Pulleys

[Jackpilot]

Any good source for small pulleys, bushings,bearings, etc ( US or Canada) for my throttle mechanism.??

[autocadplease]

I have had luck buying stuff on Ebay (R/C parts are cheap). Also, Princess Auto in Canada always has cheap items.
I have also stolen some of my kids Lego and K'Nex gears and pulleys! Please don't tell them!

[Jackpilot]

Looking for more rugged, preferably aluminum.

[KenK]

Try Small Parts Inc in Fla,USA they have a lot of stuff.

www.smallparts.com (http://www.smallparts.com)

Regards Ken K

[flightsox]

hello may be this might be of some use to u as i am useing them in my dual linked pfc yokes nice and cheep :D:D

http://www.mightonproducts.com/catalog/brass-faceplatebrass-wheel-p-8.html

[MudPuppy]

If the plastic gears inside an old VCR that you've gutted won't suffice...Find a few old power tools. Cordless drills where the battery is completely shot or jigsaws that lost their jig would be a good source of some sturdy metal gears.
(I like to tear things apart after I've worn them out...:lol:)

[diegocn]

Or you can use optical encoders or LVTDs direct.

[cscotthendry]

For bearings, you can't go past VXB. They've got bearings down to 1mm internal diameter and they're pretty cheap price-wise. Also try SDP-SI for that kind of products.

[Jackpilot]

Or you can use optical encoders or LVTDs direct.

Very interesting,
Found this too:http://www.macrosensors.com/rotary_position_sensors/rse_1500_rotary.html

How do you interface an LVTD?

[cscotthendry]

It looks like that LVDT gives a varaible DC voltage output, so I would guess that anything that can be used to interface a potentiometer could be used to read one of those LVDTs

[Jackpilot]

Seems much more precise than a pot...could be a great addition.

Maybe Mike Powell could enlighten us....Mike ...Hello...Anybody Home???

[diegocn]

Jackpilot,

An LVDT provides an AC voltage output, that can be filtered to
obtain DC voltage ( with a simple diode bridge ). You can build one,
and using the variable voltage output to get the position.

For mounting it on the throttle quadrant, you have many options.
You can mount direct on the throttle, that you will move the
LVDT in and out.

As an Optical Encoder, you could print a hi resolution print, a simple
circle with some things, and a infrared led and photo-transistor.
Then attach the circle in a way that it rotates with the throttle.

You need to provide some friction to the throttle, as this methods have
like zero friction, and so have a very low wear.

With the LVDT, the resolution is manly dictated by the LVDT construction,
some exciting parameters ( the LVDT should be excited by an AC voltage ),
and if using digital electronics for reading the LVDT output ( and you will :) ),
the resolution of the digital converter.

With the digital encoder, the resolution of the printed circle is what determine
the resolution of the encoder.

Nice info about LVDTs:
http://www.mikesflightdeck.com/lvdts.htm

[diegocn]

Some drawings to clarify

http://img195.imageshack.us/img195/8959/sinttulo1zvm.th.gif (http://img195.imageshack.us/i/sinttulo1zvm.gif/)

First is the one with LVDT.
Second and third is with optical encoder, with two mounting options;
in the side of the circle and in the circumference of it, respectively.

In the LVDT mount, the response is not linear, because the manner the
LVDT and the throttle are mechanically connected. You can get a linear
response from this non-linear response, with many ideas.

[Jackpilot]

http://i24.photobucket.com/albums/c29/jackpilot/stunned.jpg

[cscotthendry]

Uh oh! Jackjack is going to burst into flames!