Which servos would you choose?

[David Davis]

When I first moved to France, out of twenty members in my club there was only one other Mode 2 pilot and he lived in the South of France so only rarely turned up.Since putting on a flying display in the village of Sazeray last year we attracted two new members, two brothers,Pascal and Jean-Luc. Bizarrely, Jean-Luc is Mode 1 and Pascal is Mode 2! However, Pascal had never successfully flown a fixed wing aircraft, but he could fly a drone, so I took him up on my Stick with wirelessly-linked transmitters. He did alright and has now bought his own trainer. I've also been training one of our Belgian novices who's Mode 1, but like Pascal, he has done a bit of flying in the past. He has to concentrate very hard so after about ten minutes his flying starts to get a bit ragged but he's making progress and gaining in confidence. I may also have another Mode 2 novice to teach, if the lad decides to join. As a result of these developments, the club has given me a brand new ARTF trainer, something called a Lanyu Primary 40. It's the usual sort of thing, a 5 ft high wing monoplane,four channel, tricycle undercarriage etc. I will supply a receiver and a red Irvine 40 from among my engine collection and the club will reimburse me for expenses involved in buying servos etc.

I was thinking of buying four HiTec HS311 servos but maybe I should fit a servo with Karbonite gears to the rudder channel as those novices may be bending the nose-leg quite a bit.

What is the collective wisdom?

Edited By Pete B - Moderator on 16/02/2017 17:37:25

[TIM Shaw]

Hardly relevant to mode 1 or mode 2, but since you ask....

My preferred route would be to ditch the noseleg, move the mains forward to the LE or just in front, maybe fit a tailskid, and fly it as a tail dragger. In the past, our club field was rough grass and steerable noselegs are a pain on that surface - even now, when our field is miles better than it was, my Dynam Meteor noseleg is a constant source of maintenance.

Option2 would be stick with the noseleg, but lock it straight ahead and forget the steering.

Limited experience of Karbonite - when they first came out one of our more progressive members turned up with a couple on the elevons of his 60" EPP slope wing. Stripped first flight, after a not too bad landing, so I've never bothered with them since. If I need stronger gears I go straight to MGs.

JMTC - feel free to move this post if its in the wrong place!

Edited By Pete B - Moderator on 16/02/2017 17:32:25

[Bob Cotsford]

Me, I'd fit a separate metal gear servo to drive the noseleg, coupled to the rudder either through tx mixing or a simple Y lead. It wouldn't need to be an expensive servo, a midi sized one would do. Alternatively fit a single standard metal gear unit for mechanically coupled n/l and rudder, maybe an MG996R or as the club are paying, a HS645MG.

Edited By Pete B - Moderator on 16/02/2017 17:33:14

[Denis Watkins]

When you see the model heading for the Pitts, from an erratic landing

You will wish that you left that noseleg steerable !

Edited By Pete B - Moderator on 16/02/2017 17:34:20

[TIM Shaw]

And when it fails on the take-off run, and heads for the pits, you'd wish you hadn't!

Edited By Pete B - Moderator on 16/02/2017 17:35:10

[Ian Jones]

Posted by TIM Shaw on 16/02/2017 10:29:17:

Hardly relevant to mode 1 or mode 2, but since you ask....

My preferred route would be to ditch the noseleg, move the mains forward to the LE or just in front, maybe fit a tailskid, and fly it as a tail dragger. In the past, our club field was rough grass and steerable noselegs are a pain on that surface - even now, when our field is miles better than it was, my Dynam Meteor noseleg is a constant source of maintenance.

Option2 would be stick with the noseleg, but lock it straight ahead and forget the steering.

Limited experience of Karbonite - when they first came out one of our more progressive members turned up with a couple on the elevons of his 60" EPP slope wing. Stripped first flight, after a not too bad landing, so I've never bothered with them since. If I need stronger gears I go straight to MGs.

JMTC - feel free to move this post if its in the wrong place!

Oh dear I thought that outdated way of dealing with noselegs had died out. If the landing the strip is rough and/or the model is particularly poor then consideration has to be given as to if that model appropriate. Changing the undercarriage does not cure anything and it can give the impression that is has helped but it just creates more problems (broken propellers, main undercarriage detaching with complaints about the quality of the same, continued landing difficulties and poor low speed ground handling). In some cases modellers end up only flying tail draggers in the belief that all steerable noselegs are trouble and they aren't; they do have a very good purpose though.

The most common causes of noseleg trouble are having the model nose heavy and trying to land before learning how to flare the model properly. The former is totally unnecessary as any experienced modeller should be able to balance a trainer properly and any decent trainer a fraction on the tail heavy side would not be particularly hard to fly/land/rebalance. The fear of a tail heavy trainer is unrealistic these days. In the case of the latter, spending time on low speed, low passes to learn how to get a correctly balanced model properly setup for landing, is time better spent than on fixing something that doesn't need fixing (unless this advice is ignored).

Yes there was a time when some trainers had poor undercarriages but these days with a decent trainer and a decent instructor the noseleg should not be an issue.

Edited By Pete B - Moderator on 16/02/2017 17:36:24

[MattyB]

Any old standard servo should be fine - 311s are as good as any. I've certainly never seen one broken, but fit an MG version if you are worried.

Edited By MattyB on 16/02/2017 12:22:43

[Denis Watkins]

Just bend in a spring "kink" in the steering wire if it gives concern David, but otherwise I feel bendy metal steering gear pushrod is enough. They are not on the ground that long, but I do understand it can take time for some to get the "flaired landing" right.

Apart from the steering gear, the whole craft is exposed to novices, and we do our best

[Jon H]

Hitec 311's will be fine. If they hit the ground hard enough to damage the servo i doubt the rest of the model will be intact enough for it to matter!

[Denis Watkins]

Ditto Matty B,

He is the Man

[David Davis]

Actually I'm lucky enough to fly off this.

Edited By Pete B - Moderator on 16/02/2017 17:38:16

[TIM Shaw]

In that case, anything should be fine!

You asked for opinions, mine and Ians happen to be different, that's all, and I confess my training experience was mostly in the late 1980s when certainly a couple of High wing "Trainers" with dodgy noselegs may have caused me to form what is now an outdated one.

I make no apologies for my Luddite tendencies though - part of the local history round here.....

Edited By Pete B - Moderator on 16/02/2017 17:39:09

[Ian Jones]

Quite agree.

Nice strip though.

Edited By Pete B - Moderator on 16/02/2017 17:40:01

[Bob Cotsford]

With that strip there's no need for anything more than a standard servo, but I would fit a nylon or wire skid below the tail to save the rudder!

[David Davis]

Posted by Bob Cotsford on 16/02/2017 22:51:15:

With that strip there's no need for anything more than a standard servo, but I would fit a nylon or wire skid below the tail to save the rudder!

Yes but the strip is only ten metres wide.

When I fist arrived here I was used to the wide open spaces of my English club and wrecked a few undercarriages on the grass glider-landing strip alongside the tarmac. Our main trouble is that the field is home to thousands of moles!

However, my landings have improved immensely over the eighteen months I've lived here and I normally land on the tarmac these days.

I may well take up your suggestion of some sort of skid to protect the rudder, maybe the wing-tips too.