Powering a 1HP BLDC Lathe in a Van

[erikmannie]

I have looked at this before, but I ended up looking at a ridiculously large bank of 12V batteries or solar panels. Now I am planning to idle the vehicle while I work on the lathe.

What I am trying to do is (brace yourself!) put my 10X30 lathe in a van. The motor is a 1HP BLDC, and the lathe has a DRO. The lathe is currently plugged in to a 15A, 110V circuit in my shop, but I really do need to take it on the road. The lathe will spend the rest of it’s life in a van.

The lathe draws up to 7A while in use, but I wonder what the maximum startup current may be (if that is even an issue). If I needed to draw even 30A to get it going, then p=iv is 30A X 110V = 3300W. If I bought an inverter larger than 3300W, wouldn’t that power the lathe if I kept the vehicle idling?

 

[erikmannie]

I have 10 months to get this project up and running.

I would like to avoid a gas generator, solar panels and lithium ion batteries.

I am willing to build a battery bank of quality automotive or marine batteries. At some point, a large battery bank would encroach on the workspace.

Powering the lathe using an inverter & the car battery would be great space-wise, but I have a feeling that I will need a battery bank that is charged off of the car battery.

Can this be done? I sort of need to make it work. I go out of town 2 months every year, and staying in a motel room with no tools or shop isn’t working.

 

[Superburban]

3300W/12V = 275 amps. Assuming a perfect inverter conversion. The alternator in your van, is likely between 80, and 140 amps. The battery would hold for the startup. Running, would be down about 80 amps at 12 volts. Even though newer alternators are rated higher now days, many still do not last long putting out near their top rating. So do your homework on what your van has.

Also look at inverters, IIRC, there is something about many not working with inductive loads. I think you have to look at pure sine wave inverters.

 

[erikmannie]

The first specific question would be how many Amperes the alternator will provide.

 

[erikmannie]

3300W/12V = 275 amps. Assuming a perfect inverter conversion. The alternator in your van, is likely between 80, and 140 amps. The battery would hold for the startup. Running, would be down about 80 amps at 12 volts. Even though newer alternators are rated higher now days, many still do not last long putting out near their top rating. So do your homework on what your van has.

Also look at inverters, IIRC, there is something about many not working with inductive loads. I think you have to look at pure sine wave inverters.

I don’t have the van or the inverter yet (but I have all the tools!). The van, batteries and inverter will be chosen specifically for the task of powering the lathe and DRO.

I have no problem buying a robust, sine wave inverter & installing a similarly robust alternator. I certainly don’t want anything to fail when I am thousands of miles from home.

In case you haven’t guessed, most of the energy is going to come from the gasoline. Leaving the vehicle idling while I am working on the lathe is a critical part of the plan. Let’s overlook the ridiculous aspects of this plan for now; I would not be the first person to leave my engine running for awhile.

There are a lot of other considerations with this idea of a mobile lathe, but I am just focusing on powering the lathe & DRO for now.

 

[ErichKeane]

An inverter would work fine. Most inverters are 'peak' capable, for example, the harbor freight 2000W inverter can handle 4000W peak. Your lathe at 7A @120V is 70A@12V, so most van alternators will be able to do it. Depending on the motor, you can (and SHOULD!) get an upgraded alternator. For ~$500 any of the Ford Diesels can have a 200+W alternator.

The plan doesn't seem that much out there to be honest. I could see a traveling repair shop wanting to do exactly this. That said, powering by gasoline is going to be WAY worse than powering by diesel I think. At idle, a diesel is going to do a much better job. Since you don't have the van, you could look at the E250 diesel, which would run reliably for ever and has a TON of aftermarket support (including upgraded alternators) since it shares with the 1/2 and 3/4 ton Ford pickups.

 

[erikmannie]

An inverter would work fine. Most inverters are 'peak' capable, for example, the harbor freight 2000W inverter can handle 4000W peak. Your lathe at 7A @120V is 70A@12V, so most van alternators will be able to do it. Depending on the motor, you can (and SHOULD!) get an upgraded alternator. For ~$500 any of the Ford Diesels can have a 200+W alternator.

The plan doesn't seem that much out there to be honest. I could see a traveling repair shop wanting to do exactly this. That said, powering by gasoline is going to be WAY worse than powering by diesel I think. At idle, a diesel is going to do a much better job. Since you don't have the van, you could look at the E250 diesel, which would run reliably for ever and has a TON of aftermarket support (including upgraded alternators) since it shares with the 1/2 and 3/4 ton Ford pickups.

I am open to using diesel. This is why I am putting this idea out there, before I select a vehicle.

The only requirements of the vehicle is that (1) it is not too ugly, (2) it is not too long, (3) I need to be able to stand up in the work area, (4) it has just enough room for a 10X30 lathe, lathe tooling & one operator.

I like the RAM Promaster because it has a low deck height. We’ll see if those can be had in diesel. This may call for a 3/4 or 1 ton.

 

[erikmannie]

The reason I want to avoid solar panels or a gas generator is because I don’t want the vehicle to stick out as something odd. I want it to blend in.

It would be pretty easy to buy a flatbed and put a Miller Bobcat and a custom structure on there, but that is not stealth. I want to end up with a white van that looks like so many others out there.

 

[Superburban]

Yea, looks like a stealth van to me.

 

[JimDawson]

If you insist on running the van engine to power the lathe then I would install a second high output alternator and dedicate it to the tool power. Many emergency vehicles have dual alternator setups. If buying a new full size van, a dual alternator system may be a standard(ish) option. Aftermarket high output alternators are very available, and most likely full installation kits for dual setups for about any vehicle.

Having said that, a 2000W or 3000W Honda generator is very quiet and would easily run your lathe. Pure sine wave output also, and they have pretty good surge capacity. But if you go that route make sure you buy genuine Honda from a Honda dealer.

7 amps at 120V is 840W, so realistically a 2000W inverter would be fine, the start load is not going to be 3x on a BLDC motor. And good inverters have some surge capacity, but as said above, get one with a pure sine wave output. There is a lot of cheap junk out there.

Above all plan for expansion. First is the lathe and the next thing you know you will need a mill, then a band saw, and ........ and........ and........ I think you're going to need a bigger van.