Phil's F-86 Sabre build thread

[Phil Cooke]

I got sucked into the enjoyable detail work despite my best efforts! First piece of clutter aranged on the 'parcel shelf' - MUST STOP!

[Callsign Tarnish]

Are you going to drop in a pair of 6x9's too?

[Phil Cooke]

Made a start on the drop tanks today, using the excellent little drawing from G&M models - I've gone with the foam insert version as opposed to the planked version, I couldnt do it to myself... I'll finish in brown paper and glass once they're all sanded up.

[Martian]

Loving your work Chris. I printed a Sabre complete with drop tanks you could have but I guess you prefer the hard way

[Phil Cooke]

Limited time on the Sabre this past few days with work being hectic - what effort I have employed has seen me messing around with the drop tanks instead of finishing the main airframe!

I found I needed to extend the pylons fore and aft compared to the drawing to make them scale, mine are now 155mm front to back. The pylon and droptank keel is cut from 1/8 liteply (still needs many weight reduction holes adding now they fit in the wing) - the little ply tongues fit into the wing box mechanism nicely, although I think they need shaping to allow the drop tank to pitch and roll away when released.

Blue foam slugs will fit inbetween the balsa formers...with a balsa nose and tail cone. Hopefully they wont weigh too much!?

[dirk tinck]

Mould it !!They won't weigh more than 25 gr!

[Andy Meade]

3D print it - they won't weigh more than 20 gr :D

[dirk tinck]

OK , you win Andy

[Phil Cooke]

Options, options!
Dirk - I wish I had those skills! I'm a complete newbie when it comes to composite moulds from scratch - I just don't have the skills or materials to do that and would need to learn and invest. Your tank looks very good - have you made that specifically for this model or is it off another Sabre model??

Andy - I may well come crying to you cap in hand if my ply and foam attempts get too heavy - but for now I'll hold back the 3D printing order and plough on - I aim to get as much weight out of the liteply keel as I dare before the blue foam is added but I've no idea what the final weight will be with brown paper/PVA and glass. Lets see,

[dirk tinck]

It's just a tryout from a few jears back. I'm sure i can get them under 30 gr...and you could too!

[Andy Meade]

I think from Matt's experiences, balsa can still end up lighter than 3d printed parts in all honesty. It suits me as I can design quickly once, then print multiple items whilst doing other building (or God forbid, house!) jobs. Agreed that the moulded tanks looks fantastic too

[Phil Cooke]

More work on the drop tanks this weekend - they've taken far too long - but with the gauntlet having been thrown down on weight I've done all I can to shed the grams and this has led to a lot of additonal machining and sanding - all quite theraputic though in the current climate I must admit...

The central keel, including pylon and mouting 'tongue' was cut prior from 1/8th lite-ply and weighed in at a porkly 50.1g each side...

I thinned this down as much as I dared with a lengthy session on the scroll saw, bringing it down to 22.6g but theres still a lot of material and glue to add!

Before adding any of the 3D structure I had to machine the angled slots into the mounting tongues and ensure the snake retainers worked smoothly - all good after a little fiddling with the position - in the end a nice fit.

The blue foam slugs were cut to size, each part was hollowed out as best I could on the scroll saw by projecting a 1/4" wall offset from the small end to the big end... this meant the min wall section is 1/4" and gets bigger on conical sections. The dremel could remove a bit more where necessary (former 1-2 and 6-7 were worst)

With all the foam spot glued in, they could be sanded roughly to shape.

I've still got to add a balsa nose and tail cone and I'll sand the foam to its very final profile once they are fitted. Current weight is 47g all in but some balsa still to add, plus the surface covering (brown paper and PVA then glass resin?)

Oh and then paint too. So no where near the quoted 30g for a printed tank (although that didnt include pylon of course!)

[Andy Meade]

Good grief, there's more work in that than your fuselage!

The A10 looks on in disgust.

[McG 6969]

This is indeed a build on its own, Phil.

Is Andy envious of your A10 then? ...

Cheers

Chris

[Phil Cooke]

No, not envious, it's another public attempt to try and 'whoo me up' to complete a model which has been in build for many years now, shamefully.

This is the airframe last time I rigged it in full, since then many models have been started and finished - the series of PSSA Mass Builds for example with Jet Provost, Skyhawk, Hurricane and now Sabre - in fact the JP dates this photo to 2014 when I'd just finished that ready for our first MB event!

[Andy Meade]

We both had the same kit for a sixth scale A10, mine took me 6 months to build and finish - Phil's will be 10 years old before it gets a launch

[robk]

Those drop tanks look excellent... great techniques and so many different ways to make the omelette, but Im kind of glad my chosen version didn't use them as (a) I dont have to make them (b) I won't have to collect them when they fall off on landing.

[Phil Cooke]

Got the drop tanks finished and ready for brown paper and PVA, which I think is a better surface finish onto the blue foam than glass and resin alone.

50g per piece at present including the pylon and mounting tongue...how much will the paper and PVA add I wonder??

Edited By Phil Cooke on 30/04/2020 19:55:16

[Callsign Tarnish]

Shouldn't there be fins on Sabre tanks?

[Phil Cooke]

yep they sure do - I'll add them once the paper and PVA is applied to the main body - made from plasticard or alike.

[dirk tinck]

Great job Phil !

I think with two layers of 25 gr glass and perfect sanded foam you can win from brown paper and glass.

Just my opinion ...

[Phil Cooke]

yep the second layer of glass cloth would make them suitably robust, and like you say - this might be lighter than the brown paper and PVA route - I think you've sold me!

Would you put the second layer on whilst the first layer is still wetted out or do you have to let the initial lay up fully dry, sand any highspots back then apply the second layer?

[dirk tinck]

Had to think on this one ...

I would try to put the second layer on with the first still wet , and without the use of more resin,to save weight.

[Phil Cooke]

A little bit of bench trialling before we finish the tanks and pylons off ready for paint.

I've shaped the mounting tongues with a little curvature front and back allowing the tanks to pitch a little as they begin to drop away without binding across the corners. I've also added a little carbon anti-rotation pin towards the rear of the pylon which aids alignment during flight.

Harry helped me on the controls whilst I was working the camera - childs play!

[Phil Cooke]

Another good sanding session this afternoon and a number of parts are ready for glass now as a result.

The wing has had its L/E rounded and tips profiled, then an overall finish sand along with the ailerons and the rudder. The tailplanes have had their tips sanded to profile and the end faces angled to allow for the required dihedral against the vertical fuselage sides, they too are now ready for glass.

Following Dirk's advice I'm keen to glass the wing before I finish off the fuselage wing saddle, wing bolts, dowels and fillets, so with very little to do ahead of all that work, I'm going to glass these parts next... time for a good dust down and tidy up in my little garage before we get the resins and cloth out!