Snowman 8 Transistor SSG Build - Trigger Problems?

[BobZilla]

Here is the video John mentioned. Towards the end is the soldering bit.

Crimp if you want but if you know how to solder there ain't nothing ever going to come loose. Now if you do a piss poor job than yea it will, and crimping is just going to hold a loose connector on there.

Note to anyone not familiar with soldering and using the video as a reference. Not all mag wire insulation will melt away as it does in that video. You are best off scraping it off to be sure.

[John_Koorn]

Thanks for posting the video Bob. Good point, JB uses a special type of mag wire where the insulation can be melted off with a soldering iron.

John K.

[BobZilla]

You bet John..

Guys I want to explain something about soldering for anyone who does not have much experience, you can take it or leave it.

When you solder something you are not supposed to be heating the solder up and dripping it on. many beginners think of it like a glue or something and this is not the way. What you need to do is heat both components hot enough to melt the solder when you touch the solder too it. The iron is not for melting solder, it is for heating the wire and connector or wire to wire, whatever you are working on. When you are soldering on a circuit board you heat the component and then touch your solder to it and it will flow over, you do not want to get gobs of solder on your iron and try to drip it on. It is very important for the component to be soldered to be hot, if not the solder will not bond and you will have a bad connection. It may stick at first but will soon pop right off.

Do not blow on the solder either, it needs to cool on it's own or you will crackle it. Not sure what I mean, get a scrap of wire and play around. See what happens if the wire is not hot, see what it looks like if you blow on it verses not blowing on it. If you look closely you will see a difference. If you are soldering something kind of big do not solder it and then poke the iron into it because one side is not bonded, picking and poking with the iron will only mess things up. If you need to fix a large joint let it cool pretty well first instead of poking around with the iron at it and then heat the whole thing evenly, otherwise you are going to over heat your component. If it is just wire than this is not as much of a concern but just remember to get the whole joint hot all around evenly. If you need to fix a joint make sure you heat all of the solder evenly so it all flows, you may even need to use some flux if oxidation has occurred on the joint.

If you are soldering electronic components you should clip on an alligator clip to the other side of the lead if you can fit it in there temporarily. You want the clip to act as a heat sink to protect your component

For new work however the main thing I am telling you is you are heating the components and flowing the solder onto them, not heating the solder and dripping it into them. To much of that and you will have burned up the flux that is in the solder and it will not bond to a cold component anyway, it will form around it but not with it.

About the crimping, the reason I say not too is because crimping is a compression fitting which is designed for multi-strand wire termination. Mag wire is a solid core and when you squeeze the hell out of it you are just weakening and deforming the wire. With a muti-strand wire it compresses them all together to form almost like a solid core connector but that is because their is air and space between the strands which can compress.

[Tom C]

Yaro,

thanks for the input we will add to our documentation to make things a bit easier.... all new coils now being made have the word TOP on the "top" of the coil. we will add other changes to the instructions to help new builders.


Tom C

[Yaro1776]

Yaro,

thanks for the input we will add to our documentation to make things a bit easier.... all now coils now being made have the word TOP on the top of the coil. we will add other changes to the instructions to help new builders.


Tom C

You are most welcome! All in all you have done a great job in putting this together for the rank amateur - the tweaks will only enhance the product and the mission.

Happy Christmas!
Yaro

[Yaro1776]

SSG RPM Measurement - A Simple Solution

Tuning the SSG build requires RPM measurement in order to adjust the coil gap and other things. Simple - ugh! There are various ways of doing this and many are pricey and highly complex. Many experimenters have resorted to using a bicycle speedometer and a spreadsheet to do all the calculations to get the miles per hour converted back to RPM. What a pain in the left nostril!

So let us take a look at this and try to simplify the process. The Snowman went to Walmart (KMart or another is OK) and picked up a Bell 100 speedo for $12.95, tore the package apart, carefully, and the read the instructions. Yow- measure this, calculate that and the covert everything to millimeters. Sheesh - lets simplify this process with some basic algebra:

MPH= 3.1416*2R*RPM*60/5280; where R= wheel radius, RPM = revolutions per minute, 60 minutes in an hour, 5280 feet in a mile

MPH=0.0357*2R*RPM; by definition 2R= wheel diameter D.

MPH= 0.0357*D* RPM; Simple algebra shows that

RPM= 28.01*MPH/D; Way better - lets modify this so RPM can be read directly off the speed display by simply multiplying the MPH by 10. To accomplish this we select D to equal 2.801 feet -OK?

RPM= 28.01* MPH/2.801

RPM= 10*MPH Great! Now you to insert the bicycle wheel circumference value in millimeters into the Bell 100 computer.

Circumference = 3.1416*2.801 feet

Circumference = 8.800 feet or 105.6 inches; Conversion to millimeters by multiplying 105.6 by 25.4mm/inch

Converted to mm =2682 mm

Insert this value into the Bell computer and fire the puppy up. Read the MPH on the readout and multiply by 10. This the RPM read!

The Snowman has attached a crude cob job to show that it does work - used a hex pencil (flat faces), zip ties, Electrical tape and rubber bands. This will be cleaned up to look pretty and semi professional (hah!). Perhaps someone has done it this way before, anyway, worthwhile to repeat it.
Cheap, Simple and Accurate for the first time builder!

Happy Christmas,
Yaro (Snowman)

[BobZilla]

I appreciate your spirit of helping and effort.

Most people just use one of these however.
http://www.ebay.com/itm/Digital-Lase...item20dcdff504

[Yaro1776]

BobZ,

You are right - that will work well also. Thanks for the pointer! Anyway the calc exercise was a bit of a diversion...

[Yaro1776]

Impact of Soldering

Happy Santa to all,

So the last suggestion was to solder all the critical joints. Good enough! Prior to soldering of the joints we did a run on the Snowman 8 trans SSG as configured and came up with 232 RPM as measured by the Bell 100 system outlined in the previous send. The critical terminations were: 1) coil windings, 2) Trigger terminals and connections, 3) Primary(-) and Charge (+). All the 10-32 steel bolts/screws were replaced with brass. None of the screw terminals were soldered to the board.

These changes resulted in an improvement of approximately 8 to 9 Rpm or nearly 4% to 241 RPM for the config as described above. Nothing else was changed or modified. OK.

For reference purpose the Primary battery was at 12.7 volts at the start of the above run. The coil gap remained at ~1/8". No change here.

Again, for reference purposes the RPM w/ the trigger resistor was 241, while w/o the trigger resistor 237 RPM. Not much impact here...

Please note that this system is stock, bearings have not been cleaned up yada! yada!

There were no measurements on amperage from Primary to board. This will come later when the appropriate methodology is applied. So, this is a good start!

The sole intent of this thread is to document this build and the subsequent results. Your experience may differ.

Interesting note - when the nearby CFL lighting was moved there was a very minor change in the RPM, +1 or +2, then settled back to 241 - interesting!

Best to all for the holidays,
Snowman

[Yaro1776]

Impact of Aligning Wheel Magnets and Coil

The alignment of the wheel magnets to the centerline of the coil rods was tweaked yesterday. The magnets on the wheel are fairly closely centered on the rim, close inspection revealed that the centers of the wheel magnets were off approximately 1/4" or so from the center of the coil rods. This was corrected and the SSG restarted again. The steady state RPM of the SSG gained approximately 12 RPM to 253 RPM from the previous config.

So, the SSG is a sensitive beast and small changes can impact the speed of rotation. Two, seemingly, minor changes have improved speed by about 10%.

Later,
Yaro

[Yaro1776]

Restart of SSG Projest after Holiday Hiatus

Well we are done with the Holidays and its time to refocus back to more serious matters such as the idle Snowman 8 transistor SSG.

Effort has continued to establish some baseline data with the operation and performance of the Snowman SSG in its current unrefined state. Meaning that the wheel bearings have not been cleaned of the packed-in grease, the batteries are out of my mowing tractors and one is not quite prime time, the discharge method for the charge battery is way low tech - a 6 watt automotive bulb sucking up 0.475 to 0.48 amps. A simplified way to learn the base characteristics of this cool machine while it is in the untuned raw state.

So to recap the machine:
Teslagenx 8 transistor board and coil kit - nice!
22.3" Outside diameter Alloy wheel - bearings stock and greased packed for now.
21 Teslagenx magnets; spacing between magnets ~ 2.6".
Current Coil to magnet gap of 1/8" - magnet to plywood coil mount (welding rods protrude through base of this mount).
Current RPM - a stable 245, can be pushed to 250 with lots of patience.
1.35 amp draw from Primary battery.
Takes about 2.5 charges of the Primary to boost Charge battery to 15.3 volts from 12.2 volt draw down level. An Energenx 2A12, sometimes a 10A12 is used to pump up the Primary.
Takes 10 to 10.5 hrs to discharge Charge battery to 12.2 volts - patience!

Meters used are a BK 389 Test Bench, Extech 430 and for amps a Sears Pro 73756 clamp on.
Batteries are lawn garden type NAPA 8224 N and a very similar Husqvarna; both with 230 cca @ 0 degrees F. No way are these 20 amp hr batteries IMHO...

So the above is the baseline that we will use for comparison purposes to assess the impact of changes and modifications as progress is made to achieve the holy grail of a COP>1 for this machine. Truly an adventure and more to come on this thread!

Please bear in mind a quote from a now obscure manual - "Some assembly required; batteries not included!"

Regards,
Snowman

[Yaro1776]

Degreased Wheel Bearings and Removed Seals - Results

Finally got to working on the new bike wheel bearings after being reminded of this step by a number of people. So we disassembled the wheel, removed the seals and flushed out the bearings. Checked the cleaned out bearings by turning by hand, ugly! A lot of rough spots, anyway put a couple of drops of whatever super lube that was on hand and presto way better. These are new bearings installed in the wheel about three weeks ago - not really broken in as yet. A free wheel test to be done later...

Put the wheel back on the wheel mount, hooked up the power and gave it a twirl. Well sir, the machine responded by noticeably accelerating much more rapidly and increasing rotational speed to 274 RPM. About a 12% gain over the previous 245 RPM with no other mods. This works...

So let's check the output amperage from the Primary. Whoa! Preliminary read was 1.56 amps, this was confirmed an hour later w/ a similar read. A gain over the pre-mod run of 1.35 amps. So this modification does result in an increase in power consumption along with the RPM gain.

So what happens to the charging amps? Well the clamp-on reads about 0.74 amps, however we will let this go for the time being and restart another run to see the impact on charging time to 15.3 volts on the charge battery from the previous baseline of 2 to 2.5 charges on the Primary. More later on this aspect.

So the results from the bearing degreasing and seal removal leads to an improvement in RPM and charge amperage. Enough for now!

Best to all,
Snowman

[Yaro1776]

Freewheel Test

Well time to do the freewheel test - a pain to disassemble the mounting rig, but there was another 8 trans board (spare and another story) to run. It was anticipated that there would be a very marked increase in Freewheel time based on the improvement in the RPM. Not to be!

The freewheel time increased from 75 sec. to 120 sec. about a 60% improvement. Not very impressive despite the gains noted in the prior post, WE need 480 secs. Ugh!

It seems necessary to run this wheel for a while to smooth out all the minute metal imperfections in the bearings and see where this plays out.

Plan B is to get another wheel from the supplier Tom C. recommends. We learn by our mistakes!

The discharge of the Charge battery (NAPA 8224N) is accomplished (for the time being - thanks NAPA) with a 6+ watt auto marker/direction bulb (measured at about 0.48 amps with two meters). Will consider eating the West Mountain package in the future for the sake of discharge data accuracy. The batteries are rated at 230 CCA @ 0 F. The amount of time required to discharge at The C20 rate (20 hrs) for these batteries will be lengthy, like more than 10 hours... Not really sure at this time what the real amp hr capacity is for these batteries. Does anyone know? We can perhaps estimate the capacity at 10 to 15 amp hrs after conditioning. Time will tell.

There is a question as to why both batteries in the SSG have to be similar... Simpler to put in a larger battery on the primary side and monitor its discharge amperage. Why muck around with continual charges of the primary? You can't switch the batteries around as per recommendation anyway - so what is the point besides simplicity and cost?

Irrespective of the questions, this SSG project still remains as very interesting. The next goal is to establish a control performance test with a standard charger for comparison COP purposes. More on this later as matters progress.

Started to condition another battery for the actual testing when initiated.

How did we get into this interesting madness?
Yaro

[Tom C]

you said:

The amount of time required to discharge at The C20 rate (20 hrs) for these batteries will be lengthy, like more than 10 hours...

it will be 20 hrs...... if you discharge in 10 HRS that is C10.....

sorry just wanted to be clear on that.

the goal is 1 to 1 charging. having the same batteries front and back insures your are doing identical work. its all about balance in the system.

Tom C

[Yaro1776]

Tom,

As usual you are correct, the C20 time is based on 20 hours of discharge at a given rate for a particular battery size and is dependent on its level of conditioning. No question, however it is a matter of procedure and fact that a properly conditioned battery will gain capacity as the number of SSG runs and associated discharges increases. Therefore, in the initial discharge runs the battery may be well below its ultimate capacity and it may take the recommended 20 run minimum to reach this ultimate 1:1 capacity. That is understood and the goal is understood.

One of the questions for a beginner (8 trans build or whatever) is, "what is the correct battery size and what is the recommended C20 rate?" Knowing that the NAPA batteries are for starting purposes only, the C20 rate was selected conservatively as an ~ 0.50 amp draw (10 amp hr) and 12.2 volt low threshold. For beginners on a limited budget the NAPA 6 watt bulb fits the bill. Is this the correct draw? Well, that will be determined from the conditioning process as outlined by John K and yourself. Let's see how this plays out!

Thank you all for your patience in answering the tedious questions.

Yaro