Warbirds Replicas BF110

[Declan]

Thanks for the replies everyone.  The cons do seem to be outweighing the pros.

[Eric Robson]

I managed to get the fuselage covered and undercoated,  I am trying a single lipo in  the nose, the version I am making has 1 cannon sticking out further than the other 3.I have epoxied this one in to use for pulling the nose off for battery access, the nacelles will be retained by screws leaving the option for fitting 2 batteries if the single doesn't work out.. It is covered with Tesco birthday paper which goes on very well. Still a fair way to go.

[Murat Kece 1]

Looking very good Eric.. Well done..

[Paul Johnson 4]

On 20/12/2024 at 23:45, Eric Robson said:

It is covered with Tesco birthday paper

But it's Christmas!

[Eric Robson]

3 hours ago, Paul Johnson 4 said:

But it's Christmas!

It was my birthday,  I threw the present away and used the paper. 

[Declan]

Finally got my desk clear to start the build of this kit!  Exciting.

[Eric Robson]

Richard held the vertical sliding mount for the undercarriage in  place with cocktail sticks. He recommends using screws which will make removal over the whole unit quick and easy.  The vertical mount needs to have approx 6mm removed from the top to clear the hatch. 

 Two 2x12 self tapping screws one either side should be OK, where I have placed them should be accessible through the battery hatch. 

[Declan]

I've got a few pictures of my build so far if anyone is interested.  

[Paul Johnson 4]

It's always good to see everyone's builds, after all the effort put in to bring you these kits.

[payneib]

What's the space like for a stearable tail wheel? Looking at Declans photos, it looks a bit tight. 

 

Mine should be coming out of the loft tomorrow, as the Christmas gubbins disappear back up there. Still not sure when I'll be starting it, I've still got the big Acrowot to finish, and I'm trying to encourage some father/son bonding with the eldest over plastic Warhammer kits. 

[Declan]

4 hours ago, payneib said:

What's the space like for a stearable tail wheel? Looking at Declans photos, it looks a bit tight. 

 

 There was the option of steering the tailwheel I fitted.  However, the steering arm would have been very short.  How it was controlled would be tricky.  I did think of either a second linkage from the rudder servo or a linkage en route to the bellcrank.  Based on my location descion for fitting servos for the elevators and rudders I decided that simplicity was the best option.  I didn't want an overly complex solution that was going to cause me problems later on.  Given that the rudders are directly in the propwash I wasn't sure how much authority the tailwheel would have over the steering anyway.

[Chris Walby]

My understanding is that a steering tail wheel is not necessary as a mix with the rudder to throttles is sufficient for all taxi requirements + it saves weight at the back end.

[Ron Gray]

On my previous 110 I had exactly that Chris but with it activated by a switch, that meant that I could switch it off once airborne. It was extremely effective and gave excellent ground handling (there’s a vid of it on my YT channel). 

[payneib]

Just leave it castoring? I've done that on my Hurricane and it does ground steer. 

[Ron Gray]

Personally I don’t like a castoring tailwheel but then I do fly off a tarmac runway. Dead easy to link ESCs to rudder.

[gillyg1]

Personally, i prefer a steerable tail wheel, but then i  fly of a tarmac runway, and like taxing out and back after a flight.

Always make all my tail wheels steerable.👍

[Ron Gray]

That's exactly what differential thrust gives you 

 

 

[payneib]

No tarmac here unfortunately. I think I'll castor it and link the throttles on a switch. 

 

For IC "vectored thrust" what's the best balance for that? Restrict one engine to idle and give full throttle control on the other, or try for a full throttle range balance on both engines?

Edited January 5 by payneib
Sausage fingers

[gillyg1]

Payneib," good luck with that " think your over complicating things. But then your using petrol engines ? If i remember correctly,I have no  experience with these, being a glow man.

[Ron Gray]

If you have differential thrust then there is no need for a castoring tail wheel. 
 

I would go for 50% power on max rudder throw on each throttle servo (or esc if leccy). So on neutral rudder each IC engine will be on tickover, applying rudder will raise throttle on ‘opposite’ engine leaving the other at tickover. Obviously you can adjust the amount of throttle to see what is best suited to the whole taxi / take off / landing process. Mine was set to 100% and I also had it setup to become active when the gear was down but I changed that as I wanted control of when it was active. 

[Chris Walby]

1 hour ago, gillyg1 said:

Personally, i prefer a steerable tail wheel, but then i  fly of a tarmac runway, and like taxing out and back after a flight.

Always make all my tail wheels steerable.👍

Be interesting to see a lightweight steerable solution for the Bf110?

[Paul Johnson 4]

As an interesting topic, the P51, P47, Bf109, FW190 all had a steerable tail wheel... BUT they locked them straight for take off and still used rudder to steer. Using a steerable tail wheel can catch you out as when the tail starts to lift the rudder authority may not be enough and you can get a swing which might cause a ground loop. For those even daring to use the castering tail wheel on a Spitfire.... Good luck!

[Chris Walby]

Relevant IMO, but might seem off topic.

 

Firstly and unlikely, but it would spoil your day! Some ESC's don't like a signal beyond what they have been taught or set to. So if you calibrate your ESC with full throttle & min throttle, then if you are at full throttle and add rudder mix the signal goes beyond the the calibrated 100% WOT. In my case the ESC would emit a different noise (like the timing was out and not go to full power (until the ESC input was power cycled). Now the application and intent was to spin this model like a dinner plate which it does, but it recovers from a spin in about 15 ft (look up WooHoo). The solution was simple, just reduce the opposing motor signal via the rudder mix so just slow the motor in the direction you want to turn to.

 

The other thing is the use of motor differential in flight and in this case it was a small TN twin that had a fixed rudder ( I didn't want to add the weight and complexity of a moving rudder). I thought it would be easier to add motor differential (on a switch) and see what happened. WOW the effect is absolutely horrible as the motors try to overcome the vertical fin! Its the single worst un-scale like effect as the model tries to yaw, but pitch changes and rolls at the same time! I am sure if I had persisted to an extreme it would have spun...but this was not an easy model to do spin recovery with!.

 

I have not needed differential motor control for taxing as all of my twins ic/electric have a steerable tail wheel (single rudder) so don't see it as an issue on the ground + like the idea of switching it off when the gear is retracted. I can't quite work out  when you would want differential thrust with the gear up unless doing a very un-scale knife edge   springs to mind 🙂...perhaps an alternative to the Top Gun evasion manoeuvre to avoid a WR Tempest closing in for a kill 🤣

[gillyg1]

 

7 hours ago, Chris Walby said:

Be interesting to see a lightweight steerable solution for the Bf110?

Chris you can just about see my home made tail wheel assy in this shot. The linkage inside : tiller arm silver soldered ,controlled via a  seperate push rod from the rudder servo.

[Ron Gray]

My one had, as I've already said, batteries in each nacelle but the retracts had their own supply shared with the sound system (1300mAh 3S). The Rx took its power from one of the motor batteries but I really can't remember if I had a 'redundancy' battery for the Rx, the new 100 will have it though!

 

Btw, the 110 flies really well on one motor, I wanted to see what it was like so had one on a switch so that I could kill it mid flight.