• Administrator
  •  
    Before your membership becomes valid, you will receive an email that must be answered.
    Please check your spam folder or this email.
     

winter/next year project

Be kind to our tug pilots, we cant do without them.
Dave Whittaker

winter/next year project

Post by Dave Whittaker »

Hi People
I an planning to build a tug for next year been look at a 1/3 scale PA-18 with a DLE 111 up front, the question is will this make a suitable tow plane or should i be look at other planes for a tow plane, your thoughts would be appreciated.

Dave
john greenfield
Posts: 497
Joined: 18 Mar 2015, 07:52
Contact:

Re: winter/next year project

Post by john greenfield »

Dave

This is never an easy question to answer as it depends on what sort of towing you are intending to do and what size gliders you want to tow. If it is just occasional towing with reasonable size gliders then almost anything will do but if you are thinking about serious towing at glider meetings then something more specialised may be more appropriate. attendance at any aerotow meeting will demonstrate that the most consistent and reliable tugs are sport models with big engines. you only have to look at the difference and ease of operation of the SDD Greenley tugs at MW yesterday compared to the "fun" Ray had with his scale Decathlon, The Greenley's just laughed at the wind whereas the Decathlon struggled.

"Cub" types have their own challenges in cross winds and a PA18 at 1/3rd scale will be quite a big model. A DLE 111 on a good exhaust (not stock) system will have enough power for normal size models but you may struggle with some of the 40% and 1/2 scale models.

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
Dave Whittaker

Re: winter/next year project

Post by Dave Whittaker »

well Now i am not sure what tow plane to do, thought the Decathlon would have handled the wind ok, mite look at a BIDULE 111 or some thing similar for my first purpose tow plane and put the super cub on hold for now.

Dave
User avatar
Ray Watts
Posts: 128
Joined: 18 Mar 2015, 06:31
Location: Basingstoke

Re: winter/next year project

Post by Ray Watts »

Hi Dave
The big question is always scale or not.

Scale is pretty but can be expensive and fraught with lots of maintenance, whereas sport is ugly but much more practical.

My new Hanger 9 Decathlon is roughly the same wingspan as the 1;3.5 Wilga, but getting on for twice the wing area, and it is nearly 6kg lighter than the Wilga. The problem comes in on a breezy day like yesterday, where you are trying to land quickly and it is just too floaty. Great for small fields and light wind days but taxing near the ground. The Wilga is a much better all round proposition but Frisch does not want to deal with the UK and the Tomahawk kit is very expensive, so that leaves Colin Bonds plan which is a big build with a tricky undercarriage. And therein lies another big problem.

A good day for a glider pilot would see around 8 flights, so that's 8 landings, whereas a good day tugging might see 60 tows or more, so that's 60 landings, and landings on an over engined powerful tug make the whole plane and uc take a battering. It's usually landings in one way or another that kill planes. The Wilga uc is quite complicated and prone to failure. Pretty to watch when working well, but an early trip home when it goes wrong.

The sport planes are much more suited to the pounding that towing throws at them, but it's just whether that's your cup of tea or not.

A one third Cub on a 111 or DA100 will be very powerful until you hook up a big glider to it and all of a sudden it might seem a bit slow.

The main things to remember are that you always need to stay in front of the glider so speed can be your friend on a strong, heavy glass glider, but at the other end of the spectrum, always be prepared to use your throttle for the lightly loaded woodies.
Never overestimate the power of your tug in trying to climb too steep. A glass glider pilot will not thank you when it tip stalls and falls off the tow.
And always be willing to say that you are not happy to tow something which you think is too heavy or too light for the tug that you are using. The glider pilots will normally thank you for your consideration.

So scale or not. The choice is yours. There is no easy answer. But the easiest way to dip your tow in the water is with a sport model, especially one that has been designed for the job in hand.

Oh, and use the most powerful release servo that you can afford. Trust me, you may be relying on that one day.

Probably confusing, but nobody said it was going to be an easy choice ;)

Ray
It's always calmer indoors :D
Dave Whittaker

Re: winter/next year project

Post by Dave Whittaker »

Thanks John and Ray think will have to go sports type for now with a big lump up front would like to go scale and there is plenty of time for that the always next winter
Thanks Dave :D
john greenfield
Posts: 497
Joined: 18 Mar 2015, 07:52
Contact:

Re: winter/next year project

Post by john greenfield »

As a purpose designed glider tug, you could do a lot worse than an SDD Greenley with a DLE 111 on the front. Plans for the model are available as a free download from this site and a set of CNC cut wing ribs and other parts are available from the Ghost Squadron.

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
Dave Whittaker

Re: winter/next year project

Post by Dave Whittaker »

John do you know how much the CNC cut wing ribs are with a set of plans please for the SDD Greenley , I did have a quick look on ghost squadron web site but did find any prices thanks

Dave
john greenfield
Posts: 497
Joined: 18 Mar 2015, 07:52
Contact:

Re: winter/next year project

Post by john greenfield »

Dave

Drop a line to Alan Carter at alancarter1@sky.com. He is the GS team member who has the CNC machines and does all our cutting so you can discuss what you want cut. He can also supply plans if you want.

Regards

AEB
AEB = Aeronautical Energiser Bunny (with thanks to CW)
Dave Whittaker

Re: winter/next year project

Post by Dave Whittaker »

Thanks John
Post Reply