Super Noob question. First time milling

Mitch Alsup said:
a) did you make sure the vise is "in tram"--not just the back jaw face, but also the back jaw top and the inner vise "ways" where the parallels rest. Any errors here will show up directly on the part, after machining. Is the spindle tram to the table? both directions? I had to disassembly my vise and clean it within an inch of its life to get the vise to tram square.
b) you need to file the burrs from sawing off the part before installing it in the jaws of the vise--so the part can rest on the parallels and be evenly clamped by the vise. Burrs may not allow the part to rest on the parallels, or to be evenly clamped on the faces of jaws.
c) after clamping the part in the vaise, hit it on the top with a hammer (several places) to seat the part and the jaws to the ways of the vise. You can get 1-3 thou of rise just clamping a part in the jaws.
d) you can measure the flatness of the part in the jaws after clamping with the DI in the spindle.
e) as a part comes out of the saw, none of the sides are flat enough to be accurately machined. So, we square up the part by machining one surface, then square up the other sides by using the first machined surface as a reference in the back jaw or on the ways of the vise. In effect, we machine the part to square, and only then machine the part to what we want.
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A) I will to check some more. I checked the top of the vise to the head, and the ways to the head. I didnt check the jaw faces. I wanted to but I dont have a collet that will fit my test indicator arm (super noob). The table was square when I checked with the dial indicator. I dont remember the numbers off the top of my head though. These are all things where I would benefit from a fundamentals class. Unfortunately I havent been able to find anything local to me at night or on the weekends.
B) Again something I didnt even think of. Stuff like that, among many many other things, is what separates my brain from a true machinists brain. You guys are so precise and on point with everything that us regular dudes just arent. I have to train my brain to think of little things like that. I guess/hope that stuff like that will just come with experience.
C) I will definitely try that next time.
D)I clamped my dial indicator in the spindle so I could measure faces straight down or perpendicular, but I didnt have the correct size collet for my test indicator arm so i wasnt able to check jaw faces.
E) I am going to look into squaring a part right now.

Again thank you all for taking the time out to help me with my novicity (is that a word? ha) Thank you for being kind and patient. I had a busy weekend but next chance I get to mess around in the garage I will post back.
 
My 2 cents: Everybody has good solutions. The only thing I would add is to lower the piece in the vise. Use lower parallels and only leave about 5/16" over vise jaws. You said you needed to cut 1/4". The higher the piece is in the vise, the more rise from the jaws and tendency to vibrate. Also you need to cut both sides of the block. If you only cut one side you can get some weird warp and twist from stress in the metal. Not always but it can happen. Plan this in your operations. Charles
 
Threadkiller said:
Mikey, the vise has definitely seen better days. I just looked up angle lock vises and my jaw dropped ha. I knew Kurt was expensive but didnt think they were that expensive. I guess I shouldnt be surprised as everything in this realm thats quality is expensive. Gotta pay to play. Unfortunately money is a little tight at the moment especially for a $600 vise. I will have to keep my eyes on craiglist.
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The vast majority of your work will be held in your vise so having a decent one is a good idea. I own an RF-31, too, and I bought a new Kurt D-40, 4" milling vise because I wanted a good one right off the bat. A very good option to a Kurt is the Glacern GSV-440, also a 4" vise. A 4" is just the right size for our machines. That Glacern vise is an angle lock vise with a limited lifetime warranty for a decent price. I would not opt to buy the swivel base; you won't use it very often, if at all.
 
RobertB said:
It's similar to a Bridgeport, but the Bridgeport has a "rounded rectangle" base that sits atop the swivel not the round lobes this one has. It also appears to be missing a jaw.
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Ah, good catch - the orientation of the photos flipped so in my cursory look I thought there was a jaw on either side. Pretty clear from the first photo that there isn't.
The side without the jaw is also the side which is lifting (has a deeper cut), which makes sense. The cast iron of the vise is giving way or just not holding.
Making a new jaw without a vise ... well, that oughta be fun.
 
Another thing (I may have missed it in the previous posts) is that the piece might not be square where It contacts the vice jaws. If one end of the piece is wider the other end will move easily no matter how hard you tighten the vice. The solution to that of is a strip of soft material between the piece and jaw.
 
Threadkiller: My popsicle stick solution is similar to epanzella's above in post #25
Mark
 
Although not as handy as a Kurt style vise, if used properly screwless vices also will prevent jaw lift. They are less expensive, too. I started with a screwless and just recently bought a Kurt style vise.

I won't get rid of the screwless because it isn't as tall. Insufficient Z clearance can be an issue with smaller benchtop mills.

As time goes by you will find you need a variety of work holders. I found a number of good designs on Harold Hall's web site here. His low profile versions are good if you work on a lot of thinner stock.
 
Chewy said:
My 2 cents: Everybody has good solutions. The only thing I would add is to lower the piece in the vise. Use lower parallels and only leave about 5/16" over vise jaws. You said you needed to cut 1/4". The higher the piece is in the vise, the more rise from the jaws and tendency to vibrate. Also you need to cut both sides of the block. If you only cut one side you can get some weird warp and twist from stress in the metal. Not always but it can happen. Plan this in your operations. Charles
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I didn't think jaw lift was a thing before this ha. I will keep that in mind. Keep the part lower, taking smaller cuts and raise the part as necessary. Thank you.

mikey said:
The vast majority of your work will be held in your vise so having a decent one is a good idea. I own an RF-31, too, and I bought a new Kurt D-40, 4" milling vise because I wanted a good one right off the bat. A very good option to a Kurt is the Glacern GSV-440, also a 4" vise. A 4" is just the right size for our machines. That Glacern vise is an angle lock vise with a limited lifetime warranty for a decent price. I would not opt to buy the swivel base; you won't use it very often, if at all.
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I checked out the Glacern and while better than a Kurt, its still pretty pricy right now for me with just purchasing the mill and now Christmas coming up...Do you have any input on the Shars vises or Shars stuff in general? Their prices seem very reasonable. I have seen Abom use their stuff so it cant be all that bad?

epanzella said:
Another thing (I may have missed it in the previous posts) is that the piece might not be square where It contacts the vice jaws. If one end of the piece is wider the other end will move easily no matter how hard you tighten the vice. The solution to that of is a strip of soft material between the piece and jaw.
Click to expand...

That explains the popsicle stick post above. Thank you. I love learning all this stuff.

homebrewed said:
Although not as handy as a Kurt style vise, if used properly screwless vices also will prevent jaw lift. They are less expensive, too. I started with a screwless and just recently bought a Kurt style vise.

I won't get rid of the screwless because it isn't as tall. Insufficient Z clearance can be an issue with smaller benchtop mills.

As time goes by you will find you need a variety of work holders. I found a number of good designs on Harold Hall's web site here. His low profile versions are good if you work on a lot of thinner stock.
Click to expand...

Those look interesting. I will price them out.
 
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