Designing and making a powerful HMI searchlight

Searchlightexpert

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Hello,

I am new to this forum as a member but have read it for a while and discovered many good ideas from different users.

I am planning to develop a high power searchlight with short arc lamp, remote controlled from a joystick through a pan/tilt gir. The searchlight shall be marine grade for outdoor use, compact size and the drum shall be made of seawater resistant aluminium for good heat management. I have decided to use a HMI 1200W/SE metal halide lamp with a hot-restrike ignitor combined with a 12" deep-dish parabolic glass reflector with short focal distance. The focusing system shall also be remote controlled from the control panel through a servo motor inside searchlight drum so it will be possible to switch between wide and narrow beam. Searchlight shall be operational in a range of +/- 175 degrees in horizontal direction and +/- 30 degrees in vertical direction from the pan/tilt gear. Speed apx. 15-20 degrees/sec. horizontal and apx. 5-6 degrees/sec. in vertical direction. The lamp shall be cooled by an internal forced air cooling system circulating air internally inside the drum, managing the heat.

I will start with the design of the searchlight drum. When the drum is completed and all internal parts have been fitted, it is time to proceed with the remote controlled pan/tilt gearbox.

I will update with pictures here as the project progress forward. I expect a design and production time for apx. 2-3 months from now for my prototype.
 
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Searchlightexpert

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I have decided the searchlight drum to have a diameter of 35 cm and a length of 50 cm. The drum shall be made of a 2mm aluminium plate with thick walled aluminium support rings in front end and aft end.

mobileoffice

Here is the thick walled aluminium pipe which the support rings shall be made of.
IMG_1883.jpg
 
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Searchlightexpert

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mobileoffice
IMG_1884.jpg


And here is the aluminium plate the drum shall be made of.

Since this is a "one of a kind" unit, I will not spend any time designing the searchlight through use of CAD drawings for fabrication of parts by use of water/laser cutting equipment. Possibly a few parts for the remote controlled pan/tilt unit will require water cutting, I will decide when the time is there. First of all I will focus on the searchlight drum with all internal parts which will be a pure handmade unit.
 
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PolarLi

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Nov 17, 2013
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I will definitely keep an eye on this! But the pics don't show up?
Edit: now the pics work, cheers!
 
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Searchlightexpert

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I spend some time in the workshop last evening fabricating the drum out of the piece of 2mm aluminium sheet and the thick walled aluminium rings. I cutted a suitable piece of the thick walled pipe, machined it in the lathe into two pieces with correct length. One for stabilizing the forward end of the drum (glass end) and one for stabilizing the aft end of the drum where the insert shall enter from.

I calculated the correct length of the aluminium sheet, bended it to correct diameter, inserted the two thick waled stabilizing rings, one in forward and one in aft end of the drum and welded everything together with the AC/DC TIG equipment. It was a kind of precision work to achieve the correct length of the sheet but it became fine.

IMG_1888.jpg
 

Searchlightexpert

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And here are the drum with some of the stuff which are going inside it. Most of it coming from a skytracker.
IMG_1889.jpg
 

Searchlightexpert

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Jan 18, 2015
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What is this "skytracker" you talk of? Do they have a website? (What is this sorcery? :eek:)

No sorry, it was a unit which was stripped for useful parts long time ago due to a failure with motor functions. All other parts thrown in the garbage years ago.
 
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