Got Lucky - Right Place at the Right Time

[larryk]

Hi Lips, how have you been ? I found it on Craigslist in Madison Heights Michigan. It was to good to be true for $ 250.00. He, a young man in the Navy, was only asking $100.00 for it. He was reluctant to ship it to Milwaukee, (34 lbs.) but the added $ 150.00 to cover his troubles convinced him. I'll see on Tuesday if it's a scam of not. I bought a house last year, and now live 3 blocks from a medium sized airport, so I don't get a chance to fool around with spotlights and lasers in the back yard like the old place.
I sometimes go to Scott's home, CPF'er Tranquilitybase to test lights out.

 

[BVH]

Here's a pic of the Megaray battery pack being charged all at one time. Can be charged in as little as 30 minutes.

 

[larryk]

My Megaray MR250 arrived today. Man is this thing heavy with the SLA battery pack. Mine is the basic kit with the soft shipping and storage case. The only thing that may have been changed are the batteries. From what I've read, the batteries should be 10 amp and mine are 12 amp rated. Everything is working properly, that's a relieve. I'll need to get out of the city to really see how it compares to the Maxabeam.

 

[Lips]

My Megaray MR250 arrived today. Man is this thing heavy with the SLA battery pack. Mine is the basic kit with the soft shipping and storage case. The only thing that may have been changed are the batteries. From what I've read, the batteries should be 10 amp and mine are 12 amp rated. Everything is working properly, that's a relieve. I'll need to get out of the city to really see how it compares to the Maxabeam.

Need some pics of light and battery set-up Larry!

 

[larryk]

Here ya go.

 

[BVH]

Thanks for those pics Larry! Man o man, I can imagine those 3 SLA's weigh more than I do. Well, maybe close to what I weigh! I probably couldn't lift the vest. Get some light weight Lipo packs in there. Hobbypartz dot com has 6S 22.2V/3 Amp packs for $20.00 - when they're in-stock. Blue Lipo brand. Go from 216 Watt Hours to 266 Watt Hours and run the light cooler with less current flow due to higher Voltage.

 

[larryk]

Bob, have you taken apart one of yours yet. I will more than likely open mine up to see if the optic can be move forward a little. It seems on mine there is a spring clip that holds the optic in from the front. Also my optic seems to be made out of plastic. The optic is 102mm. That seems to be a common size used for telescopes. PS, BTW there's 4 SLA's.

 

[larryk]

He's a photo of the front telescopic tube. The spot will get quite smaller bringing the optic out about an inch. you would need to cut back the ridge using a lathe. I ran the light just holding the optic tube up against the front of the MR and at 7 feet gave it the tightness of the Maxabeam. But at 25 feet it produced a hole in the center. There is still room for improving the spot. You can experiment yourself by loosening the alen screws and working the tube out past the stopper.

 

[Patriot]

Great looking light Larry! The condition appears to be nearly perfect! I can imagine that vest feels like an anchor. Will be looking forward to beam shots!

 

[BVH]

Yes, partially. Unfortunately, all the circuitry and other components lay in the same half of the light except...the darn Cathode connection wire runs up thru the other half. So I separated them by about 3/4" and put them back together. I didn't want to undo the wire connector nut at this point. I did take out the telescope though and thought the same as you in that more forward movement may be beneficial. I'm not ready to separate halves yet because my new fan has not arrived so I put it back together for later. The fans are a little raspy and I could make out the brand and part number from outside the light. I ordered up new ones that are physically the same dimensions but move a little more air. I think it was 16 cfm to 24 cpf, IIRC. I may have a line on much cheaper bulbs. Report later when I confirm.

He's a photo of the front telescopic tube. The spot will get quite smaller bringing the optic out about an inch. you would need to cut back the ridge using a lathe. I ran the light just holding the optic tube up against the front of the MR and at 7 feet gave it the tightness of the Maxabeam. But at 25 feet it produced a hole in the center. There is still room for improving the spot. You can experiment yourself by loosening the alen screws and working the tube out past the stopper.

 

[larryk]

Yea that vest is unreal,it weighs about 23 pounds. Maybe it's a combo battery pack bullet proof vest if your shot in the back. I was thinking of making a removable battery box that could be attached to the base of the MR somehow. That would make it self contained and give a more stable base for it to stand on. It's quite tipsy the way it is now. I have a pair of 4s 5000ma Lipo batteries that I used in an RC boat. Running them in series would give about 30 minutes on high. The heat sink would need to be addressed though.

 

[BVH]

8S would probably over volt it if fully charged to 33.6. I've been searching and searching for a nice looking small box for the bottom and a nice, simple sliding and locking rail for ease of connect/disconnect but have not come up with anything I really like. I was going to use 2 each, 6S/4Amp in P for 6S/8Amp. Probably 25-30 minutes. I want it to look really good but have not found any boxes that do that. Nor any thin, simple sliding and locking rails. Please help!

 

[larryk]

I haven't looked for a battery box yet but I got a chance to test the light with the tube extended 1 inch. At first it looked very promising. At the short ranges (40 to 50 yards) I had available the beam was perfect. Much tighter and a perfect circle. But when I briefly shinned the light in the sky I could see that the beam about halfway up started to expand wider than normal.

 

[BVH]

I split the case on one of the MR's to replace a raspy sounding fan. Upon initial inspection, I noticed what looked to be a simple hold-down bracket for the ignitor (pic) had one of the two soldered attachment rods come unsoldered. Cleaned it up and re-soldered it. The fan coming out is a 12V, 2.5 Watt, 24 CFM unit. The fan going in is a 12V, 3.5 Watt, 29 CFM unit. I wanted to provide a little more cooling capacity over the 40 heat pipes. In earlier run tests with the front lens out, I noticed that a tiny bit of magic smoke was escaping after about 14 minutes of running. Despite a couple attempts to get it smoking and then quickly turn it off and ID the smoking culprit, I could not see anything. There is nothing flammable or smokeable in the bulb chamber except maybe the ring style Cathode electrical crimp connector insulation piece (red in the pic). So I removed it, as it serves no purpose. I also noticed a white residue coating both halves of the black body in the bulb chamber. (pic) I cleaned this off with some 95% alcohol. I also wanted to order a spare bulb and have been holding off to positively ID the bulb via a part number on the body of the bulb. It looks like the part number is covered by the yellow o-ring so I've sent pics to a bulb expert to see if he can tell me whether it's the Elliptical model or the parabolic model. I need the Elliptical, which is harder to find and more expensive. I won't know if I've fixed the magic smoke issue for a few days.


Note red crimp connector insulation piece. Suspected magic smoke source?

A little hard to see but the copper'ish looking rod on the right side has come unsoldered on the bottom half.

Repaired

Bulb mountig system front view

Bulb mounting system side view. Note the double concave lens about 3/4" in front of the bulb window

Heat pipes and fan (blurry, will fix later)

White residue in bulb chamber

 

[get-lit]

They really packed that circuit board. Being a military light, it should be weather proof, at least to some degree, and it should have an air filter. I can't make out enough from the pictures to see the source of the magic dust. Hope it works out.

 

[Lips]

Nice pics, thanks!


Did you wipe down the double concave lens for dust?


Is the cooling fan a typical computer fan?


No air filter system but it looks like it was designed that way... Blow it out with a little compressed air...

.

 

[BVH]

Yes, typical size - 60mm by 60mm by 25.4mm computer fan but none of them are really typical in the sense that the 60's on Digikey range from around 18 CFM to about 38 CFM, some with sleeve and some with ball bearings. The double concave was actually very clean but I did give it a wipe with a new eye glasses wipe. I agree that no air filter was designed into this light. The electronics and bulb chamber are 99.5% isolated from cooling chamber. The heat sensor wires and fan wires go thru a small grommet with a bit of space left over. I might just dab some silicone in there before I close it up. Then just blow and go. The only vulnerability is the fan bearing itself if it's not sealed. The two halves are mated tightly together but I would call it 99% water proof, not 100%.

Looking into the easiest way to try to get another 1/8" to 3/16" forward travel to see it the light will focus down tighter. My telescoping sleeve (which holds the flat rear/convex front secondary lens has two snap ring grooves. Normally, the lens seats all the way back in the bore against a thin bead of clear silicone and the snap ring goes in the second groove back, right against the lens. If I make a 3/16" spacer and insert it first, the lens will be moved out 3/16" and the snap ring can go right into the first groove and hold the lens snug. Just need to figure what to make the spacer out of. I have a lathe and could peel off a bit from the telescoping sleeve molded stop but I'd rather not make a permanent mod.

 

[larryk]

Was the bad solder joint causing the raspy noise ? I would be careful with that snap ring so close to the optic. My clip seems to be awfully stiff. I think it would be easier to temporally have the tube out a little past the stop to test the focus. That way you can easily test the focus between 0 and 1 inch forward. I had mine out about an inch past the stop and the short range beam was much tighter, but lost it at the farther ranges.
Maybe MR has it focused as good as it can be.

 

[BVH]

Larry, yes I'm very careful when using a tiny pick to catch the "right" end of the snap ring. Even though both ends look the same, I cannot begin to catch the left end to remove it but the right end is fairly easily caught and removed.

I don't believe the broken and separated solder joint was causing any noise. The two pieces were too far apart to vibrate together and the ignitor is well removed from where I was hearing the "fan" noise.

I see what you're saying about temporarily lighting the system up with the halves apart and the tube temporarily maneuvered back and forth. I may try that at the range because as you say, it looked good close up but not so good far away. I found that same thing when trying to optimally focus my Maxabeam at 50 feet. It was perfect until I went to the range with the same focus and it was no where near correct.

 

[larryk]

You only need to loosen the top screws to wiggle the tube out, then lightly retighten the screws. You my also want to mark you tube with a pencil when at the farthest factory setting. That way you can measure what length works best.