If your not comfortable with the MCU route I believe you can make something with a dpdt relay and some switches such that you can reverse the drive direction but if you drive into one of the limit switches it will lock out drive in that direction, only allowing it to go in reverse.

Otherwise a servo type system shouldn't be too hard to hack up (probably easier and more robust than a limit switch based one) with the new(ish) magnetic absolute position rotary sensors.

I'd suggest MCU into a victor as the way to go ;->
_________________
Mechanical engineers build weapons, civil engineers build targets

Yeah, I was thinking that a Victor and some logic would do it. Those sensors sound interesting. thanks for the tip.

Anyone know of any suppliers for colored magnet/winding wire?
Looking for something in the 0.8mm - 1mm size.

Want to wind some DLRK brushless motors and some colored wire would make identifying windings a lot easier
_________________
https://www.halfdonethings.com/

Will answer my own question... (More googling does help )

www.bulkwire.com

They stock Natural/Gold, Red and Green magnet wire in a range of thicknesses and sized rolls. Prices and shipping look reasonable.
_________________
https://www.halfdonethings.com/

Yay another overseas store...
_________________
( •_•)

( •_•)>⌐■-■

(⌐■_■)

YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

Just wondering if anyone has played with any good rotary encoders or used hull effect sensors to detect the number of rotations of an axle .
Im having trouble finding any encoders that could be useful on more then 15w motors. ATM looking at mounting it to an output on a 100W scootor. or the output from a 3:1 reduction from a 100w scootor .
Just need the RPM mostlikly. but full location of the shaft would be more ideal
Any sugestions would be apreciated
_________________
Remember to trust me, I am an Engineer.

http://www.youtube.com/watch?v=rp8hvyjZWHs

The Opensource RepRap 3D Printer Project uses a Magnetic Rotary encoder chip from AustriaMicroSystems called the AS5040. that looks pretty clever - it can indicate position speed, direction etc all from a single magnet. I checked it out a while back and thought it looked pretty useful.

Unfortunately, I couldnt find any of the RepRap Kits that were in stock at any of the suppliers, you might need to dig around some of the RepRap Kit sources to see who actually has some - might take some finding, but read up on what it can do and it looked like the smartest pos encoder Ive seen.

Theres even example code (in that Evil/Easy Arduino code that people share so friendly ) for you to look at.

Let me know if you find somewhere to buy one (or more) - I'll split the costs with you if you like, since I can think of a few uses for one myself.

http://reprap.org/bin/view/Main/Magnetic_Rotary_Encoder_1_0
_________________
Great minds discuss ideas. Average minds discuss events. Small minds discuss people

You can buy the AS5040 from Farnell Australia for $22.59/chip. Currently 3 in stock.

The rest of the circuit looks pretty trivial, quick session in Eagle and an email to BatchPCB gets you a board done for <$10. The rest of the components you can order from Farnell with the AS5040 chip.
_________________
https://www.halfdonethings.com/

Thanks brett/aaron.
You are right it does sounds like a very useful chip compared to a lot of the other options avalible. Ill look into it further

And not that evil Arduino that code is hard to read (compared to C IMHO but a lot disagree) but still guess its bassed on a c derivative so the sample code may be of use to getting it working. most of the code on the rerap page brett linked to looks like near pure C where it counts anyway.
_________________
Remember to trust me, I am an Engineer.

http://www.youtube.com/watch?v=rp8hvyjZWHs

I'm looking at those AS5040's for sensing position for sensored brushless motors.

keep an eye on the speed, the higher resolution versions are limited to like 10 RPM.
_________________
Mechanical engineers build weapons, civil engineers build targets

so yeah, even tho ive been distracted lately by other matters and not been focusing on robot stuffs i can officially say i love my job, boss is lovely, people i work with r good and ummm..... yeahhhhhh HUGE MOTORS

next to a hawker battery for comparison and rapture in background

Service department had a cleanout and one of the main techys there John should be joining this forum any day now, hes an awesome guy

But yeah ill be working through these over next week or so testing them and tossing what cant be fixed (screwed windings, brushes not there etc), already got three complete setups working (gearbox and motor) and every motor works fine practically so.....)

the motors all have electric brakes on the end and a tiny d shaft but when u rip the brake off u get a nice 4cm or 8mm shaft basically

If anybody needs a electric motor for a pump or miscellaneous project of a large size let me know via pm and well sort something out

Still got half a box at work to go through still







Oh also the gearless/brushless drives we use for some of our power chairs, literally about 12 cm diam and 6 cm thick, there insane. Ill never have one as there roughly 5 grand each
_________________
Andrew Welch, Team Unconventional Robotics

windings can be fixed, those look like awesome servo motors for CnC stuff then
_________________
Mechanical engineers build weapons, civil engineers build targets

quote:

---

Originally posted by Spockie-Tech:
The Opensource RepRap 3D Printer Project uses a Magnetic Rotary encoder chip from AustriaMicroSystems called the AS5040. that looks pretty clever - it can indicate position speed, direction etc all from a single magnet. I checked it out a while back and thought it looked pretty useful.

Unfortunately, I couldnt find any of the RepRap Kits that were in stock at any of the suppliers, you might need to dig around some of the RepRap Kit sources to see who actually has some - might take some finding, but read up on what it can do and it looked like the smartest pos encoder Ive seen.

Theres even example code (in that Evil/Easy Arduino code that people share so friendly ) for you to look at.

Let me know if you find somewhere to buy one (or more) - I'll split the costs with you if you like, since I can think of a few uses for one myself.

http://reprap.org/bin/view/Main/Magnetic_Rotary_Encoder_1_0

---

Is there anything fun I can do with a plasma screen that has a cracked screen? Picked it up off the side of the road, from a change of contrast and some vague outlines, everything up to the display seems ok-ish.

Assuming it's pointless to fix based on replacement screen cost, looking for some hack for it...
_________________
They say that he crossed the fine line, from insanity to genius.

Turn it into a fish tank
_________________
https://www.halfdonethings.com/