How well does a castor wheel type tail wheel work?
#1
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How well does a castor wheel type tail wheel work?
I am doing a Big Stick 40 tail dragger and want use a castor tail wheel
for simplicity.
How good do they work?
Jimmy
for simplicity.
How good do they work?
Jimmy
#2
I always liked it on our old grass fied. Its nearly IMPOSSIBLE on a hard surface. Also you have to pump the throttle and slap around the rudder quite a bit more when taxiing around in the grass. On the hard runway you will just spin doughnuts often when trying to make a turn.
Last edited by foodstick; 11-09-2015 at 02:57 PM. Reason: spelling, always spelling ;)
#4
My Feedback: (1)
A free swiveling tailwheel on asphalt or what we are used to out here, open desert it does not work at all and makes the airplane otherwise uncontrollable. If simplicity is a must then do as aspeed suggest and use a simple tailskid or at least CA a swivel type tailwheel into a fix position, works well and have done this several occasions. fixed wheel or tailskids work surprisingly well in many situations and conditions.
John
John
#6
My Feedback: (1)
Not hard, not hard at all Jimmy but a really bad idea adding an aft servo on a small airplane such as the forty big stick. For a giant scale yes adding aft servos works fine but on the little forty that one servo out back will now require the equivalent weight of four servos up front to balance that one servo back there in other words its like adding the dead weight of five servos to your airplane.
If you cannot fabricate a rod down from the rudder through the elevator hingeline and there threw a simple Dubro tailwheel bracket then my best recommendation for you is to secure a fixed tailskid.
John
If you cannot fabricate a rod down from the rudder through the elevator hingeline and there threw a simple Dubro tailwheel bracket then my best recommendation for you is to secure a fixed tailskid.
John
Last edited by JohnBuckner; 11-09-2015 at 01:34 PM.
#7
Here is an easy way to do it with no extra servo or pushrods..
Use a plastic formed tail wheel mount that screws into the bottom rear of the fuse. Mount it a ways in front of the rudder.. more like a scale tail wheel position.
Now where the wire comes up and threw the plastic block bend it straight BACK so that it runs parallel and beneath the fuse.
Bend a round end in it like a question mark.
Drill a small hole in the rudder at the same height as the round bent wire end.
Glue a dowel through the hole hanging out 3/4 inch on both sides.
Put a rubber band over one side of the dowel..up and thru the bent loop hooked to the tail gear wire. Then back to the other side of the rudder and over the dowel. It makes it work, but without being solid enough to eat your servos.. Its a decent setup.
Use a plastic formed tail wheel mount that screws into the bottom rear of the fuse. Mount it a ways in front of the rudder.. more like a scale tail wheel position.
Now where the wire comes up and threw the plastic block bend it straight BACK so that it runs parallel and beneath the fuse.
Bend a round end in it like a question mark.
Drill a small hole in the rudder at the same height as the round bent wire end.
Glue a dowel through the hole hanging out 3/4 inch on both sides.
Put a rubber band over one side of the dowel..up and thru the bent loop hooked to the tail gear wire. Then back to the other side of the rudder and over the dowel. It makes it work, but without being solid enough to eat your servos.. Its a decent setup.
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Im a bit puzzled as some have said no problem with a castor type tail wheel and some say they suck.
I have built this plane before and with the same Saito .62 and I had to add tail weight.
My club field has allot of very well kept short grass and a fabric strip down the middle.
I may start with the castor type and see how it works.
I will have several flights on the trainer before I try the stick again.
Thanks Jimmy
I have built this plane before and with the same Saito .62 and I had to add tail weight.
My club field has allot of very well kept short grass and a fabric strip down the middle.
I may start with the castor type and see how it works.
I will have several flights on the trainer before I try the stick again.
Thanks Jimmy
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Just being a troll here...but the word for this is caster (wheel that swivels) rather than castor (the oil in our glow fuel). There are many options available from companies such as Du-Bro and you can make your own rather than buy if you see an idea that works. Many small models I have use a torque rod attached to the bottom of the rudder surface that drives the tailwheel.
Jaybird
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You could limit the amount of swivel to a few dgrees either side of center to give some ground handling help rather than spinning around 360 degrees.
Jaybird
Jaybird
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I love free castor tail wheels. No stress on the rudder, servos or hinges.
I fly mostly off grass and it has never been a problem. As far as hard surfaces you can add limiters and friction.
If it makes sense in this plane I say go for it.
It does not mean you have to convert your whole fleet.
I fly mostly off grass and it has never been a problem. As far as hard surfaces you can add limiters and friction.
If it makes sense in this plane I say go for it.
It does not mean you have to convert your whole fleet.
#19
My Feedback: (1)
OK first my I suggestion is that no Caster is not the best or proper term and it definitely has nothing to do with castor oil. Caster is the measurement of 'Trail' built into any steerable wheel be it tailwheel, nosewheel or motorcycle for that matter. In other words it the distance from the the point where the extended steering axis contacts the ground and the center of the tires footprint connects with the ground.
Back to the whole does it work or does it not thing. And that can be answered in a simple sentence. Yes it works just fine IF (this is a really big If)-------Only if ones technique is to habitually rip an airplane off the ground at or just before flying speed is attained or one is in the habit of forcing the tail up before directional control is really possible and where one does not really care about the result of doing so.
I have spent an entire career close to half a lifetime (retired) in full scale instruction. Beleve it or not the vast majority of full scale general aviation taildraggers even the very light one's utilize steerable tailwheels but get this most of these have what is a spring loaded lockout device that will allow the airplane to full swivel for parking etc. HOWEVER when these spring devices become worn that will allow the tail wheel to full or free swivel during takeoff then that becomes a no go decision and an almost assured ground loop.
Now lets take that just a bit further, most of the heavier general aviation tail draggers lets say many Cessna 180/185 and up actually have an additional device called a tailwheel lock This rather than just the spring loaded anti full swivel device actualy fully locks the tailwheel in the straight ahead condition so it is no longer even steerable and this is mandatory before landing and take off only being engaged after line up or disengaged only after reduction to dead slow taxi speed.
Back to the model airplanes after you graduate to most any kind of scale airplane at least any that would require anything more of a takeoff roll than a foamy or some fun fly ship with extremely light wing loading and most certainly any Cub or warbird then indeed full swivel is absolutely no answer Even though as I posted originally a fixed gear can be an answer can be an acceptable solution and the little bit of extra learning and practice required can be quite rewarding.
I think a lot of the responders here do not realize the OP,s ugly stick will require more work because the rudder hingeline is forward and will require some special considerations because of the fuselage is more involved. Many of us has done it of course but to minimize that to the newbys does no body any good.
John
Back to the whole does it work or does it not thing. And that can be answered in a simple sentence. Yes it works just fine IF (this is a really big If)-------Only if ones technique is to habitually rip an airplane off the ground at or just before flying speed is attained or one is in the habit of forcing the tail up before directional control is really possible and where one does not really care about the result of doing so.
I have spent an entire career close to half a lifetime (retired) in full scale instruction. Beleve it or not the vast majority of full scale general aviation taildraggers even the very light one's utilize steerable tailwheels but get this most of these have what is a spring loaded lockout device that will allow the airplane to full swivel for parking etc. HOWEVER when these spring devices become worn that will allow the tail wheel to full or free swivel during takeoff then that becomes a no go decision and an almost assured ground loop.
Now lets take that just a bit further, most of the heavier general aviation tail draggers lets say many Cessna 180/185 and up actually have an additional device called a tailwheel lock This rather than just the spring loaded anti full swivel device actualy fully locks the tailwheel in the straight ahead condition so it is no longer even steerable and this is mandatory before landing and take off only being engaged after line up or disengaged only after reduction to dead slow taxi speed.
Back to the model airplanes after you graduate to most any kind of scale airplane at least any that would require anything more of a takeoff roll than a foamy or some fun fly ship with extremely light wing loading and most certainly any Cub or warbird then indeed full swivel is absolutely no answer Even though as I posted originally a fixed gear can be an answer can be an acceptable solution and the little bit of extra learning and practice required can be quite rewarding.
I think a lot of the responders here do not realize the OP,s ugly stick will require more work because the rudder hingeline is forward and will require some special considerations because of the fuselage is more involved. Many of us has done it of course but to minimize that to the newbys does no body any good.
John
#20
My Feedback: (1)
Any kind of limiter can be even more problematical expecially typical overweight scale airplanes That's for sure.
Here is a type of tailwheel I have used on some airplanes in this case a Senior Cadet. Did mention this is when it on wheels and oh Yea it carries over eight pounds of full Yup its fixed but yes it can handle on the ground almost as well as trigear but on take of a straight line takeoff is a piece of cake.
John
Here is a type of tailwheel I have used on some airplanes in this case a Senior Cadet. Did mention this is when it on wheels and oh Yea it carries over eight pounds of full Yup its fixed but yes it can handle on the ground almost as well as trigear but on take of a straight line takeoff is a piece of cake.
John
#21
My Feedback: (3)
Speaking as a club safety officer, I'd like to ask a question.
Your plane with a castering tailwheel is ready for takeoff and there are several other pilots on the flight line. You throttle up to take off, there's a crosswind and you find your plane heading towards your buddy in the next pilot's box. You have no way to turn the tailwheel. Do you throttle up and rudder over hoping that the plane will finally turn before it hits him at full throttle? Or do you throttle back, meaning you have absolutely no rudder control, ergo, no steering? So you hit him but not quite as fast. Or do you rethink this and find a safer way to control your airplane while it is on the ground?
Please think about safety in addition to thinking about what's easiest to build. A .40 size airplane can cause severe injuries in a botched takeoff attempt.
You need to have positive control over your aircraft at all times. This means on the ground as well as in the air.
This isn't just theory. I've seen it tried and it wasn't pretty. They eventually went back and found a way to control the tailwheel. But that was after breaking the airplane a couple of times. Thankfully, there were no injuries but it was close on the second accident. An out of control airplane is a scary thing.
Dave
Your plane with a castering tailwheel is ready for takeoff and there are several other pilots on the flight line. You throttle up to take off, there's a crosswind and you find your plane heading towards your buddy in the next pilot's box. You have no way to turn the tailwheel. Do you throttle up and rudder over hoping that the plane will finally turn before it hits him at full throttle? Or do you throttle back, meaning you have absolutely no rudder control, ergo, no steering? So you hit him but not quite as fast. Or do you rethink this and find a safer way to control your airplane while it is on the ground?
Please think about safety in addition to thinking about what's easiest to build. A .40 size airplane can cause severe injuries in a botched takeoff attempt.
You need to have positive control over your aircraft at all times. This means on the ground as well as in the air.
This isn't just theory. I've seen it tried and it wasn't pretty. They eventually went back and found a way to control the tailwheel. But that was after breaking the airplane a couple of times. Thankfully, there were no injuries but it was close on the second accident. An out of control airplane is a scary thing.
Dave
Last edited by dbacque; 11-10-2015 at 03:18 PM.
#22
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Thanks John and everyone else for your input.
I didn't consider the safety issue at all.
I will make this a steerable tail wheel one way or the other.
I will figure out what way I want to go, this plane will need tail weight so maby
a servo is the way to go.
Jimmy
I didn't consider the safety issue at all.
I will make this a steerable tail wheel one way or the other.
I will figure out what way I want to go, this plane will need tail weight so maby
a servo is the way to go.
Jimmy
#23
My Feedback: (1)
Jimmy thanks for listening to a little common sense I have one other question and I have heard you mention it several times. Its the one about this airplane requires tail weight. What is the reason you believe that to be the case? Is it one, because you need it to keep the tail on the ground during takeoff so you do not nose over and keep on breaking props. Or two, is it to keep that pesky CG at the needed spot when the airplane is up in the air?
john
john
#24
My Feedback: (3)
A steerable tailwheel shouldn't be a big deal, It's been done a million times before.
I've never flown one but there are plenty of Stick type airplanes out there and most all of them have steerable tailwheels. There are lots of solutions to get there, direct connection between rudder and tailwheel, spring type connections (probably not an option here), multiple pushrods from a single servo. I'd take the second servo as the last resort, but anything to be able to control the airplane and keep things safe.
I am glad to hear that safety considerations gave you pause to reconsider. There have been terrible accidents with model airplanes. We should always think safety when planning our projects.
Besides being a safer plane, it will be easier to handle and be more reliable.
Dave
I've never flown one but there are plenty of Stick type airplanes out there and most all of them have steerable tailwheels. There are lots of solutions to get there, direct connection between rudder and tailwheel, spring type connections (probably not an option here), multiple pushrods from a single servo. I'd take the second servo as the last resort, but anything to be able to control the airplane and keep things safe.
I am glad to hear that safety considerations gave you pause to reconsider. There have been terrible accidents with model airplanes. We should always think safety when planning our projects.
Besides being a safer plane, it will be easier to handle and be more reliable.
Dave
Last edited by dbacque; 11-10-2015 at 04:46 PM.
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Jimmy thanks for listening to a little common sense I have one other question and I have heard you mention it several times. Its the one about this airplane requires tail weight. What is the reason you believe that to be the case? Is it one, because you need it to keep the tail on the ground during takeoff so you do not nose over and keep on breaking props. Or two, is it to keep that pesky CG at the needed spot when the airplane is up in the air?
john
john
I built this exact same plane 4 years ago with the same Saito .62 eng and it needed tail weight.
2 or 3 oz if my memory is correct.
The only difference this time is the tail dragger settup.
Right now with no radio gear or battery its nose heavy.
I sold the plane but kept the eng and radio gear.
Jimmy EDIT I just balance the plane where the instructions
say to put it.
Last edited by JimmyZep; 11-10-2015 at 04:57 PM.