Replacement MC-E LED head for Canister Divelight ...

[gwilki]

Your timing is great, Will. I was going into pic withdrawal.

It looks great from here. The size is sweet, and your workmanship is first rate.

That's some mill you have there.

 

[wquiles]

Your timing is great, Will. I was going into pic withdrawal.

It looks great from here. The size is sweet, and your workmanship is first rate.

That's some mill you have there.

Still more to go, but I tackled last night one challenge I knew I was going to have with the new Agro cable gland on the canister's lid - that hole from the plumbing fitting was larger on the top side of the hole than the threads for the Agro gland. This is how I solved that problem ...

You can see the new cable gland here on top left, and the existing plumbing fitting on the middle. That hole is tapered:

Once I centered the hole, I drill it with the largest drill bit I have (1/2"), which is not large enough since the thread calls for a hole 37/64" in dia:

So what that means is that I need a boring head for the mill. The one to buy of course is the ones made by Criterium, but I have not been able to snag one cheap on Ebay for many months. I recently found this large monster - and I could not resist the cheap price nor the beefy construction - it looks like it could have been hand-made, it is built like a tank and everything is fitted incredibly well. Unfortunately it is designed for 1" boring bars, so I knew I would need an adapter:

So I decided to make an adapter for 1/2" boring bars out of a 1" dia drill rod piece I had around. The hole in the boring bar is "exactly" 1.000 inches, so I had to slightly turn the drill rod for it to fit:

I then drill and bored to get to 1/2" on the other side of the adapter:

I then took a piece of 1/2" drill rod and made my own boring bar:

and gave it the water hardened treatment once the edges look right to me (did everything by eye on the grinder):

 

[wquiles]

Here is the hand-made boring bar and the adapter:

I then drilled and tap the adapter for set screws - I later cut those much shorter:

Here it is ready for use:

and it worked awesome:

and I was able to tap the hole as needed:

Once I finished the tapping, just as I expected, I found that the tapered hole was bigger than the new fitting on the top, so I had to bore it deeper to get to "solid" threads, while still allowing removal if later needed to be replaced:

and this is how it looks now - all possible after making my own boring bar:

Will

 

[gwilki]

Looking good, Will. Who knew when I started this that it would require you to make your own tools? Certainly, not me.

 

[wquiles]

Looking good, Will. Who knew when I started this that it would require you to make your own tools? Certainly, not me.

I expected some challenges on that cable gland for the canister's top, but the real surprise was what I found when I took apart the switch to replace the boot (which was all I was initially expecting to replace as part of this job). I also remember that you could not figure out how the light turn ON by itself, which caused the catastrophic failure/meltdown of the head. Now I know exactly how/why it happen ... the switch shorted internally. Let me show you ...

Look at all of the corrosion on the outside of the switch (the inside looked worst - photos below):

and the boot looks fine, right?

not quite:

 

[wquiles]

Plus, the switch itself was not sealed to the body - it was just being held in place by the boot. It would have been even better if a little silicone was used between the switch and the body so that water could not get inside the canister.

I did buy a new silicone switch boot I will replace it (old one on left, new on right), but I might try to find something thicker, more like the original boot:

Here are the innards of the switch once I got it opened - obviously seriously corroded:

With that much corrosion, it was only a mater of time before it shorted - now you know how your light turn ON by itself. As a preventive measure, it would be good to change this switch boot more often, even if "looks" OK. I am also going to modify slightly the switch's outer delrin cover to improve the ergonomics as you were telling me that it is hard to operate the switch specially when wearing gloves.

Will

 

[gwilki]

Well, Will, it's good to know the likely cause of the "burn out". It's not so great to know that it was my own stupidity, but it's a lesson well-learned. I like to believe that I am particular about the maintenance on my gear. Clearly, I fell down on the job here.

 

[Packhorse]

Rubber boots always split. Its not a case of if but when.

Why not build a reed switch set up?

 

[wquiles]

Rubber boots always split. Its not a case of if but when.

Why not build a reed switch set up?

I like the idea of doing some experiments with reed switches and/or hall-effect sensors. I like the idea of a switch that is inherently water proof, specially something like the multiple-level selector ring that you have used in some of your lights.

One thing that worries me a little is how to prevent the reed switch from activating while in storage/transit. How can you keep external magnets (like speakers in the trunk of a car) from activating the reed switch? Is it as simple as disconnecting the battery while in transport?

 

[wquiles]

Well, Will, it's good to know the likely cause of the "burn out". It's not so great to know that it was my own stupidity, but it's a lesson well-learned. I like to believe that I am particular about the maintenance on my gear. Clearly, I fell down on the job here.

Grant, no worries. Since you want to stay for now with a mechanical switch, I found a suitable replacement switch already:

The original switch was sanded down in the corners to that it would fit, so I did the same with the replacement switch (new one on top) :

As good as new:

Will