I have a personal project requiring a few bends in some 4130 tubing using my manual bender; 2" and 1-5/8" ODs, both are 0.049" wall, 15<60 degree bends, and both dies have a 7" CL radius.
I have tried several methods and am wondering if there are any others left to test.
Lots of bending lube and elbow grease
Capping both ends after packing the tube with sand
Capping both ends after packing with wet sand
Bending with a bullet shaped mandrel
Bending with a plug/form shaped mandrel
I had mixed results with both styles of mandrel, mostly with kinks forming inside the bend. I'm sure with more testing I could get more consistent results, but the pile of tube scrap after testing isn't cheap...
I'm wondering if one of the ball style mandrels will offer significantly more support than the plug style? Has anybody tried making their own? My googling hasn't turned up many results in how those mandrels are designed so I'm weary of just winging it and ending up with an even more expensive piece of recycling.
As a last minute alternative, is there anybody out there who already has the equipment and would be willing to bend me a few tubes? Some parts of the design are flexible and may be adjusted to suit available tooling/equipment.
I am a rookie with bending this kind of stuff, so please drop some knowledge on me!
I have tried several methods and am wondering if there are any others left to test.
Lots of bending lube and elbow grease
Capping both ends after packing the tube with sand
Capping both ends after packing with wet sand
Bending with a bullet shaped mandrel
Bending with a plug/form shaped mandrel
I had mixed results with both styles of mandrel, mostly with kinks forming inside the bend. I'm sure with more testing I could get more consistent results, but the pile of tube scrap after testing isn't cheap...
I'm wondering if one of the ball style mandrels will offer significantly more support than the plug style? Has anybody tried making their own? My googling hasn't turned up many results in how those mandrels are designed so I'm weary of just winging it and ending up with an even more expensive piece of recycling.
As a last minute alternative, is there anybody out there who already has the equipment and would be willing to bend me a few tubes? Some parts of the design are flexible and may be adjusted to suit available tooling/equipment.
I am a rookie with bending this kind of stuff, so please drop some knowledge on me!