CNC machined lipo boxes...............

[recumpence]

Here are a couple pics of some new CNC machined Lipo boxes we machined today.

I wanted some very durable boxes that can contain a lipo fire relatively well along with handling a fall off a bike. I also wanted to make sure the packs fit sung for two reasons;

#1 A snug fit helps increase the "C" rating of these cells allowong them to be pushed harder.

#2 A snug fit gives much better thermal transfer to keep the cells nice and cool.

They are machined from 6061 aluminum with covers held down with 6 screws. The inside dimentions are 6 inches by 4 inches wide by 2.060 inch deep. This gives a snug fit for the popular 25C Turnigy 6S packs we are using.

If anyone is interested, they are $95 per box. Oh, there are no wire holes drilled. That way each person can drill their own hole for wire exit either through the top, front, or bottom of the box. Admittedly, these were only made for my personal builds. However, I had time and material to make more than I need. So, I made a few extra.

These boxes are made for only two packs because I wanted to make sure any battery failure would only affect one other pack. This also allows easier mounting. It is easier to mount two or three smaller boxes than one large box.

Anyway, my builds will use these from now on. I will also be using them as controller cases. I can fit two HV160s in each box easily.

Matt

 

[AussieJester]

Very nice..as always Mr Recumpence SiR...now...i want too see the billet stock
that these were machined from! thats got to be some serious chunk of
aluminium Matt!

Top work anywayz mate

KiM

 

[pwbset]

Wow those are sweet! How much do they weigh?

 

[swbluto]

Very nice..as always Mr Recumpence SiR...now...i want too see the billet stock
that these were machined from! thats got to be some serious chunk of
aluminium Matt!

Top work anywayz mate

KiM

Yeah, seriously. Where does all that cut out aluminum go?

 

[amberwolf]

The soda fairy comes by and sprinkles pixie dust on it, turning it into cans surrounding your favorite fizzy beverage. Well, the non-alcoholic ones, at least.

Seriously, that's a lot of metal.

I'd want to make them from separate panels fastened together, with a little machining for rigidity patterns....

 

[recumpence]

The excess aluminum is captured and sold. We use an enclosed HAAS production CNC with a chip auger and catch bin.

I looked into separate panels fastened together but decided to go this route for a number of reasons;

#1 It is actually much faster to make these than a bunch of separate panels (believe it or not).

#2 Weight. I have not weighed these yet. But, they are relatively light. A separate panel box weighs more if bolted together because the wall thickness is greater and more screws are needed.

Actually, the best cost/weight/material use design is separate panels welded together with a machined top section for the screw on lid. That is a bit of a hassle, though, because of the number of step involved.

Ultimately, this is the best way to go.

We do recycle all our chips. It is amazing how many large buckets of chips are sold through our shop.

Matt

 

[graemebc]

Is that not the billet stock on the floor in the back ground? Nice boxes btw Now how a bout a 11.5 x 6 inch triangle frame one made the same way dibs on that one 1st

 

[etard]

Those are stunning!! I am amazed that you can sell them soo cheap seeing how they came from a billet of aluminum. Another step forward in Lipo safety! I think these will be seen on alot of builds.

 

[TMaster]

Those boxes are nice! Would sure beat trying to piece something together!

 

[pwbset]

Now how a bout a 11.5 x 6 inch triangle frame one made the same way dibs on that one 1st

Yeah no kidding! I'd totally spend out the nose for a custom triangle one that I could throw like 6 Turnigy 5-6s 4-5ah into!!

 

[recumpence]

The primary reason I have not machined a huge triangle is material cost. These came out of a 7 inch wide, 2.25 inch thick drop from a HUGE plate. A billet plate the size of a frame triangle would be crazy expensive.

It cost me $320 for that bar to make 15 of these. Then there are the covers and well over an hour of machine time to pay for per box.

Anyway, I have begun mounting these to the trike.

Oh, I have to go. I have a customer showing up to pick up his two grand worth of E-bike goodness.

Matt

 

[MitchJi]

Hi,

Beautiful.

If they had tabs (maybe one on the end, one on the end side and one on the end top or bottom) that fitted your tube clamps they would be a lot easier to mount.

If you provided a way to fasten multiple boxes together (via the end, side and top or bottom) that might also be useful.

 

[recumpence]

Hi,

Beautiful.

If they had tabs (maybe one on the end, one on the end side and one on the end top or bottom) that fitted your tube clamps they would be a lot easier to mount.

If you provided a way to fasten multiple boxes together (via the end, side and top or bottom) that might also be useful.

Good idea!

I actually considered the tabs to use my frame mounts. But, these were meant for my trike, primarrily.

Matt

 

[nikos7]

Hi Matt

These boxes are a great idea and they look very nice too :lol: ...excellent job on machining. I agree that mounting tabs would be nice, a kind of universal tab configuration.
Have you thought about adding vents in the event of a LiPo fire to let pressure out slowly instead up building up and going off like a grenade with billet shrapnel everywhere...? Just a thought...

 

[recumpence]

Once the wire hole is drilled, any venting will exit through that hole if no other holes are added.

Oh, as for mounting; there are six 8/32 threaded holes in the bottom of the box for mounting purposes.

Matt

 

[stevepurcell]

Matt,

The inside dimensions are 4 x 6 x 2.060;
What are the outside dimensions including lid?
What is the weight?

Thanks,
Steve

 

[recumpence]

I do not have one here to weigh or measure. But, the wall thickness is 1/8 inch all the way around, plus the small protrusions for the screws.

I would guess (off the top of my head) that the box is 6 and 1/2 inches long, 4 and 1/2 inches wide and 2 and 1/4 inches high.

Matt

 

[j3tch1u]

Once the wire hole is drilled, any venting will exit through that hole if no other holes are added.

just aim that hole away from your crotch son--"nothing like the smell of napalm in the morning".

that sho is a big hunk of alum--build a little engine block with that. are you sure they don't make thick square channels in that size?

 

[recumpence]

The problem with thick chanels is I would need a cover for two sides.

I am checking into options like that, though. I have had a few interested people, but not enough to make this a normally stocked item I will machine. -------- Still, if I could get teh price down to $50 or $60 per box, that might be more tempting.

At any rate, I have a few project bikes to build a a number of drives to configure for people right now. So, I am in no hurry. This was merely an easy option for some ready made boxes to use for my own builds as well as to sell a few.

Matt

 

[j3tch1u]

would love to see some fire tests and melted metal terminator style

how about insulating with a layer of nomex? spare no expense for the family jewels box!

how much do you guys get per pound of alum chips? we have to buy garbage bags for $1.50 from the government and chase down garbage trucks 2 blocks to dump our shitz they play this abominable version of fur elise every night to let you know they're coming. i swear the tune is more popular than the national anthem.

 

[MitchJi]

Hi Matt,

The problem with thick channels is I would need a cover for two sides.

I am checking into options like that, though. I have had a few interested people, but not enough to make this a normally stocked item I will machine. -------- Still, if I could get the price down to $50 or $60 per box, that might be more tempting.

Matt

How about two end plates with machined groves to snugly fit the ends of the channels, then run bolts the length of the channels, inside the channels pulling the ends together (like a clamp)?

 

[Jeremy Harris]

What would be really nice would be some CNC machined end caps that fit standard box section alloy, or, perhaps, big diameter round alloy tube. Even those of us with small lathes find it a problem making stuff like this, because the dimensions are just to big for most hobby lathes.

For example, how about some end caps that fit into 4" x 16g round alloy tube, or maybe 6" x 2" x 1/8" rectangular alloy tube? I know it's not an ideal packing factor for lipos, but the round tube would allow space for air to circulate around the packs and could look neat on some bikes (imagine a stack of these, fitted transversely across the frame of a motorcycle, with the end caps showing on either side, for example). Some nice detailing on the machined ends, maybe fins or something, would turn them into a neat feature. The rectangular tube might be better for some purposes, as relatively thin packs could be built using it, although they might look a bit uninspiring. As far as I know, these two sizes of tube are carried as stock pretty much anywhere in the world, so you'd only need to ship the caps, people could arrange to buy the tube locally and just cut it to length.#

Jeremy

 

[recumpence]

Great idea, Jeremy.

I actually considered something very similar a while back.

I will do some looking into this further.

Matt

 

[etard]

I think it's hard to justify spending $95 on a box that is meant to protect $100 worth of batteries.

On Jeremy's idea, isn't it better to compress the batteries for lower resistance rather than try cool them? I know nothing of these batteries other than what I have read here.

I was also thinking two larger boxes that can be removed easily back beside The rear wheel for personal storage might be a cool option on those trikes.

 

[recumpence]

By the time you pay shipping, each box holds about $170 worth of batteries.

The big issue for me is safety, durability, mounting ease, and (for this build, anyway) exotic look.

The primary reason I made these is for my trike and other bikes. Selling a few is just an afterthought.

I am totally open to making affordable boxes, however, if we can some up with a decent design that is easy to make.

Matt