new mill options

[wrmiller]

They still don t lie whatever srew it is. The thread on the screw and the mating nut have the same tpi. It s the operator not the srcrew. If one cant count to five and rotate a handle and gets tripped up I think there in for a world of hurt no matter the route you take. Backlash, well learn to use numbers and how to compensate for backlash not guess how many cranks. If The screw from the manufacturer is not built right it s out of this discussion.
You guys and the modern stuff think it s all the bees knees. Ya it s great and I can guarantea they ll be question like the dro says so but my part says different. What s up with that?
Have an imperial or metric scale along your x,and y axes. Oh theres the eighteen inches i need to move so ill mark my axis and then when I look and see that mark is near the eighteen i ll look down at my dial to fine tune. Easy peasy. They don t lie they are mechanically locked. Its all operator.
Id like to see some of you with these lower end dros do some test with some jo blocks (guage blocks) and indicators and see what kind of accuracy you have now with your Dro. Add a cut in there during your testing.
It a luxury and an aid. I don t need a dro I can manage without. Bolt circles and such can all be done mathematically.
Would I like one sure! I ll wait and get by until i can get a decent unit and the shop has caught up a bit.
So here will be another new machinist going right to a dro not learning the basic skills that would force him to learn some math and trig. Which will be all computer aided and you know it s not about this mill its about getting some routes that will help and stay with a person so they can grow not looking for a computer.
My whole argument is why not learn from the ground up. There will be times you ll have to revert doing something the old way because it is all you can work with. Not having the dro forces you to get that pad and pencil out and work thinks out
I Don t think were doing these newbies any good heading down this path from the get go. Will the rotary table have a dro? You know you should revert back to zero then hit your next angle.
Screws don t lie!

Apparently, you've never read the tolerance specs on ACME screws. Whatever. Carry on.

 

[BGHansen]

Not adding anything that hasn't been said above. Power feed is nice, but DRO is a gotta have. You can do work without either one, but the DRO will speed you up more than power feed.

I have two mills and both have DRO's. Smaller one has power feed on the X-axis only. I've never felt the need to add the Z or Y on that mill. The table is relatively light (JVM-830 - ~900 lbs. mill) so cranking the table up and down isn't a real chore.

My other mill is a 2-axis CNC Bridgeport. So have X & Y programmable power feed. The smaller mill has a 4-axis DRO, BP had just the 2-axis, so bought a Z-axis read out. Had to tram in the scale which required multiple 16" travel cranks up and down. So the BP got a Z-axis power feed within a week. For a BP, I'd say 3-axis DRO, scale on the quill, then Z-axis power feed and X-axis last (just my preference).

Bruce

 

[Nyala]

My usual procedure is to bring the end mill within about .250" of the workpiece using the Z axis coarse feed then use the fine feed after that. A depth of cut of .025-.030 will make this machine work and I have been hesitant to push it beyond that. Moving the head up/down each time I want to make a .025" cut is impractical. Using the fine feed adjustment I can make a .025 change in about 5 seconds. It will take me longer than that just unlock the z axis so that the head can be moved. I have motorized the Z axis feed and fine adjustment is difficult at best.

 

[Dabbler]

Hey everybody - please remember that this particular post is targeting newbies, and that detailed explanations and differences of opinions are guaranteed. Let's examine this topic with courtesy and patience.

For my 2 cents: I was using a 9X30 mill for years, only getting to within .005 on most dimensions - until I got a DRO. I could have blamed a loose lead screw, small and flexible machine or other things, but it was just operator error. I bought my bigger mill with a Mitutoyo DRO preinstalled (I bought it VERY used) - it had a worse lead screw, and I find myself easily hitting to within .001 every time. THAT's how important a DRO is -to me.

Now Mark had a good point, learning about backlash and lead screw tolerances and counting off/ laying out your work all are essential milling machine skills. I just do better when I have the help of a DRO.

As far as power feeds are concerned, they are nice-to-have, but not essential (somethings just take longer or are harder on the wrist/shoulder). If you have a bad right wrist and shoulder (like me), then a power feed in X and Y are a godsend. Power feed in Z can be accomplished with a drill and a 20$ adapter.

 

[Dabbler]

So I needed to add something here. Lead screws are rated in tolerances of .00x per foot of travel, but that can be much farther out when moving from an unworn part of the thread to a worn part of the thread. If your machining tolerances are very forgiving, then these tolerance differences won't affect you.

To machine to sub-thousandths over the long travel in X on a mill - even a very experienced tool and die maker would have to specialized setups with gauge blocks, or just use a DRO.

 

[Investigator]

I'm pretty new to machining myself. From my experience, adding DRO to my RF30 was a huge upgrade. I would like to add power feed to my cross feed, but I would not trade it for the DRO's.
Also, DRO's can be inaccurate. I found one of my mounts was loose which allowed some "backlash" in the sensor reading. Mounting with duel screws and some red loctite solved that.