Joe’s ZFM Adventures

[Joster]

Hi All,

I figured I’d start a thread for documenting my work with the ZFM so others can see what I’m doing etc.

Here is a link to two videos. I built my first Bedini/Cole and it ran great for a few mins then the left two devices got hot and the rpms went for a dive. I think the resistors I got where too low in wattage. I remember Yaro mentioning that in his 2017 presentation but could be the devices them selves.

Also, wondering if the Bedini/Cole is intended to run with the recovery circuit (bridge rectifier) connected to the run bat or cap dump? Just thinking that I was running it with no recovery circuit at all so maybe thats what blew the transistor(s)?

Also, as a heads up, later this year I will have a completed Bedini/Cole PCB with swappable T)-246 slots, labelled component areas etc along with a Digikey BOM. That way anyone can just order the BOM and PCB and just solder it up and be ready to rock.

https://drive.google.com/open?id=11X...59BXkzpdwmsGX_

If anyone has any input as to what may be failing or any circuit build tips please feel free to let me know!

More adventures to come!

Cheers!

Joe

[Yaro1776]

I like your attitude!!!

[Yaro1776]

Joe,

The recovery circuit is just an add on and not necessary for operation of the ZFM circuit. The overheating of the transistors can be caused by several things, one primary reason is that the reed switch timing is a bit off and one switch/leg is powered up too long. Check each reed switch leg individually to ensure proper firing duration and on/off function, otherwise the board may be fighting itself.

First BP board had very hot resistors - James McD upped the resistor wattages and solved that problem. The transistors on the current BP board have heat sinks on them and they will warm up under high voltage and load. I use an oscope to measure both voltage and amperage real time since an ordinary clamp on amp meter averages out the reading and does not show the peak reads. Oscope is also very useful for getting the timing up to snuff.

I have not viewed your videos as yet - some issues on my end with .mp4 format and Google - I will get to it over the weekend.

[Joster]

Thanks so much Yaro! This is extremely valuable info for me. Yes my resistor eattages are way too low lol. I will have a dedicated youtube channel up soon to make the videos easier to view. Here is this one for now

https://youtu.be/yIvxoTFyxNo

[Yaro1776]

Checked out the YT link this morning, your ZFM Motor runs very smoothly and is very quiet. Great build!!!

Love the pillow block design and construction using the 3D printer.

[Joster]

update vid...

https://youtu.be/37N7CQIuoFU

[Yaro1776]

Latest vid demonstrates that you have overcome the initial setup problems. The reed switch support and positioning assembly is well done - this certainly will help with the timing. Assume that you are now running the full BP switch circuit.

Great progress and looking good! See what happens when you get around to progressively increasing the input voltage from the nominal 12v.

Have a good Thanksgiving!

[Joster]

oh man did i ever see what happens at 36 V with a full BP switch. Lets just say, straping tape does and can break. It sped up faster than i have ever seen before. So much so i was about to disconnect the battery and then "POP!!!!!!!!". I was looking around, i thought a transister had exploded or something, then i looked at the rotor and one of the magnets had busted through the tape and was sitting on the floor a few feet back. I was wearing safety glasses but apparently i need a face shield and helmet!! lol this was my first rotor so many many many design changes will be made on the second rotor. Anyway, man oh man does it howl. So, my question is, for connecting a generator: 1. Direct Drive vs Pulley's? 2. Axial flux vs permanent magnet dc motor spun as a generator (Which one is best? Axial b/c there is no cogging??)

[Yaro1776]

oh man did i ever see what happens at 36 V with a full BP switch.

Joe,

Welcome to the very exclusive (at this point) and very limited ZFM club that have experienced a rotor failure at high speed. Needless to say, glad all is well.

Most experimenters do not appreciate the physical forces that can be developed on the Neo's when RPM radically increases - it is a square function.

Just one of the reasons that a high strength Loctite structural adhesive is used on the YZFM builds along with the fiberglass packing tape for backup.

When your nerves settle down move on to the next build iteration. Any sense of the RPM? You can also consider adding a 6 volt battery to the equation if an adjustable PS is not handy.

Prepping to smoke a Thanx turkey starting around 7 AM Wednesday. The results are definitely wicked...

[Joster]

Thanks Yaro yes the ZFM seems to be a sparsely studied motor and yes i absolutely did under appreciate the forces occurring here. Anyhow, I fixed up the rotor and duct taped it good, replaced the reed switches and did a test at 24 volts. I figure I wont push the input voltage any higher with this build. Next, I need to accomplish the energy recovery and also put some kinf of generator.

https://youtu.be/alp6yLQ9Tb4

For the radiant energy recovery the thing is when i put the oscilloscope across the motor coil i dont see any spikes just a -12/+12 square wave. i have no idea why there is no spike. Anyone have any clue?

I will post a video showing a scope shot of exactly what I'm seeing.

[RS_]

Hi,

At the 2016 conference where JB demoed the ZFM, when i noticed that ZFM circuit did not have a Output Diode Bridge like a window motor circuit, JB told me and some others there, that the ZFM did not produce much of a spike, so no output diode bridge.... watching Yaro's vids, i do see a pretty good spike when he cranks up the voltage......

[Yaro1776]

For the radiant energy recovery the thing is when i put the oscilloscope across the motor coil i dont see any spikes just a -12/+12 square wave. i have no idea why there is no spike. Anyone have any clue?

I will post a video showing a scope shot of exactly what I'm seeing.

Joe - the Oscope wave should a form of square like wave, but with a 24 volt input to the two coil leads it should show +/- 24v on the scope. One scope lead to one coil wire and the lead's ground to the other coil wire. The pic below is one the latest 4 pole runs at 38v input and under moderate load. The blue trace wave is associated with the amperage where one grid block nearly equals 5 Amps. One can readily see when the voltage is turned off, there is a serious reverse voltage spike and then the rebound before the next voltage application. It is readily visible as the voltage is increased.



Hope that this is useful to you.

[Joster]

Thanks Yaro, yes that helps!

Here is the new 3d design Im working on that is very easily scaleable from mini to giant....

https://youtu.be/QfidMLnRi3I

[Yaro1776]

Here is the new 3d design Im working on that is very easily scaleable from mini to giant....

https://youtu.be/QfidMLnRi3I

Slick design work! The location and coil locking feature is very good. The modular assembly allows stacking of several assemblies as you have shown.

[Bradley Malone]

Joster. Wonderful work on the design. Are you by chance going to release the files? I have a prusa i3 mk3 with the multimaterial add-on and would love to try out your design. I have a few things I have designed that I could "trade".