Who's a machinist around here?

[Syph007]

Ive got a lot to learn but have some very nooby questions.  Maybe I need a machinist for dummies book.

So far I figured out my mill taper is MT2 with a 3/8-16 drawbar so I ordered an appropriate collet set for that, but it did come with one taper ( I think its called an arbor? ) that is MT2/B16 so I found a drill chuck to fit that and ordered. 

So what Im wondering is...

1.  How tight does a drawbar need to be.  Just snug?  Is it a really bad idea to run any tool in the mill that does not have a drawbar hole?

2.  Do I need special equipment to tram the mill? 

3.  Is it a bad idea to take it apart to be able to lift it on to the stand, will that mess up any factory alignment?

4.  Is it better to use a collet to hold the milling bit, or those ER spring collets, or are they the same with the ER being just more convenient?

5.  When mounting a vice to the table, how do I precicely bolt it down so that the jaws are parallel with the x axis?  I ordered a rotating milling vice.

Thanks in advance if anyone wants to shed some light on this.   

[enki_ck]

J-sews is a machinist but the "real life" has hindered his forum presents lately. Hopefully he'll be back full time in a month or so. I miss him.

But with a new toy in house I know you can't wait that long for help.

[Mercury]

I just happen to be a Machinist, having recently moved back into the field after a 6 year hiatus.  I learned machining by doing tool and die work on manual mills back when I was in high school, and now I am a CNC Machinist and I make very large oilfield plumbing connections using a 120 inch CNC lathe and various CNC mills.  Most of my work has to be loaded into my machines by overhead crane.  I'll post some pics some time.

Now, to your questions.

1.  Drawbars.  You drawbar does need to be tight, but don't ever use a cheater bar.  A standard drawbar is tightened by a 3/4 quill nut on the top of your head(the mills, not yours!). Most knee mills use MT2 quills, yours is standard.    you should tighten it as tight as you can by hand with the leverage provided by the length of your wrench.  MT1 is, in my experience at least, limited to tailstocks and older mills.

2. By "tram the mill" I assume you mean x axis auto travel.  Yes, you will need a motor for feeding your table, and I have never bought one so I'm not much help.  All the mills I have ever worked on were already equipped with that.  I do know they are pretty easy to find, and if you are so inclined you can buy a CNC controller and 3 axis servo kit to retrofit your mill whether it's a bench or knee mill.

3.  Unless you are a skilled and experienced machinist, I would avoid taking anything apart.  Re-aligning a head can be a nightmare for guys that don't know what they are doing.  I just made an 8 inch riser for a knee mill at work, so that we can lift the whole head 8 inches because a lot of our parts are fairly large.  I had a loose tolerance of + or - .001 inches, and I can tell you that it was not easy to take the head off and even harder to put it back on. 

4. I would opt for using any type of collet over a chuck, but as for the best, that comes down to experience and preference.  I prefer a standard r8 collet for most manual milling processes, ER collets are more versatile and better served in CNC applications. 



5. To properly mount your vice, you will need a dial test indicator and an indicator arm.  Mine is by indicol and mounts directly to the tool in the quill:
 
http://www.penntoolco.com/catalog/products/products.cfm?categoryID=583

Or you can get one that will fit into a collet, like this one:
http://www.use-enco.com/1/1/28533-400-min-indicol-universal-holder-test-indicator-attachments-accessories.html

Either will work just fine.  My indicator is a fowler:

http://www.globalindustrial.com/p/tools/test-measurement/Indicators-Linear-Distance/fowler-060-inch-x-test-indicator-0005-inch-graduations?utm_source=google_pr&utm_medium=cpc&utm_campaign=Test-Indicators-Gages-google_pr&infoParam.campaignId=T9F&gclid=COGcrLbiorcCFe9cMgod-mIAFg

 and you don't need anything more advanced than that to do this.  Having been a machinist for around 10 years I can tell you that for indicating a vise in, most indicators will do.  You don't have to have a Starrett or Brown and Sharpe, even an SPI will do you just fine.

To indicate your vise, place your indicator in the holder and mount it on your spindle.  Turn the face towards yourself and place the indicator tip against the rear jaw of the vice.  You shouldn't ever indicate the moveable jaw of the vice as it usually isn't perfectly aligned until it's tightened against a square piece of work.

Once you have your indicator placed against the jaw and the needle is in the middle of it's travel(usually + or - .015 inches) move your table so that the indicator tip travels over the surface of the jaw from end to end.  With some practice, you should be able to get it in within .002 from end to end.  I would recommend getting it much tighter than that, but for what you are likely doing two thousandths will likely be fine.  Remember, if you are machining a longer piece of work you need to get your vice as perfect as possible.  I usually tighten mine down about halfway to 3/4 tight, then use my deadblow hammer to tap it till it's perfect.

The same goes for both the x and y axes. 

Hope I answered your questions without creating too many more!

There are a few other tools I would recommend you get if you like, just pm me and I can give you links.

[Syph007]

Hey thanks very much for the info! Ya part of the problem of not knowing exactly the terminology to use, is its hard to google for answers.

All ive ordered so far is a collet set, drill chuck, and a clamping kit.  Im sure I'll have more questions as I figure things out.  But at least now I know I need a dial indicator.  Eventually this will be CNC converted, but not for a few months yet.  (the hardware and motors are $1300, plus then I need the electronics) I will be manually making some parts in the mean time.

You confirmed my hesitation about taking the mill apart...im not going to do that.  It came with a factory check sheet with tolerances and travel and it looks pretty good as it is now.  Realistically for what Im going to be making accuracy to a few thousands of an inch will be just fine.

Thanks again!   

[Mercury]

Glad to help!

I'm so jealous that you have a mill!  With all my moves, I don't have the money to drop on one and I don't even have a place to put one should I be able to afford it.  I do have access to a full plethora of both manual and CNC machines at work though, as long as I clear it with the owner and that's never a problem.  The problem is getting to a machine while it's not in the middle of a production job.

The clamp set is a good call, you will need it more than you realize.  Remember that clamps are hardened, and if your cutter is going to pass over or through one you need to adjust your feed.  You can't mill tool steel at the same feedrate as aluminum!!

A few more tools I feel you will definitely benefit from:

.200 Edgefinder, for this I would definitely buy a Starrett, it's worth it.

Machinery's handbook.  Don't skimp here, it's $100 but has everything you need to know for any machining operation and then some.  Mine is the 27th edition, and that one you might find a bit cheaper than the newest edition. 

Dial calipers.  Always more trustworthy than digital IMHO.  I have a good 6" set from fowler, cost around $50, and my 12" caliper is Mitutoyo, around $270, but you probably won't ever need anything more than 6".  you will also definitley need a good 0-1" micrometer, Mitutoyo makes a fantastic mic for a decent price.  Check ebay first. 

Also look into Shaviv deburring tools especially if you are going to do SAK modding.  The Mango handles are the most comfortable and they really leave a smooth finish on aluminum.  I have a full set. 

Good files are your best friend too, but you might already have those, I don't know.

If you are going to buy a new toolbox for all this, I would suggest a Kennedy 52611, it has a drawer specifically made for the machinerys hand book and it will last two lifetimes.  I have one sitting on top of my larger rollaway box, it is 7 years old and looks brand new. 


Sorry to go off!  I love machining and I love tools more!  I have well over $3,000 in my tool chest and it's pitiful compared to most machinists I know.

[Mercury]

One more thing.  If you plan on converting to CNC, you need to think about the software you will use to program it.  Fanuc makes a ton of controllers for both Conversational(shop floor) programming and Cam/G code programming.  Having done a lot of both types of programming, I can safely say that you might be better off with conversational as it doesn't require any extra and very costly CAD/CAM software.

Basically you can program processes into the controller at the machine without an external computer by using Conversational programming.  That's what most of our lathes at work are equipped with and we can fly through complex programs very quickly. 

Hmmm.  After checking some specs I would say that Fanuc might be WAY too costly.  Check into Mitsubishi controls.  Might be cheaper to buy another mill that is already fitted.  I'll call my Uncle and see if he knows any cheaper routes.  He's been machining for 35 years and has a CNC fitted Bridgeport.


BTW, what mill do you have?  I'm sooooo jealous!

[Syph007]

Its just a wee one.  But for machining Aluminum and brass SAK scales, I think it will be fine.  Big upgrade from my $80 drill press which is my current 'big tool'.

Optimum Bf20  (well the US version as its not M10 drawbar, but 3/8 inch)
http://www.optimum-machines.com/products/milling-machines/bf-20-vario/index.html

I just got it delivered on friday.



And this is as far as I got so far.  I moved the stand.  Need some lag bolts to secure it to the concrete.  Oh and I took the wood top of the box so I could look at the machine figure out what parts do what.



It looks like this though, not my pic



I was going to buy the sieg x3, but he talked me into this one as he said he can get smaller tolerances, it comes with the stand, and the company makes a CNC kit that comes with ballscrews and the motors.  And it looks like a pretty straight forward upgrade.





The only downside is the MT2 seems less common than R8, but Ive found lots of tooling on ebay to fit.  The only thing I didnt find so far was a surfacing or facing bit, but im sure there is one somewhere.

All the money from custom SAK work Ive put into SAK parts and saving for this.  So I cant afford the CNC part yet, but this will be a fun enough toy for me to play with for now. 

[Mercury]

That is sweeeet! 

Now I'm really jealous.  The things you can do with that setup, even without CNC...

You can face with a half inch endmill if you want, especially if it's small stuff.  I have a spare Carbide set of two, a rough cut and a finish cut half inch square endmill, both 4 flute I believe.  I would trade them to you if you like.  I've made a couple cuts with both but neither show any wear.  I never use my own tooling at work, I prefer to tear up company bought cutters for production.

[Syph007]

So I got to make some progress today finally on project mill. 

Here is what it looks like uncrated, and yep I was floor milling some mock alox and it was working nicely!



Then I figured I better bolt the stand down first.  I got to use my hammer drill and 1/2" concrete bit.



Now it LOOKS like someone measured wrong and put a bolt in the wrong spot there, but I'm sure that was already there before I did this...   



After lots of reading, it seemed ok to take apart the mill afterall, but I need tools to get it all back in trim afterwords, but I'll figure it out.

I took the head off first.. it was only 60lb or so, so I could move it no problem.







The column popped off next.







And then the base was just barely manageable on my own, but I got it up on the stand and bolted down.





Tomorrow I can get the column and head back on, and true it all up.  I learned today how to do proper gib adjustments and everything is sliding around nicely. 

I can see why people upgrade to ballscrews, the backlash in these stock leadscrews are awful.

I think I dont even know enough to know what I dont know about being a machinist yet... but its fun learning something new!

[Mercury]

That looks like it was fun!! 

Looks like it went together pretty easy.  I like the tray under the table, that will come in pretty handy for chip cleanup.  Do you have the collets you want yet?  I was thinking it over and I think you might like the ER collets.  The good thing about them is they are much easier to swap out without removing the main arbor from the quill. 

Keep us posted with what you are doing, I'm keen to see what your mill can do!

[Syph007]

I have the standard collets which is what Im using now, but I did order a set of ER25 ones with a holder.



I didnt quite understand what they were at first, but then when I clued in, I was like.. oh that makes sense.. so I ordered some.

[Mercury]

That's a nice set. 

Sent from my Galaxy S3 using crapatalk two point oh.

[WhichDawg]

we learned so much at the "Practical Machinist Forum" and did searches there for our mill and what we needed and wanted.

very good site and like you we learned a lot! Good Luck and good (safe) machining

[Mercury]

I've lurked at Practical Machinist for a long time. Great site with lots of info for the hobbyist and professional.