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Phil's F-86 Sabre build thread


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Below is From Martins blog.

Before joining the two fuselage halves, be sure to add the wing bolt plates and the assembled battery box, along with the tailplane bellcrank assembly. The rear slot for the actuating rod is not machined into F15 as not everyone will choose to use the SLEC item. Cut the rear slots into F15 to suit your bellcrank. Dry assemble the sides until you are happy with the fit.

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'If you have not yet planked the bottom of the fuselage, you can access the dowel holes in F4 with a short pencil or a small dowel with the end inked' - whoops! - I glued this sheeting on last night!

I was keen to see how much of the bottom fuselage could be sheeted as apposed to full planking...not too much is the answer! - the compound curvature of the nose meant i couldn't quite finish the job as expected - it was tight and needed a load of pins to get it to form as shown, even after a lick of ammonia softened it up a little...

lower sheet 1.jpg

I'll think I've still got to add 3 planks each side...

lower sheet 2.jpg

As an escape, I made up the tailplanes. I'm going to glue my tails on, so was keen to create some nice box channels for the steel rods to sit in (will be epoxied later) and this 3 way laminate approach guarantees accuracy. 3/16th, 1/8th, 3/16th balsa laminates.

tails 1.jpg

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Hiya Dallas,

If you are glassing your wings then spruce really isn't essential - hard balsa would be fine - the final assembly with all the shear webbing front and back is very robust. I didnt have any spruce of the right dimension either - good on width but not deep enough for the pre-cut rib slots. So I laminated what I had with balsa to achieve the depth. The top spar was just balsa, cut from hard sheet.

Balsa would be fine top and bottom if you cant get hold of any spruce or alike.

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Still finishing the fuselage planking here and about to make up the tailplane rods...

team sabre 3 view copy.jpg

I've spent an evening sizing and scaling some of the decals for my Yugoslavian aerobatic scheme - and with all the data to hand I've just sent Callie at Callie Graphics an email for a quotation. Excellent service as always she has quoted within 24 hrs meaning I've now placed my order for some gloss vinyl roundels, stars and registration codes. Another weight off the mind... still plenty to do!

Callie has a few sets of Sabre decals already within her 'off the shelf' range - but will also make up any bespoke decals to any scale - well worth a look if you're thinking of self adhesive vinyl as opposed to paint!

[email protected]

roundel.jpg

 

Edited By Phil Cooke on 21/02/2020 22:41:22

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Hiya Dirk - yeah Callies work is really good, I'm looking forward to seeing these unusual roundels when they are complete!

As for the canopy frame - I have so nearly sent you a mail asking for one of your frames on 2 evening updates now, but I'm trying to avoid giving us both the extra work!! I'm going to resist - on the Hurricane and the A-4 I was able to make a little framework ridge with the airbrush and tape - with a grey or green coat first (to get the colour on the inside) and then a few top coats upto a double thick tape mask you can easily achieve the 0.5mm ridge with paint. I'm going to keep it simple and go that way again I think, but many thanks for the kind offer of making one for me!

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Hiya Dallas,

I think the 85MG+ is a sound choice for this model so keep going with your planned installation!

I will be fitting an 85MG+ on my elevator for the increased torque, as I've also done on the twin drop tank release (might be overkill here but when I was building it ad-hoc I wasn't sure how smooth the final operation would be and chose the bigger servo for a confident release)

I've found the 65MG+s are more than adequate when using one per flying surface on the ailerons of PSS models of this sort of size, they are a little smaller and only half the weight of the 85MG but still give a 2kg pull - so this is all good - and well proven on the 2018 mass build Hurricane.

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Hiya Dallas servo choice is very subjective. I am also using the 85mg for elevator for exactly the same reason as Phil. Rudder can be a much cheaper servo as the torque is less. I am using a £10 KST servo. I would not use the Hitec 85MG for ailerons because it is a bit heavy to put near the wing tips I am using 2 Emax metal geared servos which are vew cheap and reliable also about 5 pounds. If you are doing torque rods then OK but a bit overkill 65mg would be a better choice. For flaps I have gone for Savox 255mg £16 and 3.7kg of torque. Just what you need for the force required when trying to slow it down at 40mph. Other servos will do but this is my choice.

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Before I can complete the top planking its time to build up the tail actuator and fit a pushrod and servo to suit.

I've gone for a centrally mounted servo positioned slightly rear of that shown on the plan - at a depth where the central wing pushrods will all clear whilst still allowing access to the battery box. With the fus inverted a reinforced plate sits between the flats on F4 and F6.

ele servo 1.jpg

On the other side the joint is then bolstered with triangular section.

ele servo 2.jpg

Edited By Phil Cooke on 29/02/2020 09:33:34

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So I got all the metal work done for the tail actuation this afternoon...

Having fitted the servo I marked its position on the plan and made up a simple pushrod. Now I know some of my peers 'take the mick' but wherever possible I still like to make a traditional pushrod with a drilled, angled threaded rod, bound with a strong thread and all potted in PVA. Very 1940's I know, but oddly satisfying.

ele pushrod 1.jpg

ele pushrod 2.jpg

With that all done I did a trial fit to see if I could slide this in from the rear - it just went in over the top of F10 meaning the rest of the assembly would go ahead all ok...

Having cut the 2 rods and the brass tubing to length I also made up a couple of light ply spacers to stop the unit moving laterally between the 2 F15 formers... these were cut from 1/8" but needed to be sanded down a little on width. The wire bending went ok although in a small vice its not easy to keep the dihedral angles exactly co-planar - I did have to make a couple of adjustments but we got there in the end! All assembled it looks like this!

ele pushrod 3.jpg

Fitting the pushrod externally then sliding the whole assembly in from the rear again allows the units to drop into the slots in F15 - a second arched slot needs to be cut to allow the unit to articulate downwards.

ele pushrod 4.jpg

All in place with the pushrods fitted and the clevis secured with some heat shrink tube.

ele pushrod 5.jpg

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1st of March - thats 4 months into this Mass Build window - with just over 3 months to go to the event in June!

Got a bit more planking done on the nose ahead of the cockpit opening and I've fitted a 1/8" balsa cockpit floor ahead of F4 extending about an inch forward of F3.

To get it in - this had to be fitted in 2 pieces with a joint on the centreline but it sat down really nicely on top of the battery box and onto the mid height stringers in the fuselage sides. This will give a good representation of depth to the main cockpit area - and I've asked Andy Meade if he'll kindly 'sculpt' his 3D printed model seat and pilot to a 95mm depth which will suit this false floor.

cockpit floor.jpg

Edited By Phil Cooke on 01/03/2020 12:52:32

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