Modelman
Titanium
- Joined
- Sep 12, 2007
- Location
- Northern Illinois
One of my 1996 Battenfeld molding presses just broke a tie bar... again. This has happened before, and was sent out for repair, which was expen$$ive. This time I'd like to try to get the repair done locally, but I'm wondering if anyone here has ever been involved with this.
The bars always break in the threaded section... the originals because Battenfeld used a strange tapered washer that collapsed and gripped the thread so hard that it spalled chips off the thread, which then led to cracks propitiating from the chips. The repaired ends welded an extension on, then machined a new thread, and provided new cylindrical spanner nuts. The one that just broke did so at the weld, and there is a slag inclusion in the break... sh*t happens.
Since I already have an account with a tool welding shop that does all sorts of mold and die repair, and also an account with a heat treater, I figure I can get stub welded on the broken end, send it out to have it stress relieved, and find a local shop to turn the weld smooth, cut the thread, and and make a matching nut, rather than try to match Battenfeld's metric threads. The total size of the bar is 50mm (2") x 60" long. The last repair threads were 1.75 X 6 TPI.
My question mostly concerns the welding, since the Battenfeld documentation does not specify a steel for the bars, and I'm sure an inquirey is going to get "just order zee replacement from us..." for a response. My guess is something like 4140 would be suitable, but does anybody know? Just how much trouble will mis-matched steels cause the welder? Heat treat should be a simple anneal cycle... Judging from the upsets the nut lock set screws left on the ends of the bars, they are not hardened at all.
Anyone ever do this sort of work? what am I missing?
Dennis (out of his league, but trying to stay in the ball park)
The bars always break in the threaded section... the originals because Battenfeld used a strange tapered washer that collapsed and gripped the thread so hard that it spalled chips off the thread, which then led to cracks propitiating from the chips. The repaired ends welded an extension on, then machined a new thread, and provided new cylindrical spanner nuts. The one that just broke did so at the weld, and there is a slag inclusion in the break... sh*t happens.
Since I already have an account with a tool welding shop that does all sorts of mold and die repair, and also an account with a heat treater, I figure I can get stub welded on the broken end, send it out to have it stress relieved, and find a local shop to turn the weld smooth, cut the thread, and and make a matching nut, rather than try to match Battenfeld's metric threads. The total size of the bar is 50mm (2") x 60" long. The last repair threads were 1.75 X 6 TPI.
My question mostly concerns the welding, since the Battenfeld documentation does not specify a steel for the bars, and I'm sure an inquirey is going to get "just order zee replacement from us..." for a response. My guess is something like 4140 would be suitable, but does anybody know? Just how much trouble will mis-matched steels cause the welder? Heat treat should be a simple anneal cycle... Judging from the upsets the nut lock set screws left on the ends of the bars, they are not hardened at all.
Anyone ever do this sort of work? what am I missing?
Dennis (out of his league, but trying to stay in the ball park)