Gilllette generator heads

[Simtech]

Anybody have any experience with these?  According to a couple of online reviews they're supposed to be excellent quality heads, their main claim to fame is their "Kleen Power" with only 7% harmonic distortion.

If weight is any indication of quality they weight about the same as equivalent sized Winco heads: i.e a 6000W head weighs 84lbs

http://www.gillettegenerators.com/index.html
http://www.gillettegenerators.com/beltkit/specs11.html

[EBI-WPO]

I have a 3.5K 8hp Briggs Kleen power by Gillette (propane). It is of course a two lobe rotor (3600rpm) design, but Gillettes claim to fame is a "scewed" rotor. (Think of rifling twist) This is supposed to share loads better between phases (legs), and mine (for what it is) works great. It starts larger loads than most, and seems to have very little distortion (verified with O-scope)

Note: Scewed rotor DC motors exhibit minimal "cogging" and are used in high torque, low speed applications.

Terry

[Simtech]

I wonder if both legs could be wired in parallel so the full output is available on only one circuit.

I'm starting to shy away from the ST brushed heads because of the waveform issues and am inclined to get a good quality brushless head instead.

[BruceM]

I concur with you Simtech, on the ST heads.  Here's my take on them:

The utter simplicity of the ST's plus price is the only real plus. When I designed a basic AVR for the ST-3 and ST-5 and made it available publically for free, I got back some o'scope images of waveforms. Some were pretty horrible, some were not too bad.  I had to replace my ST-3 bearings and diode bridge in less than 100 hrs; so rumors of these particular items being of poor quality are true.

The only other head I've seen waveforms on was a Marathon- and it had no ratcheting or spiking, and was excellent.

I would insist on seeing a representative o'scope trace for any head; 6.9% THD isn't all that great. You can get near that with a 2 step "modified sine wave" (modified square wave, really).

For me the ST-3 has an important advantage- I put a switch in the field excitement circuit so that the rotating field can be switched off, leaving only the much weaker residual magnetism...so I can stay in the engine room briefly with the head belted.  That may be possible in a brushless head, but I wouldn't know until I took a look inside one.

Likewise, I can reduce the ST's ferocious diode noise on the output AC (pretty bad by the AM radio interference test) by putting 0.1uF caps around the bridge. I don't know how bad the RFI/EMI is on some of the brushless units, or how accessible the bridge diodes are for remediation of this might be. Since the bridge diode will be rotating, it may not be practical.

So I'll have to stick with the ST-3, but for healthy folks I don't think I'd recommend them, unless the budget issue is critical.

I think BobG indicated before that the skewed rotor design eliminates the "ratchet" distortions, so that's what I'd want.

[EBI-WPO]

Simtech,
In need of full wattage at 120, my 3.5K is wired in parallel.

By the way, your name and location would suggest Altus and C17 sims?

I worked for Flightsafety twice. 1989-1994, and 2001-2004 (building 1st C17 sim)

Terry

[Simtech]

Simtech,
In need of full wattage at 120, my 3.5K is wired in parallel.

By the way, your name and location would suggest Altus and C17 sims?

I worked for Flightsafety twice. 1989-1994, and 2001-2004 (building 1st C17 sim)

Terry

Actually I'm at the McChord C17, why'd you move on?  Its a pretty good gig.

[EBI-WPO]

Simtech,
Agreed, some of the most interesting work I've done. I specialized in Controls and Motion.Came up from the analog days overlapping Digital, so a lot of my time was spent working the "old" stuff, as the newer guys couldn't "tweak pots" worth a damn. Travelled my butt off, as Field Engineer. Last partial year of work, I was home less than 20% of the time. Hard to keep sane, no less a marriage.

Still miss it sometimes.

Terry

[EBI-WPO]

Simtech,
Sidenote - Look for old Kato Generator heads. Lots of times you'll find a 50 hz generator belt driven by a Kato electric motor. Upon inspection, the motor is brushless, field excited/controlled (for speed) as well as the gen and you've found you have two generator heads for the price of less than one if you've shopped wisely. The 50hz head doesn't care if you happen to spin it to 1800 rpm instead of 1500 rpm to make 60hz.
Seriously take a look at some of these, the website still has some of the old data, they're built like tanks, and I'm sure the 5K heads that I've got would support another 50% load above that without problems.

See pics. Not great ones, but will give you an idea of the size of the 5K units.

Terry

[EBI-WPO]

Simtech,
This link is to a 20K direct driven unit that is priced quite high, but the pics will show you how they mirror a motor and generator. (They do direct drive as well as belt driven). Also look at the data tag carefully. Look at the field current/voltage specs on the motor as well as the generator. Usually a few on Ebay that are pretty good deals (I all but stole mine as I got it for the initial bid).

http://www.ebay.com/itm/20KW-KATO-Engineering-Motor-Generator-Clean-Power-Unit-/280559732207?pt=LH_DefaultDomain_0&hash=item4152a9c5ef

Terry

[deeiche]

SNIP

http://www.ebay.com/itm/20KW-KATO-Engineering-Motor-Generator-Clean-Power-Unit-/280559732207?pt=LH_DefaultDomain_0&hash=item4152a9c5ef

Terry

Side note, that thing is 7 miles away from me.  Most likely came out of one of the national labs or a local AFB.

[EBI-WPO]

Deeiche,
That particular one is not a "great" buy, but still offers a lot of usable equipment. Most of the time the Motor/generator units are sold, the seller has no idea of what they can be re-tasked as, and as a result are seen as specialized equipment and underpriced.

Terry

[Simtech]

That 5K is HUGE, I imagine it'd store a lot of kinetic energy as well.

Thanks for the tip!   I'll keep an eye out for Kato generators