Howard Johnson Replication Tube Claim

[X00013]

as far as companies that are willing to do what mylows is not , i found this place     

http://74.125.93.104/search?q=cache:YLYzCE1e3CMJ:www.servorepair.com/why_choose.htm+remagnetize+service&cd=1&hl=en&ct=clnk&gl=us

and they say this

Why do we re-magnetize all motors?
It is important to understand that once a servomotor, stepper motor or tachometer has been taken apart for repair, it will usually not work properly again until the magnetism is restored to its proper level.
The signs of weak magnets or improper magnetism are low torque, high current and/or intermittent failures. We know how to solve these problems for you. We have the drivers and the fixtures necessary to re-magnetize almost any motor you send us. If a fixture does not exist, we will design and build one to do the job. We don't just re-magnetize a motor and hope it's right. We have the test equipment necessary to do the complete job. We check the flux density and pattern throughout the total magnet assembly to insure that you get the maximum torque the motor was designed to produce.*

So, looks as tho all mylow had to do was send his build to this place and they will make it all better!, Thanx Gnite

[JRHall]

I ran a couple of experiments today.  Since I haven't been able to find the channel magnets I put together groupings of magnets made by sandwitching a neo between two pieces of bar stock I purchased at Home Depot.  The bar stock was 1/4 and 3/8 square in 1" lengths.  I set up a 1 1/4" X 3/4" U shape magnet on the rotor.  One note is this was run on Plexiglas, not aluminum. 

With the set up as described by Mylow I got the expected kick in one direction and the rotor was blocked in the opposite direction.  Magnet spacing in relation to the U-shaped magnet length made a huge difference in how well it worked.  Also, the U-shaped magnet face for N & S is .308" wide.  The 1/4" magnets worked better then the 3/8".  Based on the results I got today it looks like the stator magnet face width needs to be wider then the rotor maginets.

Since I am seeing the rotation with the incomplete setup I had today on plexiglas I think I will finish the setup to and hopefully will see the full rotation.  Three and four magnet setup gets just about a full rotation on very bad bearings.

[nyctuber]

I ran a couple of experiments today.  Since I haven't been able to find the channel magnets I put together groupings of magnets made by sandwitching a neo between two pieces of bar stock I purchased at Home Depot.  The bar stock was 1/4 and 3/8 square in 1" lengths.  I set up a 1 1/4" X 3/4" U shape magnet on the rotor.  One note is this was run on Plexiglas, not aluminum. 

With the set up as described by Mylow I got the expected kick in one direction and the rotor was blocked in the opposite direction.  Magnet spacing in relation to the U-shaped magnet length made a huge difference in how well it worked.  Also, the U-shaped magnet face for N & S is .308" wide.  The 1/4" magnets worked better then the 3/8".  Based on the results I got today it looks like the stator magnet face width needs to be wider then the rotor maginets.

Since I am seeing the rotation with the incomplete setup I had today on plexiglas I think I will finish the setup to and hopefully will see the full rotation.  Three and four magnet setup gets just about a full rotation on very bad bearings.

JR, Mylow indicated exactly what you observed regarding the width of the stator in relation to the rotors in this recent video. http://www.youtube.com/watch?v=OnhBevG5Sz8&feature=channel_page  Excellent that you validated this effect.

[capthook]

CLaNZeR -
Great to see you replicating this.  I (and I'm sure MANY others) look forward to your results!  Thanks for all you do!!!

- - -
As to remagnetizing the stator:
Using neos stuck to the stator for a time - say overnight - should offer reasonable results.
For example: take an N42 neo and force a small ceramic magnet in repulsion to the face of it.  Once contact is made, the ceramic magnet will actually 'flip' its poles so that it is now in attraction rather than repulsion. (basically 'remagnetizing it in the opposite polarity)

There are numerous ways one might orientate the neos to the stator magnet to remagnetize.  Attached is a pic of some examples.

#1 would be a good one to try, but may not produce the desired field.  #2 may be better, but it's harder to get a magnet of the desired dimensions with the poles through the length rather than the width/thickness.

Trying different arrangements of the neos to the stator and observing the fields produced should results in the desired fields at some point.
(edit: Summary: as Mylow stated his attempt to remagnetize his stator with neos was unsatisfactory, it may just require a different orientation and/or size/strength of the neos.  how/what arrangment did he use?  Magnet size/strength etc. etc.)

(sterlinga - might you pass these thoughts on to Mylow on remagnetizing his stator?)

Any other recommendations/orientations on this?
Any FEMM simulations that would show this/assist this?

- - -
Of interest (IMO) is the ongoing attempts to 'rig' neos into a similar stator field... please keep posting ideas/tests/results.
A neo driven device shouldn't demagnetize (at least so easily) and should offer greater torque meaning a more useful device. (that is IF the effect isn't ONLY due to the stator demagnetizing)

[derricka]

So, if this is a problem, and you know the actual pole configuration, you just wind a coil around it. Hit the thing with a high amp pulse of DC and it is back in service.

Hey BEP, great idea. Building your own magnetizer should be easy.  Start with 120 VAC fed through a 1N4943 diode to charge a 300uF 200V DC capacitor through a momentary pushbutton labeled "charge". Another momentary high current switch labeled "Magnetize" would dump the capacitors charge into a ten turn, 14-16 gauge, wire coil. The coil should wound just big enough to go around the end of the magnet. Of course, with the high voltage capacitor involved, building this circuit into a properly insulated case would be essential. Adding a fuse and a 1 to 5 Meg ohm bleeder resistor across the capacitor would also be a good addition for safety. 

P.S. For those tempted to build this circuit:
Don't build this circuit unless you are familiar with proper high voltage safety procedures!