Easy-to-build steerable nosewheel?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
8,124
Location
Fort Walton Beach, Florida, USA
OK, I am thinking of going with a steerable nosewheel for the single-seat design I am working through Raymer's book for homebuilders, mostly because I did my microlight training with a steerable nosewheel and motorcycle-style single handbrake on the joystick and I like the combination. I would like to come up with a simple steerable nosewheel design, both the fork end and the steering bit, ideally bolted together with little or no welding. Does anyone have any inspirations to share? Cheers, Matthew
 

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
8,124
Location
Fort Walton Beach, Florida, USA
Thanks, Hugh, I did see your design in another thread but I am looking for something simpler and easier to fabricate. I was wondering, for example, if I might add delrin or nylon spacers to either side of a square aluminum or steel tube, a similar plug inside the tube to prevent crushing, aluminum or steel plate sides for the fork and a coulple of AN bolts through the whole works? I was also kicking around ideas for a double nosewheel, perhaps using a pair of oversize electric scooter wheels.
 

AdrianS

Well-Known Member
Joined
Jul 5, 2014
Messages
603
Location
Australia
Can you use a bicycle front end as a base? A friend races downhill mtb's, and they have a very solid, light, long travel suspension.
I have also seen single-sided bicycle ffont ends.

What is the design suspension load ?
What height (ground to top support bearing) ?
 

Jay Kempf

Curmudgeon in Training (CIT)
Lifetime Supporter
Joined
Apr 13, 2009
Messages
4,279
Location
Warren, VT USA
Can you use a bicycle front end as a base? A friend races downhill mtb's, and they have a very solid, light, long travel suspension.
I have also seen single-sided bicycle ffont ends.

What is the design suspension load ?
What height (ground to top support bearing) ?
Downhill MTB forks can be $2000 a copy. It might be cheaper to buy a motocross fork used.
 

henryk

Well-Known Member
Joined
Mar 8, 2010
Messages
5,900
Location
krakow,poland
Motorcycle forks, even small ones are a bit overkill for an UL nose gear. He's probably thinking of the cheap Chinese Walmart special MTBs.
002.jpg =not very simple,3.2 kg heavy,12cm stroke,air spring
\controlled\+oil dampfer.
=for flying scooter project...
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,896
Location
Las Cruces, NM
I suppose the front suspension off a Vespa scooter would be too heavy but they have a really neat single sided, tailing link arrangement.

vespa_20_steering_fork_5649775.jpg
 

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
8,124
Location
Fort Walton Beach, Florida, USA
Neat, Fritz, but definitely too heavy. That carbon fork I posted costs US$140 and weighs 350g (~12 oz) and looks like it could be built in to a rubber disk or bungee sprung system quite neatly.
 

Aerowerx

Well-Known Member
Joined
Dec 1, 2011
Messages
5,725
Location
Marion, Ohio
I have thought about bicycle forks myself.

Unless you heavily modify it, in which case you could have built one from scratch, you will be limited to very narrow tires. Most of them are also way too long to be used as an ultralight nose gear anyway.

I have a couple of pencil sketches around here of nose gear that uses bolted and riveted aluminum extrusions and tubing. Maybe I will try to locate them and scan them in.
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,896
Location
Las Cruces, NM
The only thing about bicycle forks is how much side load they can carry. You can't put much side load on a bike (you'd fall over) so they're not designed to handle much.
 

Lucrum

Well-Known Member
Log Member
Joined
Jun 10, 2008
Messages
956
Location
Canton, GA
Not to change the subject or your mind. But I decided on a free castoring nose wheel, for simplicity. I have experience with the SR22 which has a free castoring NW, it's not difficult to steer.
Even the P-38 had a free castoring NW.
 

cluttonfred

Well-Known Member
HBA Supporter
Joined
Feb 13, 2010
Messages
8,124
Location
Fort Walton Beach, Florida, USA
Not to change the subject or your mind. But I decided on a free castoring nose wheel, for simplicity. I have experience with the SR22 which has a free castoring NW, it's not difficult to steer.
Even the P-38 had a free castoring NW.
I hear you, Lucrum, but a free-castering nosewheel means a more complex brake arrangement in the form of toe brakes, heel brakes or dual hand levers. Plus, since I am leaning toward an H-tail for my design, the rudders will not be in the propeller slipstream for taxiing so I think a steerable nosewheel would make sense.
 

autoreply

Well-Known Member
Joined
Jul 7, 2009
Messages
10,763
Location
Rotterdam, Netherlands
An extra brake handle and line is like ten times less complex and expensive as adding a steerable nose wheel.

It really starts to add up when you look at the loads and the failure mechanisms of a steered nose wheel.
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,896
Location
Las Cruces, NM
I agree, you're already going to have two brakes, it's just a matter of adding another brake pedal or handle. A swiveling NW might be the lightest, simplest and cheapest way to go. But if a positive link NW steering is what you want go for it.
 

AdrianS

Well-Known Member
Joined
Jul 5, 2014
Messages
603
Location
Australia
The only thing about bicycle forks is how much side load they can carry. You can't put much side load on a bike (you'd fall over) so they're not designed to handle much.
If you watch the racers in a climb, the bike is leaned left-right as they pedal, at least 15-20 degrees, so the suspension/fork has to take a fair side loading.

I agree forks limits wheel width, I will try and find the single-sided bicycle front end a mate has.
 
Top