2015 POTD Thread Archive

[MozamPete]

Not sure what is in the little black enclosures you can see on the cables - I assume some sort of voltage and/or current limiter. Upstream of that they are intended to just connect to the vehicles 12V to 24V supply, so pretty much unlimited in available current (as the battery is capable of putting out hundreds of amps), and probably not a very stable voltage. If anything I will probably need to add some additional resistance to tone them down as they were very bright.

The ID fits perfectly just over my ER32 collet mill spindle and quill. Could probably just attached it with double sided tape to the mill head, but I'll probably turn up an aluminium ring to fit it into (and then stick that to the mill head with double sided tape if I can't figure out any other way).

 

[Franko]

I think LEDs require some sort of transformer (magic box). I was looking on Amazon and saw a pair that looked just like yours, but the photo didn't show anything but wires. There were two sets I looked at. One was $7.50 and didn't show anything before the LEDs, and the other was about $16 and showed them.

The ring lights I used had three set screws which worked very well. I think some sort of ring with a bit of a top flange for a shade would be good to keep down the glare of the LEDs.

 

[MozamPete]

Normally it is just a matter of limiting the current flowing to the LED - too much current will kill them pretty quickly. As these are specifically designed to connect to a car 12V system I would assume some sort of current limiting is build in, possible in the small case. Will pull one apart and have a proper look over the weekend.

 

[Franko]

All I know, it's a magic box. I just know that all the LED lamps I've seen have some sort of circuitry that filters or conditions the power to them.

 

[mattinker]

I think LEDs require some sort of transformer (magic box). I was looking on Amazon and saw a pair that looked just like yours, but the photo didn't show anything but wires. There were two sets I looked at. One was $7.50 and didn't show anything before the LEDs, and the other was about $16 and showed them.
.

LED Light emitting Diode, a diode allows current to flow in one direction. LEDs require Direct Current, these 12volt ones will run off a 12volt wall wart or any other 12 volt DC power source with enough milliamps ! Not very magic!! If wired backwards they won't work, shouldn't hurt them just change the wires round.

Regards, Matthew.

 

[Brain Coral]

Nothing to do with machining, but I had bought an old surveyor's transit level, made by C.L. Berger and sons, back in the summer at a large flea market. The mahogany box looked a little rough and the leather carrying strap was quite rotten. So, I decided that I would clean up the box and then make a new leather strap. The old strap had a bulged section in the strap where one's hand would grasp it. I wasn't sure what was inside to create this bulge, but it turned out to be a wooden dowel with the ends chamfered. So, using the original as a pattern, I cut out the leather pieces and shaved down the edges of the strap in this area to better conform to the dowel. Also, I wet down the leather to allow it to stretch over the whole works. There are quite a few additional steps that goes into hand sewing leather, but I won't bore you with the details.

Here's the kit before I worked on it...







Some pics of the sewing underway...





And the final finishing...









I had to partially dismantle the transit to free up the horizontal rotation of the scope, but it works beautifully now. I need to apply some neatsfoot oil to the leather to darken it down some.

Brian

 

[hman]

Nice restoration! Do you also have a tripod and a rod?

 

[Brain Coral]

Thanks John

I do have a tripod and a rod, but not antique ones. I might make a tripod based on photos of old ones, just for fun...

Brian

 

[Franko]

Nice work, Brian. I always wanted a transit. I don't know what I'd do with it, but they seem like a swavey tool.

 

[Brain Coral]

Nice work, Brian. I always wanted a transit. I don't know what I'd do with it, but they seem like a swavey tool.

Thanks Franko

I love old tools of all kinds, and with me being a carpenter, it has special appeal. It has a very sensitive and adjustable level and can still be used to check the level of structures, forms and footings and can check for the squareness of a building. For it's age, it's quite sophisticated in it's design and use. For $50.00, I couldn't resist.

I also have a more modern T2 theodolite made by Wild/Heerbrugg of Germany that I purchased at the same flea market a few years ago. This unit is far more complex and can do so much more. I am still trying to absorb all of the functions and settings.

Brian