Powering a 1HP BLDC Lathe in a Van

[erikmannie]

I am not sure how many batteries I need, but this is an example of a good candidate.

 

[matthewsx]

So, how much room do you need to live in and how much for the shop? If you can justify a small RV at ~$30k for something decent and a tandem axle cargo trailer you might have a winning combo for staying in a campground.

2009 Winnebago Chalet 26 FT With A Slide Out And Rear Bed - rvs - by...

we are selling our one owner winnebago chalet and this is built on a E450 Ford chassis with a...

sfbay.craigslist.org

https://sfbay.craigslist.org/sby/trb/d/gilroy-7x14-tandem-axle-enclosed-cargo/7096547346.html

 

[erikmannie]

You have to think that a police officer could find no fault with somebody working on a lathe in a van with the engine not even running.

The battery bank would allow me to open doors and/or windows without exposure to vehicle exhaust, and allow any battery offgassing to clear out.

 

[matthewsx]

When you start building battery banks leave room in the budget for a good charge controller. Also, they do need to be vented outside while charging.

 

[erikmannie]

So, how much room do you need to live in and how much for the shop? If you can justify a small RV at ~$30k for something decent and a tandem axle cargo trailer you might have a winning combo for staying in a campground.

2009 Winnebago Chalet 26 FT With A Slide Out And Rear Bed - rvs - by...

we are selling our one owner winnebago chalet and this is built on a E450 Ford chassis with a...

sfbay.craigslist.org

https://sfbay.craigslist.org/sby/trb/d/gilroy-7x14-tandem-axle-enclosed-cargo/7096547346.html

When you start building battery banks leave room in the budget for a good charge controller. Also, they do need to be vented outside while charging.

Finding a place to sleep is not a problem.

Wow, I did not know that batteries needed to be charged in a well ventilated area. So not charging inside a motel room, I guess.

 

[matthewsx]

Also remember, your lathe wants to be leveled. Driving around with it and parking in random places isn't likely to allow for that. If you can block up a trailer and leave it in place for the two months you'll be there it should be a lot better for precision work.

 

[matthewsx]

Finding a place to sleep is not a problem.

Wow, I did not know that batteries needed to be charged in a well ventilated area. So not charging inside a motel room, I guess.

Charging lead acid batteries creates hydrogen gas (boom)

 

[Superburban]

If you're going with a dual alternator, I'd consider finding one that could be wired up for 120v directly. A quick googling shows that they are reasonably easy to convert.

You will end up with something like 500 or more cycles per second (HZ). Most generators run at 1800, or 23600 RPM, to keep the cycles at the 60 HZ that most of our tools need. Many things do not care about the HZ, most motors, and electronics do care. Although, I think I read a VFD, that can have 400 to 500HZ on the input line.

I would take a look at the class C (Conversion van) RV's. There are some that could be modified for your needs, and still look like a simple van.

Another idea, is a handicap van.

 

[Aaron_W]

I wonder what a police officer would think about some guy parked on the side of the road or in a, say Walmart, parking lot idling his motor and inside working on a lathe.

California plates, they look for drugs, there aren’t any, so I wonder if there’s any problem there?

I was thinking more parked in front of a business or residential area. Walmart parking lot is a lot less likely to be an issue.

If you saw a van parked outside your house with the engine running I'm sure your first thought would be, hmm wonder if he has a lathe in there but a lot of people might wonder if it is somebody up to no good, casing the neighborhood, getaway van for a home invasion etc. People get paranoid, and call the police for some rinkydink stuff, like a neighbor running a lathe in his garage. Of course you aren't breaking the law and you might even get a police officer who was into it and get a good conversation out of the encounter, find out the best local coffee place.

An old box style ambulance would be a good candidate for conversion. They are usually fairly cheap, most are diesel, have a beefy electrical system, and good interior space. Many also have external compartments which could be good for material storage, or for mounting a generator if you choose to go that way. Not as incognito as a plain white van, but they look like a working vehicle so less likely to attract negative attention if seen parked with activity inside. Depending on the prior owner many are well maintained, although they can have been run hard, quick starts from cold to 60mph and often extended idling.

One downside, having worked on ambulances if you get one gut the patient compartment and use more bleach than you have ever used before to clean it out.

Something like this





Not to distract but let me offer you another option to make chips after class.

Sherline lathe 30lbs, and you could fit one with tooling into a suitcase. Maybe take up small engine building or clock making. You can take it as checked luggage on a plane and use it in the motel.

Sherline

 

[AlanB]

The power consumed by a lathe varies a lot. So using 1hp continuous as an estimate is probably very high.

Lead acid batteries can only be drawn down about 50% if they are to last. So the capacity is only half what they claim.

Best to work in watt-hours. 12V 100 amp hour battery is 1200 watt hours. Use 50% would be 600 watt hours. Or about 600/749 = 0.8 hp for an hour. So each battery would run the lathe for nearly an hour at a fairly heavy load. Factoring in the inverter efficiency at 85% will reduce things a bit further to 0.68 hp for an hour per battery.

Lead Acid Batteries must be vented. The compartment must be vented outside, or the battery boxes with vent pipes can be used.

Lead acid batteries exhale a mist of acid, handling them is not a good idea. Everything within a few inches corrodes from this. Connections for this level of current are heavy and another reason not to mess with the batteries frequently.

Charging them will take awhile. The most charger you can use with a regular AC outlet is about 1200 watts, so it would take about a half hour to bulk charge each battery, and a lot longer to finish the charge which occurs at slower rates. This is a fairly expensive charger (approximately 100 amps). Batteries don't like to be charged that fast, so it will reduce their service life. Charging four at once will help here, reducing charging current to 25 amps per battery.

The noise coming from the lathe might not be neighbor friendly. The truck might need to be soundproofed. Also good ventilation is required with oil smoke, solvent and other unhealthy things needing to be conducted outside.

Class C motorhomes commonly have built in generators that have outside compartments. Perhaps get a used class C and gut it and convert it to a mobile shop.

Running the vehicle engine to provide power is very inefficient It will consume a lot of fuel and generate a lot of pollution. An onboard generator is a better approach.

A Class C towing a box trailer with the shop in the trailer would be my choice.

You may also need heating and cooling, the RV will be set up there too.