The Terry S from Graupner

[Peter Wood]

It looks great and I love foam models. I am just wondering what power system it uses. Peter

[David Ashby - Moderator]

Anything from a brushed can 400 motor to a brushless inrunner Peter. I'm going to be using a Mega 16/15/5 (from memory) with a 7x4 folder prop, 3s 800/1600mAh Li-POs which gived 170 watts - not bad for a model weighing 1lb 3oz - and a very slim streamilined one at that

[Tim Mackey]

I would have suggested something like this
'cos I thought it was a sort of powered glider type thingy, so sugges a fairly large prop ( maybe 10 X 6 or so ) and an outrunner of lowish Kv - with a 3s LiPo this setup would give you around 160 - 200 watts or so....NICE!

At that power on the 3s you would only be drawing about 15 - 20 Amps max, so a lipo of about 2200 mah of maybe 15 -20 C would be fine ...very common size and cheap as chips these days.

However David ( who knows the model ) seems to think its more of a hot liner type, and now that Timbo has actually bothered to read the article - it seems it is a bit more of a hotliner - Inrunner may be easier to fit too. However the review does suggest that the powertrain chosen will dictate its flying style and performance, so its up to you really!

[Peter Wood]

That seems great but how much is the Mega 16/15/5

[Tim Mackey]

Mega are not cheap motors but are very highly regarded  - with justification. Puffin models carry a wide range of these motors, and John Emms the proprietor will as always give excellent advice on suitable props and batteries etc.puffin

[David Ashby - Moderator]

Tim/Peter - I'm home now and the motor is here - a 16/15/6 from Puffin. It's an upmarket motor at £53 top quality and performance I should say. I did chat to John Emms about the set-up and we decided to go for a hot version. That said the model is one of those rare types that can do everything for everyman and some have used it as a trainer with a cheapie £5 speed 400 motor, some fly it with a mid-range set-up and some have put a  250 watt system in it

[Richard Cooper]

The original Terry had superb flight characteristics from a good flat glide to aerobatics.  The only problem was the strength of the wing: mine finally met its demise in a sharp pull out from a power dive done to avoid our large flock of lapwings, or plovers; they always hated the model and took off as soon as I started flying with it in order to start a dog fight!  Other models are not as threatening for some reason.  They always chase wedge tail eagles and other  raptors.    The wing snapped in half, which is reparable, but the motor/fuselage did not survive the plunge into hard ground.  Has the new Terry a good spar in the wing?

With regard to electric power trains, is there a simple table which will tell one what range of rpm to expect for each prop size?  Having read recently, (special issue RCME 2005 I think) that a given motor/bbattery set up will always attempt to mainain the revs for each prop size, I am once again in trouble trying to understand  how all the facts relating to component choice come together!

[Tim Mackey]

Simple?  you want simple !! 'fraid not Richard....there are several variables and different motors ( even with the same supposed Kv ) will drop revs diferently with different props. As an example, I have a 1200Watt 600Kv motor which on a 4s LiPo swings a 14 X 7 prop at  7600 RPm, yet with a 15 X 6 will only do 7000. Theoretically, on the 14V 4s Lipo it should swing at 8600 ( un-loaded ) If I stick a 14 X 6 on it, then it gets closer at 8100 RPM. Prop design and efficiency also affect it, as does of course the battery's ability to hold voltage.

[Richard Cooper]

Many thanks.  No wonder there isn't the information around that I was looking(hoping) for!  I gather therefore  that experimenting is the way to go.

[David Ashby - Moderator]

I'll let you know how it goes Richard, first flight soon.

[Cyberfyn]

Just ordered one for a 'keep in the car' plane. I always liked the shape of this little plane (won't be putting the Terry stickers on though!)

Got a spare Mega 16/15/4 motor, 11.1v 1800mAh Lipo and a Castle Creations Phoenix 25 ESC that should do the job. Will try the 6/3 Folder for a start, but think a bigger size will be best..... Then I'm thinking of adding alierons later and carbon bracing the wing a little more.

 Ian F.

[David Ashby - Moderator]

First flight ysterday evening - went very well - a nice aeroplane and very fast on the set-up but not too much to handle. She makes a lovely whistling noise on a motor-cut fast fly-by - just like a large glider. Need some more fly time yet but first impressions very good ......which wont come as suprise to the Terry fans out there

We got a nice set of pics and here she is...

 

 

[Cyberfyn]

When's the review going to press David?

[David Ashby - Moderator]

Looks like Aug or Sept issue.

[Cyberfyn]

Had a couple of flights on mine now................. I believe I've found the melting point of Solidpor/Elapor

 A word of warning about jamming a hot brushless motor into the front of a Terry. There is NO cooling airflow around the motor, indeed the motor will be sitting in one of the worls best known insulators! Granted, I fitted a 3 turn Hong Kong eBay special with no through cooling. Does have a nice fitted heatsink to it, not that it can do any good in the Terry.

I think Daves choice of a mild-ish 5 Turn motor is the best option. Or leave alone and fit a 400/480 brushed job.

Terry's not dead, but I have had to make a larger hole in the fuse and construct a thin titanium cage mount that allows good airflow all around the motor (Working at Rolls Royce Aero Engines has it's ups)

 Ian F.

[Tim Mackey]

You have access to titanium for playing / stealing - wow !

[David Ashby - Moderator]

How did she fly ian?

[Cyberfyn]

How does she fly? Like a little hotliner really. After a bit of trimming and a few circuits I tried started to wring her out a bit. Unlimited vertical and huge loops. The roll is as expected with rudder only, but I used longer servo horns than recommended to get a lot more throw so it will roll, but I only tried it at height. Low fast passes are great and she really whistles ! But turn the taps off and it'll stooge around at 1/4 throttle, and I even caught a thermal or two (we fly from Rolls Royce Hucknall's wartime concrete runway)

I'm well impressed, and now the cooling proplem is sorted it's a little gem. Perfect for beginners on a soft setup or hooligans on a brushless system.

 Still not sticking the Terry stickers on though.......

 And no, I didn't steal any Titanium. It all came out of the scrap bins

 Ian F.

[David Ashby - Moderator]

Yup, pretty much the same Ian - she's really grown on me these last few weeks. Vertical performance is good and she'll keep going and then tear down for a whistling pass. I did contemplate ailerons but the more I fly her, the more the model seems somehow 'right' like she is?

My motors been just fine and I'm getting good 20 min flights when climbing and gliding (on a 1100mah Li-Po)

[Old Geezer]

I have put a Vortex 28.35.2500 inrunner in the front of my Terry, about 24 quid from All Electric R/C, takes about 16A at full chat from an 1800 3S pack with a 6x3 CAM folder. Not as quick as your Mega powered Terry - but I'd got the Vortex (recycled from a Zagi), and they're half the price. Nice little plane to keep in the car and not so noisey as my FunJet.

I did try with a brushed 400 initially, but although quite pleasant for whiffling around in quiet conditions doing low and slow close-in passes, touch and goes, brushless inrunners are the way to go.

[David Ashby - Moderator]

I just love the Terry to bits, fabulous little aeroplane.

[Mark S]

My Terry is on the way to me and I'll be going with a 16/15/4 on 3 cell with the 6x3 folder although I would like a 6x4 if I could find one? I'll be adding ailerons and beefing up the wing fixing as those two screws don't look that strong! Can't wait to get it in the air

[David Ashby - Moderator]

Mark, it's worthy flying rudder/elevator first to see what you think, you may find you like her....er him enough like that. Mine flies on 170 watts and the wing bolts have been fine. About 30 flights so far.

[Mark S]

David, I was thinking of taking some dihedral out of the wing and adding ailerons for faster turns. I will not be using the rudder. Current draw will be around 20 amps with a 6x3 but a 7x4 should work fine with the 16/15/4 if the drag is low. Do you think this plane can handle 100mph with a little reinforcement as I'm after cheap speed and performance? What size spinner did you use by the way?

[David Ashby - Moderator]

Mark, she's so smooth at 50-70mph that I'd say yes to 100mph but at that speed I agree that you'd be wise re-inforcing and lengthening the wing spar and attachment bolts. The spinner came from Puffin Models, just a little carbon jobbie to match the canopy. As for taking dihedral out, Hmm not sure - I can see the reason but I'd be worried I'd spoil handling