Adding sensors to a Astro 3210 motor

[methods]

Unfortunately the change in forum settings means that you now have to click each picture - but here they are for reference:

Cyclone hall setup

-methods

[gwhy!]

There is no reason that this method could not be used for out runners also but mounted to the front of the motor but will also need a different number of mags in the rotor.

I think positioning the sensors in a small arc around the edge of the can (as you have already done) would be an easier solution for the HXT style outrunners.

Given that these outrunners are usually 14 pole motors? the sensor spacing could be as little as 120/7 = 17.14 degrees.

I think i will start a new thread to discuss adding sensors to these motors

Burtie

Yes it would be tight i didn't think of that, The arc method was pretty easy and do work well.

[Miles]

There's about 1/2" of space at the end of the inside of the rear of the motor. I think your nifty little widget will fit inside there.

Just measured mine:

The core starts 15mm in from the inside face of the end-cap.

The internal dia. of the core is 45mm.

The outside dia. of the bearing housing is 25.4mm and it protrudes 7mm from the inside face of the end-cap.

The rotor endcap is 3.5mm thick with an integral spacer 15.7mm dia. protruding 5mm from it (to the bearing).

Anyone want to see photos of the rotor?

[Burtie]

Yes please Miles!
Pictures are good

[Miles]

Ok. Here's the rotor:

[Miles]

Here's the stator:

[bigmoose]

Miles are the magnet poles made up of 10 thin magnets? What does the goo look/feel like between poles? Are the magnets captured under the aluminum end caps? If you have a macro lens, a couple more close ups of the rotor structure appreciated!

[Miles]

bigmoose,

That's about as close as I can get with my big camera. If I can get my old Coolpix 990 working, I'll take some close-ups

It looks to me like thin magnets on edge, bonded into slots in steel. I'll see if I can get a better shot and post the full-sized image.

[Miles]

Here's the full-sized version of the above rotor pic.

[bigmoose]

Thanks Miles! From the large photo, it almost looks like a pole composed of magnets; followed by an iron pole; then another magnet composed pole. Does it look like that in person?

[Miles]

That's what it seems to me. There is a steel bar with slots cut in it. The magnets are bonded edgewise into the slots and are set below peripheral surface of the iron. So, the wide poles are iron and the narrow ones are the magnets. Does that make sense?

[Miles]

Here's the full-sized version of the stator pic:

[fechter]

Cool. I've thought about doing it that way before. That should really keep the magnets from flying out.
I wasn't sure if you built the poles like that if they would be limited by saturation. I wonder what kind of steel it is?

Is the goo stuff hard like epoxy?

[Miles]

I wonder what kind of steel it is?

Is the goo stuff hard like epoxy?

The steel's quite hard, that's all I can say

The goo is hard, too......

[bigmoose]

One last question, I promise! How many magnet poles, and how many iron poles, & total poles, just to be sure they add up?

[Miles]

One last question, I promise! How many magnet poles, and how many iron poles, & total poles, just to be sure they add up?

8 of each - 16 in total

[Miles]

Well... Looking at this rotor in the light of day.... I'm not sure my initial interpretation was correct....

The surface on each of the wider pole pieces differs and the way the surface is pitted at the corners looks more like a sintered/cast product....

[Miles]

Here's another pic:

[Burtie]

Thanks for the pictures Miles, always nice to know what the inside of stuff looks like! I am sure they will give all our motor designers here some food for thought.

etard wrote:
Maybe you could connect a blue LED that turns on each revolution too!!

I am sure that most people here have a good idea about what hall sensors do.
But just for fun , here is a very short clip I made showing the operation of a latching type of hall sensor.
[ Edit: hall sensor is Honeywell SS411A ]

http://www.youtube.com/watch?v=qr2QtTzuiaw



Sorry etard, ---I didnt have a blue one .

Burtie.

[Ypedal]

How high RPM can you keep up with using halls ? ( this may be a very dumb question, i apologize in advance if it is.. ) hub motors < 1000 rpm, RC motor 8000+

[gwhy!]

How high RPM can you keep up with using halls ? ( this may be a very dumb question, i apologize in advance if it is.. ) hub motors < 1000 rpm, RC motor 8000+

My setup runs nice at 10k so I don't think there will be a problem with switching speed..

[TylerDurden]

With that space, would Luke's optical system be as good or better? (Gary mentioned this idea)

http://endless-sphere.com/forums/viewtopic.php?f=28&t=14477&start=0

[MitchJi]

Hi Y,

How high RPM can you keep up with using halls ? ( this may be a very dumb question, i apologize in advance if it is.. ) hub motors < 1000 rpm, RC motor 8000+

Different question but somewhat related. Justin said that the controller that he took on his cross Canada trip (that works in either sensored or sensorless modes) would not work in sensorless mode on most RC motors due to speed.

[johnrobholmes]

We run three slot motors past 50k with sensored RC car setups, and I have spun 12 slot sensored motors past 12k. I don't think the hall effect sensor will be the limiting factor on commutation speed, moreso the controller's max commutation rate.

[Burtie]

I now have some pictures of the sensor unit fitted to a double shaft 3220 motor

3220 sensor front on.jpg (106.88 KiB) Viewed 958 times

3220 sensor side on.jpg (101.51 KiB) Viewed 1093 times

I will wire it all up and test the motor in both Delta and Wye configurations and post the results when I get time .


Still looking at embedding some similar implementation inside the end-cap, not there yet tho.

Burtie.