Workshop In An Alternate Homepower Environment

Page 1 of 13  

I am posting this subject in three different groups to hopefully get a good cross section of ideas. I apologize ahead of time if this offends anyone.
When one considers a workshop with metal and wood working capabilities, what tradeoffs have you made to have a working shop in an alternate homepower environment where every amp is precious?
Obviously hand nonpowered tools take on a special importance.
Cordless tools come to mind but which ones and what batteries?
When considerng stationary tools like drills, lathes, mills, saws, grinders, etc., which ones fit best in an environment where one is off grid?
Special operations like welding and using air compressors would seem to need consideration because of their unique requirements.
I would be interested in hearing how others have approached this situation and what implementations they have adopted.
Thanks for any suggestions or comments that you can offer.
TMT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

cordless tools violate the 'every amp is precious' premise.
Charging batteries is *extremely* ineffcient.

PTO-driven ones. The 'drive' can come from nerly anything -- a water-wheel, a steam-engine, a tread-mill, etc. Even an electric motor, in extreme circumstance. :)

Welding -- gas, instead of electric arc.
Air compressor -- gasoline/deiesel engint, steam-powered.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Good point on the battery charging of cordless tools.
I was thinking that they might fit in where they could be run from the main bank of batteries themselves.
TMT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I second what Robert Bonomi has said. What's wrong with good old fashioned human power? Such machinery was once very common. Take a look at some pictures of old machinery, and you will find an apprentice who is busy turning a flywheel all day long, and observing his master at work, thereby gaining a firsthand knoiwledge which no number of words can communicate. Nowadays, however, such flywheel turners tend to be very expensive. Therefore, I recommend that you build yourself a squirrelcage apparatus, and purchase a greyhound to run in it. Retired racing greyhounds are put to death if nobody wants them. I know a lady who has a retired racer, and he is a wonderful pet. A racer is happy when he is racing. This is of the very nature of a racer. So give a veteran a job, for god's sake, and build a squirrelcage power plant.
Mike Mandaville providing meaningful solutions for the workaday world
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think there are other considerations besides efficiency. This depends on your method of power generation, and how often you work. Cordless tools can be useful because you can charge them when you have peak power available from your source. The same is true for compressed air. If your home's battery bank is fully charged, you can divert your energy to building spare power for the shop in your cordless batteries, and building up compression in your air tank.
I also think that, depending on how you work, the loads may not be so bad. You most likely don't crank your saws constantly for hours on end. You use these things in bursts. You may be able schedule your work so that the extra load from these machines is manageable.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 14 Jun 2005 19:21:32 -0000, snipped-for-privacy@host122.r-bonomi.com (Robert Bonomi) wrote:

That depends. For a typical windpower setup, you have an excess of power you can't store when you don't need it, then a shortage when you do. Even inefficient batteries can improve _overall_ efficiency
--
Cats have nine lives, which is why they rarely post to Usenet.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
1. Go to a big power tool store. 2. Buy a generator. 3. Buy a whole bunch of gas. 4. Start said generator 5. Plug in tools 6. Build.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Booo! Hissss! Generators as a sole source are often the worst choice for home power. Their only advantage is low up-front cost. But in the long run they'll cost more, and are no fun to live with compared to solar/wind/inverter/battery. Home use tends to be relatively high energy but low power, while shop use tends to be high power but low energy. So adding shop power usually means increasing charging sources and batteries a little, but making the inverters substantially larger. And if one were to choose a generator well suited for shop use, it's likely to be way too big for backup on a properly sized home power setup.
Wayne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Some people, unlike you, have a real life though.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 14 Jun 2005 20:19:59 -0400, "John P Bengi" <JBengi (spamm)@(spamm) yahoo,com> wrote:

1. If you think that generators on their own make good sense for permanent off-grid workshops, then that's another subject that your sock puppet army doesn't know squat about.
2. Any guy who'd post under the name "pizza girl" shouldn't be allowed around electricity or power tools, unless it's for electroshock therapy, or for having a frontal lobotomy hole drilled.
3. Two of your identities, including the one you're using now, already claimed to have killfiled me, so any response from you to my posts is just more BS.
Wayne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 18 Jun 2005 07:32:19 +1000, Lectrouis

Yup, that looks like gymmy bob/bengi alright. http://tinyurl.com/df7mb He's been complaining about top posters since 2001? Yikes! I sure wish his social worker would give him a scroll-wheel mouse already. Anyway, alt.support.tinnitus? Ringing in the ears, probably due to cranial defect... that explains a lot.
Wayne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gimmy-John P BengiBoob wrote:

You wouldn't be in a position to know, you top posting loon.
mike
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Only real solution for running tools at home is a generator. A propane generator might be the way to go if you already have auxilary heat that way. Typically the machines don't run terribly long at a stretch, except maybe a sander. My jointer and table saw only run a few minutes max.
If your pace is slow, hand tools will get it all done. Watched alone in the wilderness the other night. He did amazing time with cutting through several feet of spruce tree with a large western hand saw.
Alan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Nonsense.
Wayne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Too_Many_Tools wrote:

1.1kw + , (2) arc/mig,tig welder 2.2kw + , some large routers and table saws . the list is endless . I at presant can run my 12speed pillar drill or chop saw (not both) from my 1 kw mod inverter . high batt voltage will help you start large motors so use in day light hours only (solar)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 14 Jun 2005 12:07:53 -0700, "Too_Many_Tools"

8kW (surges to 16) can handle most everything a home shop is likely to have. We have a few limitations - Hypertherm 600 suffers nuisance cut-outs above 45 Amps. It will also temporarily shut down if the compressor starts mid-cut. So I let the compressor tank fill, then shut the pump power off before starting the cut. For prolonged cutting at max output, I run the backup generator for boost. Lincoln SW TIG 175 can't be run at full output off our inverters, amp draw is too high. Could be solved by trading up to an inverter based unit if I didn't already have an engine driven substitute for the bigger jobs. Powermig 255 seems perfectly happy at full output.

Yuck! Perish the thought.

Cordless tools are great for jobs where the cord is a nuisance, but there' isn't any special need for them with home power. Careful though if you're using some of the modsquare (often called modsine) inverters, they can cook the chargers included with some cordless tools.

There aren't really any special considerations unless you're trying to get away with too-small inverter capacity. Keep in mind that if you're maxing out system capacity in the shop, it won't be available in the house at the same time. Having said that, I don't bother to tell my wife what I'm up to in the shop. If together we managed to exceed capacity, the inverters would trip off automatically. And that could happen more easily if for instance batteries were low, and you have surges due to large loads starting. The temporary voltage drop might be sensed, and cause a shutdown.

One thing I've done with all equipment purchases is to make sure they're easily returnable just in case they're not compatible with the inverters. VFDs could be an issue for instance. Although the only thing we've ever returned due to incompatibility was a bread maker that ran at double speed.
Wayne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I only use my compressor for about 15-30 minutes a day. Right now I'm using a gasoline generator to run it but I am considering the possibility of using a belt-driven generator and replacing the AC motor with a 12 VDC motor. For my purposes it won't matter much if it takes a little longer (lower gear ratio on the compressor) to fill the tank. I also always manage to find something to do while compressor is filling the tank anyway. The main problem I see with a 12 volt compressor is motor life and having to change the brushes etc.
I also use more human-powered tools than I would if I was connected to the grid. For example I make custom picture frames and I can either (in most cases) use a big noisy double-miter saw that uses a lot of power and throws sawdust all over the place or use a foot-powered chopper that makes hardly any noise and produces wood chips that I expect will be suitable fuel for the woodgas generator that I plan to build in the not-to-distant future.
A few people mentioned that cordless tools are ineffecient but hey, it sure is nice to be able to grab a cordless drill when you only need to drill a couple of small holes and not have to go start anything up or turn anything else on.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the reply.
I would agree that cordless tools have a spot in the AHP workshop since one can recharge them during off load hours.
Where would one find 12v motors in the suitable HP and speeds to retrofit something like a table saw?
In considering this subject, a lineshaft approach does come to mind but unfortunately you rarely see the needed equipment at HD or Lowes. I am not to crazy about chucking all the stationary power tools that have taken me decades to collect. Also, lineshafts take up room, linedriven tools are required to stay in one place and cannot be mounted on wheels to optimize shop space as needed. A workshop should be no larger than necessary for the heating/cooling aspect that also takes energy.
TMT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Too_Many_Tools wrote:

cordless tools on the higher end beginning to use lithium ion batteries instead of nicads. Apparently they can give one hell of a current draw and run at a slightly higher voltage (28V?). Anyway, along with the usual benefits for contractors on cordless drills and such there was great promise for cordless table saws and larger equipment due to the ability to run for extended periods at the higher current draw.
It doesn't help today but there is hope in the near future for the off-gridders and job site work.
Koz
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15 Jun 2005 11:36:20 -0700, "Too_Many_Tools"

I really hesitate to jump in on this topic, but I advise you to make sure to do your research carefully before pursuing the replacement of AC motors with DC motors.
In the early days of homepower which was nearly universally 12V on the primary side, this was a pretty common practice, but in the overall picture of things today I'm not sure it's warranted in the general case.
At one time I was given to understand that DC motors are just innately more efficient than AC. It appears that this is not necessarily so, and has much to do with the crappy design and build quality of "shovelware" AC motors than any basic electromechanical principles. To know whether you would actually be further ahead after a DC conversion, you would have to consider each case individually. Ignoring power factor, a 12V load of power "x" draws 10 times the current that an 120VAC load will draw. Will the losses you avoid by bypassing the inverter get chewed up in the wire? How close to the battery room will the workshop be?
I started out at 12V primary by virtue of buying a house with an existing PV system. Like many frontier homebrew systems, it had started as a purely DC system to which an inverter was added later.
Having no plumbing in the house, I've acquired a number of small 12V pumps for various specific purposes, such as our bucket shower. Fortunately this hasn't represented a significant investment. With each system upgrade I left myself options for going to a higher primary voltage, and recently made the move to 24V when we replaced our chargerless mod square wave inverter with a sine wave inverter/charger. At some distant point in the future we might even make the jump to 48V, but for the moment, 24V was "just right."
The punchline is that our little pumps (and other 12V DC loads) are now running off a 24V/12V DC-DC converter. In the overall picture of things this crazy scenario actually still makes sense here, but again these are *small* loads.
The moral is that when you choose to run DC loads, you're creating specialized equipment and there are serious implications that might not be immediately obvious. If you stick with AC loads, your wire runs can be far longer for a given power throughput / wire guage, you can reconfigure the primary side of your system without affecting anything on the load side, use a common AC generator when it's more convenient or more sensible to do so, or take your gear with you and use it elsewhere.
Having "inherited" a mixed DC/AC system and lived with it, off-grid, for five years, there is no question in my mind that the new house we build here will be wired almost entirely for conventional AC and will likely have only some emergency lighting (power room!), and perhaps a few very special-purpose devices and outlets wired for DC.
YMMV.
-=s
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.