a better sign wave generator?

[fattywagonman]

I ordered a couple of belt drive heads from these folks... IMO a better deal than an ST....

http://www.gillettegenerators.com/klnpower/kpower01.html

Brushless, good sign, lifetime guarantee on diodes and caps... made in the US... and cost is about $500 for 5kW...

[Tom]

Yea, but 2 pole 3600 rpm for anything less than 19 kw.

[fattywagonman]

Yea, but 2 pole 3600 rpm for anything less than 19 kw.

Sorry but I don't understand what you meant by this?

[Jim Mc]

I think he was just pointing out that the main redeeming feature of the ST heads is they are 1800 rpm, 4-pole machines.   The small Gillette heads are 2-pole 3600 rpm.   

Still, I would never have guessed you could buy a domestic 5 kW machine for $500!

[binnie]

Hi Jim,
Hit me if I'm wrong...but from what I understand (and I am just learning this stuff)....4 pole gen heads give a 110v/220v output option and the 2pole only the 110v output.
At 3600rpm from a lister flywheel you would need a tiny pully on the gen head to get that speed. Am I right? binnie

[ronmar]

You would need a 4.24" pulley on the generator head to get 3600  generator RPM out of a 650 RPM lister with a 23.5" flywheel.  You would also need more tension than with a larger pulley to get proper friction to transmit the torque under load without the generator pully slipping.  This is harder on the shafting and bearings that support this overhung load.  You would also loose some spinning mass with the smaller pulley, but the 3600 RPM head would store more energy(F=MA) in the faster spinning rotor.

Ron

[fattywagonman]

The 3600 RPM does require a smaller pulley but so far that has worked fine for me....I can order multi V pulleys and belts from mcmaster....  I don't have the new heads yet but I've been using these without any problems...
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45416
 in fact I put one on the scope and they make a darn good sign wave...
Makes me wonder why folks are so into the ST heads.... I've seen so many failures that are caused by brushes....
I don't think I would purchase anything but a brushless design...

[Jim Mc]

Hi Jim,
Hit me if I'm wrong...but from what I understand (and I am just learning this stuff)....4 pole gen heads give a 110v/220v output option and the 2pole only the 110v output.
At 3600rpm from a lister flywheel you would need a tiny pully on the gen head to get that speed. Am I right? binnie

Partly right: the driven pulley is smaller on a 3600 rpm machine compared to a 1800 rpm machine.

Partly wrong: A 4 pole machine refers to the number of magnetic poles on the field.  They operate at half the speed than a 2 pole head. (1800 rpm on a 4 pole machine gives 60 Hz, but a 2 pole machine takes 3600 rpm) The number of poles is not related to the voltage configuration.  So, a 2 pole machine could be 120/240, 120/208 3 phase, 120V only, etc. 

Since they operate at a lower speed, 4-pole machines can last longer, and are usually quiter.  But they require more copper and steel, so tend to be larger, heavier, and more expensive.

[Jim Mc]

...Makes me wonder why folks are so into the ST heads...

The one and only reason: they are the lowest cost 1800 rpm head available.

If you don't see 1800 rpm machines as advantageous, they are not the best choice.

[binnie]

Thanks Jim,
For the input....appreciate your being here for us Nubies...binnie

[Doug]

All things equal I might buy the 2 pole over the 4 in a brushless unit. Higher brush wear in a 2 pole becuase of the extra speed would be my only concern.

From a design POV a 2 pole head will be a little more efficient and smaller.

A lot depends on how well the machine is designed and built.

Doug

[dkwflight]

Hi I sent an e-mail and their response was quick.
I may decide to go for one.

BDN4-190-1-1 is $ 1818.05
I assume + shipping

Dennis

Welcome back Doug

[jtodd]

Hi I sent an e-mail and their response was quick.
I may decide to go for one.

BDN4-190-1-1 is $ 1818.05
I assume + shipping

Dennis

Welcome back Doug

I recieved some quotes from a local reseller (EC Power, here in Portland) on the smaller 2-pole generators from Gillette, as well.  The prices aren't fabulous, but if they produce a cleaner power than the ST-10 then maybe it's worth it to live without a power filter and the subsequent loss inherent in that system.  The prices for the 9kw and 12kw models are below, and probably reflect a dealer markup of 10% or so.  Shipping for these smaller units to the dock was under $150, from Indiana. 

9kw BDN2-90-1-1 is $857
12kw BDN2-120-1-1 is also $857

JT

[Doug]

See thats not so bad when you consider some venrders will try and mark up a 250 dollar ST as high as 800 ( the price aint the only thing high in Canada ).

Doug

[fattywagonman]

I think their 4 pole stuff is just Marathon.... The last Marathon I purchase was a 4 pole 12kW head that said made in China all over it... I think you could do better by purchasing a Stamford or Marathon clone...

Better yet get a 2 pole head /  capacitor regulated..... very simple... since folks are already reducing speed I don't see the advantage of a 4 pole gen... 2 pole works great and from what I understand it's more efficient and simpler.... Just think how much cheaper the pulley is... Mc Master has them for $50 for the 4.5" serp....