Re: John Slater Airspeed Tern
Posted: 12 Jan 2020, 08:37
Hi Tern Watchers
Belated New years Eve wishes to all. It has been a busy time over the holiday period. With lots to do and the odd health issue. Also I appear to have been the victim of an on line 'trick/scam'. I ordered and paid for a model that was never sent, the guy that did it vanished off the 'Messenger' page' where we 'spoke', and is not responding to phone calls.
So if some one offers a Flair Sunrise gilder on line be very cautious. I suppose I was a bit naive and lost out to the tune of £100.00. Still we live and learn. I am not mentioning the guys name as I understand this is not allowed. It is a shame because he seemed like a nice chap. I am more disappointed than annoyed.
Moving on to more pleasant things, my Fair K8 and Chris Williams 1/4 scale T21 have both been flown and went really well. Now back to the John Slater Tern. The final rigging has been done and the ballast weight added to get to the specified COG. Like most vintage gliders a fair bit of lead was needed to do this, 9.00 ounces to be exact, as you may recall the under sheeting at the front was not finished to allow me to do this. So in this gap went the lead, or least 7.00 ounces of it. Two ounces were left as 'trimming weight'' to be added at the front of the cockpit so that after the test flight and dive test I could go either way with the COG depending on the out come of the test.
If you plan to build this model please make sure you keep the back end as light as possible, the all up weight has come out at 12 lb 6 oz, I don't think that is too bad (?). But with out care during the build it could have easily made 13-14 lbs. The areas to work on here are obviously all the bits at the back (rudder, elevator, fin), however the selection of material remains important, for example 0.4 mm/0.6 mm ply were used at the back and 0.8 mm was used at the front end for sheeting the fuselage. Ply was not used on the wing sheeting, I went for balsa painted to look like ply. The front wing joiner is 10 mm steel and the rear 8 mm. The nuts and bolts holding the wing joiner boxes in the fuselage were replaced with cover pieces of 2 mm ply. This saved precious weight over all. It is never one thing that saves the weight but little bits all the way through the build that do it.
The final sheeting was then added and stained to match the rest of it. I enclose a picture of this. So all that remain now is the test flight, I will keep you posted on the outcome.
All the best Barry
Belated New years Eve wishes to all. It has been a busy time over the holiday period. With lots to do and the odd health issue. Also I appear to have been the victim of an on line 'trick/scam'. I ordered and paid for a model that was never sent, the guy that did it vanished off the 'Messenger' page' where we 'spoke', and is not responding to phone calls.
So if some one offers a Flair Sunrise gilder on line be very cautious. I suppose I was a bit naive and lost out to the tune of £100.00. Still we live and learn. I am not mentioning the guys name as I understand this is not allowed. It is a shame because he seemed like a nice chap. I am more disappointed than annoyed.
Moving on to more pleasant things, my Fair K8 and Chris Williams 1/4 scale T21 have both been flown and went really well. Now back to the John Slater Tern. The final rigging has been done and the ballast weight added to get to the specified COG. Like most vintage gliders a fair bit of lead was needed to do this, 9.00 ounces to be exact, as you may recall the under sheeting at the front was not finished to allow me to do this. So in this gap went the lead, or least 7.00 ounces of it. Two ounces were left as 'trimming weight'' to be added at the front of the cockpit so that after the test flight and dive test I could go either way with the COG depending on the out come of the test.
If you plan to build this model please make sure you keep the back end as light as possible, the all up weight has come out at 12 lb 6 oz, I don't think that is too bad (?). But with out care during the build it could have easily made 13-14 lbs. The areas to work on here are obviously all the bits at the back (rudder, elevator, fin), however the selection of material remains important, for example 0.4 mm/0.6 mm ply were used at the back and 0.8 mm was used at the front end for sheeting the fuselage. Ply was not used on the wing sheeting, I went for balsa painted to look like ply. The front wing joiner is 10 mm steel and the rear 8 mm. The nuts and bolts holding the wing joiner boxes in the fuselage were replaced with cover pieces of 2 mm ply. This saved precious weight over all. It is never one thing that saves the weight but little bits all the way through the build that do it.
The final sheeting was then added and stained to match the rest of it. I enclose a picture of this. So all that remain now is the test flight, I will keep you posted on the outcome.
All the best Barry