KKW entry to machine made - 3rd annual build competition (updated 8-4-15)

Update 8-4-15

So at the prodding of n10sivern I gathered my thoughts and put together an update for the progress (small though it may be) so far.

I have 3 fresnel lenses I bought from Edmund Optics. 11’‘x11’’ fresnel lens I’ve done some handheld testing with an XM-L2 at about 4 amps with a lens from a sipik sk98 clone as a precollimator. I think the lens diameter is pretty close to what it needs to be to be an effective precollimator. I also tried it with a 50mm and 100mm lens to see if there was any improvement in output, and although I could shorten the focal length more with them and achieve focus, the area of the fresnel lens being used was too small. With the 100mm lens is was effectively “punching through” the fresnel, and the output was essentially that of the 100mm lens alone. I didn’t have an RA on this LED, so I don’t know how it compares, but with the mediocre quality precollimator it produced about 1.5mcd.

I also pulled the lens off of the Deerelight DBS V3 aspheric that I finished up with a collar recently, that light with the 50mm lens produces about 318kcd, behind the fresnel it produced a max reading of 3.2mcd.

It looks like the 1.5mcd output goal will be easily achievable, especially considering I’ll be driving XM-L2 T6 4C’s at around 6 amps. I’m going to try at least a couple other small lenses around the same size as the SK98 lens and see if I can find something that produces even more output, or larger projected image size. I have thought of going with an XP-G2 but I’m concerned about the period of on time as sweeps, so the bigger the better on projected image size, and at 1.5+mcd it should have plenty of range as a beacon.

The mechanical side of the design has been roughed out, but I’m starting to think seriously about how I might be able to further simplify by reducing the number of parts in the design. Here’s a picture of the current model roughing out the positions of the main components relating to the frame and rotating element.

I did find a solution to simplify the battery pack, charging circuit, and wiring of the entire build. These adjustable boost controllers are capable of 6A output, with a maximum of 9A input. I’ll use 3, one for each LED, and the input amperage shouldn’t exceed 9A even when the batteries drop to 3v. I’ll add one more to power the 12v gear motor and a 12v fan.

This means I can have one big parallel battery pack, with a single 4A charging circuit from Mountain Electronics.

It will take a long time to charge all the batteries up, but it’s safer, and that means a lot to me. If I use 24 batteries in parallel I should be able to expect at least 2.5 hours of runtime at full output, and about 14-15 hours to charge. The boost controllers themselves should be about 90-93% efficient. I’m pretty sure I can wire two resistors through a DPDT switch as a replacement for the control pot to give it two safe modes without having to use any sort secondary drivers to give it a lower mode. I’d need to figure out the exact resistor combination to use through a little trial and error I suspect.

That’s about it for now, I’m probably forgetting a few things, but at least there has been some movement, even if I am freaking out at this point about the time crunch.


(thinking outside the box)

So, I’ve finally decided what to build. It’s inspired by my recent family vacation to Florida where we visited the second tallest lighthouse in America. Ponce Inlet Lighthouse

They had a really cool collection of fresnel lenses. In honor of that I’m going to build a portable lighthouse. The plan is for something that can be carried out to a high location and act as a beacon. I plan to have it rotate, and am aiming for a minimum of 1.5mcd and may hit 2+ times that, which is 4-7x the candela of the brightest fresnel lens they had on display.

I’ve been talking with MEM to get some direction for the lens system I’ll need to use. He pointed me towards the fresnel lenses at Edmund optics as good quality without destroying my wallet (still pricey though at $107 each, fortunately I found someone who wanted to donate some money for this build). The fresnel lens focal length is a bit too long by itself to shrink the whole thing down as small as it can be based on their width. By using precollimating lenses I can bring the focal length down to the desired distance I need so that the 3 fresnel lenses can be held in a triangle by three vertical rails, with the LED’s and precollimating lenses mounted on a central post. The RA collars are probably overkill, but it just feels right to have some sort of reflection mechanism at work inside of the portable lighthouse even if it’s not a parabolic mirror rear reflector like in the original kerosene lamps. The entire triangular lens and LED assembly will rotate as one unit. I’m thinking that the batteries, switches, gear motor, and all wiring will also have to be housed in the rotating assembly to eliminate twisted wires and oddball connection methods.

The top and bottom of the lighthouse will be stainless or aluminum sheet rolled into rings and then welded together. There will be some sort of bracing to hold them together with space in between for the lamp assembly. These rings will be what the tripod and carrying mechanisms will be mounted to. I haven’t decided yet what kind of bearing system I’ll use to allow the lamp to rotate, but my first inclination is 6-8 adjustable bearings riding in a track on top, and 5-7 bearings (some for horizontal, some for vertical control) and a drive wheel on the bottom.

Estimated Parts List:

3x 11”x11”x7”FL Fresnel lenses (Ordering from Edmund Optics)

3x 40-70mm precollimating lenses (Possibly Jax Z1 lenses as I already have 2-3 of them)

3x RA collars (Will make from SS or aluminum and then painted with clear acrylic if aluminum)

3x XM-L2 T6 4C’s, dedomed, on Noctigon boards (probably, I’m looking to get a very warm color to be close to a kerosene lamp tint, Have the LED’s)

1x Frame to mount Fresnel lenses (Milling at home from aluminum)

1x Central mounting post for the LED’s and precollimating lenses (Probably copper tube)

1x Switch to turn on (Probably have already)

1x Gear motor to rotate the lens and LED assembly (Plan to purchase locally I hope)

1x Tripod or stand assembly mounted to the lighthouse (Plan to make from tubes or 80/20 track)

1x Outer shell to mount everything to (Plan to roll from aluminum or SS sheet)

12-16x Bearings for rotation

2x Rolled rings to trap lamp assembly vertically

1x Battery pack built from Sanyo laptop pulls (probably 15-20 batteries, Have the batteries)

1x Driver to push around 70-75 watts to the LED’s (need to find)

1x Driver for gear motor (this may be a pretty simple circuit, or nothing more than a resistor inline with an on/off switch)

1x Cooling Fan

1x Cooling Fan driver (same note as Driver for gear motor)

1x 4A charging circuit (Have)

1x Huge amount of time (trying to source, will be contacting wholesalers soon to see where more can be found)

(gratuitous pictures from lighthouse)

More details to come.

more details

Have you ever been in the box?

Boxes are small and smell like cardboard, I avoid them.

better a cardboard box than a pine box :wink:

Sounds like you need some higher quality boxes bro

Some really nice flashlights come in boxes!

Fixed that for you. :slight_smile:

NL-post gave me a special deal. Starting this year ALL my flashlights come in crushed boxes. At no extra cost :_(

Good luck in the comp., KKW! :beer:

Oh man am I glad you are in the Machine Category. If you build anything that is on par with your knives, it will be very special indeed.

Best wishes :)

Speaking of knives, I need a blade... Oops, different forum.

Looking forward to the build!

Actually a knife light that doesn’t suck is what I’m leaning towards right now. I’ve never seen a good one. Nothing is set in stone, just the first thing I’m seriously considering.

Nope, it’s going to be a lighthouse.

I thought I had something funny to say but forgot what it was. Had to do with knives, hacking, boxes, and zombies. Will it be a boxcutterpoisonpeknifelight?

Dunno, I’m still trying to think of something better. A knife light feels a bit predictable, but a good one would be a first that I’ve seen.

KKW is building a bayonet/machete with a LED to attach to my bazooka!


Plan is starting to materialize. :bigsmile:

More details added to OP.

I’ve always wanted a lighted head choppin’ muderin’ axe… J)

You could easily use a slip-ring assembly to get power from the base with batteries/motor in it to LEDs in the rotating head. They can be had for a decent price (Ebay). Probably not quite as reliable as having everything in the head, but it probably makes for better packaging.

The only reason you’d need that is in the zombie apocalypse after the batteries are dead in n10sivern’s zombie killing bazooka.

I’d do it on commission though. :bigsmile: