Tail Wheel Steering, Springs vs Fuel Tubing or other setups

[IMAC FANATIC]

Question, the ball link adaptors on the ends, where are those from? The ones at the horn and tiller base.not sure how positive steering would be with that but it makes sense to at least try. 

 

[Terryscustom]

The_Wreck said
The most full proof method with the least amount of slop and positive steering is a direct drive setup.

I actually like the theory of the direct drive but have never had one hold up in the long run on a 3D plane, but I've never tried one of yours.      Actually just ordered a couple more J&J's and one is for my 108" 3DHS that is set up for the direct drive.....never even gave it a thought.

Cool shock idea, curious if it is cost effective and if it's purchased or hand made.      Looks like the internal spring gas shocks for RC cars are WAY too much $$ for my tailwheel budget.

 

[stangflyer]

IMAC-FANATIC said
Question, the ball link adaptors on the ends, where are those from? The ones at the horn and tiller base.not sure how positive steering would be with that but it makes sense to at least try. 

Terryscustom said

The_Wreck said
The most full proof method with the least amount of slop and positive steering is a direct drive setup.

I actually like the theory of the direct drive but have never had one hold up in the long run on a 3D plane, but I've never tried one of yours.      Actually just ordered a couple more J&J's and one is for my 108" 3DHS that is set up for the direct drive.....never even gave it a thought.

Cool shock idea, curious if it is cost effective and if it's purchased or hand made.      Looks like the internal spring gas shocks for RC cars are WAY too much $$ for my tailwheel budget.
I am not certain of where the ball links are from. As I mentioned, this was my friends set up. They are in fact hand made. I believe he purchased the shocks from rc4wd.... then did some retrofitting. Changing up the springs inside to get just the right load tension both directions. They are spring loaded both in and out on the shaft, so it turns out the steering was very positive. Look cool as heck. But you are very correct Terry, kind of spendy. I looked up the shocks that were fairly close to what he purchased. About $35.00 per set. I did some modifications to my setup and tested it out today. Yeah, pretty much sucked as badly as before. So I am back to square one. I really feel the direct drive system is probably the most positive of all systems, as mentioned. 
At present I am toying with some surplus Robart Air cylinders that I no longer use. Bought them new for a project but the plane never flew soooo.... I have a plan. Yikes....

 

[The_Wreck]

Terryscustom said

The_Wreck said
The most full proof method with the least amount of slop and positive steering is a direct drive setup.

I actually like the theory of the direct drive but have never had one hold up in the long run on a 3D plane, but I've never tried one of yours.      Actually just ordered a couple more J&J's and one is for my 108" 3DHS that is set up for the direct drive.....never even gave it a thought.

Cool shock idea, curious if it is cost effective and if it's purchased or hand made.      Looks like the internal spring gas shocks for RC cars are WAY too much $$ for my tailwheel budget.
I have a direct drive titanium on my 40% Carden for 3+ years and have not had any maintenance on it.  Our steering wire design (now copied by others) that pivots as the tailwheel flexes eliminates the breakage point that was common on other direct drive systems.  I actually prefer to have the pivot point of the tailwheel about 2" back of the rudder hinge line, it gives more turn with less rudder movement and allows for great taxiing on low rate rudder.

Another advantage is that it puts zero load on the servo in flight, unless you run the springs really loose or the geometry is perfect, they will impart some load on the rudder servos when the rudder is deflected.  This would be my primary concern with using a shock linkage like what is shown above, I cannot believe that the geometry between the rudder tiller and the tailwheel is perfect, so you are using some of your rudder servo power compressing the springs in the shocks while in flight.

The absolute cure for perfect steering and no load on the rudder is to add a separate servo for just the tailwheel, but who wants the added weight.

 

[Pistolera]

Yeah...if you're gonna add a separate servo, use it for something cool...like turning the pirate's head !!!! 

 

[stangflyer]

The_Wreck said
Another advantage is that it puts zero load on the servo in flight, unless you run the springs really loose or the geometry is perfect, they will impart some load on the rudder servos when the rudder is deflected.  This would be my primary concern with using a shock linkage like what is shown above, I cannot believe that the geometry between the rudder tiller and the tailwheel is perfect, so you are using some of your rudder servo power compressing the springs in the shocks while in flight.

The absolute cure for perfect steering and no load on the rudder is to add a separate servo for just the tailwheel, but who wants the added weight.
This too has been a concern for me. I don't want any load on the tail wheel in flight. I can not speak first hand of the geometry of the shock type system, But looking cool is not enough for me. It seems that last couple of weeks have been a nightmare for me. I have tried just about every configuration of springs and geometry and tension I can dream up. Either it is too tight, too lose or just plain sucks all the way around. Both my 50cc'ers  have direct drive and work great. I've just been trying to stay as scale looking as possible on my big birds. But what ever the cost, I want to get it nailed down before I put the new Sukhoi up. And come to think of it, Don't think the idea of separate servo has not crossed my mind. I just almost did it until I realized there was no place in the back of my fuse to put one. The extra weight would not have bothered me. I have weight back there any way to balance. Would simply have removed it to counter act the servo weight. I may end up going over to the dark side. Fuel tubing or a J&J direct drive system. I am so done fighting the tail wheel steering issue. 

Pistolera said
Yeah...if you're gonna add a separate servo, use it for something cool...like turning the pirate's head !!!! 

Oh yeah, I thought of the turning head idea too... Maybe on the next one. LOL

 

[Jetpainter]

Only if can spin all the way around in a really creepy manner.

 

[Pistolera]

I've had the standard style compression springs setups on 3 different planes and have never had any major issues.  Set them up so they are just shy of slack (not tight, but not loose) when the tail wheel is off the ground.  When resting it will have a little bit of slack, but still provides good steering, at least on higher rudder rates.  I always take off and land on high rates anyway.

 

[Robotech]

stangflyer said


The_Wreck said


Another advantage is that it puts zero load on the servo in flight, unless you run the springs really loose or the geometry is perfect, they will impart some load on the rudder servos when the rudder is deflected.  This would be my primary concern with using a shock linkage like what is shown above, I cannot believe that the geometry between the rudder tiller and the tailwheel is perfect, so you are using some of your rudder servo power compressing the springs in the shocks while in flight.

The absolute cure for perfect steering and no load on the rudder is to add a separate servo for just the tailwheel, but who wants the added weight.


This too has been a concern for me. I don't want any load on the tail wheel in flight. I can not speak first hand of the geometry of the shock type system, But looking cool is not enough for me. It seems that last couple of weeks have been a nightmare for me. I have tried just about every configuration of springs and geometry and tension I can dream up. Either it is too tight, too lose or just plain sucks all the way around. Both my 50cc'ers  have direct drive and work great. I've just been trying to stay as scale looking as possible on my big birds. But what ever the cost, I want to get it nailed down before I put the new Sukhoi up. And come to think of it, Don't think the idea of separate servo has not crossed my mind. I just almost did it until I realized there was no place in the back of my fuse to put one. The extra weight would not have bothered me. I have weight back there any way to balance. Would simply have removed it to counter act the servo weight. I may end up going over to the dark side. Fuel tubing or a J&J direct drive system. I am so done fighting the tail wheel steering issue. 

Pistolera said
Yeah...if you're gonna add a separate servo, use it for something cool...like turning the pirate's head !!!! 

Oh yeah, I thought of the turning head idea too... Maybe on the next one. LOL


Put a single 500+ oz. on the rudder and use the other rudder servo hole for the tail wheel. Alternately, you could use pull-pull on the rudder and use one of the rudder mounts for the tail wheel.

 

[stangflyer]

Pretty good idea Robo.... I actually spent the afternoon contemplating a number of options. I got so frustrated, I decided, "screw it", I am putting a "steering" servo up in the fuse to control the tail wheel via pull-pull cable. My plan was to add some "relief" springs out at the tail wheel to absorb any extreme forces. Plus, this would have made it very scale looking... upon looking at the full scale Extra, this would have been the cats meow. I have a "TON" of room and what is 2 oz. when you have a 157CS up front right? Well, had I had a HV servo, that is probably what I would have done. I did however, NOT have an extra one sooo....I succumbed and slipped to the dark side. 

What I opted to do is like so many others have done. (I'm hard to convince like that) Fuel tubing, (since I have a ton of it on hand from my glow (shudder) plane days) and zip ties. What I came up with was something I did "not" expect. An actual operational and fully functional tail wheel assembly with some pretty darned good steering. Guess we'll see once the weight of the stabs and wings are on huh? 

I operated the rudder side to side, and noticed movement at the tail wheel I have not seen for well, ever if I remember correctly. I then operated the tail wheel and believe me, it will pull the rudder around side to side. To top it all off?? It actually don't look all that bad. Just gonna take some getting used to. Oh yeah, while I was at the tail end...I decided since I "sealed" all the hinge lines on the ailerons and elevators when I completely recovered this plane, I might as well seal the rudder hinge line. I wasn't going to because I thought at some time I may want to remove the rudder for transport. Been to Wenatchee and back and the field about two dozen times and I have not removed it yet. No since in NOT covering it now.