MadModder

The Shop => Tools => Topic started by: Baldrocker on December 07, 2010, 06:34:31 PM

Title: tacho reflector
Post by: Baldrocker on December 07, 2010, 06:34:31 PM
Hi
For those who use a non contact tacho when you run out
of the supplied reflective strip try using a piece of ordinary
aluminium cooking foil shiny side out. Works for me.
br
Title: Re: tacho reflector
Post by: Bogstandard on December 07, 2010, 10:15:08 PM
BR,

I have a fairly old digital tacho (marketed for checking propellor speeds on model aircraft engines), and I use a white paint stick for the reflector.

One thing to look out for though, on mine, it doesn't give a true reading under flo-lighting. Something to do with the wavelength of the lighting.

To check it out, measure it inside, and without stopping the engine or moving it's setting, take the same reading out in daylight, or with the flo-lighting off.

On mine it over reads by about 300 rpm under flo-light.

It might be worth checking out, just to be on the safe side.


Bogs
Title: Re: tacho reflector
Post by: John Rudd on December 08, 2010, 07:35:33 AM
Bogs,

A bit of useless info...

The over reading is caused by the fluorescent lighting, its a multiple of the mains frequency at 50Hz....( your tacho reads 3000rpm..) I bet if you take your tacho outside it reads properly when reading a spinning object...for our American chums the tacho would read 3600 rpm ( 60Hz...)
Title: Re: tacho reflector
Post by: Bogstandard on December 08, 2010, 09:43:24 AM
John,

It is a fair while since I used it (when I made my turbine) and I knew it read 3 something over, what's a zero between friends, and yes, as mentioned, I always measure by the open door, so it is in pure daylight.


John
Title: Re: tacho reflector
Post by: Noitoen on December 08, 2010, 12:51:14 PM
At our local AKI store they sell some tape reflector in strips from TESA to use on motorcycle helmets. It comes in red and white and is as good as the original tape. ;)
Title: Re: tacho reflector
Post by: Alan Haisley on December 14, 2010, 01:12:30 PM
Here in the states, 3M markets a product in hardware & home improvement stores. This is a heavy gauge aluminum foil tape for sealing ductwork. (Duct tape is no good for ducts, imagine that    ::) ) A roll of this could be cut into a bazillion reflective tabs for use with optcal tachs.

Alan
Title: Re: tacho reflector
Post by: Ed ke6bnl on December 15, 2010, 12:57:19 AM
Here in the states, 3M markets a product in hardware & home improvement stores. This is a heavy gauge aluminum foil tape for sealing ductwork. (Duct tape is no good for ducts, imagine that    ::) ) A roll of this could be cut into a bazillion reflective tabs for use with optcal tachs.

Alan

Thats the stuff I used cut up some small strips and always have them ready. Ed