A cork pusher

[jdaw1]

Is 7mm between pistons truly sufficient? That does seem plenty for a normal bottle, but might required a full cleaning of the top of a bottle before use if the bottle has a thick rubber/wax capsule.

For a normal bottle, 4mm would just be enough. How thick is the wax? How much do you need?

[PhilW]

I think 2mm is not enough, and would suggest minimum 3mm. Perhaps just 3,6 or 4,8mm would be sufficient?

I had similar thought to Derek regarding combined *if* full-push-in were also wanted. Noting that once the cork is moving nothing like the same pressure is required, the bar would not need to be 10mm all the way; the image in my head was similar to Dereks, with a few minor variations:
- 5/6mm circular bar, 100-120mm in length
- half the length flattened to 10mm wide, with the two push protrusions of 4mm, 8mm
(the flat section could be central or at one end; I was picturing central to allow more balanced use)
- one end split and flattened into a T, which would both stop the tool being able to fall into the bottle, as well as being more comfortable when using for full push-in.
- other end just smooth edge to prevent catching in pocket.

Very similar to some double-ended right-angle screwdrivers I have, with the mid-section flattened and one screwdriver end removed; single simple cast metal, optionally chromed.

[PhilW]

Is 7mm between pistons truly sufficient? That does seem plenty for a normal bottle, but might required a full cleaning of the top of a bottle before use if the bottle has a thick rubber/wax capsule.

For a normal bottle, 4mm would just be enough. How thick is the wax? How much do you need?

Agree with Glenn; I would allow 20mm from the centre of the first piston to the edge of the next, thus accomodating total capsule width of max 40mm; this is likely excessive, but better safe than sorry; I certainly wouldn't want less than 30mm. assuming 10mm pistons, then that would mean 15mm flat section between (and at outside); with 2 pistons that would be 15/10/15/10/15 = 65mm total, with three 90mm total.

[DRT]

Custom engineering is £$€-tastic. A simple piece of rigid hard metal, no threads, no screws, no moving parts, might well be more economical. This leans against DRT’s more complicated arrangements.

I think you should test that theory with an engineer. Your current design is a complex shape from a single piece of steel that would, I think, be expensive to manufacture. Five or 6 simple components that screw together might well be cheaper.

An alternative would be to use aluminium, in which case you could have it made by a CNC machine.

[PhilW]

Additional evidence-based justification for spacing >10mm between pistons: I use neck-tags on all bottles to aid in-rack identification. The previous neck tags I used had a 30mm dia hole, and I fairly often find on older bottles this is not enough to allow the tag to pass over the capsule unimpeded. I deliberately bought the latest tags with a wider hole; this is 36mm, and goes over almost all capsules; matching this would be a >=13mm spacing between 10mm pistons. Am assuming that piston depth at 8mm is potentially sufficient to otherwise foul the remaining capsule, and that you don't want to have to remove further capsule from neck (which would facilitate closer spacing).

[jdaw1]

We have the flat mode (proposed bay me), and the long-cylinder model, being varies variants of Alex’s picture.

What about a simpler long-cylinder model? Cylinder, solid metal, 16mm diameter, about 100mm long. One end is widened (details TBD), for better grip, and to prevent it falling in the bottle. Near the other end are transverse holes. Each hole is 1mm diameter, and spans the whole width of the cylinder, causing there to be holes 180° apart. There is such a pair of holes starting 2mm from the end. There is another such pair 30° offset from the first, and 1mm further from the end. And several more, each 30° offset from the previous, and 1mm further from the end.

There is also a metal stick, 1mm across, which can slide into any of these transverse holes, the choice of tunnel thereby selecting the maximum depth of push.

I like it less. The two pieces will eventually become separated. It’s less simple. Less tactile. YMMV.

[jdaw1]

An alternative would be to use aluminium, in which case you could have it made by a CNC machine.

Your words suggest knowledge that I lack. Please say more about the “CNC machine”.

I have a bottle opener which is a flat piece of metal with appropriate holes. It feels absolutely rigid, and is 2mm thick. Upgrading.

Made of aluminium.

[jdaw1]

Additional evidence-based justification for spacing >10mm between pistons: I use neck-tags on all bottles to aid in-rack identification. The previous neck tags I used had a 30mm dia hole, and I fairly often find on older bottles this is not enough to allow the tag to pass over the capsule unimpeded. I deliberately bought the latest tags with a wider hole; this is 36mm, and goes over almost all capsules; matching this would be a >=13mm spacing between 10mm pistons. Am assuming that piston depth at 8mm is potentially sufficient to otherwise foul the remaining capsule, and that you don't want to have to remove further capsule from neck (which would facilitate closer spacing).

Useful actual data. Assume a 16mm piston width. With 10mm separation between pistons, a 36mm wide neck could always be accommodated. I’ll update the design to make the spacing 12mm, so there is a mite spare.

[jdaw1]

As of 12:30 Mon 03 Jan 2022. Volume ≈ 5906 mm³. Aluminium density ≈ 2710 kg m⁻³ ⟹︎ weight ≈ 16.0 g.

[jdaw1]

Pistons reordered. The wobbliest push will be with the shortest piston, so to assist balance, the shortest moved to the middle.

[JacobH]

An alternative would be to use aluminium, in which case you could have it made by a CNC machine.

Your words suggest knowledge that I lack. Please say more about the “CNC machine”.

I think Derek is thinking of a computer-numerical controled mill which would, I think, be the only way of producing this from a single piece of metal. Essentially a computer controls a tool which removes material from a block of metal until the design is left. It is usually used for producing quite complex pieces that can’t easily be made by traditional machining: https://www.youtube.com/watch?v=osqX7iQEnuI.

It would be quite an inefficient way of making your tool since you’d have to start with a piece of metal that is c. 10mm × 100mm × 20mm and remove quite a lot material. But that might not be a problem since it is quite small. However, I have no idea how much it would cost to prototype one.

If you were making this by hand, the obvious way would be to chop some 16mm rod into pieces of the right length and attach them to a piece of flat bar of an appropriate size. However, attaching them might be tricky. Considering that the 2mm disk is pretty small, I’m not sure you’d be able to bolt it from the back and you wouldn’t want to drill large holes in the base plate to increase the size of the “pistons” because that would significantly weaken it. I guess silver soldering it might work, although then you would have a small lip around the join rather than a sharp 90° angle. That could easily reduce the effective height by 1mm.

Probably best to identify who might make this for you and have a chat with them about ensuring a workable design.

[DRT]

An alternative would be to use aluminium, in which case you could have it made by a CNC machine.

Your words suggest knowledge that I lack. Please say more about the “CNC machine”.

I think Derek is thinking of a computer-numerical controled mill which would, I think, be the only way of producing this from a single piece of metal. Essentially a computer controls a tool which removes material from a block of metal until the design is left. It is usually used for producing quite complex pieces that can’t easily be made by traditional machining: https://www.youtube.com/watch?v=osqX7iQEnuI.

Correct.

My experience of CNC machined parts comes from my interest in astronomy. Many complex parts of telescopes (focuser housings, mounting plates, etc) are made using this technique. I don't think it is quite as wasteful as Jacob suggests as the material removed by the machine would be easily recycled.

Perhaps a good start would be to find someone who could 3-D print a prototype?

[JacobH]

Sorry- I was thinking more in terms of how long it would take to remove the material since I think that is the usual way of calculating how much a piece costs to machine. But, realistically, these aren't going to be issues unless Julian is thinking of going into full-on commercial production!

[jdaw1]

Volume ≈ 5906 mm³. Aluminium density ≈ 2710 kg m⁻³ ⟹︎ weight ≈ 16.0 g.

It’s not much metal.

[nac]

Having it milled or CNCed from a single piece of metal would be prohibitively expensive, even if you were producing in bulk.

An alternative might be to obtain (not sure where from) a solid tubular piece of steel(?) of the correct diameter and then cut this into slices (not sure how) of various required thicknesses and then either screw or weld these onto a piece of steel(?).

I think as a starter you need to find someone with a metal working lathe and metal cutting facilities.

[nac]

Having it milled or CNCed from a single piece of metal would be prohibitively expensive, even if you were producing in bulk.

An alternative might be to obtain (not sure where from) a solid tubular piece of steel(?) of the correct diameter and then cut this into slices (not sure how) of various required thicknesses and then either screw or weld these onto a piece of steel(?).

I think as a starter you need to find someone with a metal working lathe and metal cutting facilities.

If you know anyone this this sort of kit (and they know how to use it) then I’m pretty sure they’ll be able to come up with a manufacturing solution.

[jdaw1]

https://www.youtube.com/watch?v=osqX7iQEnuI

That would do the job. How is it programmed? What instructions would I need to prepare?

[jdaw1]

As of 15:25 Mon 03 Jan 2022. Volume ≈ 5970 mm³. Aluminium density ≈ 2710 kg m⁻³ ⟹︎ weight ≈ 16.2 g.

[DRT]

https://www.youtube.com/watch?v=osqX7iQEnuI

That would do the job. How is it programmed? What instructions would I need to prepare?

https://get-it-made.co.uk/quote/

[DRT]

Do you have a cost in mind?

[akzy]

https://get-it-made.co.uk/quote/

Thought I'd chime in here as I often get lots of things like this made. It ain't gonna be cheap - I'd suspect around £100 per unit for a small run.
I've made the 3D model for it as it's relatively simple. https://1drv.ms/u/s!AgU8XS8Q_6e81VQSX1I ... J?e=seCYQI

One thing I should point out is that stainless steel perhaps isnt the best option here. 3D printed carbon fiber such as carbon SLS https://3dprintdirect.co.uk/materials/

[akzy]

As another heads up, get it made is business to business only.

[PhilW]

Per current diagram, width of tool is same as piston dia at 16mm - all good, and means tool would also fit inserted in bottle lengthways, so could be used per Alex for full push-in; if one end were widened slightly instead of just rounded off at same width, that would also stop tool being able to fall into bottle if used for this purpose also.

[akzy]

I've used one of our suppliers to get a rough quote using "any grade aluminium".

[akzy]

Per current diagram, width of tool is same as piston dia at 16mm - all good, and means tool would also fit inserted in bottle lengthways, so could be used per Alex for full push-in; if one end were widened slightly instead of just rounded off at same width, that would also stop tool being able to fall into bottle if used for this purpose also.

This would be incredibly difficult to mill. Would need at least a 3 axis CNC, probably 5 axis.