How Many Axis?

[Damn Yankee]

Hi All,

I just purchased a backordered G4003 lathe from Grizzly. I have the time and have been pondering a DRO for it. My mill has a 3-Axis Ditron D80 which I love. So, I have been wrestling with how many axes should I spec? The Z and Y are a given, but:

• I see using the Compound close to the chuck. The D80 supports vectoring and the Griz degree scale is not bad.
• I can either use the tail stock to "push" the carriage to read precision dill hole depths from the Z or add a DRO to the tailstock. I can order a scale with a short whip and an extension to the display so I can remove the tailstock without the problem of the cable. This also means I don't have to remember to turn off a battery operated, tail stock-only DRO.

The cost in terms of adding 1 or 2 additional axis to the display is minimal (it is the scales that drive up the cost - but it IS a new toy!). The only downside as I see it is the numerical display becomes slightly smaller to accommodate 4 lines of data rather than 2 or 3.

What say you?

Thanks,
John

 

[rabler]

Well, it's a personal decision (unless someone else it paying). You can do a lot without a DRO, lots of folks get by with dial indicators. That would drive me crazy. I get by with a 2 axis DRO on my lathe. I drill with the carriage so a tailstock DRO is not pressing. My next lathe I'll add a compound axis with suitable capability.

If you think you'll want it, get it now, it'll cost you more long term to swap it out later, not to mention more time in installation and getting up to speed on using it.

 

[mattthemuppet2]

A digital read out on the tailstock is pretty handy. Not essential, but nice to have. Couldn't imagine needing one on the compound though.

 

[Damn Yankee]

Well, it's a personal decision (unless someone else it paying). You can do a lot without a DRO, lots of folks get by with dial indicators. That would drive me crazy. I get by with a 2 axis DRO on my lathe. I drill with the carriage so a tailstock DRO is not pressing. My next lathe I'll add a compound axis with suitable capability.

If you think you'll want it, get it now, it'll cost you more long term to swap it out later, not to mention more time in installation and getting up to speed on using it.

I never thought of drilling using the carriage. Huh... I must have been sleeping under a rock.

 

[pontiac428]

Longitudinal, cross, RPM, compound with vector summing, tailstock position, and tailstock quill. You might need two head units, but you would always know the tool's position.

I've thought about it, but just don't really need it on the lathe. Handwheels and calipers seem fine in analog. I have toys and bells and whistles, but no DRO and no plans for it. The mill is another story, but lathe DRO is meh in my opinion.

 

[BGHansen]

I have a Grizzly G0709 14" x 40" with a 2-axis DRO (and a digital caliper on the tail stock) and a Clausing 5418 12" x 24" with 1963 technology.

I do most of my turning on the Grizzly and use the DRO quite a bit. I use it to get close on the radius as I trust a micrometer more than my DRO. However, I use it a ton for shoulder depth and groove positions (Z-axis work). My cut-off tool holders all have their width written on them with a paint marker. I'll bring the tool up to the end of the part, and set Z on the DRO at the tool width. Then crank on down the part to where I need the groove or shoulder. Same for depth when using a boring bar. Touch the tool to the entry point, Zero Z, and bore to depth.

The tailstock caliper is nice for depth of hole, though I've not relied on it for anything better than 0.050" resolution (reads in 0.001"). The "lazy man" feature is I can zero it at any TS quill position. No more, "Let's see, I want to go 3/4" deep and the quill spindle is at 11/16" when the drill is just going into the work, that means I'll either have to count 12 1/16" tick marks or go to 3/4" + 11/16" " if that makes sense. It's handy to start the drill bit into the work, zero out the caliper and go to the mark.

I use my Clausing with a 2" travel dial indicator for Z-axis positioning. Count tick marks on the TS quill, and use the hand wheels for the compound and cross feed.

Which do I prefer? The DRO, no question. It's what I have become accustomed to though I can jump to the manual method on the Clausing with no issues.

Bruce

 

[markba633csi]

I must be living under a rock too. Lathe DRO- meh

 

[pontiac428]

One of the things that attracts people to DRO is the ability to use some sort of global/absolute coordinate system. I could give a rat's poot less. Relative coordinates are actually more flexible to use. I'll never understand why absolute coordinates matter, just like I refuse to understand why "losing zero" on a round column mill or "losing Z offset" for a long tool change is a problem. Those are simple issues when using relative coordinates. The lathe is just where is becomes obvious that absolute coordinates are a crutch for avoiding the reality of coordinate relationships. I think the perceived need for fixed coordinates comes from limitations in the user's ability to visualize the work. Plopping a part on a coordinate plane and cutting features is how a machine will calculate the movements, but for us higher forms of intelligence, isn't it enough to make movements referenced off of other features instead of some supposedly fixed cartesian zero? To me, DRO is a convenient sanity check, adds some nice features, but is by no means a requirement. Not by a sight.

 

[RJSakowski]

Absolute coordinates on a lathe DRO have no value to me. I change my QCTP location and orientation often to suit the task at hand. I cut my teeth with a lantern style tool holder and every tool change required referencing the tool as a first step. I have continued that practice with my QCTP with the exception being that I am using a tool previously referenced in that same setup.

I have a three axis DRO on my lathe. Actually, the fitst DRO was on the tailstock. Like @BGHansen, I tired long ago of counting tuns on the tailstock dial. I prefer to drill tsing the tailstock rather than going through an alignment of the drill to the spindle axis every tome I want to drill. There is an advantage of using the tailstock when peck drilling long holes but Joe Pieczynski showed a neat way to accomplish that while using the tailstock.

For many things done on the lathe, I don't bother activating the DRO. My mike, calipers, and rule are always close at hand. But when I need the DRO, it is there.

 

[benmychree]

One of the things that attracts people to DRO is the ability to use some sort of global/absolute coordinate system. I could give a rat's poot less. Relative coordinates are actually more flexible to use. I'll never understand why absolute coordinates matter, just like I refuse to understand why "losing zero" on a round column mill or "losing Z offset" for a long tool change is a problem. Those are simple issues when using relative coordinates. The lathe is just where is becomes obvious that absolute coordinates are a crutch for avoiding the reality of coordinate relationships. I think the perceived need for fixed coordinates comes from limitations in the user's ability to visualize the work. Plopping a part on a coordinate plane and cutting features is how a machine will calculate the movements, but for us higher forms of intelligence, isn't it enough to make movements referenced off of other features instead of some supposedly fixed cartesian zero? To me, DRO is a convenient sanity check, adds some nice features, but is by no means a requirement. Not by a sight.

Agreed!