The firm in Germany proved to be really responsive. They even checked it on the real oil bottle, to make sure the thread is right.
They used to supply flat packed card funnels if you bought oil by the box.They were long and thin, so it was possible to stick the end of the oil contaianer into the top of the funnel, it worked even in the wind.
My aircraft almost never needs topping up :)
Edit: This is similar
Getting it from Sporty’s would cost me $1M in shipping 
so I emailed Friebe in Germany. It’s obviously the same item, but 3x more expensive in Europe as usual.
If they don’t reply I will harrass some German pilot to help me 
Many thanks for that link.
Try using one in a strong wind, or in the rain.
Not everybody is disallowed from working on their plane in its hangar…
And even then, filling oil is normally done before flight – perhaps there are advantages, unappreciated as yet, to flying only in good weather
< copied from the Carcassonne thread >
I have a cut-off soft drinks bottle as a funnel, whose thread exactly fits my Lycoming filler tube. Drips are contained by screwing on the original bottle top. This bottle lives snugly in another bottle in the cockpit, to contain any oiliness. No weight at all, no messy funnels.
That sounds like a clever and effective arrangement – are you sure you didn’t fly microlights at one time? Cut-off soft drinks bottles can serve many purposes, I use one to hold my pcb drill without breaking the bit, and they also work well for catching flies and other flying nuisances.
but what’s wrong with a plain old funnel?
Try using one in a strong wind, or in the rain.
Another more subtle thing is that whatever device one uses, it has to be carried in the plane, and one can’t just keep something in the back which is dripping with oil. A big funnel takes some cleaning out. Normally I rinse them with avgas, drained out of the wing, but the result has to be dumped somewhere…
The filling adaptor is small enough to be wrapped up in a rag and that’s it.
Personally, I tend to just roll up some used paper from my knee board into a funnel shape. It does the job perfectly, and the oil doesn’t make it’s way through the paper. I just need to find somewhere to dispose of the paper (or store it until safely at home) without destroying anything else. But that problem will also exist for such a device (storage without getting only on other things).
Excuse me if I’m stupid, but what’s wrong with a plain old funnel? I use one like this, simple, cheap, and efficient.
Many thanks all – very useful. I need to buy one of the type posted by Dublinpilot or RXH. Both are very similar.
BTW, AFAICT, the Aeroshell bottle doesn’t screw into my IO540-C4 oil filler.
See e.g. here and here and here
Also I always put the whole bottle in, but given that the filler is some 5cm below the top of the TB20 cowling there is no way (if there is any wind) to screw an upside-down bottle into the filler, even if the thread was right. The method I normally use to avoid spillage is to pour the oil along the (partially extracted) dipstick. Surface tension keeps the oil flow attached to the dipstick. But this won’t work in 20kt wind.
Silvaire wrote:
Just in case somebody isn’t aware, the narrow neck Aeroshell bottle pictured screws directly into a Lycoming dip stick tube. That’s only useful if your cowling allows room for the bottle to be screwed in. Both mine do.
Exactly…. Just means you only top up in increments of 1qt….let it run down to 6 and top up to 7 (on an 8qt max Lycoming IO360 anyway)..,no need for any funnels or adapters…
