Mini "Jaws of life" for bench work. - Page 1
Forum section: electronics / general

author: aargee
author_rank: Frequent Contributor
timestamp: December 11, 2017, 01:49:16 am
content: Hi all,I'm looking for a mini electrical version of the hydraulic "Jaws of Life" that rescue crews use to tear apart car wrecks after an accident.What I would like to do is split open well sealed plastic battery cases to retrieve Li-Ion 18650 cells (these are not normal clip together type laptop packs)In theory it would be a case of Dremmelling a small slot on the seam and then splitting from there.I'm not sure if such a thing exists or if it does, how horrendously expensive it would be.Anyone with info or ideas?

author: andtfoot
author_rank: Unknown
timestamp: December 11, 2017, 03:11:45 am
content: How about a bench or drill press vice with something pointy added to the jaws if needed. I've used something similar to split apart power supply cases on the odd occasion.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 11, 2017, 03:15:58 am
content: I've seen people crack this kind of case with a bench vice. Just apply pressure along the seems until it pops. Be careful not to squish the batteries, of course.

author: DTJ
author_rank: Super Contributor
timestamp: December 11, 2017, 03:43:31 am
content: Consider a small Arbor press. It will give you good feedback when splitting cases that a powered tool will not.Just make custom bits for the end of the ram. Lots of uses, IDC crimping, lug crimping, cutting wire and heat shrink tubing batches.https://www.machineryhouse.com.au/P118

author: aargee
author_rank: Frequent Contributor
timestamp: December 14, 2017, 09:32:54 pm
content: Thanks guys, the cases are pretty effectively glued. So far the best way has been with a Dremel disk to cut/melt through three seams on the case ant then tear them apart with the help of non conductive spludger type tools used for car interior panel work.Splitting cases using force has not worked.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 14, 2017, 10:02:43 pm
content: I've yet to fail at opening an ultrasonic-welded battery pack or AC adapter using my seam-cracking method :https://youtu.be/C3YksbvYnKY?t=393

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 14, 2017, 10:39:29 pm
content: Quote from: mikeselectricstuff on December 14, 2017, 10:02:43 pmThat's surprisingly similar to how you can split a coconut in two with fairly minimal force. If you whack one with something like the the back of a knife across the "equator" of the coconut it naturally tends to split cleanly there.

author: tablatronix
author_rank: Regular Contributor
timestamp: December 14, 2017, 10:42:37 pm
content: I use large split jaw pliers and crush them the seams just pop, you could also grind thencorners the do the same. But i can see not wanting to apply any force to something with lions innit.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 14, 2017, 10:48:20 pm
content: If you're going for bulk, table saw with the blade set very shallow. Or bandsawJust have a fire extinguisher handy.

author: Mr. Scram
author_rank: Super Contributor
timestamp: December 14, 2017, 10:49:14 pm
content: Quote from: tablatronix on December 14, 2017, 10:42:37 pmLions can get slightly cross when you squeeze them too hard.

author: aargee
author_rank: Frequent Contributor
timestamp: December 15, 2017, 07:43:13 pm
content: Nope, nope and nope.I have used your technique with great success in the past Mike, first seen on your channelbut these packs are glued not welded, I’ve whacked the crap out of it with my screwdriver handle an it ain’t moving.(BTW - my modded Flir E4 is still going strong, apart from a hot pixel, thanks for your work there!!)The vice compression method crushes the pack too without any signs of seam popping.Gentle, careful use of the Dremel has been the way so far, then plastic spludger and brute force to tear the pack open. Nervous stuff close to a large open area of concrete, if it all goes pear shaped.

author: andtfoot
author_rank: Unknown
timestamp: December 16, 2017, 02:02:30 pm
content: How about sticking something to the vice jaws, then running it in reverse to open it outwards.Like this (orange bits added to vice):You would still need to get it partly open to fit it over the jaws, but it would make the brute force part more controllable.

author: Mickster
author_rank: Contributor
timestamp: December 16, 2017, 02:28:01 pm
content: How about these external snap ring pliers?https://www.knipex.com/index.php?id=1216&L=1&page=art_detail&parentID=1365&groupID=1454&artID=1719Regards.

author: aargee
author_rank: Frequent Contributor
timestamp: December 17, 2017, 12:09:00 pm
content: There’s two good ideas. I’ve got some circlip pliers somewhere, I’ll give that a go.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 17, 2017, 04:34:56 pm
content: Use a small neodymium magnet to find the actual location of the cells, then use a soldering gun with a cutting tip to cut into the case between two cells. After that, careful work with some cutting pliers will get the rest of the case apart.