Lathe update/questions

Just get .1 dials and put them on your existing screws!

Some lathes are .1 and some are .125. Cutting threads is the same on each, it is only when one counts five turns in the mind... One must calculate and figure all of the time anyway.

It might have been metric !

Martin

Mart> Wayne,

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They are all basically made by the same small group of factories, we in the trade affectionately call The Red Dragon Noodle and Machine Tool Collective

Gunner

True, but different importers and brands do set different spec and quality standards with consequently different pricepoints.

GM makes a wide range of automobiles, Springfield offers 1911's in a range of grades with most mfg done by Taurus in Brazil, and so on.

I'd just accept it and move on. I have used a lot of lathes. Each one is a bit different and you quickly adapt to it. The diameter of your dials have an effect too on how fine you can position the cross slide. Big ones are nicer than small diameter ones. We are only talking 25% coarser in pitch anyway.

Now what really irritates me is that every lathe I've used except for mine, pulling up on the half nut lever disengages the split nuts :(

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Correct.

The better quality machines are made on Tuesday through Thursday.

Gunner

Martin,

True, but it would be back at their warehouse by now had that been the case :)

Bill

Don,

You gave me pause for a moment - thanks for clarifying.

Bill

I am not surprised. It looks like a very solid machine, which is why I took a few days to raise concerns. The news-server disconnect had something to do with it too ;)

As an aside, what do you say to the comments about tearing down and cleaning to remove grit? Have you removed the top cover on the headstock? Would you recommend removing that to check for whether a cleaning is appropriate? Or, is it all just gears and no way to see past them?

Honest answer: I am not certain of what you mean by that. I typically do not bother (all on my mill so far) dimensioning rough cuts, as I can usually do the corrections on a piece of paper. For windows, I often use a spreadsheet that takes wall locations, tool diameter and how much metal to leave for cleanup, and creates a crude table/picture with tool center locations. I have been known to print that and then use Harold's

• trick for the actual work. Sometimes I skip directly to the latter.

I have no problem "over-dimensioning" as needed to make my life easier, and I dimension consistent with how I expect to make the part.

Does that answer your question? Please fire away if there is something I should know or a book I should read.

Having written the above, I suspect my answer to your question might be "no, most of the time." Maybe it is better to say that I do not (typically) use drawings for the dimensioning. I *do* use layers to represent tools for potentially complicated situations (RT setups, etc.), and I think I see where you are going with respect to dimensioning for the lathe dials.

One way to have the drawings tell me the ballpark on the dial would be to dimension from a 1/8" grid. I recently described a boring head setup that I dimensioned from a few inches "back" from a part specifically to have the drawing contain the dial reading. Similar tricks would probably work on the lathe. I could be wrong, but instead of (an extreme example) a plate with 40 or so slots, windows, and holes (combined), I would probably have a handful of diameters on a lathe part, so some extra work to dimension them would not be a big deal.

However, all of this depends on a reliable zero location. Short of chucking something of known diameter, or turning and measuring same, I am not sure how to get such a reference. It seems it would be blown away by any adjustment of the toolpost???

That's not true - I can conceive highly intricate disasters :)

Good point. I still maintain that I would not tolerate it on a mill, but 1/8 dials are probably ok on a lathe.

Understood. Thanks for the reply.

Bill

Tom,

It and the compound are 0.125 marked at 0.001. The question is whether that would drive me batty like it would on a mill - the answers seem to running very much in favor of it being ok on a lathe. Please speak up if you disagree.

Bill

:)

Fair enough. My approach was to buy the smallest lathe that had a cam-lock spindle (I expect to make a large number of interrupted cuts and decided against a threaded spindle). At 1000 lb and the sale price, it seemed like a good match to my needs. I have it a little backwards in that (assuming I end up keeping it) I will have more lathe than mill, but I found no way to put the tooling of my choice on a smaller lathe. I also wanted to avoid seriously under-buying in this case. I expect to buy another mill in the future, but I am still struggling with what I want, and my current mill works well.

The point is that I know next to nothing about running a lathe - this machine will allow me to fix that, and will hopefully provide enough lathe to meet my needs for a long time. Given the surprise on the dial specs, I came here for advice to enable a good keep/return decision.

Thanks!

Bill

Don,

Yes, and the markings are not of much value.

I assume that most lathes use a rack and worm gear to reserve the leadscrew for threading, right???

I thought of that, and it is indeed a possibility for the future. However, given the responses in this thread, it appears that I will not have much trouble over it. I simply did not want to tell myself that and regret it later.

I was afraid someone would use the J-word :) Having had trouble with them in the past, I doubt I would even consider a Jet machine. I _hope_ I would not even consider a Jet machine. I think I would sooner buy another Buick. The hostility is of course *not* directed at you, and your point is well-taken.

The Grizzly version of the lathe in question appears to be exactly the same base with some nice looking dials and handles and some paint. I am waiting for a response from them about the dials, but would probably have to wonder whether they are indeed a metric "equivalent." Also, we have Richard's "friend of mine" comment, and so far no such favorable review of a Grizzly.

However, the question stands: if anyone knows of a true 10 tpi lathe in the same class, I will take a look as I am doing with the Grizzly. So far, I am leaning toward keeping the machine.

Bill

Tom,

Let's keep the satire to a minimum: we're talking about important things like machine tools here, not something frivolous like choosing a leader for the free world.

Bill

It is not a question of "getting stuck" - I have the option to return the machine. At this point, I suspect that would be a bad idea, but I am researching options.

Just out of curiosity, what does a DRO measure on a lathe?

Bill

A DRO on a lathe measures exactly what it does on a mill...that is it shows the position relative to the zero that you establish that is usually going to be the centerline of the spindle on the X axis and, generally, the face of the part on the Z.

A readout can be a pretty good time saver, but if you are going to have just one, I'd get the DRO for the mill...there are other ways to speed up the fast cuts on a lathe.

Mike

Yup. A good QC toolpost as Aloris helps, but generally when a toolchange is made then I take a light cut with the new tool, measure the workpiece, set the dials to agree with the measurement and proceed.

If I'm after accurate threads I'll wipe a bit of toolmaker's blue on the work and sneak up on it with the threading tool until it "marks", then set the dials accordingly.

I'm sure my approach is very "old school". I am an amateur, by no means a professional machinist. That said, I would not expect the absolute accuracy/repeatability of a CNC lathe from a much-less-costly manual lathe. And, I imagine there's a certain amount of "fartin' around" necessary to set up a CNC lathe for a given job. Since I rarely make more than 1 of anything, I just do the fartin' around along the way rather than all up front.

I couldn't resist pulling your leg! However, the remark had some validity. My dials mean nothing to me until I start getting close to where I need to be, and then nothing when I get really, really close. I guess it depends on what the job is but I rely on my measuring device and an intuitive twist of the screw.

My pocket scale is the ticket until we get close enough to care.

Wes

In particular, does it account for the compound angle and slide position?

I have a hard time seeing the "need" on a mill - clearly people got along just fine before they existed. One of my first things I expect to do with the lathe is turn some spud- or probe- like gizmos to allow me to effectively stick a narrow drill bit into pretty much any of my collets. It will mostly be make-work to have something to turn for practice, but they should save some time too. Once I can see +/- 0.1 where I am, the problem is solved.

Bill