generator for small demo lathe

[ALAN THOMAS]

Hi Guys
I have recently been asked to demonstrate at a couple of out-door events and would like to use my normal demo lathe which is a Jet 1220 variable speed. I would like to have a quiet running petrol generator so as not to disturb the peace too much Has anybody used the small suitcase gennies ( 1000 watt ) and if so would they power my Jet ( 560 watt DC motor )? I know that there can be issues around having sufficient power from a small genny to actually kick the motor into life but I wondered if there was any experience with these gennies out there.

 

[John Torchick]

There are many manufacturers of generators but I have never seen a generator that was what I would call quiet.

 

[Fred Belknap]

I have worked around a lot of generators and the Honda unit was considered the quietest in small generators. Using a extension cord and placing the gen behind a wall or something solid will absorb a lot of the noise. Use a good extension cord, I use ones with 12 gauge wire (same as house wiring) for anything that has a motor.

 

[AlanZ]

A Honda EU1000i should do the trick. These Honda inverter generators are small, lightweight, and very quiet.

I use two of the next larger size (EU2000i) as backup power for my home.

 

[waltben]

Honda, Yamaha and Subaru all make gasoline generators that are extremely quiet. I've two Yamaha 2300's (I hook them together to make a 30 amp feed for our RV) and have used one of them at many shows while demonstrating or just to run fans (gets hot here in VA in the summer!). They sometimes get more attention than anything we're trying to sell - "Where did you get that generator; it's so quiet!" If all you want is to power a total of under 1000 watts, look for the best price unit at that rating. They're all quality units.

 

[MichaelMouse]

Also recommend the Hondas. Best setup I saw involved the generator in a heavy blanket cube tent about 8 inches larger on a side than the generator. It took off quite a bit of noise with a couple inches of ground clearance for cooling.

As you shop, limit to those with the lower Db@(Distance), then get out there and start them before you buy. While you're at it, consider larger capacity as backup for the house. Don't make noise the sole criterion.

Demos are great until the painters that tend to run the shows find out how much wood is waste. Limit that with good prep, and stand both you and the lathe on a tarp for 4-corner cleanup. Believe it or not, some people will complain about cherry shavings mixed in with a ground clutter of maple twigs and leaves.

 

[Jake_Debski]

Ditto the Honda's

 

[n7bsn]

I've used the Honda EU2000 at outdoor demos. We had the generator about 20 ft behind the both and it had no impact on the demo.

Now, the EU1000 (or similar from other makers) would run your lathe just fine. But what it wouldn't do is say, run your refer in a power outage.

For that reason I would recommend either the Honda EU2000 or it Yamaha 2600. Either can be carried by one person. I would not recommend the EU3000 as it takes a very strong person to carry it.

As for brand, I would stick with the brands that can be connected together (for those that don't know, it's electronics), that is the Honda, Yamaha, and a few others. I would avoid the Chinese ones that can't.

Why this could be important is to run more things in your home during an extended power outage. Personally I own two Honda 2000's and the kit to hook them together. This provides enough power to run refers, small A/C units, space heaters, etc (obviously not all at once). I also take them along when we are boon-docking in the RV.

There are a few mail-order firms that well Honda EU200's at a couple hundred less then retail (Mayberrys, Alamia etc), including shipping.

John, if you haven't "heard" the modern generators, you need to get up-to-date. They are really quite quiet. An EU2000 is 55 to 59 dB, while a normal conversation level is 60 dB and a vacuum is about 70 dB. Now dB are not what you might expect, a 10 dB increase is NOT 10x as loud, but rather 10x as much energy. This is because of how the ear works.

 

[Bill Boehme]

... As for brand, I would stick with the brands that can be connected together (for those that don't know, it's electronics), that is the Honda, Yamaha, and a few others. I would avoid the Chinese ones that can't. ...

So are you saying that they can be phase synchronized?

Also, how much does one of these generators need to be derated for inductive loads due to power factor? Just wondering what might be needed for a 3 HP motor.

 

[AlanZ]

Just a note about inverter vs contractor style generators.

Contractor style generators need to run at a constant 3600 rpm to generate 60 cycle per second, 60 seconds per minute.

They need to be at 3600 rpm regardless of whether they are running a saw or a 5 watt light bulb. So contractor generators with an "eco" switch, simply drop down to idle when there is absolutely no demand for AC power.

Inverter generators vary the engine speed depending on demand. So with low AC demand, the engine may run at 1/4 or 1/2 speed (and consume less fuel while doing so). When a refrigerator's compressor kicks in, the generator ramps up... it might lower the voltage slightly for a few seconds while doing so, but the appliance motor doesn't seem to mind at all. Also, unlike conventional generators, the AC output of the inverters is very clean... nearly a sine wave, so it's safe to use on electronics.

In my home, I added a bit of extra "smarts", a transfer switch that features configurable load shedding (it can temporarily shut down a circuit if another circuit needs more power than the generator can supply if both circuits are live)... cool stuff.

I've run a Stihl electric chain saw using a single EU2000i, and consider this size generator the best bang for the buck. It's larger than the EU1000i, but the sound level is the same.

By the way, it's easy to compare sound levels (assuming the db is measured at the same distance... not necessarily a good assumption)

Every +3db is twice as loud. So, 10db works out to be about 10 times as loud. For example take any db and add 3 = twice as loud... add another 3 to that and it makes the new value 4 times as loud as the original... add another 3 to that makes it 8 times as loud... add 1 to that makes it roughly 10 times the original volume.

Here's a video I made last year about my setup. It shows two Honda EU2000i generators with extended run fuel tanks and an APC Automatic Transfer switch.

http://www.youtube.com/watch?v=Y2B4Vvz9Xqw

I need to make a new video soon as I added the ability to run the generators using either gasoline, propane, or natural gas. No more gasoline lines for us during the next outage!

I hope this is helpful to woodturners who consider adding a generator to their arsenal.

 

[AlanZ]

Also, how much does one of these generators need to be derated for inductive loads due to power factor? Just wondering what might be needed for a 3 HP motor.

Bill,

3 HP should be about 2,240 watts of draw... IF there was no efficiency loss.

I'm guessing that a Honda EU3000i or EU3000i Handy (the lighter weight model without the electric start) would do the trick. And certainly, two Eu2000i generators "paralleled" together would work.

 

[n7bsn]

....
Every +3db is twice as loud. So, 10db works out to be about 10 times as loud. For example take any db and add 3 = twice as loud... add another 3 to that and it makes the new value 4 times as loud as the original... add another 3 to that makes it 8 times as loud... add 1 to that makes it roughly 10 times the original volume. ....

Sorry Alan, wrong, common misconception.

3dB is twice the ENERGY, it is NOT twice as loud (same goes for 10dB and 10x)

The human ear is neither linear or log (like dB). Just what is "twice as loud" to the human ear varies with frequency, level and other factors. But a 3dB increase is not twice as loud. Through much of the normal human hearing range a 9dB increase is perceived as "twice as loud".

I worked in acoustics for years and have seen this misconception a lot.

 

[AlanZ]

Agreed with the comment about frequency, and about power. I've seen/heard the numbers argued many ways with regards to the practical effects of the perceived sound.

I recall when using a CB radio, a guy close by could key his mic and "step" on my conversation... his silence was "louder" (actually more powerful) than my speech!

So let's just say that the inverter generators are WAAAAY quieter than conventional generators.
The number of "A"s one puts between the W and the Y may vary < vbg >

 

[n7bsn]

So are you saying that they can be phase synchronized?

Also, how much does one of these generators need to be derated for inductive loads due to power factor? Just wondering what might be needed for a 3 HP motor.

Yes, in fact it is automatic, IF THE GENERATOR CONTAINS THE CIRCUITS.

How these work is the generator produces AC power at some frequency (which varies some between models, makers, etc), which is then converted to DC and then synchronously inverted to 60 Hz AC. The circuitry senses if there already is voltage "at the output" then the electronics "syncs" the output to it, so it is in phase.
This is similar to how the home solar panels can be connected to the main utility and provide power that is in phase.

Now NOT every inverter-generator has this parallel ability, Honda held a patent on their circuit for years, and I'm not certain if the patent expired or was "worked around". Infact Honda has to "remove" the parrallel jacks from EU's sold in Canada as their safety board does not think this is a "safe" thing to allow.

I've never looked a the PF derating in these, but I can tell you that a single EU2000 (about 1800 continuous) will usually start a 13,500 BTU A/C unit, but will not start a 15,000 BTU A/C unit. For the 13.5 units, a softstart CAP wired into the system will usually allow any 13.5 KBTU A/C to start.

 

[ALAN THOMAS]

Thanks for the information guys. I have looked at the Honda generators and to be honest they are a little too expensive for my budget ( over $1000+ here in the UK ). I may just buy a cheaper model and make a sound dampening box or cover ( I'll make sure that it does not interferes with the exhaust or air flow ) and see how that works out.

 

[Gretch Flo]

generators

A little off the subject concerning generators-not a power issue but starting one.
I have an old one -2500 watts, Power reach (hausfield Campbell), and never had been used,(think ex bought it) Had a power outage a couple of years ago and had a fellow visiting started it. I later tried, got it going once, then not after that. It's on wheels, not that heavy and it would move when I got toward end of "rip." preventing effective "rip to turn the engine over. Tried bungying to a tree-didn't work. Have had shoulder surg so maybe strength not there +short arms. How to stabilize?? Fortunately the power came back after 8-9 hours. Gretch

 

[Tom Hamilton]

Gretch -

Would it be possible to put a foot on it to hold it down when pulling the starter cord?

Or if that won't work how about bolting a 2x4 on the bottom of it to stand on when starting?

Tom

 

[Gretch Flo]

Gretch -

Would it be possible to put a foot on it to hold it down when pulling the starter cord?

tried that. Maybe I'll try the 2x4 the next time (10 yrs???) a big storm is predicted, Gretch

 

[n7bsn]

tried that. Maybe I'll try the 2x4 the next time (10 yrs???) a big storm is predicted, Gretch

General "generator" thing, starting the generator once a month or so, and running for 15 to 30 minutes is a really good idea. Many of the commercial stand-by units are set to run weekly