Mobile fab shop power???

[mdd0127]

Hi Everyone,

I'm setting up a small parts fabrication shop in a 24 foot box truck so I can build a prototype ultra light electric dirt bike. Working my regular job and designing this bike is eating up all of my time. I have a ton of research to do and could really use some pointers on getting mobile power for the shop. The frame will mostly be 1/8" or less 6061 but there are a few heavier welds required. I had a Longevity 160PI Tig/plasma back ordered but their new shipment is behind and I need to get started ASAP so I'm now looking into a Miller Diversion165. I figured I can at least tack the thick stuff and get it welded by someone with a larger machine. I'm trying to figure out the most cost effective way of powering the shop and thought some of you guys might have some pointers.

First, I'll list the equipment in the shop, then my ideas so far for power.

Equipment:
Miller Diversion 165 tig 50A max 230V
Micro Proto 4-Axis DSLS CNC Mill 10A 120V
drill press 4A 120v
belt/disc sander combo 6A 120v
bench grinder 4A 120v
computer/monitor for mill 5A 120v
fluorescent lights 5A 120v
dremel tool 2A 120v
heat gun 10A 120v
lipo charger 10A 120v
bench power supply 20A 120v
oscilloscope 5A 120v

Total 230V amps=50 11,500 watts peak
Total 120V amps=81 9720 watts peak

I'll only be running the welder with about 30A input most of the time and would like to be able to have the lights on, mill and computer running, and have another 15 amps for extras. I'd like a generator backed solar system so I only have to run the generator/engine while welding or pulling a bunch of amps from everything else. I can also run a small ext cord from the house to help offset some usage, or top the batteries off on heavy usage/low sun days. I'll be using the shop daily and would rather rely upon the truck's engine for generator power because it's more reliable than a small chinese generator engine, and it's easier to remote start the truck.

Actual usage 230v amps=30 6900 watts intermittently
120v amps=35 4200 watts for 5-8 hours/day 175-280aH/day

I'd rather not have a generator running all of the time and running a separate service to it is not possible. It needs to be mobile. My budget for truck power is around $2-3K but somewhat flexible.

Here's watt() I've come up with so far:

230V generator options:

Northern Tool 230V 10kw generator head mounted in place of AC compressor on the 366 gas engine that runs the truck and belt driven, or mounted in box and driven hydraulically from power steering pump with hydro motor spinning generator head. Will a big ford ps pump sustain 20hp?

genny head $900
belt drive $60 vs hydraulic(preferred) $300


or,

10,000 peak portable generator. not sure of brand or reliability, not integrated with truck, lots of negatives

$1000

http://www.northerntool.com/shop/too...&ci_sku=162661


120V options

8 Kaneka 60 watt panels $500ish
Sun SM3624 3600 watt continuous inverter charger $550
4 120ah sealed 12v agm batteries $1200

So, the best I have come up with so far is:

230V intermittent system
hydraulically driven NT Genny head $1200

120V 480 watt continuous 5kw peak solar system $2250

Total $3450+ $300 for price fluctuations, shipping

That's way over budget for a system that might barely be suitable. As you can see, I'm in need of a little help. It would be awesome if I could just order a 15kw solar backup kit but that's definitely not in the budget! As least not yet!

Anyone have any suggestions?

Thanks,
Danny

 

[mdd0127]

No mobile power gurus on the sphere?

 

[vanilla ice]

I vote gen head mounted in place of AC compressor!

I've been dreaming about a tire roller setup to drive a portable gen head.. that would allow you to use any vehicle. May be too bulky and expensive to actually build for a 4wheel. Hrmm, for a motorcycle it could be easier..

 

[TylerDurden]

TD votes hydraulic PTO, keeps the head out of the oven.

Although I do like the roller concept... scary fun.

 

[bigmoose]

Danny, I have been thinking about your price point and I can't come up with an elegant solution for you there. A power steering pump won't deliver 20HP. My backhoe hydraulic system is rated around 24 HP and the gear pump is the size of a 3lb coffee can for reference. You will never make your price point by adding hydraulics.

If I recall correctly, an alternator is about a hp load and a air conditioning compressor is around 5 to 7 hp. Keep in mind that you are going significantly above that with your concept, so you may need to redesign the drive system with a wide dedicated serpentine belt to drive the alternator. Again more cost. You will also have zero resale value for a modded truck design generating system.

We did this for a mobile machine shop for work about 10 years ago. We used a skid mounted diesel generator. If you are using this 4 or 5 hours a day, your fuel costs can be cut in half going from gas engine to diesel. We had the generator installed in a fireproof enclosure in the front of the trailer with fuel tanks below, under the trailer frame.

Here is a 20KW skid mounted diesel for around $4.5K you can use it for a few years, and it will have a resale value of $4.5K! http://www.dieselpro.com/2-71detroitdieselrebuiltgenerator20kw.aspx

Here is a natural gas/propane set, if you have natural gas available: http://www.machinerytrader.com/listingsdetail/detail.aspx?OHID=7226579

Get something good as a generator set, mount it on it's own dedicated enclosed trailer and you have something that will work for you and has resale value. I have no connection, nor personal recommendation for dieselpro. The price looks good on that generator set.

I grossly under bought generating capacity for my lab/shop. I have 10Kw and should have gone to 20 or 25 Kw. There are a lot of used 20/25Kw diesel units around. I have a 3 cyl Yanmar diesel, and the engine is fantastic!

Good luck. Overbuy generating capacity, you will use it.

 

[mdd0127]

Thanks for your responses. The only thing that comes to my mind, is that there's no way I can run the generator the entire time I'm in there. I also won't be welding the whole time I'm in there. There will be many many hours spent in with nothing but the lights on and me sitting over a pile of drawings scratching my head. I can't be burning fuel the whole time I'm working on the project. I guess this hits the same point that the overall build does. I'm extremely underfunded for what I need to do but have to figure out a way to do it anyway.

I ended up ordering a Longevity 160PI welder and talked to the guys that sell them. They said that they have been able to run their welders at full output on a 6.5kw generator, started easy arcs, and ran good welds. They said the IGBT design pulls less current and the power supply in these welders is very stable. I told him about my power problem and the generator head I'd like to use and he said it should run it with room to spare. The truck is an F600 and the power steering pump is HUGE. I'm going to get the part number off of it and look for some specs. It it will even do 10hp continuous with 15hp peaks, it should be fine. As for rounding up parts for a hydraulic system, I was going to pull stuff off of junk tractors and use other stuff I have lying around so the cost isn't too much, mainly just two t's, some hose, and some self sealing quick disconnects. I think I'm going to try it because I really don't want the generator head sitting on top of the motor.

If I was going to use this truck a few times a year for a few hours at a time, pulling a trailer with a dedicated generator would absolutely make the most sense, but using it every day and constantly running the generator would cost way too much. Basically, whatever I do needs to be solar with a generator backup. I just need to figure out the cheapest way.

Thanks again for the suggestions.

 

[etard]

I vote for diesel generator run on vegetable oil. It might cost a little bit more at the startup bit if you find a free source from a restaurant for oil, it will pay off long term. Only downside could be hunger from smelling fries all night. Runnin that f600 motor for say 20 hrs a week is gonna kick your ass later down the line. I'm loving your mobile workshop though, pictures would be nice too. You can come park in front of my house anytime, I'll even plug you in. :lol:

 

[mdd0127]

I'd LOVE a diesel generator, but on my budget, I can't afford one. I know running the big truck for 20hrs a week will get pricey but I'm hoping to have most of the welding done in a month or two. It's not like I'm planning on welding in there for 20 hours/week for the next few years or anything.

I converted a Ford F-350 to run on veggie oil a few years ago. It ran beautifully, smelled awesome, even better when I got oil from the donut shop! The only problem was picking up the oil and filtering it took all weekend and the most I ever got was 60 gallons. I came to the conclusion that if I had simply worked my crappy but better than swimming in veggie oil job all weekend, I could have just bought twice as much diesel fuel. I had a pretty cool setup too. It just wasn't efficient at that small of a scale. Neat idea though.

Here's a link to some pics of the project so far: http://s193.photobucket.com/albums/z112/mdd0127/Electric%20Bike%20Project/

I'm about to dig a 100 foot trench and bury some 6-3 in conduit. It's absolutely not the way I want to go but the welder came in yesterday and I'm itching to try it out!

 

[katou]

I have a friend in a similar situation, he lives in a treehouse, and makes knives in the forest in a small trailer. No kidding. His power needs are met by a 6500 watt (peak) gas generator that he got from a discount tools (like Harbour Freight) place we have here in Canada called Princess Auto.

It seems like your problem is energy storage. And here you are in the heart of battery country. Coincidence? Storing energy is never cheap though, if you based your costs per kwh, you would find that BigMoose is correct in his approach. The welder is indeed the highest wattage appliance you are likely to use (aside from the space heater, they're energy pigs) but that is also based on your usage style. When I weld, it's usually

1. weld for about 3s for tack, add piece, tack again,
2. find out piece was cut wrong, go grind it down
3. tack again, start full welding
4. drop slag into my shoe, dance the dance of burning feet
5. keep feet further from action, go back to full welding of pieces
6. repeat

So in 10 minutes of "welding" the machine is actually in idle for probably 7 minutes. That decreases the energy need considerably.

My buddy was always on the lookout for a big diesel generator at a good price, but so far, he's still looking.

Katou

 

[mdd0127]

We weld in a very similar fashion.

I think I've over estimated my power needs but I always like to over build.

I'm going to get what I can done with the extension cord until I figure out a permanent solution.

Anybody ever tied the outputs of two 5kw 12vdc- 115vac converters together in series for a 10kw 230v supply?

Big enough inverter, batteries, HO truck alternator, and a 120v charger might do it for now, then add solar panels later?

I haven't much luck finding 230v inverters though.

 

[katou]

If you are going to use wire for a bit, why not monitor your usage? If you can find an old electricity meter (like goes on the side of the house) you could note the energy used each day, and even before and after large usage events like the welder. Give'er hell and find out what you would actually use without cramping your style.

Create figures that represent everyday (constant) usage and a different figure for highest usage, and for what period.

Voila, actual measurements of peak and continuous power needed.

You might be able to do it by measuring amperage with a clamp-on ammeter, then multiply by voltage and time, but then you aren't measuring actual power used.

Katou

 

[bbagsby]

Listen Danny, this is a good idea. If your going to have that much power you will need to be grounded, in case i come shake your hand while your on the truck after you've been welding. equipment ground. in order to store power from your panels you will need several deep cycle/marine batteries, i would use 12v but these are heavy. Then invert your stored 12va into 120vac. Im not sure that your 60a alternator can "keep up" in amps with your welder, remember that is maximum out not sustained. You dont want to get into 240 volt demand if you are storing power in batteries, inverters are expensive or you have to use two different ones on two different phases of output. i will mull it over. i have to work tmro call me on friday k

 

[mdd0127]

Thanks Brett,

replying in the forum to spread information in case anyone else is working on something like this.

A ground rod is a given! I've been shocked by welders and definitely learned my lesson. They used to spray me with water WHILE I was stick welding at the excelsior plant to keep fires from starting.

I found a bunch of stuff out since I got home. First, the cheap panels are 67 volt. They really seem like nice panels but aren't normally used for non grid tie installations. I still want to use them, 10 of them at $59 each. $590

So, I'll need a charge controller. The Outback Power FLEX 60 looks like it will take the 67v from the panels and send it to the batteries. It's $540.

Now for inverters. Can I buy two 2500 watt inverters for less than one 5K? Maybe get one with true sine for computers/mill and one mod sine for grinders, lights, etc? Researching that tonight.

Batteries: I'm looking at sealed AGM's. 12V 220AH
Maybe 2 of these: http://www.ecodirect.com/ProductDetails.asp?ProductCode=MK-Battery-8A4D-Sealed-AGM&site=google_base

$1000 shipped.

So, Panels for $700 shipped, charge controller $570 shipped, $1,000 for batteries and a $3000 budget for the solar system leaves $730 for inverter/s.

I think this is doable and I haven't researched batteries or inverters much.

I'm fairly confident the 230V side of things is handled. We talked briefly about running the truck and using the alternator to top off the batteries if the solar couldn't keep up. While this is an option and will probably come in handy, the alternator won't run the welder reliably and you're right that 230v inverters are pricey so I'll be mounting a 10,000 watt 230volt generator head where the a/c compressor used to sit and belt driving from the engine with a latching throttle and tach inside the shop. The generator's sweet spot is 3600 rpm so it should work fine with similarly sized pulleys on the 366.

I update this as I find out more.

Anyone know the best value in storage batteries, inverters?

 

[mdd0127]

Oh, BTW....Welcome to the Sphere! Good luck sleeping for a while.

 

[mdd0127]

So, I'll need a charge controller. The Outback Power FLEX 60 looks like it will take the 67v from the panels and send it to the batteries. It's $540.

I got a quote from Sunelec.com for a 615 watt system with a 1.5kw inverter for $3100ish. I don't think the inverter is up to the task so I started comparing my other finds. I ran into a possible issue with running the 67 volt Kaneka panels and a 12 volt battery bank. In the PowerFlex 60 manual, it states that the maximum recommended system wattage at different battery voltages. If I run a 12v battery bank, allowing me to use cheap inverters, the maximum recommended system voltage is only 1500 watts. Will pulling more than the recommended actually damage the charge controller, or is it just "not recommended"? I realize that the charge controller would be stepping the 67 volts from the solar array down to 12 volts, creating a lot of heat, thus the low wattage rating. What about hooking up a diversion load water heater element? Would this allow higher power handling at higher array to pack voltage differences?

I attached the quote from Sunelec.

I'm thinking along the lines of possibly ordering their kit without the panels, charge controller, and inverter reducing the price of the kit by $1913, and ordering the Kaneka panels, outback charge controller, maybe a diversion load, and a sub$700 12v-120v inverter. Overall cost would be about the same in the end but I'd have a much bigger inverter, possibly nicer panels, and a better charge controller.
I'm waiting to see what Sunelec comes up with before I do anything else.


I have a lot to learn!

Where are the solar gurus?

 

[bbagsby]

You can get 5000 w 120 v inverters for 500.00 solar panels take up square footage, but just get the voltage you want. the batteries are a hundred dollars each. how much storage time amp hours.

 

[mdd0127]

Update:

It's alive!

Everything's finally installed and works great. Building all of the panel mount racks took a while! I ended up with the Lonvegity TIG and it's AMAZING. I've gone through three S size argon bottles running the welder on the engine mounted generator and the solar is more than adequate. I ended up using 520 chain and a sprocket on the end of the waterpump pulley to run the generator. I can run every tool in the shop, mill, grinders, lights, stereo, computer, on solar alone, and the batteries are still topped off when I shut down every day. I don't have time to do a full build thread right now but if anyone else is interested in building a solar powered mobile fab shop on the cheap and has any questions, just ask!

 

[grindz145]

Nicely done! Thanks for taking the time to post it.

What inverter did you end up using?

 

[mdd0127]

I got a 5kw pure sine from dcacpower.com

I'm still not happy enough with it to recommend it to anyone though because it barely works below freezing and buzzes until it gets warmed up. This is the only issue I have with the system and it's more of an inconvenience than anything. Under $700 for a pure sine 5kw inverter is pretty dang cheap so I really don't have any room to complain but I can imagine others being very frustrated if I recommended that inverter and they tried to use it somewhere cold. The guys at DCACpower are very nice but I don't think they have much technical knowledge.

 

[mdd0127]

Ok, I got tired of the noise and looked inside the inverter today. I didn't find anything obviously wrong but the solder joints were all a little weak for my tastes....very poor quality manufacturing inside.

Anyway, it seems to be fixed now. It's almost totally silent. I don't know what the trick or if it was something stupid like a little metal shaving inside or something but it's fixed now and it rocks. Just for a torture test, I loaded it down with the 5hp compressor and a 1500watt electric heater. It barely got warm. So, like almost everything these days, it's a great value if you have some patience.

 

[amberwolf]

I was about to type up a post of suspects you could look for when I saw your fixed-it post above.

Two things I would have suggested would be:
-- cold/cracked solder, which when cold will make a poor connection (or no connection), causing things to not work especially at extreme temperatures. But when warmed up it'd work fine. This could also cause buzzing when cold if it caused a cyclic interruption of power due to high resistance leading to improper feedback in the system, making it think something was wrong (well, something *would* be). The buzzing would happen because transformers or coils with current pulsing thru them at the cyclic interruption rate would physically vibrate due to magnetic fields moving things around.
-- bolted-together electrical connections that were not fully tightened down, causing the same problems/symptoms as above.

 

[etard]

DUDE!!! 8) That's frickin awesome!!! Questions:

Does it drive around like normal truck?
How much did it cost?
Can you snap more pics of the whole setup?


Thanks for sharing.

 

[AussieJester]

DUDE!!! 8) That's frickin awesome!!! Questions:

Does it drive around like normal truck?
How much did it cost?
Can you snap more pics of the whole setup?




Thanks for sharing.

^^ would appreciate answers to these questions also if you don't mind

I also had a question about the solar panels and the mounting, are they fixed in this position or can they be laid flat when the truck is in motion. I might of missed the price and model of the solar panels in the thread if so my apologies, would you mind repeating (if it was mentioned) where they came from and what price per panel... I'm very keen to have my garage setup and an aquaculture setup all powered by DIY wind mills and DIY solar setup...next project after i kick this e-bike addiction.

I think you have done a marvelous job, can't wait too see what you build in there!

KiM

 

[mdd0127]

It can drive around like a normal truck but it takes an hour or so to be road ready. I have to take the master link out of the generator chain so the generator doesn't spin too fast while driving. Probably wouldn't hurt to leave it connected but it's geared pretty high and I don't like the idea of the generator spinning at 7K rpm, so I just pull the chain off. I also have to flip the plugs around on the fans to reverse their direction for driving. The last step before driving is lowering the panels. I just have to get up there and unbolt the verticals, then bolt the panels straight to the feet.

There are lots of things I would have done differently if I had money and more time but since the bike build is the main focus of all of this, I really just had to get it together as quickly and cheaply as possible. Little things like the conduit coming out of the combiner. I calculated the conduit to the inch because I couldn't afford another ten foot stick...really....anyway, I forgot to account for the bell ends so the conduit looks a little weird coming out of the combiner..works though. Wires not in conduit from the charge controller....ran out of wire..

There are a million little things that I'll probably redo when I get more time but for now, it may not be pretty but it works!

I had to build the solar racks from scratch so that took a little while. It would have cost over $500 for pre-built ones and they'd still probably need to be modified.

As far as costs go, I don't have everything separated but I can give some ballpark figures.
The generator setup was about $1700 for the parts.
The solar system probably ended up around $5K. I've been on my own as far as financing goes as of a few weeks ago so I've got a pile of receipts to go through. The little things are what get you. I probably made twenty trips to home depot to finally get everything.

Here's a basic component list and rough cost breakdown for the solar:
10- 60 watt 67 volt Kaneka panels from Wholesale solar ---$750
Outback Flex60 MPPT charge controller from AltEstore---$650
5KW pure sine inverter from DCACPower.com--------------$650
Midnite Solar 12ch MNPV12 combiner box from AltEstore---$150
DC and AC breakers----------------------------------------------$100
8- Trojan T-105 6v 220ah batteries from wholesale solar---$1000
14 gauge wire, 4 gauge wire, 2 gauge wire, 14-2 wire-------$200
Conduit, boxes, ac breaker box, bolts, etc....................$500
Aluminum for racks from speedymetals........................$200
Argon refills and welding supplies...............................$300

I'm sure I missed a bunch of stuff here but that's the general idea. I'm learning to double every estimate I make though because there are always surprises.

Also, I'm really pumped on the panels I got. They're the cheapest ones in the world at $0.97/watt but they're amorphous and the array actually puts out 70V at 3A under full clouds. The only disadvantage to going with the cheaper panels was the need for a more expensive charge controller but watt for watt, I think I've put a pretty economical system together.

I'm working on getting familiar with the mill this week. I can't afford any software and g-simple sucks so I've been writing g-code for stuff the old way. I did a 1800 line program a few days ago for the adapter to install the CSK on the rear wheel and I wrote the whole program for a 3/8 endmill....which I don't have....so I had to order one or rewrite the code. End mill ordered. It's been so long since I've played CNC, that stupid little things like fixturing are really slowing me down. I made some cash last week working on a Subaru and spent all of it on stuff for the mill. I should be cutting parts by next week. Overall, this has been an unreal amount of work but should pay off in the end.

 

[spinningmagnets]

Absolutely fantastic! Your mobile shop is so complete, I can't think of a single thing you need to add...except...well,...maybe this?

http://www.fnherstal.com/index.php?id=658