Author Topic: Monospar ST.25  (Read 1875 times)

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Balsabasher

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Monospar ST.25
« on: October 27, 2013, 12:39:09 PM »
The Monospar ST.25 was a pre-war 1930's twin Pobjoy engined small charter type aircraft,its interesting shape presents some challenges to capture the character of this succesful light twin which was well ahead of its day.
Here I have cut the templates and made the first wood cutting step with the fuselage blank next to the Hindustan HT.2.
Barry.





Balsabasher

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Re: Monospar ST.25
« Reply #1 on: October 29, 2013, 01:54:20 PM »
The wing blank was cut today in readiness for sanding and shaping,a kit of parts is being built up between other jobs,I tend to move around in my model building as you can see,I find this way you progress towards different areas on different models and arrive at various stages meaning things are ongoing and completion is always in sight for one model,I also do my paintings the same way having various pictures on the go at one time,many artists work in a similar fashion,each to their own in the way that they work,I think Lou uses a similar way of working with projects always on the go.
Barry.


buccfan

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Re: Monospar ST.25
« Reply #2 on: October 30, 2013, 02:51:24 PM »
nice work on this and all your new projects Barry, there's no stopping you now in your new shed, maybe one day I will be able to fit my other jobs around modelling, but at the moment it's fit modelling around everything else.Best regards Paul J.

Balsabasher

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Re: Monospar ST.25
« Reply #3 on: October 30, 2013, 04:32:06 PM »
Yes Paul I am making the most of my new found freedom,it makes me realise what I have been missing.
Barry.

Balsabasher

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Re: Monospar ST.25
« Reply #4 on: November 11, 2013, 12:42:33 PM »
Two more instructional videos,one on marking datum points prior to shaping hexagonal fuselages such as on the Monospar ST25


http://s180.photobucket.com/user/UDAZONE/media/SHAPINGFUSELAGES.mp4.html


http://s180.photobucket.com/user/UDAZONE/media/VIDEODATUMPOINTSANDPINPRICKING.mp4.html
« Last Edit: November 11, 2013, 12:53:59 PM by Balsabasher »

Balsabasher

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Re: Monospar ST.25
« Reply #5 on: November 11, 2013, 01:02:25 PM »
Shaping the fuselage and engine nacelles on the Monospar ST25,also see supporting videos.








1.JaVA_LGorrit

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Re: Monospar ST.25
« Reply #6 on: November 11, 2013, 01:50:58 PM »
nice work on this and all your new projects Barry, there's no stopping you now in your new shed, maybe one day I will be able to fit my other jobs around modelling, but at the moment it's fit modelling around everything else.Best regards Paul J.

+1  ;D

It is nice to dream about it though!

Balsabasher

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Re: Monospar ST.25
« Reply #7 on: November 16, 2013, 04:12:07 PM »
The complex shape of the Monospar ST25 wing was carved today,from the front the outboard panels taper in the normal fashion midway of the wing towards the tips, however the inboard sections just in line with the small Pobjoy powerplants rise upwards and then down towards the centre section,this was a common feature on the manufacturers General Aircraft Ltd aircraft types,the Westland Lysander used the same front wing planform andno doubt there is a good aerodynamic reason for this shape but nothing comes to mind as to why ?

Only one Monospar survives today and that is in the UK and has been on rebuild to static condition for many years,the machine was way ahead of its time and the powerplants made by the Pobjoy manufacturing company at Heston airfield,the well known Comper Swift was the aircraft that made this tiny engine popular.

Next the slots to take the engines were cut out and the engines glued into place,the next task is to add some dihedral to the wings by cracking the centre section half way and using Gorilla glue to re-inforce the joint.

Barry.








lastvautour

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Re: Monospar ST.25
« Reply #8 on: November 17, 2013, 11:06:14 AM »
Looks like another beauty Barry.

Lou

Balsabasher

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Re: Monospar ST.25
« Reply #9 on: November 17, 2013, 02:46:34 PM »
Made good progress today on the Monospar ST25,the slot for the wing was carefully marked out and cut,then the wing without the dihedral was trial fitted,then a half crack was sawn into the top surface in the shape of a 'v' with a razor saw this was then filled with cement and gently eased in my warm hands to the required dihedral,the trick is to listen to the wood cracking and stop when the noise goes,it sounds odd I know but it works,go too far and you end up with two pieces in your hands that makes life difficult as you have to effect a repair,the heat lamp soon dried the joint so that I could carry on to the next stage,fitting the wing.

After a few hours I cut strips of wood in the shape of wedges and pushed them in to the slots side of the fuselage standing proud of the sides for trimming later,a small frontal fillet was cut and fitted so that the leading edge of the wing will blend nicely once it is sanded.

The odd wing shape made fitting it a bit of a challenge but hey we are not mere assemblers but builders and face these problems with solutions head on,the challenges a real part and parcel of the fun.

Barry.






lastvautour

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Re: Monospar ST.25
« Reply #10 on: November 17, 2013, 03:04:15 PM »
Cutting dihedral breaks are not normally my way of doing business except for the WWII ID Tutorial. Usually I use a larger block and carve the dihedral into the wing. However, my method uses a lot more wood than creating the dihedral. Your comments on how far to go is an art in itself, hence many of my dihedral breaks had to have a splice to keep things straight. You will see when that part of the Hampden come up.
 In your favour, is your talent. Excellent job to date.

Lou

Balsabasher

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Re: Monospar ST.25
« Reply #11 on: November 17, 2013, 03:31:14 PM »
I have always loved that Royal Gull,there is something about cranked wings thats what gave the Junkers Ju.87 its real character and stability in the dive.

Another technique that I have used is to make dihedral keepers from 1/16th ply,you can glue them up and alllow the ply to stand proud sanding it flush later,Gorilla glue is good for this like a lot of tricky joints that need good glue to grab the joints.

My word thats some carving achievement there Lou on your Royal Gull,a very pretty aeroplane,its interesting how we each tackle things in a different way and above all learn from each other as well.

Barry.

Balsabasher

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Re: Monospar ST.25
« Reply #12 on: November 18, 2013, 01:07:07 PM »
After a good sand it was time to tackle the undercarriage,the main legs were formed from brass tube and the positions marked to take the main legs,a spot of cyno locked these into place all ready for the next undercarriage braces that need to be fabricated and soldered into place onto them.
Barry.




Balsabasher

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Re: Monospar ST.25
« Reply #13 on: November 19, 2013, 01:42:12 PM »
Time to get the soldering iron out and sweat up the joints on the undercarriage brass tubes,a tiny bit of brass craft wire assists holding things together while the soldering operation takes place,the tail wheel was made from brass tube also with a small rubber O-Ring used for the wheel which just slips over the tail wheel leg.

Barry.




lastvautour

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Re: Monospar ST.25
« Reply #14 on: November 19, 2013, 01:46:10 PM »
Such small engines. You are doing this aircraft justice.

Lou