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Re: GREENLEY TUG BUILD THREAD 88"

Posted: 25 Sep 2018, 08:12
by john greenfield
Wayne Thompson wrote: 24 Sep 2018, 23:57 There were some comments about some using thicker ply for the sides and top bottom of the fuz as well as comments about the 10mm stab / fin being strong enough without the use of the spar but this is my way and you are welcome to change to your way. to be honest the thicker ply fuz would have so much easier i think at 1.5mm i could have just got it laser cut with a 45 degree puzzle joint.
Wayne
Who has commented about needing thicker ply for the sides? ALL the SD and SDD Greenleys use 0.8mm ply for the sides, top and bottom of the fuz and I can assure you it is strong enough, same with the 10mm balsa tail, it does not need a spar.
The "improvements" being suggested to you will only add weight and detract from the model's overall performance.

What you may not be aware of is that the Greenley has been continuously developed over a period of 20+ years to refine the design and improve its performance. Built exactly as per your plan they have proved amply strong enough for the rigours of towing over many seasons. It is not a "one off" design that has not had the benefit of hundreds of hours of real testing and development.

John Greenfield
Greenley designer

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 25 Sep 2018, 10:45
by steve dowell
Hi Wayne

If I were you I'd stop. Think of the Greenley as a very well sorted tug just as it is. Not only that but if you ask anyone who has one its their go to hack model. why fix what's not broken!

Steve Dowell

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 27 Sep 2018, 07:53
by john greenfield
Wayne Thompson wrote: 27 Sep 2018, 02:36 ok, finally got the wing plan printed.

thought i would share some pics of the bits that are important to me. The shear webs are 1.5mm and im struggling to find it right now - i can get 2.5 and 1mm no problem.
John , could i do 1mm both sides if i cant find 1.5mm (1/16 " ) ?
Wayne
1mm ply on both sides will be fine if you can't find any 1.5mm.

Regards

John

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 28 Sep 2018, 08:01
by john greenfield
Wayne

If well fitted hard balsa is used as packing between the tube and the spar then you could use 1mm ply on both sides in this area as well.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 11 Oct 2018, 09:09
by Stuart Ward
It is a lovely facility. The guys have spent a lot of time forging a positive relationship with the owner and other users of the land.
Stu

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 18 Jan 2019, 08:17
by john greenfield
Wayne Thompson wrote: 17 Jan 2019, 19:32 After Stuarts build marathon i was inspired and started to assemble more parts, got Gwyn to laser cut some nice 3mm ply for the false LE ...... Which i thought was balsa for some reason. The front top and bottom ply wing skin will be butt joined to the false ply leading edge and will cover over the TRAILING EDGE.
Wayne
The false leading edge is balsa. No harm to make it in 3mm ply but it will make the wing heavier and it is a little more difficult to shape prior to sheeting.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 23 Jan 2019, 07:36
by john greenfield
Wayne

A bit late now but for future reference, it is normal on a model with a false leading edge to sheet the wing before attaching the thick leading edge. The sheeting is stuck down onto the false leading edge and any overhang trimmed back Only then is the main thick leading edge added and shaped.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 23 Jan 2019, 12:09
by Peter Balcombe
Wayne,
I would suggest that rather than just butt the skins up against the false leading edge, you install some strips between each rib on the rear of the leading edge to provide a glueing land - otherwise the front of the skins can easily separate from the false LE.

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 23 Jan 2019, 18:03
by john greenfield
Peter Balcombe wrote: 23 Jan 2019, 12:09 Wayne,
I would suggest that rather than just butt the skins up against the false leading edge, you install some strips between each rib on the rear of the leading edge to provide a glueing land - otherwise the front of the skins can easily separate from the false LE.
Wayne
You would be better cutting the leading edge off and redoing it with a 1/8" false leading edge sanded to shape. Attach the 0.8mm wing skins as my post above and after trimming back add the thick leading edge. Trying to put balsa between the ribs and then sand them to profile will be difficult and will probably result in an uneven surface and a poor leading edge.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 27 Jan 2019, 09:06
by Stuart Ward
Hi Wayne I have posted a close up photo of the construction of the Greenley wing leading edge at the root rib.
The only difference between what I have done and what John has described is that I have used a 3mm ply false leading edge not a balsa false leading edge.
The false leading edge was cut to width and planed with the bevel tangent to the ribs, before being but glued to the ribs.
The the 0.8mm ply is then glued using you proffered method (wet glue and masking tape, or iron on method) leaving the front of the ply overhanging a little and sanded back flush after the joint has been made.
Only then do you add the 1/2" balsa leading edge.
Hope this helps
Stu

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 21 Feb 2019, 08:31
by john greenfield
Wayne
The tip is just a sheet of 1/4" (6mm) balsa sheet stuck onto the last rib and angled up at 45 deg. we do this by cutting the front and rear spars to the correct angle and just sticking the balsa sheet to the ends of the spars. Then, using the ribs as a guide, sand the balsa to the correct shape top and bottom before adding the ply sheeting to the wings. Ply sheeting is also added between the front and rear sheeting from the last rib out to the balsa tip.

Hope that helps.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 27 Feb 2019, 20:09
by Barry_Cole
This is the way I did mine.

I left the spars long, and cut the ends out of 1/8" balsa as per the drawing. The spar slots are not deep enough, but I just deepened them until it fitted at the correct angle I made then 45 Deg from the top surface. When they were glued in, I got a piece of about 2" wide timber 24" long, and stuck coarse sand paper on the last 6 ". The wood then rubbed on the main ribs, and the end got sanded to the correct size and angle. After sheeting I stuck 1/32" ply on the end, to stop damage in the event of a 3 point landing.

It's a nice place for stickers too.

:shock: :shock: :shock: :shock:

BC

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 28 Feb 2019, 20:38
by Stuart Ward
That's the story, Wayne. Rough cut oversize and sand it with a long bar. Then ply the tip bays.
Stu

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 01 Mar 2019, 09:22
by john greenfield
Wayne
I notice that you did not cut a 45 deg angle on the bottom spars, they seem to be cut flush with the end rib. A 45 deg angle on the bottom spars would give more support to the tip but you can cut some 45 deg triangles from 3/8 balsa and stick them to the ends of the bottom spars to do the same job.

AEB

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 04 Mar 2019, 20:37
by Barry_Cole
Ouch, and Yuk....

:cry: :cry: :cry: :cry:

BC

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 05 Mar 2019, 07:42
by Stuart Ward
Ohhhh( cringe) in the words of my grand daughter "hurt ' morning"
Stu

Re: GREENLEY TUG BUILD THREAD 88"

Posted: 29 Mar 2019, 08:12
by Stuart Ward
Wayne Thompson wrote: 28 Mar 2019, 19:20 Stu is making a tow release for me then i can sheet the middle section etc
I had better get on and do that then

Stu