improved Nozzle idea

[Mickyblueeyes]

As some of you may have seen I have had to remake a few of the Nozzles as the original parts on the machines were unusable, this has got me thinking as the replacement parts have been stainless steel why not remake the whole nozzle that way. I can see a problem with using metal nozzles is that they might get bent If knocked or worse still damage a feeder or the arm, so my current thought is that if the tip were held in by a reasonably strong magnet it could then detach if a problem occurs saving both the nozzle and the machine. Any thoughts?

Mike

[phonoplug]

There are a few issues with this. Firstly it must be black otherwise the vision analysis will not work as it will see the tool as part of the component being visioned. Also, as you mentioned you need something to be sactificial in the event of something going wrong, and tools are the cheapest and easiest part to replace, so unfortunately you need to accept they could be damaged - its a lot better than having a bent R axis shaft. I don't think a magnet would work as it must hold the tool perfectly on the centreline of the head and not have any runout. I don't know of any other machines that take this approach so I expect thats for good reason.

It seems a reasonably good idea to have the syringe insert put in to lengthen the life of the tool, but the insert must be smaller than the narrowest dimension of the parts the tool is used for else it will affect the vision of them. Given that its a thin walled insert I would hope it will still give way in the event of a head crash.

[Mickyblueeyes]

Hi Phono, I can't see how the colour of the tip can affect the vision system as the tip is smaller than the part and the vision system is looking from below it, the main body of the nozzle could still be coloured black or indeed be made of plastic as it is now, we already vision both white and black parts on a black tip.
the sacrificial idea is simply that the tip falls away on any sideways impact and can simply be placed back afterwards, accuracy will depend on how the tip and body is machined around the magnets and shouldn't be a problem.

When I get a few spare hours I will investigate it further, the fact that we don't have a ready supply for the Nozzles is my main reason for considering it.

[Jason]

Yeah Phono is right the vision system will see any light being reflected back from the nozzles.
One option would be black anodised aluminium but any metal nozzle could do a fair bit of damage and I prefer the idea of sacrificing nozzles rather than damaging something more important.

[Mike]

Yes - the nozzle acts as a dark background for the edge of the parts so it's important it has a featureless, dark surface. As mentioned, the nozzle should be the sacrificial part - a metal nozzle would just transfer damage to something less readily replaceable.

I don't see any benefit to magnetic attachment  - you still need a seal, so the current o-ring arrangement works OK - just needs an occasional dab of silicone grease. 

[Mickyblueeyes]

Hi, I haven't placed many parts as yet with my stainless steel tipped nozzle in fact the machine will be doing its first production run starting tomorrow, I hadn't worked out that the 1mm tip is slightly larger than the width of the 0603 parts I am trying to place and being bright stainless it has affected the vision and explains why the system is reporting a .040 width on the parts, its not a problem on the size 3 because of the O ring. so yes phono was right the camera can see it, I am going to take it off and reduce the dimensions and blue it and see where that gets me.
the point I was making about the magnetic tip was that it is only the tip of the nozzle that is magnetically held, the body of the nozzle would still be held in place by the current arrangement so this could therefore be machined into a scrap nozzle.

[Jason]

It's not just the tip, the whole body will be degrading contrast of the image.
It might work under your current lighting conditions but could make things unreliable.
That's why there is a black disc above the whole nozzle mechanism.

There might also be weight considerations which could increase wear on the
Z-axis rack.

Stainless can also get magnetised so I would expect small components could
stick to it.

[Mike]

Only some types of stainless are magnetic - not sure about the stuff they make needles from, but can't see how it would become magnetised.
Compared to the weight of the Z-axis mech I can't see a few extra grams of a nozzle making any difference.