Hacking a laser tape measure

A neat cheap little 50m range (checked true) measurer, would it be possible to change the f crystal to hopefully f/3 or so and get 150m range. Assuming (looks possible) to split send and receive and enlarge the 15mm capture window to 150mm window. Also assuming I can identify which is the crystal and is not integral with the ASIC, not epoxied over anyway. Would the LCD likely become unreadable at 1/3 the original drive f. Accuracy would be worse but decimeter resolution over 150m would be fine

Reply to
N_Cook
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MY concern would be whether or not the optics would support the longer distance. After all the trouble, you might have just a piece of landfill.

A Bosch device capable of that 150 feet is about US$60 these days, or less. And a cheaper off-brand device may be had for less than US$30.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

Its optics I'm playing around at the moment with this 17GBP 50m (150ft) not poking around inside yet. Just in the process of boring/grinding a hole through a 150mm glass 3 dioptre magnifying glass to try passing the the transmit beam thru the centre and then larger capture area for the focussed received, to see how that works at 50m initially, ie how much darker a "reflector" would be the new minimum .

Reply to
N_Cook

So far , so good. 5mm hole ground in the centre and simply holding unit in line with the hole, can produce a 5m reading without forcing errors from its operational window , across the room. Now to mount in a rigid tube , to try outdoors, over 50m span.

Reply to
N_Cook

return power on the detector will be 81 times less than it is right now, (twice the square law), so I think you are out of luck.

Reply to
Sjouke Burry

hence the larger window, 100x the area.

NT

Reply to
tabbypurr

You might consider using a retroreflective surface as your target (there's corner-cubes, bike reflectors, or Scotchlite products available).

Reply to
whit3rd

Perhaps that depends on whether the target being ranged is barely intended to be aware of the red dot on forehead! (I have not been reading all this thread...)

BTW Does the bigger window have a lens to concentrate the flux onto the same sensor?

Mike.

Reply to
Mike Coon

Whatever the intent - this is a perfect example of running down the proverbial rabbit-hole. Even if entirely possible, the results are dubious and the utility of the equipment destroyed except as a curiosity.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

We don't know yet if the laser measure will work. Whether its utility is destroyed or not. In fact, it seems to be working so far. I'm glad he is posting his experiments. Eric

Reply to
etpm

That reminded me one of these was laying neglected in the store, broken power supply ISTR.

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the 14 version. I dug it out and opened it up before trying to power up.

1978/79 CMOS and TTL and a rat's nest of after-thought/fudge flying components, despite OEM. Mini Nixi tubes I think rather than the pre-7 segment LED, electroluminescent displays , or perhaps mini CC display, difficult to view. Looking at the manual the original spec was up to 60km range with exceptionaly clear visibility it says ,and requiring one of those multi-prism reflectors , they left on the moon. I'd still rather mod a new replaceable DIY unit than this EDM that should be in a museum.
Reply to
N_Cook

Eric:

I am writing from the perspective of one who must rely on accurate measurements for revenue, and whose instruments are calibrated to this end.

For the purposes of a hobby - that is an entirely different matter.

Peter Wieck Melrose Park, PA

Reply to
peterwieck33

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