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Soft jaws, leaving parts on parts

Djstorm100

Cast Iron
Joined
Jul 26, 2014
Location
Richmond
Hey guys, looking for some tricks of the trade here. I have 1x2 parts that I hold long way parallel to x axis. When doing Op 2 I'm leaving marks
at first I though I was torquing the vise to night but stepping back looks like I failed to put a radius on the parts in red. As these are where the marks on my part match up to the vise. Vise is a Orange and VF2ss. So my question is, am I right in my assessment here.

12315946.jpg
 
Hey guys, looking for some tricks of the trade here. I have 1x2 parts that I hold long way parallel to x axis. When doing Op 2 I'm leaving marks
at first I though I was torquing the vise to night but stepping back looks like I failed to put a radius on the parts in red. As these are where the marks on my part match up to the vise. Vise is a Orange and VF2ss. So my question is, am I right in my assessment here.

View attachment 279578

I used to run jaws like that, havent for 10+ years now. too many problems plus you cant use them for longer parts.
now I just cut the step in the x section and then cut a slot in the y using a .250 wide endmill.
then use .250 x .125 thick or .060 thick flat steel to use as a stop/locator. I get it from mc car its cheap cut them into lengths of lets say 4-6" long. make sure you have slots in both jaws and the slots are .010-.020 deeper then the step in the jaws put the straps in both jaws then take a punch and light punch the side of the slot so the metal doesnt move. doesnt take much and you can take them out when not needed.

benifit to this way is you dont have to make a Special program or drill holes do rads on edges etc etc.
 
I used to run jaws like that, havent for 10+ years now. too many problems plus you cant use them for longer parts.
now I just cut the step in the x section and then cut a slot in the y using a .250 wide endmill.
then use .250 x .125 thick or .060 thick flat steel to use as a stop/locator. I get it from mc car its cheap cut them into lengths of lets say 4-6" long. make sure you have slots in both jaws and the slots are .010-.020 deeper then the step in the jaws put the straps in both jaws then take a punch and light punch the side of the slot so the metal doesnt move. doesnt take much and you can take them out when not needed.

benifit to this way is you dont have to make a Special program or drill holes do rads on edges etc etc.

Thank you for this, The way you describe works well for op2/3 parts as well I'm assuming
 
I see two possibilities;

1. You cut those jaws using an adaptive toolpath from Fusion using 10 million IPM feedrates that you saw Titan yelling about in one of his videos. This combined with the lack of a blend radius caused your Haas to overshoot on one of the corners leaving the back edge concave and causing your soft jaws to contact the part on two points only.

2. You drilled out the corners first but miscalculated the size/position slightly, thereby failing to remove all of the corner radius left by the endmill.

If it's the first, add blend radii and a realistic feedrate for your finish pass, two finish passes if necessary.I

If in any doubt blue up the jaw and see how it contacts your part.
 
I see two possibilities;

1. You cut those jaws using an adaptive toolpath from Fusion using 10 million IPM feedrates that you saw Titan yelling about in one of his videos. This combined with the lack of a blend radius caused your Haas to overshoot on one of the corners leaving the back edge concave and causing your soft jaws to contact the part on two points only.

2. You drilled out the corners first but miscalculated the size/position slightly, thereby failing to remove all of the corner radius left by the endmill.

If it's the first, add blend radii and a realistic feedrate for your finish pass, two finish passes if necessary.

If in any doubt blue up the jaw and see how it contacts your part.
Thanks for replying.

Rest a sure, Titan, I don’t care for in most cases, S/F, boom boom boom and uh’s are one of several.

I own my machine, it doesn’t go above 9k rpm, yet. Out of choice of course
Adaptive, contour and pocket was the op for these. I come from a Chinese mill so I’m taking steps to run my Haas faster and faster (realistically). I didn’t add a 2nd pass for contour. Radius was my oversight and discovered it as I was making my post. Thanks again!


Sent from my iPhone using Tapatalk
 
Would it be easier to mill a flat across the entire softjaw and install a stop to locate your part vs making those cut outs. You could install a dowel pin to the left or right side of each cut out you have showing.
 
I had the same problem. The parts finish at .100 thick so clamping on about .080. Started with the pocket on the left which is similar to yours and I did radius the corners, but I still had the problem. Re-cut them like the pocket on the right and problem solved. That's what worked for me.

Jaw pocket.jpg
 
Here is how I make sharp-corner soft jaws:

soft jaw corner.jpg

There is a relief radius in each corner, but it is just enough to clear the corner, and the relief radius is filleted back into the part profile. So no sharp edges to mar the part.

Regards.

Mike
 
It shouldn't really leave a mark on the part, but I usually put a slight radius on the sharp edge out of principle. My guess is, your Haas/ CAM system overran the internal corner a little bit and you have a high spot. Run a test indicator across that face and see if it comes up a couple thou. Then use a smaller endmill that will go into the relieved area on the contour pass. I also do this out of principle.
 
I'm with the majority here- use a smaller endmill, blend a radius from the drilled/round hole into the straights. Another thing, pet peeve of mine, skip the drill altogether and just model/draw your jaws with a corner relief like Finegrain shows in his pic. I worked with a guy that always wanted to drill the corners, because it was "easier than milling" :toetap: Well, then you have what the OP has, unless you've drilled the holes way big, but then you lose gripping - locating on the flat areas......
 
Other than radiusing the corner, another trick I've used is to put kraft paper between the part and the jaw. Adjust your WCS accordingly and move on. Does a great job when you need clean parts with a machine finish.
 
Another reason I don't much care for a mickeymouse-ear corners is that chips have the incredible sense to find and get stuck in every stinkin' one of them!

I use spring pin dowels whenever possible as a stop.
 
I'm with the majority here- use a smaller endmill, blend a radius from the drilled/round hole into the straights. Another thing, pet peeve of mine, skip the drill altogether and just model/draw your jaws with a corner relief like Finegrain shows in his pic. I worked with a guy that always wanted to drill the corners, because it was "easier than milling" :toetap: Well, then you have what the OP has, unless you've drilled the holes way big, but then you lose gripping - locating on the flat areas......

I milled the holes, granted I did them on the big side because I only had a 1/8" end mill to that could cut 3/8 loc
 
Do you have a picture of this?

Not much to show really.
In your case, on the floor of the step just drill a couple of 1/8 holes on either side of the part width and put in spring pins.
Even better, if depth of the step is large enough, I'd put the dowels horizontally. SOmetimes that gives less chance for chips to get stuck in.
 
I too do as Finegrain shows but I typically use a .0675" radius with .01" blend radiuses so I can use an 1/8" end mill. How much clearance with the corner of the part depends on if I am clamping on rough stock with possible burrs or a machined 2nd op part. Done right you shouldn't have chip problems. I find if you keep open spaces below .01" width chips are not a concern.

A bit of critique, you should only locate on one end and move your parts further from the center of the jaw. As close as yours are you may get loose parts especially if one is a bit wider than the other. I was doing something very similar recently and had a part pull up some breaking 2 tools before I caught it, but I saved the next tool which was a multi-tooth thread mill $$$. The parts were within .0005" of the same width.
 
A bit of critique, you should only locate on one end


David.
When you say "one end", are you talking about side-to-side "end" or front jaw-back jaw "end"?

If you mean front and back, then yes, I do agree.
Side to side containment however CAN be useful at times.

As far as the spread, unless it's absolutely required, I always leave the setscrew of the front jaw a bit loose.
At least on a 6" Kurt, it will give you a 3 - 4 thou "bonus" if the parts are spread by more than 1".

In some other cases ( such as extrusions), I leave the front jaw bolts just a bit loose and put a .005 shim in the middle....
 
David.
When you say "one end", are you talking about side-to-side "end" or front jaw-back jaw "end"?

If you mean front and back, then yes, I do agree.
Side to side containment however CAN be useful at times.

As far as the spread, unless it's absolutely required, I always leave the setscrew of the front jaw a bit loose.
At least on a 6" Kurt, it will give you a 3 - 4 thou "bonus" if the parts are spread by more than 1".

In some other cases ( such as extrusions), I leave the front jaw bolts just a bit loose and put a .005 shim in the middle....


I too do as Finegrain shows but I typically use a .0675" radius with .01" blend radiuses so I can use an 1/8" end mill. How much clearance with the corner of the part depends on if I am clamping on rough stock with possible burrs or a machined 2nd op part. Done right you shouldn't have chip problems. I find if you keep open spaces below .01" width chips are not a concern.

A bit of critique, you should only locate on one end and move your parts further from the center of the jaw. As close as yours are you may get loose parts especially if one is a bit wider than the other. I was doing something very similar recently and had a part pull up some breaking 2 tools before I caught it, but I saved the next tool which was a multi-tooth thread mill $$$. The parts were within .0005" of the same width.


Correct me if I’m wrong, here please. If David means locate on one end, is he saying I should indicate more of my part’s width more on the back jaw versus splitting the distant equally? Sorry I’m a visual person
 
Correct me if I’m wrong, here please. If David means locate on one end, is he saying I should indicate more of my part’s width more on the back jaw versus splitting ...

Back Jaw: YES!!!
Do Not split!!! ( If you don't have to ) in the X!
Do Not Split!!! (like almost) NEVER!!! in the Y!

IOW: Whatever does not/can not move = candidate for X, Y and Z reference.
If it can move : Do not use for reference!
In case of a vise ( ANY vise! ) the moving jaw is not to be used as a reference!
No
Matter
What!
 








 
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