ST Heads in the Pacific NW

[Doug]

It would be nice to get a list  of Heads types and who is selling them.

Obviously a lot of people don't want to share who they buy from so you have to take it on faith they have a good head and this is a real Piss Off!

Jack:
I'll assume from your statement George suplied you with a new head from another builder for MT2 and this one isn't a dud.

I'll also assume the first one machined by a beaver was also suplied by George.

Did these have a nameplate on them indicating who mae them or did this get replaced?

If its just machining issues this can be fixed. Its a pain in the back side to have to repair things before you can use them but at least with an alternator head there is realy nothing there that can't be fixed.

Doug

[duh]

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Hi duh:

I see that you posted a couple of days ago and I didn't notice it until today--sorry about that.

Thanks for the traces. Can you tell me what your sampling rate was on those? And would you be willing to send me the raw data you sampled to make the traces? (If you are, just let me know and I will pass along my personal e-mail address to you by PM.)

Best regards,
Andy Hall

Hi Andy,
The sampling rate was every second.
Help yourself to the raw data (basic text files):

http://www.diesel-bike.com/Lister_Gen/ST_Hz_track_375rpm_OnEngine.txt

http://www.diesel-bike.com/Lister_Gen/ST_Voltage_track_375rpm_OnEngine.txt

Hope they are of some use.

duh

[hotater]

Doug---   The first ST was a doorstop in somebody's warehouse.  I got it really cheap.  The second was a new generation of the same idea and was about a lightyear difference in quality.

[Copybell]

Andy,
   Full output voltage takes about 2-3 seconds.  The exciter has always worked for me, I have never had to 'flash' the unit.

Copybell

[Doug]

What was the name plate on the forst one Jack....

At least thats a starting point for who to avoid....

Doug

[hotater]

Doug-- The first one looked like maybe a forklift wiped that side off a little.   
It was still in the a crate but by the grace (and expense) of steel banding only.

#2 has a bright Power Solutions plate on it.

[Doug]

Is this the one you mean?

http://home-and-garden.webshots.com/photo/1272471803028237237LsxbXS

Doug

[hotater]

Now I guess you could investigate if somebody else sold his doorstop or he sold HIS doorstop...

It went to a good home that fixed it and used it for nearly two years...it's a spare now.   

[Doug]

I'm just having a little chuckle at your expense Jack lol.

So maybe this was a one off oops, maybe there was a whole load of them, it doesn't realy matter no one has complained, but if brand X has machining issues it would be nice to finger the brand.

George has been good to you and many others, I'm sure he would have said something and or replaced any with problems.

Doug

[Joe]

This is really very encouraging…if a “doorstop” from e few years back can run for 7200 hours (albeit with some massaging) and is still capable of making juice…the current (excuse the pun) generation of heavies (which has gotta’ be more copper) with good bearings and  diodes should run till the cows come home…

Joe

[Doug]

No its not impresive at all actualy. I would expect a minimum of ten years service from an electric motor made in Poland of Brazil in an industrial aplication used everyday. The rated life of a good set of bearings is about 10,000 hours with a 50% failure. Most go longer of properly greased and cared for..

I have cleaned and serviced some machines like a 1920s GE compressor motor that is still using its original winding and babbit bearings in regular service at a local brewery.

A wound rotor motor on a crusher I service was installed in 1942. Its has been stripped cleaned serivced rewound several times and runs on and on in the nasteiest enviroment you could amagine.....

I'm not saying that 7200 is bad or a disapointment, but I would hope for more considering what a cheap elelctric motor is capable of.

Doug

[hotater]

Doug---

It's run 7250 hours so-far.... I took it out of service just to put an new engine and genhead on line at the same time.

The first Door Stop genhead had a badly machined shaft and the brush holder looked like cast iron styrofoam but the original bearings are still in it and it's only on the third set of brushes.  I screwed up one set with a 'hope it'll do' repair that didn't.

I consider even an old, 'first run' ST a REAL bargain..... as compared to the Genrac 4kw 2pole that lasted almost exactly as many hours as new 'MT-II' engine and head has run so-far,  818 hours this morning, in just 53 days.

It's good if it last as long time...it's excellent if it'll last a long time, and I can FIX IT.

Doug-- There is a saying popular with Southern coon hunters, "Never keep the first mail order puppy."

It just means that when shipping is a major part of the price the guy selling in India KNOWS whatever he sends will stay here....so they send some junk.

 It's like the cricket bats...some get one and some don't.      Welcome to the Indian Engine Roulette game. 

[Doug]

I know Jack they're not expensive and they are easy to fix. Personaly i think your better off with a cast Iron head myself because it a little more durable and when the time comes it easy to just machine a steel sleave. Shafts can be a bit more trouble, but generaly he sub arced and reground them. I had this nice french fellow rebuild shafts and housings for me. It cost a bit more but he held the line to .0005 on his machining and it realy showed up when you assembled things.

I'm sure if you had stripped the St head and spotted the problems before you ran it you would have had less trouble. BTW what tollerences did you use for the outer race to the end bell and shaft to inner race?
I have some tables for that some place ( looked for it tonight and I can't find them ).

I noticed a lot of the Lincoln electric motors ( aluminum housings ) didn't last, some of the first Wegs ( Iron ) had a bad rep for loose machining. These would run good for while but as soon as you start to get a little movemnt inthe housing , especialy with the aluminum end bells they would wear egg shaped and go for a crap on you. Then if you machined them too tight or too loose or just not right you had issues again in short order.

I remeber one motor for a local bakery it was a real ood ball unit that just didn't feel right on assembly. So I called my foreman over. He was a greasy frenchman with a real hate on for me. He'd been up all night winding the thing with another guy and I came in for day shift to do the fitting and testing before delivery. We wiggled and poked at it after the fact. I knew i should have miced it but it was a rush job. Later that afternoon we recieved a call from the bakery. The little movement I could feel translated into an egg shaper drive end bearling housing and the mill rights rejected it when they started to assemble the compressor.

I got in trouble for that, nopt much just a little slap on the wrist because my foreman cleared it to leav as a rush job......

since that day I never cut a corner on import jobs like fiitting.

Doug

[hotater]

I guess you could call me a 'comparitive' machinist that's never had a foreman, or super, or punch clock, or QC division,  or ANY of that stuff.   I  DID work in a shop with an engineer one time, but  not long.   

I used the same degree of slurpiness fit that I did when I built my high speed (5Ksfpm)  belt sander in 1970...and I use it every day or two now, but it ran six hours a day for several years.  It seems to work.

Without temperature compensated measuring instruments, perfectly cleaned and lubricated parts and other 'clean room' QC tools it doesn't do much good to get too wrapped up in the numbers.   A bad mechanic will assemble something with contamination JUST because he believes the dimensions MUST be right so this is how it MUST fit.

An oily finger can feel what a micrometer can't measure.

[Doug]

I don't pretend a machining or expert judge of machining, but I know what worked for me. Its had to be smooth, round and offer a little resistence to assembly even with a light coat of  # 20 oil. You don't want the outer race squezed and distorted thats just as bad if not worse than too loose.

Tight enough to hold the race and not allow it to move in the bore under normal conditions. This I found is less critical  on small bearings and next to impossible to acheive on aluminum housings.

You said something that's kind of important about touch and feel. And your dead right about it, somethings have to feel right and fit right not just be machined to a specification.

DOug