PriddyShiddy
Cast Iron
- Joined
- Mar 1, 2011
- Location
- anaheim, ca
Need some help.
A customer ordered C360 to replace some parts that were originally bronze. The print calls +0/-.002 and I charged accordingly. Unfortunately I don't usually work with brass and didn't know it warps if machined heavily on one side :-/
Material came .625" x 1.75" x 6.25". Final dimensions are .495" x 1.625" x 6.109". I faced .01" off one side with a flycutter (beautiful finish), flipped and roughed to +.01 using .030" DOC with carbide insets on a small 90° face mill. Then finished all 33 parts with a flycutter without moving Z. I was happy to hit all 33 within .0004" under the .495". Way higher tolerances than I'm used to.
Went in this morning to find all the parts warped like crazy. I can slide .014" feeler under the center of some, others are only .003" out. WTF. I then found a few threads saying its the internal stress from rolling causing the work to warp if not cut evenly on each side. SOB. Funny that never showed up on the 30 or so threads I read looking up tips/feeds/tooling info.
HERE IS MY REAL QUESTION: (2 actually)
I tried bending it back on the vise using 2 points of contact on the ends of the concaved side and one in the convex side. Seems I can bend them back close and face a few thou off each side after getting okay from customer. Before calling him I want your input. The part Is essentially a gib and is going to fail at its intended purpose anyways... bronze ones wore out so he is trying brass... looks like I'll be running the parts regularly... or changing to bronze next time. lol Any thing to worry about bending it back and having? quick test reduced the convex to .003" but its warped out of square the other way too so I'm thinking .005" on each side should get them back to perpendicular to the other edges.
SECOND QUESTION-
I need to slot .125" deep at .75" wide the while length and drill and tap 2x 3/8/16 along the center. Well this slot cause more warping? should I use a smaller EM? HSS instead of carbide? I was planning on using Data Flute ARF20500 2fl carbide .5".
I also am now questioning the 60.5° angles along the length (fits to a dovetail). If it warped when I carefully cut .125"... what the heck is gonna happen when I shave of a large chunk off at an angle along the part?
I really don't want to pay for all this brass... not do I want to spend hours straightening the parts out if they are going to warp later. little frustrated... appreciate any help.
A customer ordered C360 to replace some parts that were originally bronze. The print calls +0/-.002 and I charged accordingly. Unfortunately I don't usually work with brass and didn't know it warps if machined heavily on one side :-/
Material came .625" x 1.75" x 6.25". Final dimensions are .495" x 1.625" x 6.109". I faced .01" off one side with a flycutter (beautiful finish), flipped and roughed to +.01 using .030" DOC with carbide insets on a small 90° face mill. Then finished all 33 parts with a flycutter without moving Z. I was happy to hit all 33 within .0004" under the .495". Way higher tolerances than I'm used to.
Went in this morning to find all the parts warped like crazy. I can slide .014" feeler under the center of some, others are only .003" out. WTF. I then found a few threads saying its the internal stress from rolling causing the work to warp if not cut evenly on each side. SOB. Funny that never showed up on the 30 or so threads I read looking up tips/feeds/tooling info.
HERE IS MY REAL QUESTION: (2 actually)
I tried bending it back on the vise using 2 points of contact on the ends of the concaved side and one in the convex side. Seems I can bend them back close and face a few thou off each side after getting okay from customer. Before calling him I want your input. The part Is essentially a gib and is going to fail at its intended purpose anyways... bronze ones wore out so he is trying brass... looks like I'll be running the parts regularly... or changing to bronze next time. lol Any thing to worry about bending it back and having? quick test reduced the convex to .003" but its warped out of square the other way too so I'm thinking .005" on each side should get them back to perpendicular to the other edges.
SECOND QUESTION-
I need to slot .125" deep at .75" wide the while length and drill and tap 2x 3/8/16 along the center. Well this slot cause more warping? should I use a smaller EM? HSS instead of carbide? I was planning on using Data Flute ARF20500 2fl carbide .5".
I also am now questioning the 60.5° angles along the length (fits to a dovetail). If it warped when I carefully cut .125"... what the heck is gonna happen when I shave of a large chunk off at an angle along the part?
I really don't want to pay for all this brass... not do I want to spend hours straightening the parts out if they are going to warp later. little frustrated... appreciate any help.