Interesting project - coil/magneto/flywheel tester

[browning]

I'm still having fun playing with rare earth magnet replacements for model t magnetos, just for giggles. They work well but it is hard to quantify outputs and I'm not crazy enough to build another engine every time I make a modification. I hit on the idea of using a defective engine block/crank/cam and driving it with a variable speed motor. Kevin Prus made one available to me and I set about modifying the front of the crank to accept a belt pulley and modifying the rear by drilling and tapping for a 7/8" stud for quick attachment of the flywheel. I built a stand and inverted the engine block and bolted it upside down on the stand and drilled the main caps for oil cups. I mounted a three phase motor and drive it with a VFD which is easily adjusted with a ten turn potentiometer. Speed is indicated by a magnetic pickup tachometer with the magnet glued to one of the rod throws and the pickup attached through a hole drilled in the side of the engine block. By installing the cam I am able to fix a timer to the front cover and I have installed a coil box to the contraption so I can operate four coils and spark plugs along with monitoring voltage. Now to add a spark plug attachment that will allow me to pressurize the plugs and vary the regulator to see where they fail while watching through a window. I'm looking for a suitable AC voltmeter in the 0-50 volt range that has an antique look to it - any ideas appreciated. It is still in a rudimentary stage but I have already been intrigued by what it has revealed. Some guards are in order as the crank whizzing around at 1500 rpm is rather intimidating as is the open v-belt. Best toy I've gotten for Christmas for over sixty years!

[TXGOAT2]

Neat idea. I'd like to know the voltage at hand cranking speed into a 1.5 amp load.

[Jerry VanOoteghem]

https://www.ebay.com/itm/397182355284?_ ... R7SnsoXcZg

[browning]

My plan is to wire two 1156 sockets in series so I can select one or two with a double throw switch to vary the load and check at speed or bypass them to operate the coils and plugs. Parts on order - will advise.

[browning]

The lower setting on my VFD is 10 cps which nets 240 rpm. Below that the motor torque sort of disappears. What would you think cranking speed would be?

[TXGOAT2]

I'm guessing it would correspond to about 40 to 50 RPM.

[browning]

Surprisingly’. I have found that with a freshly recharged stock flywheel adjusted to .030 clearance the volts per revolution per minute is very constant at about .025 volts/rpm which would equate to 1.5 volts at 60 rpm. There is some degradation as the speed increases but very little in contrast to the neodymium magnets which seem to improve as speed increases, as much as 15% at 1500 rpm - no idea why.

[speedytinc]

1.5V @ 60 rpm isn't enough to start with the hand crank.
1500 rpm calculates to 37.5V. You really seeing that?

[browning]

The voltage I observed is almost perfectly in line with the Ford repair manual. There is some degradation as the speed increases from .025 volts/rpm at 200 rpm down to .0218 give or take at 1200. I left my notebook at home this morning but will confirm what I found soon. I can reprogram the minimum speed of the VFD and assume that if I start the motor at higher rpm I will be able to reduce the speed without stalling the thing. I also did a speed by speed comparison with one of my neodymium flywheels set at .060 to .070 clearance and had the same 5 volts at 200 rpm but it increased to about 30 volts at 1200 rpm if my poor old tired memory is correct. again, will confirm.

[Jerry VanOoteghem]

1.5V @ 60 rpm isn't enough to start with the hand crank.
1500 rpm calculates to 37.5V. You really seeing that?

...the volts per revolution per minute is very constant at about .025 volts/rpm which would equate to 1.5 volts at 60 rpm.

He is speaking in terms of volts per revolution, not total output. V/rev would tell the performance of the magneto at various intervals of rotational speed.

[big2bird]

60 rpm on a vfd will most likely cog.

[TXGOAT2]

Most hand crank starts involve less than a half revolution at whatever speed the cranker can develop. I'd think the mag voltage, with some load due to the coil primary drawing some current, would need to rise to 4 volts or so to open the points and allow a plug to fire.

[TXGOAT2]

Are all AC voltmeters accurate at the very low frequency the Ford magneto would provide at hand cranking speed?

[TXGOAT2]

A better test of the mag voltage might be to connect a DC voltmeter through a diode, then note the peak no-load voltage, and then connect it to a T coil and note the peak voltage with the voltmeter and diode still in the circuit.

[browning]

Here is the comparison between Ford book(column 1) observed Ford flywheel and magnets @.030 gap (column 2) Neodymium high temperature magnets @.070 cap (column 3) samarium cobalt magnets @.130 gap (column 4)

RPM--------------------1--------------------2---------------------3-------------------4

200-------------------5.0------------------4.8-------------------5.0----------------6.25
400-------------------9.8------------------9.5------------------10.1---------------12.5
600-----------------14.4------------------14.4-----------------15.1---------------18.9
800-----------------18.8------------------18.8-----------------20.2---------------25.0
1000-----------------22.8------------------23.1----------------25.1---------------30.8
1200-----------------26.2------------------27.0----------------30.0---------------36.7
1500-----------------31.6 est.------------32.7---------------- 36.7---------------45.2

Still playing with various size magnets and gaps. Not sure what the optimal output would be. Flywheel weight reduction would be in the seven to nine pound range. Your mileage may vary!

[TXGOAT2]

I'd try the cobalt magnets at stock gap. That ought to make for a dependable hot spark at hand crank speeds. Voltage at higher speeds could be controlled with a choke. I'm not sure that higher voltage at higher RPM is of much importance, assuming the magneto is used exclusively for ignition, since the coil points will open well before the ignition coil is harmed. Improved "self advance" might be noted at higher RPM.

[Dan Hatch]

What is old is new or is what the other way?
https://mtfca.com/phpBB3/viewtopic.php?t=1109

[browning]

I had my guys help me reprogram the VFD today and checked the voltage with the stock magneto/flywheel arrangement and it yielded 1.0 volts @ 40 RPM and 1.5 volts @60 RPM still maintaining the .025 volts per RPM.

[J1MGOLDEN]

Henry Ford once said he did not need to know about mechanics and/or electricians, as he had enough money to buy good ones.

That he did and he got the very best of the best.

We have a few members that have demonstrated they had or still have abilities enough that they would have been hired by Henry.

Then there is another old saying, "if you don't know what it does, leave it alone!" or leave it the way Henry had it made anyway.

[Rayboy]

Here is what I did with mine as I didn’t have time to experiment before putting my engine together. I bought 1/4” thick magnets, and 1/2” thick spacers to make the total distance match stock. My goal was not to reduce weight but to create a mag that wouldn’t lose its charge over time. Works well.

IMG_1718.jpeg (52.03 KiB) Viewed 291 times

I also used shims to adjust the gap as the new magnets are brittle and can break. Ray

[Rayboy]

I also had the whole assembly dynamically balanced when I was done. It was about 38 grams out. Ray

[Jerry VanOoteghem]

... the new magnets are brittle and can break. Ray

Aren't you concerned that they'll do exactly that, and trash your engine/trans, as well as allow your original magnets to come loose?

[speedytinc]

Here is what I did with mine as I didn’t have time to experiment before putting my engine together. I bought 1/4” thick magnets, and 1/2” thick spacers to make the total distance match stock. My goal was not to reduce weight but to create a mag that wouldn’t lose its charge over time. Works well.IMG_1718.jpeg
I also used shims to adjust the gap as the new magnets are brittle and can break. Ray

How does adding brittle little magnets keep the magnets from loosing their charge?
Magnets don't loose their charge over time unless DC voltage is introduced. Am I missing something?
In trying to re-invent the wheel, you have added serious potential failures. IMHO
A better understanding of the system would be preferred to blind experimentation.

[Rayboy]

Jerry, All the new high strength magnets are brittle when struck. It’s the materials they are made from. Using the normal method of striking to adjust the height risks cracking / breaking the magnet. That’s why I used shims instead of striking. They won’t break/crack unless struck and are extremely strong unless hit. Appreciate the comment. Ray

[Scott_Conger]

Since the vast majority of donut rare earth magnets are axially magnetized (and not diametrically magnetized), it appears that Ray's creation works in spite of the improvements rather than due to them and is a testament to the robustness of the original design. If diametrically magnetized magnets were in fact purchased, then my hat is off to him for his ability to get those suckers to stay in alignment while tightening them.

FWIW, the coil is going to fire on the waveform when it reaches 1.3A (or wherever you set your coils). 3V hand cranking, 28V at road speed, 75V with rare earth magnets, or lightening from the Lord Almighty. It's simply a science project and if you bought your T to advance the cause of science, by all means, have fun, and it sounds like you guys are, so good for you, but I suspect that Elon's not losing sleep over it nor interested in buying it. I just don't view it as an improvement, because the other 15,000,000 Model Ts all ran fine as produced. Personally, it is my desire to simply experience automobiling as it was in 1920. But that's just me and there seem to be damn few people these days like me who are satisfied with JUST an antique car if this Forum is any indication. People like myself will be gone in due time and there will be no one left to pee in anyone's cornflakes over this sort of stuff, so be patient.

I am glad I am no longer in the market to purchase a T, and that mine were bought before scientists found the hobby and wiring made from lamp-cord was the worst thing you'd likely encounter. As they presently sit, the cars just work, and have no hidden grenades in them. No magnet recharges needed, ever. Oh, and I don't flat tow them in neutral, either.

So buy with confidence when you attend my estate sale some day.

[browning]

There are some of us that enjoy challenging the accepted norms of the hobby, not for financial gain, but for the satisfaction of seeing with our own two eyeballs what might be. I'm convinced that there are two fundamental types of people, those who say "why" and those who say "why not" and neither is right or wrong. Henry Ford was one of the "why not" variety and he certainly had his detractors. Those who dared to experiment brought us to multi-viscosity oils, orange drop capacitors, kevlar bands, plastic coil box kits, and many other rather handy products. It's not like we are trying to sell you anything so just give us some room to move and if you would rather not hear about our progress, or lack thereof, just don't read or respond to the posts - our folly will be our problem. Henry is reported to have been famous for saying "start it up, lets see why it doesn't work" and that is how those of us with overactive curiosities operate. For those few who enjoy testing the status quo I have attached pics of my test stand and the samarium cobalt enhanced flywheel which, by the way, deals with the brittleness issue quite effectively.

[Scott_Conger]

FWIW I have multiple patents applied for in the Aerospace Industry and was the guy who made things work in the lab or machine shop while Management was simultaneously holding meetings saying "It can't be done" and eventually, I would prove them all wrong. When asked how I "did it" I usually replied "because I was too busy to attend your meetings to hear you tell me I couldn't". If I'd spent my time making "the same thing, only different" I'd have been fired, but because it was "Holy Cow, we can make a ton of money from that" they'd just look at each other and walk away, leaving me alone, which was just fine with me. I left that mess at 58 and retired to a quiet bit of nowhere and could not be happier.

The hobby's plenty big to support all sorts of folks but all I see here is "the same thing, only different" and I don't see the point...but like I said before, that's just me, and that's what makes the world go 'round.

34 years of doing what couldn't be done and I am now enjoying my 4 (soon to be 5) antique cars for what they are...antiques and not laboratory testbeds.

So, am I a "why" or a "why not"?

[Henry K. Lee]

Very Nice David..., Rock On!

[Ron Patterson]

Wow.
When I went to engineering school I learned and understood Faraday's principle.
I have studied and writtten about the magnet and pole relationships of the Model T magneto and how it relates coil power and subsedquent ignition timing
I understand rare earth magnets and Curie temperature, but rare earth magnets come in all sorts of sizes and shapes.
Can someone show me a diagram depicting the magnetic North/South pole orientation with the respect to the physical shapes of the magnets shown in the above implementations?
Ron Patterson

[Rayboy]

Ron, I have always appreciated your posts and articles. Thanks! The magnets I used are poled on the flat sides. When I inserted them next to the original magnets I put then n to n and s to s. That way they enhance the magnetic strength of the pole. The other advantage is they don’t loose strength over time like the originals do. They will also prevent the old magnets from losing strength. My idea for this design is to build a mag that doesn’t loose magnetic strength over time but keeps the same power without a ton of added expense. Let’s all do what we enjoy and have fun doing it. Ray

[Scott_Conger]

The belief that Model T's simply must always be periodically recharged seems to be a relative new thing. Sometimes they do, but it is not a fait accompli

If a T built in 1913 is still running on the original engine with no magnet recharge, such as mine, as well as vast numbers of others, exactly what has been "improved" with this new "design"? And how exactly is this work superior in time and labor relative to an in-car recharge if such a recharge is required?

Stating that if you don't want to mess around and "improve" your car, you're stuck in the past and won't have fun reminds me of the guy who obnoxiously and frequently insisted you simply could not enjoy your car unless you had a (insert your favorite aftermarket clutch material here) in your car. Many thousands of T owners would refute that statement, but it was totally lost on him. I acknowledge that tinkering is fun but don't suggest that someone wishing to keep their car as designed is somehow a luddite to be viewed with derision or pity, or at least isn't having the time of their life! Very few 100+ year old mechanisms could not technically benefit from improving, but is the point of owning an antique/historic vehicle, the vehicle itself, or is the point of owning it because it is simply an easy target for improvement? For myself, it is a device that transports me back to my grandfathers' era and for a very short time, allows me to experience life at a pace unknown to 99.99% of the world's population - and I genuinely feel sorry for folks who have the same opportunity and fail to appreciate that aspect of the hobby and do not understand those that do...I really do.

[browning]

I have collected somewhere near seventy five antique tractors, hit and miss engines and old cars over the years and getting them to start easily is the most common problem I have encountered. Most of them have some type of magneto ignition and I have discovered that after I have exhausted considerable time and expense in trying to remedy their starting problem it is almost guaranteed that recharging and rebuilding the magneto is the solution. Battery ignition systems work or not, but magnetos, in contrast, get weaker bit by bit, year by year, until they run all right but are cantankerous to start. It is to the point now that any new acquisition that has a mag gets it redone before I put any effort into going further. Steel magnets (model t) have very low coercivity and are subject to magnetic degradation while rare earth magnets have coercivity values hundreds of times higher and can withstand exposure to electrical and magnetic fields with little or no detrimental effects. They aren’t necessary but interesting to contemplate. One of my planned tests is to expose a freshly recharged stock flywheel to current applied to the mag while rotating and measuring the voltage loss and comparing that to the same test with a rare earth setup. The test stand makes empirical comparisons and outcomes meaningful. I will also be able to simulate an “in car” magneto recharge and compare output voltage to that of the freshly rebuilt flywheel. I have always been curious about the efficiency of recharging in the car.

[Rayboy]

For Ron

[Rayboy]

Browning, Thanks for the great posts. I will look forward to future posts on the subject. Ray