect the reason why they have ended up a bit further out in relation to the tailplane is because of the wings been slightly stretched. Wish I had noticed the relationship to the tailplane tips dooh ! That's some scale points deducted already.

Link to comment
Share on other sites

  • 3 weeks later...

Having produced various decal sets to support the A4 builds, I thought it useful to pass on some tips.

Some of the sets contain trad waterslide decals and these can be difficult to apply to matt paint finishes, film covering and overlays on vinyl decals.

The technique described here is applicable for all finishes as it provides a solid adhesion that is water resistant,

1. Applying on Matt Paint finishes, If your not careful its difficult to get the decals to stick and they 'show' against the matt finish.

The technique is to paint the surface where the decal is to go with a Gloss clear acrylic, I use Tamyia Gloss clear X22, which is crystal clear and resists yellowing with age, the tip is to apply it with a wetted in water paint brush to thin it slightly and slow it drying time.

Then apply the decal, I then brush down with a wet brush to remove the traces of gloss and then dab very gently with a kitchen tissue.

Once dry overcoat with a matt WBU, or acrylic spray, I tend to use Wilko Matt Water Based Varnish which is cheap and works a treat.

app7.jpg

Example being applied to My Hack Nigel Hawes Tucano, this is finished in Matt Dulux (tester Pot) which is then overcoated with Wilco Matt Clear WBU, don't try and apply direct to a matt emulsion finish with out sealing the finish first.

app6.jpg

Applying the Tamiya X22 Clear Gloss

app5.jpg

Dabbing the decal with Kitchen Roll

app8.jpg

Example of EJT Triangle

Both these pictures before applying sealing coat of Matt Clear, which once applied makes the decal backing almost invisible and seals in the decals against the elements

Link to comment
Share on other sites

yes a good question Ade... needs to be considered to avoid ruining the scale lines...

I was lazy on the prototype and simply fitted it to the top spine, including the Futaba ON/OFF plate - which didn't look too clever in the photos...

Pete Garsden used a very neat 'magnetic' switch on his Israeli A-4 - which had no external visible features but for a small diameter hole - easily 'passed' as a scale feature.

I think on my 'production' model Ill be mounting it on the spine again, but at a height so the top of the switch is flush with the fuselage profile, and I wont fit the Futaba ON/OFF plate. This will just leave a 3/16" black square visible in plan view - and no evidence in profile. There are a couple of vents on the top side of the full size, so it could be positioned to represent on of those.

Link to comment
Share on other sites

Thats a good idea Phil, although I was toying with the idea of using the 'fin' just behind the canopy as the extended swicth mechanism. Will it give me credence with my peers though..............

Life is a learning curve.............that gets steeper..............

Cheers

Ade

Link to comment
Share on other sites

  • 9 months later...

A bit more about Skyhawks.

The team here called 'Sky Resources' are capable of multi-roles in use as a camera drone or other accessory, available for film or movie shoots. These professionals have aircraft ready for contract hire to specialized operators and military contractors. Also their have recent experience as target drone tugs and as mock dog-fight/aggressor training simulation.

The aircraft and personnel available for any special event or airshow. Our team will deliver the aircraft wherever needed.

Link to comment
Share on other sites

Re Switch. used a magnetic switch from T9 Hobbysport which I installed just over the wing on the port side

You can't see it at all. The way it works is that the section with an S is where you swipe the magnet. At the other end is a blue pilot light, which shines though a hole in the fuselage. When you swipe the magnet across it comes on and the same for off. This circuit board, of course sits inside the fuselage and senses the magnet through the wood or fibreglass

**LINK**

Edited By Peter Garsden on 24/06/2017 17:13:41

Link to comment
Share on other sites

Interesting Peter, practical and useful for a scale installation.

Firstly the pilot ejected safely after a engine failure.

Another interesting and different video, a team climb up to the hills around Anza - Borrego area looking for the wreckage of a A4 Skyhawk. 

The Douglas A-4A Skyhawk Bu No 137828 based out of Los Alamitos Naval Air Station, Naval Air Reserve Squadron 776 crashed on 17th July 1968 in the Anza- Borrego area Pilot: Lt. Jerry P. Shafer, USN ejecting safely due to engine failure.

Especially watch at video time - 3:50 - when the whole tailplane is moved and seems very light.

Edited By Mark Kettle 1 on 25/06/2017 07:45:26

Link to comment
Share on other sites

  • 1 year later...

Hi Steve - thanks for your interest in building the A-4!

No-ones flown their Skyhawk more than Pete (I recall him finishing his well before the Mass Build event) so I would go with his description - Only to add - the A-4 wing loading is ~18oz/sq ft with a wing built as per the plan and with an AUW of 2.5lb, some were built lighter, some heavier. Equate that to a typical sports model like a Phase 6 (yes, I still live in the 80's) of ~14 oz/sq ft and you start to get a feel for the models lifting characteristics...

That said the A-4 won't slow up like a sports model - they need to be flown in - any hanging on the elevator at low speeds will drive a tip stall, nothing to be afraid of - but to be aware of!

No question it's a model best suited to good hills with a medium wind strength - I've flown mine in much, much more and it handles high winds well too, but I'd be too chicken to chuck it off in anything less than 15mph even on a good coastal slope like the Orme.

Edited By Phil Cooke on 20/11/2018 19:24:36

Link to comment
Share on other sites

  • 5 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...