Aerotowing newbie

[Chris Bott - Moderator]

Once it's embedded you can change the size in the forum just by right clicking in edit post. 450 wide seems to be the best setting.

Or for a new vid, you can set the size as you are getting the code.

[Chris Bott - Moderator]

I should be telling you off! but it's your thread...

We have some Tim style tutorials here and even a thread to practice in..

Have a look at the one for links - that has really changed..

[Tim Mackey]

Got it

Sussed the links thing ages ago mate.

Edited By Tim Mackey on 29/05/2012 22:51:47

[Danny Fenton]

Really enjoyed the vid Tim, some great flying by glider and tug

[Tim Mackey]

[Tim Mackey]

Something odd here. I typed a long post detailing all the tug / flight experience, then added a few pictures from the album, and the text has all disappeared!

[Chris Bott - Moderator]

Sounds very odd Tim, and sounds really annoying!

[Tim Mackey]

Just re-doing it in word now Chris

[Tim Mackey]

We are both relatively inexperienced at aerotowing, but thankfully experienced pilots. The main issues are

1. Keep the wings level on the glider
2. Keep above and in line with, the tug
3. Watch the towing speed

 

If the speed is too high, the glider can try to get in front of the tug- not good!

Also if the line is too short, the glider can oscillate and porpoise, and that makes it hard for the tug pilot too. Our first couple of attempts resulted in a few tweaks, although the flights were fine. I reduced the CAR, and also added tailweight, as I found myself “hanging on the elevator” a bit. We also used a stronger and thicker towline harness at the glider nose release as the first one broke (and was never found) in the early part of the climb – both models landed safely. I found the roll response a little odd – seemed to have little effect, then suddenly….too much, so I removed almost all the expo on aileron. It still feels a little odd, so I may try adding back a bit more CAR. The baby flies really slow and looks very majestic in flight. I was really pleased with the dolly, my fears of too narrow a wheel track proving unfounded. I had also added a couple of pounds of lead sheet to the underside, to help ensure it stayed on the ground at point of rotation – worked fine. ROG happened very quickly as can be seen from the video. With a brisk side wind across the strip, I used almost full right aileron right from the off - to keep the wings level, with a bit of left rudder to aid tracking. Fifth flight I stretched things a little too far and found myself in “sink” as I was on finals… I didn’t quite make the field, landing somewhat un-ceremoniously in a hedge which runs alongside a stream separating our filed from the neighbouring corn crop field. I walked around to recover her, and found her sitting straight and level about 4 feet up in the bush – not a mark on it!

Unfortunately a broken prop ( £80 ) on the Maule halted any further flights, but all in all, well pleased.

Edited By Tim Mackey on 30/05/2012 09:46:41

[Olly P]

Great video Tim.

Just a comment from my Full size glider experiance. you will tend to overshoot a lot less if you try and keep the glider level or just below the tug during the tow. As my instructor said - from the cockpit you should be looking at a tailwheel and cross!

this does a couple of things - it makes it harder to overshoot or spin off the line in a turn, it also makes it easier for the tug pilot to control his attitude - if you are towed behind and high above it tries to tip his a/c nose down - not good.

When flying fullsize the strangest bit of towing is initial ROG - the glider floats about 5-10 feet up until the tug is away - any higher and the tug can't rotate as you are pulling his tail up!

[Chris Bott - Moderator]

Olly doesn't it depend on where the towing point is on the tug?

What I've seen of model glider towing has the line attached at the top of the fus, around the C/G area. This is to minimise, how much the glider can affect the tugs attitude. So flying slightly above keeps the line clear of the tail.

[Tim Mackey]

Good points Olly - thanks. I assumed the reason for keeping the glider above the tug on the tow was to prevent the line from pulling down on the tug elevator - the fin has struts to keep it clear from that, but what about the poor old elevator?

[Tim Mackey]

Chris beat me to it.

The tug does indeed have the tow attached right on the COG on the fus top.

Edited By Tim Mackey on 30/05/2012 10:12:40

[Olly P]

Ah - in that case no problem with the glider being higher - I'm used to the tow rope being mounted low and to the rear.

move along.....nothing to see here....

[Delta Whiskey]

You may notice in my thread **LINK** on here you can see a small white tube just behind the CoG where I fitted my line release servo on the Tug, I did not even notice I was towing anything !

 

Edited By Delta Whiskey on 30/05/2012 10:35:38

[Martyn Johnston]

Great vid Tim, my Grunau's coming along well but I think I'm about a year behind you.

I just bought a 1:4 scale pilot for mine last week and he looks huuuuge. Yours looks tiny in comparison.

[Ian Jones]

The RDMFC Aerotow is only a week a way, will I be ready in time??

Well it will be a close thing but yes I think so.

I've taken out the nose weights to reveal the hole that already existed in the nose:

I then enlarged the hole to accept the barrel of the tow release and jigged it up in a cradle to ensure a smooth action in the right direction:

I made an extra plate for the tow release servo, epoxied it in and fitted the servo:

I will either fit a snake outer to protect the push rod or make a bridge so that the battery can sit on top without interfering with the release mechanism.

There's some calm weather forecast during the week so if I sort the CG out and get a few test flight in that will be it - A55 here I come!!

Edited By Ian Jones on 23/07/2012 00:51:38

[Ian Jones]

Finished - I hope - test flight today.

Battery will sit on bearers:

and fits nicely:

This model seesm to be quite CG sensative and I have some batteries on order that are 12 grammes heavier than the one shown so balancing weights will have to be removable:

Here's hopin

[Ian Jones]

Well I spent ages balancing it this morning and it was worth every moment .

Motor raised or lowered it flew very nicely, best setup I've had. Only problem is that I've had to sacrifice my flaperons to have a channel for the tow release. Hope there's a long low approach available at Rhyl .

[Ultymate]

If the wind is a westerly Ian you can come in low over Liverpool

[Ian Jones]

As long as I don't end up needing a different soprt of tug - across the Mersey - that will do it .

[Ian Jones]

I was planning on airbrushing in some artwork but I've run out of time. I may still do it later but for now this is it - Rhyl Ready!

[Ian Jones]

Yipeee.

Made it to the Rhyl Aertotow and survived (almost intact). First flight no problem, yes my first ever aerotow passed without incident.

2nd & 3rd attempts resulted in rold sto inverted without getting more than a foot off the ground - loast a wing tip and cracked a motor door in the process.

Took both motor doors off and taped up the wing tip for the 4th attempt, this time with the help of Tim Mackey holding my glider aloft to ensure it got away with the wings level and it worked. A good long flight in some thermals.

5th attempt equally good.

For the 6th attempt I'd spotted some lovely blue sky coming over, waited for and up I went. Probably towed hight that I'd been before and released the tow. No problem except that as I did so my glider left the cloudy backgorund and into the blue.... somewhere. It just seemed to melt into the blue. I rolled the wings and got sight of it and headed back under a patch of cloud and that was fine. Well it was still quite beezy and the cloud soon disappeared and the glider verty nearly did too. I was wearing high viz specs but it was stiull a problem. Anyway I rolled it on it's side again and being able to see the shape it was safe to push the nose down and get some height off.

So 4/6 attempts had me airborne and the only real drama was that last flight when my expected good visibility under the blue sky proved to be quite the opposite.

I've no photos of my flights but I did run off a few snaps of others so I'll post them on the RDMFC Aerotow thread.

[Ian Jones]

Has anyone ever replaced the motor mount on the ST DG1000?

If so, how did you go about it?

I've got the repair pack which also has the rest of the assemebly but I only need to replace the legs.

It's looking like a lot to do for a seemingly common problem.

[Ian Jones]

Posted by Ian Jones on 06/09/2012 18:11:59:

Has anyone ever replaced the motor mount on the ST DG1000?

If so, how did you go about it?

I've got the repair pack which also has the rest of the assemebly but I only need to replace the legs.

It's looking like a lot to do for a seemingly common problem.

The problem is that the prop stop breaks away taking part of the motor mount legs with it and to be able to get the intended use out of the glider this needed to be fixed.

Either I'm missing something but I couldn't see how to remove the the old mount and install the new one without some major surgery and in the end decided to try for a repair job instead.

This amounted to using carbon fibre to replace the broken parts of the mount legs and using epoxy putty to fill and shape. This still left the problem of fitting the prop stop which will probably break off again anyway - solution rather was rather simple, a piece of fuel tubing fastened in place with wire ties.

This is still work in progress so far as making it look pretty goes but I had four flights with it like this today with no problems at all.

In the upright position the fuel tubing is out of the way:

In the part parked position where the old prop stop came into play the fuel tubing now projects forward and does the job instead:

 

So some more smoothing and testing and I think I will be happy to re-fit the doors. Of course I'm hoping that this fix will last much longer than the original.

Edited By Ian Jones on 14/09/2012 01:15:00