delusional wrote:
What’s a nubbin? It’s not much.
It’s a little cylinder of plastic, shown on the left here:
Picture credit to JasonWW
The nubbin fits into the center ring of the larger piece of rubber, and they both go into the FW3A’s switch mechanism.
The Switch of an FW3A will not work without the nubbin.
When you twist off the tailcap of an FW3A, the switch mechanism falls apart.
They were saying something about glueing the switch, but it didn’t happen, might happen in the future, who knows?
In the meantime, the nubbin is very easy to lose. I opened my tailcap once with no problem, but on the second time I lost my nubbin.
I didn’t even know there was “nubbin to lose.” So I wasn’t really watching for it. Now I need a new nubbin.
_
It took me about three minutes to make a new nubbin.
I took out one security bit, marked CR-V4, from a set.
You can see it’s got an outer rim and a cup in the middle. This is designed for “security” screws.
_
Next I hammered the bit through a plastic drink bottle cap. See the left hole? This did not work because my nubbin got stuck inside the cup of the bit. I damaged the nubbin prying it out.
On the second attempt I stopped a little short, leaving a bit of plastic remaining around the outer ring, and the nubbin was still attached to the cap. I cut the nubbin from the cap with a knife.
See the nubbin on the right, still attached?
_
And finally, you can see my new nubbin, in it’s new home, ready to reinstall in my FW3A.
It seems to work really well. …. at least it’s been holding up very well for a few hours.
You also see the drill bit on top, and on the left, the nubbin that got damaged.
I had a half dozen more bad puns ready to go, but decided it’s better if I don’t.
If others would like to join in, there’s nubbin stopping you.
…
@ delusional … If you want to resize your pics I’ll delete this.
That’s the main symptom of a switch tube contact issue. I haven’t seen it happen on my production sample, but I know the issue well from seeing it on earlier prototypes.
Loosen the tail a bit, loosen the head, then tighten the tail as much as you can, then tighten the head. The issue should go away.
If the issue returns, loosen the head, tighten the tail again as much as you can, then tighten the head. Try to keep the tail as tight as possible. And always tighten it tail-first.
The circle on top of a lego brick is 4.8 mm across.
The FW3A nub is 2.0 mm across.
If you’ve ever had coarse-grain sugar, like “raw” or turbinado brown sugar, the FW3A nub is about the size of one grain of sugar. Maybe a relatively large grain, but still. It’s basically the size of a single cake sprinkle.
Seems like a piece of a plastic welding rod would be suitable here. Harbor Freighr used to sell this pack but couldn’t find it on their website any mor. Is it possible for that store to go downhill?
I am thinking about this nubbin issue, (piston) while I do not have a light yet after only reviewing images and M4D M4X ’s video, would it be easier or more practical to bond a suitable object to the dome of the switch?
More thinking and experimentation would be required. the dome probably deflects or deforms which would cause a distortion and break the bond. I don’t know I don’t one have to futz with.
The switch to me appears to be metallic in fact it looks a dome of a membrane switch.
To replace the nubbin itself Amazon offers these items Plugs
I can image cutting one of the smaller ones 1/16 inch diameter to size these plugs are tapered so the size could be improvised. Then use some RTV to bond it in place.
I am just thinking out load here so I really don’t know if this would work.
This nubbin issue is really bothering me I don’t know if I will buy a light because of it. It is IMO a manufacturing flaw the design is clear I think it was executed improperly.
Also a suggestion for the adhesive - Pliobond. It’s a very tacky contact cement that resists solvents. I’ve been using it when repairing old cameras, gluing everything from light seals to rubber bumpers to the old peeling leatherette on the bodies. If it’s improperly placed, once the carrier solvent evaporates it peels away with no residue.