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locating work on bandsaw cut edge?

madmachinst

Stainless
Joined
Jan 15, 2007
Location
Central FL
I am wondering if it is worth the trouble to finish 2 faces on the workpiece to locate off of. I have a CNC mill, BP type machine and its not got a tool changer. This means I change the workpieces out when I have small batches rather than slap the workpiece in the vise and changes the tools each op. As usual my first op is drilling holes. My workpieces all have 4 faces that are saw cut and 2 faces that have a smooth mill finish. One of those mill finish faces on the parallels. Should I machine each workpiece so that faces touching the vise's solid jaw and workstop have a good finish or is that just a waste of time?
 
I always square my workpiece up with all edges having a machined finish.

Depending on what you are making it may not matter but I'm anal and want everything to look pretty.


Referencing from a rough edge is far less repeatable than a smooth edge.
 
If you want to use the drilling as the first operation you can make a simple fixture plate and locate off the holes. Shoulder screws are great as locators. You drill and ream the fixture plate so that the shoulder section locates in the reamed portion and the head pulls the job down tight. Simple but effective.
 
I am wondering if it is worth the trouble to finish 2 faces on the workpiece to locate off of. I have a CNC mill, BP type machine and its not got a tool changer. This means I change the workpieces out when I have small batches rather than slap the workpiece in the vise and changes the tools each op. As usual my first op is drilling holes. My workpieces all have 4 faces that are saw cut and 2 faces that have a smooth mill finish. One of those mill finish faces on the parallels. Should I machine each workpiece so that faces touching the vise's solid jaw and workstop have a good finish or is that just a waste of time?
It depends...
What level of accuracy are you looking for on the finished job?
Do they need to be aesthetically pleasing?
How accurate are your saw cuts?
 
I thought I was being ridiculous and overly anal by wanting to have finish machined surfaces against the workstops. Nah, just being a machinist.
 
I thought I was being ridiculous and overly anal by wanting to have finish machined surfaces against the workstops. Nah, just being a machinist.
No, being silly. Castings are machined all the time, they have much more variation than you're talking. But when you bother to mention the two thou requirement it changes the entire picture.

btw, you could probably skip the milling op by going with a cold saw. But that takes money ...
 
I thought I was being ridiculous and overly anal by wanting to have finish machined surfaces against the workstops. Nah, just being a machinist.
Like I used to tell my employees:
It takes a person with knowledge, skills and precision tools to tell if a part is right.
The kid who sweeps the floor can tell if it looks like sh*t.

When I was an apprentice I was doing a keyed shaft late in the day (beer job).
Fred was pushing me to hurry and told me to just sand the ends and chamfers.
I refused. When he asked why, I said "Someone is going to look at that and ask who did it. You're going to tell them that I did."

Machine work is expensive, it should look like it.
 
No, being silly. Castings are machined all the time, they have much more variation than you're talking. But when you bother to mention the two thou requirement it changes the entire picture.

btw, you could probably skip the milling op by going with a cold saw. But that takes money ...
The material that I use comes from a mill that cuts material off plates with some kind of humongous bandsaws. if it be 4140 PH decarb or 7075 or 6061 or whatever they offer. This means 2 faces will be bandsaw cut, then I cut to length so 2 more sides on the ends bandsaw cut.
 
No, being silly. Castings are machined all the time, they have much more variation than you're talking. But when you bother to mention the two thou requirement it changes the entire picture.

btw, you could probably skip the milling op by going with a cold saw. But that takes money ...
Cold saw would only just give me end cuts with a good finish. The face against the solid jaw will still be rough.
 








 
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