1/4 Scale ASK21

Let us all watch your new project progress.
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GeeW
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Re: 1/4 Scale ASK21

Post by GeeW » 17 Mar 2018, 19:08

Two more emails should be awaiting your pleasure in your inbox. :D

Regards

Gordon

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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 02 Apr 2018, 14:59

Many thanks for all the pics and recent dimensions Gordon.
I now have a good scaled 3 view drawing of the wheel fairing, so will break out the foam or balsa shortly to make a more realistic 1/4 scale fairing.
Peter

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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 08 Apr 2018, 19:03

Old main wheel fairing removed and underside of fuselage made good.
New fairing made and just glued in place (scaled from full size photos & dimensions kindly provided by Gordon).
Hopefully this looks more like a real fairing now (not that you probably see this view of a full size glider that often!!)
Fairing still needs to be faired in.
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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 10 Apr 2018, 17:33

Main wheel fairing blended into the fuselage a bit better now.
A final check to fill the last few blemishes, then on with the pattern coat I think.
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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 27 Apr 2018, 17:31

After a couple of coats of pattern coat primer, initial sanding with 120 grit, then working through the wet & dry grades (used wet) to 800 grit, followed by a polishing paste, I think I have a fuselage plug about ready for the mould making process.
A photo below shows the fuselage complete with its 2 small canopy aperture blanks which will be hot glued in position after a few more coats of wax polish, then the joints sealed with wax.

Next job is to prepare the parting board.
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Cliff Evans
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Re: 1/4 Scale ASK21

Post by Cliff Evans » 27 Apr 2018, 17:37

Well done Peter.

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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 15 May 2018, 16:21

With whole plug prepared with 6 coats of beeswax, it’s time to prepare for making the 2 part mould.
After measuring the fuselage width and getting some 3mm parting board material, I made up a box (screwed only, so easier to dismantle once 1st side of mould made) which allowed the split line to be on the upper parting board level when the fuselage is sat with one wing root on the bottom of the box. The fin is also supported to be at the correct height.
Previously positioned marks on nose, rudder post and top of fin show the splitting line.
Once the fuselage outline is cut out of the parting board (and edges also supported at correct height), the fuselage can be sat into place, the gap filled with wax (carefully cut back to give a flat surface into fuselage) prior to adding mould registration features.
The photos below show the mould box before & after fuselage plug is sat in place.
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Mould box
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Plug in position

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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 23 May 2018, 20:20

First side of mould now laid up.
A bit of a learning curve, but hopefully it will come out ok in due course.
Need to get more resin for 2nd side as it used a lot more than I expected ;)
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Simon WS
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Re: 1/4 Scale ASK21

Post by Simon WS » 24 May 2018, 07:04

Looking good Peter. Was making a mould something you fancied trying or are planning on making more than one for your mates?!

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Peter Balcombe
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Re: 1/4 Scale ASK21

Post by Peter Balcombe » 24 May 2018, 09:12

Thanks Simon,
Although initially thinking of going down Roo’s one-off route, I somehow decided that I would have a go at making a mould as a project!
This was partly because at the time, I wanted to try the process to make another fuselage off of an unused DG100 fuselage I have & partly because I thought it might be useful to be able to make a spare if needed.
I haven’t seen 1/4 scale ASK21 models about, so thought it a good subject.

There is a looong way to go yet though ;)

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