converting veron robot to 2021 radio control

[aduncan]

My flying buddy has just built a veron robot and fitted with rudder, elevator and throttle (electic motor). On its maiden flight yesterday it was a handful, it continually rolled side to side and was a bit of a pig.

 

I wondered if the dihedral should be less than with the original escapment system.

 

Advice anyone?

[Shaun Walsh]

I wouldn't change the dihedral.

Is the COG correct?

What motor/prop combination is fitted. Does the rolling reduce if you throttle down? I have seen a model do this before, vastly overpowered KK Outlaw would oscillate madly around the roll axis until it was flying at speed or throttled down, caused by the torque produced by a large motor swinging a big prop.

[aduncan]

The cg is going to be checked, and it has plenty of power. Although it seemed not to be flying very fast. Maybe try a smaller prop.

[John Wagg]

This is known as "Dutch Roll". (I don't know why it's called that. ?) Make sure the CoG is correct to start with.

The simplest way to control it is to reduce the rudder throw. I do mine by using duel/triple rates on the Tx but altering the linkage connection can also work to reduce the throw of the rudder. (Reducing the dihedral will have the same effect but dihedral is still required for control to work.)

Basically it will be just gentle turns, figure of eights, maybe loops, low slow passes & stall turns.  

Remember this is basically a free flight model and use the RC just to keep it within the park.?

 

Edited September 19, 2021 by John Wagg

[Peter Christy]

I have a Veron Robot powered by an OS 15, which I bought from the estate of a deceased clubmate, and it is a delight to fly - just like my original was back in the 60s.

 

I normally use it to fly with my 2.4 GHz converted Grundig "reed" set (bang-bang, not proportional), however I occasionally switch it back to my Taranis (proportional, rudder, elevator and throttle) to let beginners have a go on the sticks.

 

Those who have flown it marvel at how easy to fly it is compared to modern "trainers"!

 

I would suggest that first you check the CofG, as suggested above, and second check the control throws. It doesn't need a lot of movement on either elevator or rudder, and its possible you are over-controlling it - especially if its a bit over-powered! Try switching some rates in (60%?) and see if that helps. Use the rate switches rather than mechanically adjusting it initially, just in case! ?

 

Also once airborne, throttle it back to a point where it is maintaining altitude, or only slowly gaining height. The original was designed for 1.5 to 2.5cc engines. Whilst you would have had to build it very light to fly on 1.5cc, 2.5cc (=250watts approx) flies it very nicely.

 

The Robot is one of the best trainers ever designed, and works perfectly well with modern equipment. If yours is misbehaving, there is a reason!

 

--

Pete

 

[aduncan]

Thanks everyone for the advice, which I will pass on to my mate. The Robot was his first radio model way back in the year dot, and he says it flew fine with rubber powered escapements.

 

Andrew

[FlyinBrian]

The Veron Robot was my first powered rc model, it was designed for single channel rudder only and I flew it with RCS single ch and a conquest escapement. Power was a Frog 150 (1.5cc) diesel

 

It ended up with three channel propo and a 2.5cc Taifun Zyklon diesel, it was a delight to fly. As suggested reduce rudder throw and check the CG is correct.

 

Don't alter the dihedral unless you fit ailerons - it gives stability.

 

Edited September 19, 2021 by FlyinBrian
Additional info

[Engine Doctor]

The Veron Super Robot was an excellent 40 sized 4 channel trainer if you wanted to upgrade .  My youngest son learnt to fly very quickly with a very nice second had one bought from local model shop  back in the late 80s . Very stable even in gusty windy conditions and very robust construction with no vices. 

 

I never flew the Robot 3 channel version. Dutch Roll could be caused by a high incidence angle of the wing .  Try packing up the trailing edge by small increments and test until your happy then adjust the wing seating permanently. The high angle of attack or incidence is from the original design for a slow glide on free flight models . A lot of vintage designs suffer the same issue when converted for rc flying .

 

Why don't  model manufacturers make something like them today ? Us flying teachers are constantly trying to teach new flyers who turn up with foam models that are just too light and get buffeted around in gusty condition robbing them of stick time.

[Alan H]

I flew a Veron Robot powered by an OS15 and controlled by Galloping Ghost back in the day. It was an absolute delight to fly. As others have said, check CG and control movement. Too much rudder movement can lead to Dutch roll with rudder/elevator controlled models through over control. Setting up rates and use of expo recommended.

[J D 8]

              While there is no definite answer as to  where the term " Dutch roll "came from it is thought it comes from the action of a speed skater, something the Dutch are still good at.  It may be early aircraft makers [ Fokker ? ] came up with the term. 

[Robin Colbourne]

The Veron Robot plan (below) shows considerable downthrust and some side thrust.  If these had been omitted when installing the electric motor it might cause problems.

 

The Precedent Flyboy, the three channel smaller brother to their Hiboy, used to dutch roll immediately after take off on the climb out, but would settle down once airborne and throttled back.
 

[Barry W]

I looked at the plan and instructions on the Outerzone web site. They say that for the for the Robot to fly correctly it is important that some "reflex" be built into the wing trailing edge by packing it up 1/16 on an inch. I have never come across this before but they say this is important. So if the plane is still not flying correctly check that the wing has the requited reflex built into the trailing edge.

[Outrunner]

Barry, is reflex another word for washout, possibly American?

 

[Peter Christy]

Not really. Washout refers to a twist in the wing, reducing the angle of incidence towards the tip. It is intended to reduce tip-stalling, and usually only necessary on tapered (or swept) wings.

 

Reflex is a slight upturn in the trailing edge of the entire wing. On model like the Robot it has the effect of reducing "zooming" - a tendency to climb when exiting a turn, usually where the speed has built up a bit.

 

Remember, the Robot was originally designed as "rudder only" - no elevators! Controlling this zooming tendency was quite important on trainers with no elevators.

 

Whilst not strictly necessary when elevators are fitted, it nonetheless reduces the strain on novice pilots, and is one of the things that makes the Robot such a benign trainer.

 

--

Pete

 

[PatMc]

IMO, the reflex isn't necessary at all, also since the model has throttle control the downthrust isn't important. When designed most suitable engines didn't have throttles but even if a throttle equipped engine was used the control would be by a primitive 2 or 3 position escapement. Certainly neither reflex or downthrust will have any effect on dutch roll. 

Incidentally the Robot was designed for RC it was never intended to be flown FF.

I built mine around 1998 and remembered an article in the RCM&E about a club group who used multi channel reed gear with full REAT control so I did the same but with then up to date 35meg gear. I found a copy of the article several years later & found my aileron mods were similar to theirs. The engine was mounted on a paxolin plate in order to experiment with different engines, from memory these included a Yin Yan 2.5 diesel, PAW 3.5, Fox 15 & Enya Mk4 09. It flew best on the Fox but the throttle was always iffy, the Enya was nearly as good on power & had a reliable throttle.

Around 2005 I modified the Robot for electric, initially with a power rating of 115 W/lb, which proved to be more than any of the previous ic set ups. I've since refurbed it & downrated the power to about 60W/lb. The model has proved nicely aerobatic a delight to fly in with every power chain used so far.  Never experienced any sign of dutch roll & BTW it will roll nicely using rudder instead of ailerons despite the reduced dihedral.

 

 

Edited September 21, 2021 by PatMc

[Peter Christy]

Nice looking Robot, that!

 

--

Pete

 

[David Ovenden]

13 hours ago, Barry W said:

I looked at the plan and instructions on the Outerzone web site. They say that for the for the Robot to fly correctly it is important that some "reflex" be built into the wing trailing edge by packing it up 1/16 on an inch. I have never come across this before but they say this is important. So if the plane is still not flying correctly check that the wing has the requited reflex built into the trailing edge.

Don't want to "muddy the waters" regarding the reflex issue. I don't disagree with what has been said by Peter and PatMc. But my take on this, is that it was to simplify the building of the kit. Why? The plan data box states it has an N.A.C.A. 2412 wing section. That is a bi-convex airfoil. The plan show a wing section with a distinctly flat, straight lower rear profile. Do doubt that was to make building the wing over the plan easier for beginners. The packing up of the trailing edge (reflex) was to give some sort of approximation to the NACA 2412 section that Phil Smith used on his original design. I could be wrong, but it makes sense to me!

I too am looking at building a version of the Robot for 4 channel radio with a classic Enya15 engine for power. I will modify mine to have an accurate NACA 2412 section and see what happens!!

[PatMc]

David, the wing underside is open structure without even sheet between LE & spar, the top surface is also open structure but with sheet between LE & spar. Unless you completely sheet the wing it's not going to have the stated NACA 2414 section due to covering sag.
IMO it would make more sense to sheet the underside LE to spar, that would at least maintain a NACA section up to the spar & also stiffen the wing structure. It's one of the mods I made when building mine. 

 

PS mine will hold inverted beautifully with just a smidgeon of down elevator held in.

Edited September 21, 2021 by PatMc

[David Ovenden]

1 hour ago, PatMc said:

 Unless you completely sheet the wing it's not going to have the stated NACA 2414 section due to covering sag.
IMO it would make more sense to sheet the underside LE to spar, that would at least maintain a NACA section up to the spar & also stiffen the wing structure. It's one of the mods I made when building mine. 

 

PS mine will hold inverted beautifully with just a smidgeon of down elevator held in.

Don't disagree with you Pat. I was going to sheet the underside to the spar. I just find the kicked up TE a bit strange and whilst cutting ribs it's no hardship to make them true NACA 2412. With strip ailerons one could add reflex  ( if you really need it) just by adjusting the quick links.

 Got to build the model now!

[Peter Christy]

One point worth adding: the reflex is also probably unnecessary if you fit the model with ailerons!

 

On a rudder-only model, as the model banks the rudder also has a "down elevator" effect. This is why the speed can increase in turns. Back in the days of single channel (when the Robot was designed) much of the time, the model was left to straighten itself out, following a turn. Due to the increased speed from the aforementioned "down elevator" effect, the model would pitch up a bit when recovering. The effect was even more noticeable if you applied opposite rudder to stop the turn, as this produced an "up elevator" effect.

 

Reflexing the trailing edge slightly reduced this effect noticeably.

 

Ailerons generally suffer slightly from "adverse yaw", where the model slightly yaws in the opposite direction to the applied aileron. This is why many sport models use differential aileron - more up than down - to correct for this. Without the nose down pitch in a turn, there is less speed build up and less need for reflex.

 

Similarly, many models of that era have steeply raked rudder hinge lines - the Robot has a noticeably raked rudder. This was an attempt to introduce a slight "up elevator" effect when rudder was applied into a banked turn, again reducing the speed build up.

 

The combination of the raked rudder and reflex gives the Robot a very benign rudder response, one of the reasons it makes such an excellent trainer.

 

Whilst I'm no purist, adding ailerons and reducing the dihedral does draw attention away from its very clever design!

 

I do wish someone would start kitting it again! It was a far better trainer than most of today's models, and the quality of the original Veron kits was superb!

 

--

Pete

 

[Shaun Walsh]

"I do wish someone would start kitting it again! It was a far better trainer than most of today's models, and the quality of the original Veron kits was superb!"

You mean like this?

Veron Robot kit

[Alan H]

19 hours ago, David Ovenden said:

Don't want to "muddy the waters" regarding the reflex issue. I don't disagree with what has been said by Peter and PatMc. But my take on this, is that it was to simplify the building of the kit. Why? The plan data box states it has an N.A.C.A. 2412 wing section. That is a bi-convex airfoil. The plan show a wing section with a distinctly flat, straight lower rear profile. Do doubt that was to make building the wing over the plan easier for beginners. The packing up of the trailing edge (reflex) was to give some sort of approximation to the NACA 2412 section that Phil Smith used on his original design. I could be wrong, but it makes sense to me!

I too am looking at building a version of the Robot for 4 channel radio with a classic Enya15 engine for power. I will modify mine to have an accurate NACA 2412 section and see what happens!!

This was my understanding as well. A semi symmetrical section is less prone to ballooning with a rudder only model. It also enhances the aerobatic capability if elevators are also fitted.

[PatMc]

1 hour ago, Alan H said:

This was my understanding as well. A semi symmetrical section is less prone to ballooning with a rudder only model. It also enhances the aerobatic capability if elevators are also fitted.

"Ballooning" is a characteristic of a forward cg position, very little to do with the wing section.