Occasionally you run into questions on which the whole internet seems strangely silent. Perhaps I’m not looking in the right place, but I’m trying to make a tailskid for my aircraft, which has a tailspring scavenged from a whishbone suspension spring – about 38mm wide.
The current skid works beautifully, except that it’s wearing away very quickly. I made it out of 38mm bent gauge plate that I then hardened by quenching in water. My aircraft has been flying from grass, but has taxiied a bit on concrete/tarmac. The plate is fairly flat against the tarmac so there’s a fair surface area to wear away. It was fairly straightforward to make, but I don’t fancy re-making one every 10 hours or so, and gauge plate isn’t the cheapest material either.
I’ve thought of trying to make replaceable shoes out of ball-bearings or piano wire – something not too labour intensive but unlikely to fall off at altitude either. Or possibly incorporate a small wheel that would only really be active on a hard surface. Any good solutions out there?
kwlf wrote:
Or possibly incorporate a small wheel that would only really be active on a hard surface
That would require you make a ski kind of system where the wheel only slightly protrude below the ski/skid. I would think it would be better only to use a wheel?
I’ve been building a wheel – for which there are plans. I’m aiming to make them interchangeable with the skid. Just interesting to explore the different handling.
In the dim and distant past I remember tail skids having removable shoes which were refurbished by getting an arc welder and laying down some beads of weld on the ground facing surface. I don’t know if it was a special welding rod but it lasted quite well.
On gliders with tail skid the typical arrangement is of a rubber block glued to the glider tail and a plate bolted to some insert in the rubber block. Operating from hard runway you get to change plate or refurb it. Operating from grass, the rubber fails first usually.
One thing to watch is not letting the plate go to thin and the screws head being worn.
I’ve heard of people using stick welder to protect the screw heads. I’ll ask this weekend if they use a particular type
The wheel is already invented and proofed to be useful. Anyhow you like to use a skid. Fine. Go with a wearable shoe that bolts on with recessed boltheads. Make it out of Delrin or better a UHM plastic. That will wear maybe faster that steel, but create little heat.
Snowbirdxx wrote:
The wheel is already invented and proofed to be useful.
I already have two wheels on the aircraft so have no deep-rooted prejudices against them.
My only experience so far is a cub with a big tailwheel versus my turbulent with a skid. On grass, as soon as the skid goes down there’s an useful braking action that gives you very good lateral control for the landing rollout. I wouldn’t go so far as to say it makes a groundloop impossible – that would be tempting fate – but it certainly makes it less likely than on the cub.
On a hard surface it’s another matter, but then the Turbulent’s plans-built wheel is free castoring so I don’t see much disadvantage. The other issue is that it’s a small aircraft so the tailwheel is necessarily very small and so could get stuck in a rut. This would be very unlikely with the skid.
It’s also aerodynamically cleaner, and I believe Redhill gives discounts to aircraft with skids!
LeSving wrote:
That would require you make a ski kind of system where the wheel only slightly protrude below the ski/skid. I would think it would be better only to use a wheel?
It seems this a good, and commonly used methode. Then you won’t have any fast wearing parts anyway. Have a look at his image, should be possible to make a similar tail skid isn’t it? The welding beads idea is also smart, though they would wear of quite quickly I would suppose do the small surface area.
Ok, got the idea why you want a skid. Did you consider a small lockable tailwheel? if yu unlock it, it will be either feree castering or steered- Somthing like the Haighs tailweel.
