Super Noob question. First time milling

[machPete99]

Some basics...
Hopefully you have the cutter mounted in a collet and not in a drill chuck.
Check the gibs on all axes and make sure there is not excessive play. Lock the gibs for all axis that you are not moving.
Make sure the quill is fully pulled up so there is less flex (assuming this mill has a quill...).
Look for "Cobalt" HSS cutters on ebay, they are relatively cheap and usually of better quality.
Save up for the better vice if you need to do precision work (cry once).
After the vice, look into carbide tooling, Glacern has some decent pieces, although not cheap.

Edit:
Also make sure you are not "climb milling". Only engage part of the cutter, feeding into the cutter teeth.

 

[ThinWoodsman]

> Although not as handy as a Kurt style vise, if used properly screwless vices also will prevent jaw lift.

Those look interesting. I will price them out.

They are much more affordable than a Kurt or Glacern, if your work is small enough for the 2" or 3" versions.

You can put a screwless vise in your current vise, get it all clamped and square and everything, then just put work in the screwless vise and never touch the big vise again.

It *is* worth replacing the big vise with a glacern or kurt at some point (for certain definitions of "worth", generally not financial) but they are pricey. Better, in my opinion, to find alternate, cheaper ways to do things when starting out. You can work on the table (see the Harold Hall stuff above), you can buy good-enough equipment from Shars (e.g. a screwless vise), you can make do. Once you are good enough to determine that yes, it is indeed the equipment and not your technique which is causing the loss of precision, then you can make the decision on buying the good stuff - until then, you're just spending more and more money hoping for some magic to happen.

 

[pontiac428]

Before going out to buy a new vise, deburr that part and remove the swivel base from your vise. Also adjust and lock your gibs, that's a big deal on a Rong Fu. The RF is capable of good work once you learn its kinks.

 

[Threadkiller]

Some basics...
Hopefully you have the cutter mounted in a collet and not in a drill chuck.
Check the gibs on all axes and make sure there is not excessive play. Lock the gibs for all axis that you are not moving.
Make sure the quill is fully pulled up so there is less flex (assuming this mill has a quill...).
Look for "Cobalt" HSS cutters on ebay, they are relatively cheap and usually of better quality.
Save up for the better vice if you need to do precision work (cry once).
After the vice, look into carbide tooling, Glacern has some decent pieces, although not cheap.

Edit:
Also make sure you are not "climb milling". Only engage part of the cutter, feeding into the cutter teeth.

The end mill was in a collet, yes. The mill does have a quill. About the vise, that's my question. I am looking to learn and while a super precise and great quality vise would be great, its just not financially in the cards right now. Are there people out there learning and making nice parts on more budgety vises like a Shars?

They are much more affordable than a Kurt or Glacern, if your work is small enough for the 2" or 3" versions.

You can put a screwless vise in your current vise, get it all clamped and square and everything, then just put work in the screwless vise and never touch the big vise again.

It *is* worth replacing the big vise with a glacern or kurt at some point (for certain definitions of "worth", generally not financial) but they are pricey. Better, in my opinion, to find alternate, cheaper ways to do things when starting out. You can work on the table (see the Harold Hall stuff above), you can buy good-enough equipment from Shars (e.g. a screwless vise), you can make do. Once you are good enough to determine that yes, it is indeed the equipment and not your technique which is causing the loss of precision, then you can make the decision on buying the good stuff - until then, you're just spending more and more money hoping for some magic to happen.

I agree with finding alternate cheaper ways to do things especially starting out. I mean I would have loved to start out on a restored Bridgeport with a nice Kurt vise and all carbide tooling but obviously that's not in the cards for most hobbyists at least that I know of. Can I get away with learning and being decent on more of a budget? My problem is I have too many responsibilities and expensive hobbies ha. Why couldn't I like something that's cheap..

Before going out to buy a new vise, deburr that part and remove the swivel base from your vise. Also adjust and lock your gibs, that's a big deal on a Rong Fu. The RF is capable of good work once you learn its kinks.

I assumed it wasn't the mill. In fact I assumed all of the problem was me and my lack of experience/knowledge.

So on the gib locking. Does everyone lock the gibs on the axis they aren't currently using every time? Or is it one of those things that's just good practice that people don't do?

 

[mikey]

So, here's the thing about vises. They are the foundation of your milling set up. If the vise is square and precise enough then you can do decent work. If the vise is off then your work is off. I feel that you can cheap out on some things but not on your milling vise. On the other hand, I do understand that your budget is a real thing so you need to make this work without blowing it.

My opinion is to use a screwless 4" vise until you decide on or can afford a decent milling vise. They are cheaply had on ebay and will be more than rigid and precise enough to do good work. In fact, most screwless vises are more accurate than most milling vises. They are slower to use but a few more minutes in set up is not a big deal for a hobby guy. I happen to own four of these vises so I know they will work for you.

As for Shars vises, I have no direct experience with them. From the comments I've seen regarding Chinese vises, most of them require some tune up/grinding to work right. However, Shars has a better rep than most so best to wait for an opinion from someone who owns one.

Personally, I would use a screwless vise until I saved up for a good Kurt or GMT vise. There are thousands of Kurt vises in pro and hobby shops for very good reasons - they work and they hold up to use over time. In the end, a good vise is cheaper than a cheap vise.

 

[ThinWoodsman]

Can I get away with learning and being decent on more of a budget?

I look at it this way: people were doing accurate work before there were Kurt vises. There's always another way.

One of the problems with watching videos is you're usually seeing some guy with hundreds of hours of experience on the specific machine he is using, doing something he's practiced (and probably mucked up while filming) a few times already. When he just chucks a hunk of metal in the vise and skims off a perfect 0.0017" on the first try, it looks pretty easy. But it isn't; it takes a lot of time, practice, and learning to get to that point. So don't expect stuff to work like just in the videos - you have the ugly reality of your own machine and tooling (or lack thereof) to deal with on top not ever having done this before.

So on the gib locking. Does everyone lock the gibs on the axis they aren't currently using every time? Or is it one of those things that's just good practice that people don't do?

Lock everything that doesn't need to be moving for the cut you are taking. That one time you don't lock it will be the one time that the table lurches in that partcular direction, guaranteed.

 

[mikey]

So on the gib locking. Does everyone lock the gibs on the axis they aren't currently using every time? Or is it one of those things that's just good practice that people don't do?

I agree with @pontiac428 - adjust your gibs to remove any unnecessary slack. You are supposed to lock any axis that is not moving during the cut; this is just good practice. However, I rarely ever do. I just get my machine gibs adjusted well and make my cuts and have had no issues with chatter so far. Of course, I'm not making honking huge cuts on my RF-31 but I do push it when I need to and haven't had any problems with it.

Why not tune up your gibs and try your hand at squaring up that work piece you're having trouble with? I suspect you could do a fair enough job with that vise you already own if you work carefully. If you need detailed information on how to do that, PM me.

 

[Mitch Alsup]

I look at it this way: people were doing accurate work before there were Kurt vises. There's always another way.

One of the problems with watching videos is you're usually seeing some guy with hundreds of hours of experience on the specific machine he is using, doing something he's practiced (and probably mucked up while filming) a few times already. When he just chucks a hunk of metal in the vise and skims off a perfect 0.0017" on the first try, it looks pretty easy. But it isn't; it takes a lot of time, practice, and learning to get to that point. So don't expect stuff to work like just in the videos - you have the ugly reality of your own machine and tooling (or lack thereof) to deal with on top not ever having done this before.

Let me amplify this point. At my stage in machining (2.5 years in), I typically make 3 parts when I need two. Earlier on I used to make 3 sets of parts in order to have one set that meets tolerances. Each failure can be traced back to improperly thinking about how to perform the machining or improperly using measurement tools. Sloppy thinking leads not measuring enough which leads to out of tolerance <scrap> parts. The old adage of measure twice cut once applies in spades.

By measuring before you put the part in the vise, measuring with the part in the vise, then measuring after the machining step with the part still in the vise, and them measuring again after the part is removed from the vise; you learn what your vise wants in order for it to hold the tolerances you are attempting. Listen to what you vise is telling you. Listen to what the measurement tools are telling you. And practice on those pieces of scrap you just produced.

We, in machining, are LUCKY in that our tolerances stop at 0.001". In telescope optics you <often> have tolerances in the 0.000,001" range (a fraction of he wavelength of light. You end up building rooms with still air just so you can measure the parts before more work is performed. Moving air will disturb the ability to measure optical surfaces at the precision necessary.

 

[Threadkiller]

So, here's the thing about vises. They are the foundation of your milling set up. If the vise is square and precise enough then you can do decent work. If the vise is off then your work is off. I feel that you can cheap out on some things but not on your milling vise. On the other hand, I do understand that your budget is a real thing so you need to make this work without blowing it.

My opinion is to use a screwless 4" vise until you decide on or can afford a decent milling vise. They are cheaply had on ebay and will be more than rigid and precise enough to do good work. In fact, most screwless vises are more accurate than most milling vises. They are slower to use but a few more minutes in set up is not a big deal for a hobby guy. I happen to own four of these vises so I know they will work for you.

As for Shars vises, I have no direct experience with them. From the comments I've seen regarding Chinese vises, most of them require some tune up/grinding to work right. However, Shars has a better rep than most so best to wait for an opinion from someone who owns one.

Personally, I would use a screwless vise until I saved up for a good Kurt or GMT vise. There are thousands of Kurt vises in pro and hobby shops for very good reasons - they work and they hold up to use over time. In the end, a good vise is cheaper than a cheap vise.

Mikey, I have both your posts to reference so I will quote both. I totally understand having a good foundation and that is something someone like me really cant afford not to have. Eliminating one variable off the hop would definitely help. I have been looking at screwless vises. I think I may have found what I want for Christmas this year

I look at it this way: people were doing accurate work before there were Kurt vises. There's always another way.

One of the problems with watching videos is you're usually seeing some guy with hundreds of hours of experience on the specific machine he is using, doing something he's practiced (and probably mucked up while filming) a few times already. When he just chucks a hunk of metal in the vise and skims off a perfect 0.0017" on the first try, it looks pretty easy. But it isn't; it takes a lot of time, practice, and learning to get to that point. So don't expect stuff to work like just in the videos - you have the ugly reality of your own machine and tooling (or lack thereof) to deal with on top not ever having done this before.



Lock everything that doesn't need to be moving for the cut you are taking. That one time you don't lock it will be the one time that the table lurches in that partcular direction, guaranteed.

Thank you for the advice and thank you for saying that. I often wonder what happens behind the scenes in those videos. I figure they mess up here and there but its still hard to think of these experienced guys who make everything look so simple, screwing things up. I mean I know we all make mistakes but they just make it look so perfect ha. Id love to see a screw up video where they show everything start to finish.

I agree with @pontiac428 - adjust your gibs to remove any unnecessary slack. You are supposed to lock any axis that is not moving during the cut; this is just good practice. However, I rarely ever do. I just get my machine gibs adjusted well and make my cuts and have had no issues with chatter so far. Of course, I'm not making honking huge cuts on my RF-31 but I do push it when I need to and haven't had any problems with it.

Why not tune up your gibs and try your hand at squaring up that work piece you're having trouble with? I suspect you could do a fair enough job with that vise you already own if you work carefully. If you need detailed information on how to do that, PM me.

I will send you a PM. Thank you.

Let me amplify this point. At my stage in machining (2.5 years in), I typically make 3 parts when I need two. Earlier on I used to make 3 sets of parts in order to have one set that meets tolerances. Each failure can be traced back to improperly thinking about how to perform the machining or improperly using measurement tools. Sloppy thinking leads not measuring enough which leads to out of tolerance <scrap> parts. The old adage of measure twice cut once applies in spades.

By measuring before you put the part in the vise, measuring with the part in the vise, then measuring after the machining step with the part still in the vise, and them measuring again after the part is removed from the vise; you learn what your vise wants in order for it to hold the tolerances you are attempting. Listen to what you vise is telling you. Listen to what the measurement tools are telling you. And practice on those pieces of scrap you just produced.

We, in machining, are LUCKY in that our tolerances stop at 0.001". In telescope optics you <often> have tolerances in the 0.000,001" range (a fraction of he wavelength of light. You end up building rooms with still air just so you can measure the parts before more work is performed. Moving air will disturb the ability to measure optical surfaces at the precision necessary.

Ok, first off I couldn't even fathom tolerances in the 0.000,001" range haha that gives me a headache. I like picking your guys' brains on this stuff. It really gives you a broad sense about all the different types of ways to do things and make quality parts.

I said it before and I'll say it again. I really do appreciate all you gentlemen taking time out to help a clueless aspiring tinkerer like myself. It is very appreciated.

 

[Threadkiller]

So I finally had a chance to get in the garage last night to do some milling. Taking everyone’s input into consideration really helped. Thank you all. I slowed the speed down to 125rpm, I locked the gib on the axis I wasn’t using, I clamped my part in the vise using a popsicle stick and I didn’t gorilla the part into the vise like I did last time.

I actually was curious after watching some videos on vise jaw rise and put an indicator on it and it really doesn’t take much force to get .005-.008 rise on the movable jaw. I’m sure that didn’t help last time either. I tend to over tighten things which is why I torque most important fasteners when I’m working on cars.

Onto the next problem. I didn’t think I would need a Spanner wrench to tighten the draw bar as I figured I could just grab the pulley and tighten it. That worked initially when I was taking light cuts and the surface finish looked great and I wasn’t having chatter which I’m chalking up to running too fast if a spindle rpm last time.

Once I started experimenting with larger and larger depths of cut just to see how it would react I saw the need to really tighten up that draw bar. I was taking a .25” depth of cut on that same mild steel flat bar just to see how it would react and it was actually cutting great. Until I noticed that the end mill was slowly getting pulled out of the collet and walking its way deeper into the part. Kind of a bummer since I was on my way to salvaging that part from last time but live and learn. Guess I’ll be fabbing up a Spanner for the draw bar sooner rather than later.

After all that I decided to take the table, lead screws and y axis off and clean and readjust and re oil the gibs and ways. Everything looked great but it felt nice to freshen the machine up and I was able to get some chips out of some spots that have probably been there for years and adjust the gibs. Unfortunately half way through when I had parts everywhere I lost power for absolutely no reason as it was a clear night no wind or precipitation ha. Thankfully I was able to get it all back together using a couple work lights.