« Eating Southern-Style | Main | Yahoo! Mail Beta - don't install it! »

April 17, 2011

Comments

Will

" once you occlude them, you can't see them,"
Exactly! That means "stop now, you have lost alignment". Actually, one for each side would be best. If you lost one target beam, you are at an angle.

Another, perhaps simpler, way would be to stripe the pavement with an appropriate paint to use as a tire guide. Adding some reflective particles before it dries would help at night or when raining. Maybe check with a roadworks crew to locate the right paint and sparkles for your surface. Then you just need some light, either yard or truck mounted.

I would suggest locating it to the outside of your driver's side tire(s). A centerline position would not be accurate enough.

Jim

You don't need taxi lights on your ramp. You need one of these:

http://www.walmart.com/ip/Sumas-Media-Car-Rearview-System-SMC-DUAL-EX/13812321?findingMethod=rr

You could probably camoflauge the camera in some "mil-spec" appearing housing or gadget of some kind. And just keep the monitor in an O.D. gear bag under the dash, and magnet mount it in view when you need it.

There's your 2nd soldier, Airman!


Jim
Sunk New Dawn
Galveston, TX

Rivrdog

Yeah, Will, that thought occurred to me also. Some of those "rope" lights on the fence and under the eave on the Shed next to the pad. I could even get fancy and hook it all up to a remote control which I could keep in the cab. First, I will experiment with a series of reflectors, and a medium light source on the truck to light them up, something like my directional LED lanterns, of which I carry two. I'll rig some sort of magnetic mount to them, and they'll direct a wide beam to the rear/sides t light the reflectors.

I think I would stay away from lasers: once you occlude them, you can't see them, whereas there is enough scatter from a LED lantern beam to see even if the beam is a bit off-target.

Will

Looks like you need two (or more) lights for alignment. I would suggest a series of LED lights running down one side of the pad that you can line up in your mirror. Another option would be to use a laser that would be targeted on a part of the truck in front of you, such as the front fender. Position and alignment of the beam would have to be accurate to work properly. You could mount it on the truck, to reflect off a stationary mirror mounted at the back of the pad, but this adds sensitivity and complexity to the design and use of the system. Best to keep it simple.

Mounted at the back of the pad, you want the target surface to have enough vertical surface to accommodate any height change of the truck as it moves through the critical distance. If the target surface is too small for this, you can stack multiple lasers to always keep a beam in view. Check alignment of them with a broom handle, or similar straight object, on occasion. I suppose you could make a target board that would mount onto the truck for this purpose, if the fender doesn't work. Keep it near the power switch for the laser?

Try to avoid using your rearview mirror as the target, as even the little pointer lasers can cause vision problems with enough time exposure (direct impact to the eye, not scatter). More power makes even shorter time exposure a possible problem. Not trying to scare you, just imparting my own experience with HeNe alignment lasers used in optical systems. It can leave your eye(s) feeling like you looked into the business end of a tactical flashlight on strobe. Annoying, and could last for days, with the industrial type (higher power-different class) HeNe's.

The comments to this entry are closed.

Categories

Blog powered by Typepad