Vibration Sensor prevents Flywheel launch

[BruceM]

My off grid Listeroid has served me well for 16+ years.  It gets less use now that I have expanded my PV system and designed an ultra low EMI inverter which does almost all the AC power generation now.
It still serves as air compressor when I need more air flow, often combined with the inverter powered air compressor.   

I implemented some serious idiot proofing (I have impairments related to MS and epilepsy.) when I installed it 400 feet over a small hill from my homesite. A site chosen for sound, before I found out about the lovely sound of the CS series which does not need such a distance or a hill.  I added remote starting and shut down, and monitoring of oil (high and low levels), temperature, rpm and vibration. It can still be run entirely manually.  I used the Picaxe 40X2 pin Basic running PIC chips to implement this, which predated the now prevalent Arduino. The control panel in my shop communicates to the Lister engine shed via a couple pairs of a 450 foot run of CAT5 cable, using a simple opto isolated 600 baud asynchronous serial current loop.

Wednesday of this week I was running the Listeroid for some Gast 1UP based yard trimming, and it shut itself down showing a vibration fault.  On inspection, I found the red vibration sensor indicator showing.  The flywheel tapered key was on the floor against the North wall, and the (unloaded) generator side flywheel moved outboard from the engine about 2 inches. The flywheel had rotated on the shaft about 1/4 inch at the key- and this had caused the imbalance before the flywheel walked outboard all the way off the shaft.

This happened after 16+ years of running, and that flywheel key had never been removed.  I had neglected to add a 2" split collar to block the key to this side...something I will be adding later today.

This is the second time that my idiot proofing has paid off.  Once before it caught a low oil situation.

How I missed this key loosening on my monthly service and manual start and why it did so after 20 years is a mystery.  But I'm glad I had been ambitious about monitoring of this remote but highly valued engine.  It could have been a very expensive and dangerous disaster if the flywheel came off the running engine and through the wall of my shed.   

For a vibration sensor I used a surplus industrial mechanical vibration sensor unit that uses a magnet and spring, and have it adjusted to JUST not trip during the normal start up vibration. Cheaper new sensors are available now but this one, bolted to the cylinder just below the head did the job nicely.

Idiot proofing saved this idiot.

Don't trust your flywheel keys.  Put on split collars!

Best Wishes,
Bruce

[ajaffa1]

Thanks for the heads up Bruce. I`m currently working on getting backup power generation for my home and shed, this will include my old CS 6/1. I will definitely be investing in some split collars after your experience.
When I was doing maintenance work in a large sawmill we had a lot of equipment with gib keys. These would work themselves loose at this time of year due to the temperature changes at night. 40 degrees during the day and down to zero at night.
Very glad all that work you put into electronic monitoring paid off, I can`t begin to imagine how much damage a flying CS flywheel would cause at 650 RPM.

Bob

[BruceM]

I think you hit the nail on the head, Bob.  The daily temperature swing here is 30-40F in the high desert of Arizona. My off side gib key is held in by the pulley for the air compressor. The split collar "insurance policy" will go on the generator side as soon as it arrives. 

I hope your new home will be a boon for your and your wife's health and happiness.

Best Wishes,
Bruce


 

[veggie]

Hi Bruce,

450 ft. of CAT5 cable for control signals?
Is that 3.3 volt or 5 volt ?
I am surprised that there is any signal remaining at the end of that distance.
Are you boosting in any way ?

Veggie

[BruceM]

Low frequency current loop was often used for long distances to teletypes in the earlier computer days.  This one is 5V but would work the same at 3 or 12V drive with the right current limiting resistors. 

I applied it here with opto isolators to avoid problems with lightning caused shifts in DC ground levels between two separately (PV plus 12V battery) powered buildings.  You really want to use either optoisolators or better, fiber optics for long runs.  This is too long for plastic optical fiber, 300 feet is about the practical max for POF.   Mulitmode glass fiber is good to over 1500ft but I didn't want to spend that much (connectors and transmitters/receivers are a bit spendy) where it isn't really needed.

No boost is needed and this loop worked fine with only 5 milliamp current pulses.  I didn't need to go higher (which is what you'd do for better noise immunity). Current loops on twisted pairs are quite immune to common mode noise.  I didn't go faster than 600 baud as this was asynchronous serial - no data clock, and I was NOT using crystal oscillators, just the internal RC oscillators. Soft slow edges at 600 baud also means no EMI. 

[cujet]

That is one of the best stories I've read on here. Congrats for getting the safety systems right!

I don't use any safety systems on my engine, but it is probably time I do.

[BruceM]

Thanks. Cujet.  I just did an oil change and service and moved the compressor pulley inward 1/4 inch against of the off side gib key. With the new split ring collar now I'm feeling more secure. 

 The Picaxe monitor also shuts down if there is no air compressor or generator load for 10 minutes.  That has been very valuable for my memory problems.

There's now plenty of cheap, useful hardware not for the Arduino that lets you just hook up modules instead of doing your own PCBs.  I did a solar tracking project a year ago using them. I use the Arduino Nano with ADXL345 3 axis accelerometer and DS3231 real time clock module for a recent single axis PV solar "tracker".  Plus a BTS7960 H bridge for controlling a 12V linear actuator. The accelerometer lets you measure the angle of the solar panel, so I have the real time clock wake up the Nano (with LED's removed to save power) every hour, reposition the panel to the designated angle for month and hour, then go back into sleep to save power.  I have 3 single axis tracked PV arrays which have been doing the daily dance for a year now.  Nice to not need any active sun tracking, just a sealed box screwed underneath the rack.  If anyone here needs such a thing I'll make a post about the details. Very cheap and mechanically simple, unlike 2 axis...  I was not a fan of trackers before, but this about $130 per 18 foot rack using this actuator:
https://www.ebay.com/itm/275015055633?var=575299527943

Having much more PV power early and late in the day is a nice luxury. It was a fun low budget Arduino Nano project.

Best Wishes,
Bruce M

[AdeV]

There's now plenty of cheap, useful hardware not for the Arduino that lets you just hook up modules instead of doing your own PCBs.  I did a solar tracking project a year ago using them. I use the Arduino Nano with ADXL345 3 axis accelerometer and DS3231 real time clock module for a recent single axis PV solar "tracker".  Plus a BTS7960 H bridge for controlling a 12V linear actuator. The accelerometer lets you measure the angle of the solar panel, so I have the real time clock wake up the Nano (with LED's removed to save power) every hour, reposition the panel to the designated angle for month and hour, then go back into sleep to save power.  I have 3 single axis tracked PV arrays which have been doing the daily dance for a year now.  Nice to not need any active sun tracking, just a sealed box screwed underneath the rack.  If anyone here needs such a thing I'll make a post about the details. Very cheap and mechanically simple, unlike 2 axis...  I was not a fan of trackers before, but this about $130 per 18 foot rack using this actuator:
https://www.ebay.com/itm/275015055633?var=575299527943

Hey Bruce,

Good save with the safety shut-downs, I'd never considered a vibration monitor for my (as yet STILL unused in any project) CS engine, but I'll definitely be looking to add one in when (if!) I ever do get A Round Tuit.

Definitely very interested in your solar "tracker" project! I've just been looking into what I need to do something like that myself, as my roof points in all the wrong directions for good solar capture (especially in winter), so a free-standing small array of moving panels will, I think, be the solution for me. I've been struggling to find good DIY guides for a "proper" tracker; your simplified solution sounds much more up my alley!


Cheers,
Ade.

[BruceM]

I'll try to collect some photos for this soon. 
One thing to note is that if you either have lots of batteries or are grid tie (grid as battery), tracking makes little economic sense in that there is less power (and time) at lower sun angles. In these cases, ground racks with seasonal tilt (adjusted twice a year) will get you almost as much sun harvest with the simplest, most reliable possible setup.  i used the seasonal tilt method for more than a decade despite being off grid with a modest battery bank.  Because I already had tiltable racks, I was able to experiment with adding single axis tracking on the cheap to my existing racks.

When you are off grid, with a modest battery bank size, it can save fuel and/or battery replacement cost to extend PV direct power (through the battery but no draw on it) to earlier and later in the day.  That is where single axis tracking on a budget can pay off, especially for the non-winter months.  In the month prior and following winter solstice,  well oriented fixed panels will do nearly as well, as the azimuth range of the sun is limited, and the elevation range of useful power is also much restricted.

My two older racks  face SSW.  They now tilt from 60 degrees up from horizontal to -25 degrees from horizonal (northerly) to catch early sun in spring through fall. (This is a central eastern Arizona mountains location.) 

My newest 1700W rack is oriented N-S tilt axis, and tilts from East 60 degrees to West 60 degrees.  This one provides great early, mid and  late day power spring, summer and fall.  +-60 degrees is about the max you can do with a linear actuator...more than that requires a chain or gearbox drive ($).  New 2 inch x 0.1 thick square tube steel plus angle stock and 3 inch x 0.25 angle posts for this was about $550. (Same as seasonal tilt.)  Arduino tracker/and linear actuator about $160. 

For me, this means power for electric cooking, laundry, and power for tools (compressed air or other) much earlier and later in the day, most of the year while having a smaller, cheaper battery bank.  it does not make sense to do this where you have a bigger battery/grid tie.

Bruce M

[cujet]

I just retired and while the listeroids are not a priority, I will spend some time buffing them up. The safety aspect becomes ever more important as we age.

[BruceM]

I agree, Cujet.  One safety weakness of my engine shed design is the shaft on the IP side which drives the ST-3 is unshielded.  Less of a concern since I mostly do remote starts, but still, the risk of clothes being grabbed by the shaft at a moment of thoughtlessness or instability is something I'd like to correct.  I had a PVC drain pipe with cap cover over it at one time but it was friction fit relying on some electrical tape and didn't work out long term.

I wonder if you or some others have already come up with a nice solution.  Your high quality workmanship is always inspirational!

[cujet]

Thanks,

When I move to TN, from FL, I will probably mount the twin properly in my shop (on helicopter blade bushings) and make it the standby powerplant. A nice flywheel cover is absolutely in order. I was thinking of using simple EMT tubing from Homeless Depot, and bending it to shape. Welding it up and attaching metal screen, such as a robust hardware cloth.

The single listeroid is on a wheeled cart, and can be pulled around easily, so that one stays like it is.

[BruceM]

A floor mounted, EMT frame with wire mesh cage might be a good solution for my 6/1 setup.
Thanks for the good idea, Cujet.  I hope your move goes smoothly! 

[AdeV]

When I move to TN, from FL

Isn't that the opposite direction you're supposed to go when you retire? ::confused:: 

[broncodriver99]

When I move to TN, from FL

Isn't that the opposite direction you're supposed to go when you retire? ::confused:: 

Ade there is a semi-annual migration. The "snowbirds" all drive VERY slowly south to Florida for the winter then return north for the summer to get away from the Florida heat and crazies. I am in Virginia and when all of the snowbirds around here head to Florida they are replaced with snowbirds coming down from Canada. Interestingly enough actual birds do the same thing.

We spend half the year dodging Canadian Geese who just do whatever the hell they want. One of their favorite pastimes appears to be waddling around in traffic or slowly walking through parking lots in a manner as to cause the maximum traffic back up possible. It's as if they know they are protected by the migratory bird act which makes pretty much anything involving them a felony.

Not exactly what cujet is talking about but Florida is HOT in the summer. I can't imagine moving there just to sit inside in the air conditioning. Then there are the Hurrricanes. Tennessee is much more habitable in my mind.