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| Crimpers for automotive |
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| mendip_discovery:
For those that like the reassuringly expensive tools I think the 3M TR-490 might fit the bill for automotive use. My shed just has a set of cheap red/blue/yellow, a un-insulated set and recently I bought a cheap hydraulic set for battery terminals. I do have it on my list to buy a set for doing old british bullet and modern Japanese bullet connectors. |
| Siwastaja:
--- Quote from: shabaz on March 10, 2024, 07:50:05 pm ---A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper. ... For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper. --- End quote --- So hydraulic crimper is not OK? Pretty interesting viewpoint, given these non-ratcheting tools are how pretty much all mission critical large crimps are being made. Can you explain how the crimp knows if the mechanism had a ratchet or not, given that the crimping pressure and die shape are exactly the same, and pressure is applied in monotonically increasing curve? This is what hydraulic crimpers, lacking your beloved ratchet, do, and what we also emulate when we use hand tools without ratchets, which obviously are larger and need more care to use correctly. So can you explain where exactly does the difference come from? |
| shabaz:
If you have tools capable of interfacing with a hydraulic system and designed to crimp with the required pressure, I don't see anyone suggesting you shouldn't use it? My comment was in response to the person who suggested the PAD tool (which is not a hydraulic tool). Not sure where you're going with "beloved ratchet". Can you keep the question technical without emotion, and I'll do my best (if I can) to answer it politely? |
| shabaz:
For what it's worth, I can't completely recommend Knipex MultiCrimp but it's not bad. The crimping dies are automatically attached/removed by pushing the crimper into the holder. The tool has worked reliably, I have no complaint there, and it's comfortable to use, but a disadvantage is that there are only about half a dozen different crimping die choices. The second photo shows how the hot-swapping works. The jaws are held aligned using a flip-out lever, and then the jaws are docked into the holder and a round metal button on the holder is pushed back to release the dies from the holder. |
| nctnico:
--- Quote from: Siwastaja on March 13, 2024, 06:52:18 pm --- --- Quote from: shabaz on March 10, 2024, 07:50:05 pm ---A pull test will confirm the huge difference between a non-ratchet crimp result, and one done with a ratcheting crimper. ... For automotive, I'd be really unhappy to know if the engineer used a non-ratchet crimper. --- End quote --- So hydraulic crimper is not OK? Pretty interesting viewpoint, given these non-ratcheting tools are how pretty much all mission critical large crimps are being made. Can you explain how the crimp knows if the mechanism had a ratchet or not, given that the crimping pressure and die shape are exactly the same, and pressure is applied in monotonically increasing curve? This is what hydraulic crimpers, lacking your beloved ratchet, do, and what we also emulate when we use hand tools without ratchets, which obviously are larger and need more care to use correctly. So can you explain where exactly does the difference come from? --- End quote --- You missed the point where ratched crimpers have eccentric pivot mechanisms so you can build up the required pressure manually without needing a pump action tool (like a hydraulic crimper) to amplify the force from you hands. Just take a good look at a professional ratched crimper and you'll see that for each 'click' the jaws close less while the (angular) movement of the handles for each 'click' stays the same. If you picture an eccentric (for example a piston + rod on the crankshaft in an engine) and rotate it starting from 90 degrees towards 0 (top dead center), you'll see that the amount of movement per degrees of rotation decreases when approacing 0 degrees. If you apply a constant torque + speed = constant power to the excenter, the closer you get to 0 degrees, the more force you can excert. This is because power = force * travelled distance. As the power (which can not be lost) is constant, the travelled distance becomes less the so the amount of force must go up. Tools like the engineer pliers don't have this feature and thus can't produce enough force on the crimp to create a cold weld. |
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