Mill Tips??

[wla421]

Looking to get a mill for home.

I have a Rotwerk Lathe and I quite like it, so I may just stay with that brand name here in Germany.

The questions?

This will be my first mill, and I don't wish to start off learning ANY bad habits from the beginning.

Any tips....hints...things to look out for?

I know the basic saftey issues....No jewelry, loose clothing, don't leave the keys in the chuck ect..

Any tips on beginning milling techniques, tooling, tool holders.....ie..what would be a good vise, and other attachments?

And probably a million other items.

I got dial indicators, micrometers and such as what I use with my lathe..

Any tips gratefull.

George

 

[Tin Falcon]

George: Here is a starter package available from http://littlemachineshop.com this should give you an Idea

If you have not already done so get yourself a copy of arm TC 9-524 fundamental of machine tools and read the layout chapter and mill chapter.And or read the Navy machinery repairman's manual appropriate sections.
Available to download the links are here. http://www.homemodelenginemachinist.com/index.php?topic=3216.0 or on the wells South Bend site.

The first thing to know about a mill is the head and vise need to be trammed in.
As far as tooling:
1) Drill bits a full set of 115, a metric set if you prefer or purchase as needed.
2) a set of center drills.
3) a drill chuck
4) some sort of collet set as appropriate for the mill to hold mill cutters
5) Mill cutters
6 ) a set of fly cutters or make one or several.
7) a vise A set of hold down clamps good to have but a vise is more often used.
8) Edge finder and or wiggler set for locating work.
9) as set of parallels hold the work off the bottom of the vise help accuracy prevent holes drilled in vice most of the time. Steel packing strap makes cheap thin parallels.
I think this is most of the basics.
Tin

 

[kvom]

I think that the MIT video series would be an excellent starting point for learning the basics.

 

[rklopp]

In the beginning, I'd skip the 115 set of drills and just go with the common tap drill and clearance sizes, plus common fractionals. You're probably better off with two of each tap drill size than one of each letter size that you'll never use. Also, I'd buy a couple of spotting drills instead of center drills, for spotting holes in the mill. The tips of center drills are fragile, and the drill angle is wrong for getting the subsequent twist drill started well.

A tap guide is very useful in the mill. Get a 90-degree countersink (or a 90-degree spotting drill) for chamfering holes. Chamfer after drilling but before tapping to minimize thread burrs.

 

[Speedy]

I think that the MIT video series would be an excellent starting point for learning the basics.

at this link
http://techtv.mit.edu/search?q=machine+shop&x=0&y=0

 

[fdew]

For the best finish tighten the Gibb lock on the two Axis you are not moving.

Frank

 

[zeeprogrammer]

I'm a newbie at all things metal...and still dealing with some frustration at getting a good finish off the mill.

One of the fellows on the forum suggested looking at the gib strips...they often have burrs on new machines and need to be polished. Sure enough for me...helped a lot.

There have also been somewhat recent discussions on direction of feed...sorry I can't remember where to find them but the search engine is often helpful.

I bought that start kit pictured in this thread...

I have yet to use the collets (keep in mind I cut my very very first piece of metal two months ago...on a lathe).

I've broken both ends of one of my center drills so far. But that's probably because I used too small a one. I thought the comment about the drill angle is interesting and didn't know about spotting drills.

The vise seems huge compared to the little table of my mini-mill. I've taken the bottom plate off as well as the two thing-a-ma-bobs on the bottom that align it to the plate.

The two T-nuts, and bolts you see above the slot cleaner were worthless to me. One broke the first time I used it...the other the 2nd time. I don't think I was too heavy handed when tightening it down.

Pretty happy with the clamping kit and parallel bars. Haven't really used the 1-2-3 blocks nor the edge-finder...simply 'cause I don't know how yet.

Wavering on my opinion about the cutters. As I said...I haven't gotten near the finish I expected yet...could it be the cutters? And the chorus begins...no it's me it's me it's me. I've used two of them so far.

Overall though I'm okay with my purchase...I was in a position where I wanted tools on hand when I needed them rather than taking the chance of putting of my learning while waiting for a tool. As it turns out though...there seems always to be another tool that's needed.

Indicators, calipers, and shims are a must.
LMS has been great for me...but I suspect it's not as helpful for the more experienced.

Hope that helps.

Oh...if you ever do want some bad habits...I've got a few I wouldn't mind palming off on someone.

 

[kvom]

The fact that you haven't used the collets yet seems to mean that you are using your drill chuck to hold endmills. I would advise you to hole your endmills in the collets; they hold better and may help with the finish.

 

[zeeprogrammer]

The fact that you haven't used the collets yet seems to mean that you are using your drill chuck to hold endmills. I would advise you to hole your endmills in the collets; they hold better and may help with the finish.

Once again, a reason for my being here.

Thanks!!!

I want to feel stupid...but newbie status means forgiveness. Right? oh:
:wall: Did it never occur to you (me) to ask what these are for?
Need a smiley kicking himself.

 

[Tin Falcon]

ZP: it is ok to hold drills in a collet but as pointed out not good to hold end mills in a drill chuck.
As far as forgiveness the reach out and smack button is disabled on this version of simple machine forum . However this does not prevent a chunk of metal from smacking you in your shop!! Work safe!!!!
Tin

 

[zeeprogrammer]

To your point...metal and machines do not forgive.

Only people can forgive...and occasionally my bestest friend...if I'm good...and I grovel sufficiently.

Staying safe as best one can.

 

[putputman]

ZP, the collets are precision ground for one specific size. 3/8 is for 3/8 only. Never try to hold a drill or end mill slightly larger or smaller in that collet. In other words, do not try to hold a 11/32 drill in the 3/8 collet. It will ruin the collet.

 

[zeeprogrammer]

Right. Ran across that question already when I was trying to use an indexing table. The combination of table, 3-jaw chuck, drill bit, and chuck didn't leave any room. Thought about a collet but it differs by 1/64. Didn't go there. Someone suggested using a sacrifical collet...well maybe once I have ruined enough tools or get lucky and find a cheap supply somewhere. But I lean towards (or try to)...using the right tool for the right job. (And I don't mean making tools, jigs, etc. doesn't count...I just don't want to use a tool in a way it wasn't designed for until I have enough experience to 'redesign' it.) Another possibility I'm considering is raising the head...but I need a bit more experience before making mods to the machine. I've made so many mistakes I'd likely ruin the mill.

I've been following tmuir's thread using the mill with great interest.

 

[tmuir]

There have also been somewhat recent discussions on direction of feed...sorry I can't remember where to find them but the search engine is often helpful.

That was in my thread here
http://www.homemodelenginemachinist.com/index.php?topic=4767.0

Basically don't climb mill or you will break your endmill like I did.

This website has pictures that explain climb milling far better than I can.
http://www.quadrantepp.com/default.aspx?pageid=201

or go down to the bottom of this page for even better pictures of climb vs conventional milling.

http://en.wikipedia.org/wiki/Milling_cutter

 

[Loose nut]

When I was starting out and I had just set up my mill/drill, I really had no idea what I was doing, I put in a 1" end mill to make a "practice" cut on a piece of steel. I didn't pay enough attention to the belt position chart, it was printed backwards in relation to the actual pulleys, and proceeded to run the end mill into the steel at 2400 RPM. Totally not good for the end mill.

Double check everything until you are totally familiar with your equipment

 

[BobWarfield]

FYI, these resources may be helpful:

http://www.cnccookbook.com/MTMillSurfaceFinish.htm

http://www.cnccookbook.com/CCMillTipsTechniques.htm

Cheers,

BW

 

[zeeprogrammer]

If this was intended for me...and I think it was since I'm probably the least experienced here...

thank you thank you

Very helpful.