First time using super glue chuck

[whateg0]

I see the same comment about the size of the part vs. The size of the machine made about lathe work. Why is it such a strange concept to make small parts on a large machine?

[Harold_V]

One thing that often creates issue in regards to small work on large machines is spindle speed. One generally has to compromise from what might be ideal. Feeds, too, often are too coarse, although so long as change gears are available, that can be addressed if necessary.

It is difficult to do small work on a large lathe, as the holding equipment tends to be too large, so small items can't be gripped. They also cause you to lean over (assuming you keep watch on the cut, and I do), so you tire easily. Large machines often lack the feel that is useful for small work.

I could have benefitted by higher spindle speed when these parts were made.

Unlike CNC machines of today, spindle speed for most vertical mills topped out in the low 4,000's, although there were some exceptions. Gorton made their Uni-mil that had a 10,000 rpm spindle. The machine was correspondingly small, and was operated from a sitting position.

I gave serious thought to buying a production jeweler's lathe when I was actively machining. I was stopped by the $15,000 price tag.

Imagine grinding a small diameter on a typical centerless grinder. By grinding below center, something as small as .06" can be ground. No big deal until you consider that a #2 Cincinnati centerless runs a 20" wheel 6" wide.

H

[John Hasler]

Though it has a six speed transmission my mill tops out at 1800 RPM. This is often quite limiting. I've seen designs for high-speed adapters, either complete spindles that have their own motors and attach to the quill or systems that are belt driven from the main spindle. Are these useful?

[pete]

There's also what are generally called Spindle Speeders John. Basically a planetary drive to multiply the main spindles rpm. And with usually some type of small collet nose for the tooling.New = expen$ive, they do show up on Ebay, but it might take some searching and time. Fwiw Hemingway Kits in the U.K. offer a kit to build your own spindle speeder. http://www.hemingwaykits.com/acatalog/S ... easer.html Then there's air driven turbine spindles that get held in the main spindle with a collet for 40K +++++ rpms mostly used on mills to do rudimentary jig grinding. They eat air and again aren't cheap. But those would be probably well outside what you'd want. I've seen a few home designs using a Proxxon upgrade to the Dremel on a sub plate locked to the main spindle. While I've not used one it seemed pretty mickey mouse but maybe they work ok.

[Harold_V]

I can't speak from experience, as I've never used a speed multiplier. I can attest to the value of higher spindle speeds, though, as my first mill (Bridgeport with step drive) was limited to about 2,700 rpm, while the second one, a vari-drive, offers 4,200 rpm. I use the top speed quite often, as it is very useful.

The Haas TM-1 I own is the model without the tool changer. They come from the maker limited to 4,000 rpm (a safety issue), as it also doesn't have a full enclosure. The previous owner altered the programing, changing the default speed from the original 4,000 rpm to 6,000 rpm, so the machine will operate like its brothers with full enclosures. I have used the top speed routinely, not only for engraving, but for drilling. I'd like more speed, but that isn't to be with the stock spindle unless I use a speed multiplier of some description.

While I don't have a link for you, I know that Glenn (one of our moderators) built one from a high speed right angle grinder, and uses it for engraving. It allows feed rates that make engraving a snap (he uses his on his CNC).

H

[GlennW]

Here is the link to what Harold is referring to.

https://www.chaski.org/homemachinist/vi ... =engraving

[Mr Ron]

Well, I finally finished all the parts, 36 in total. I used the "strip" method and was able to accurately index all holes and slots using DRO settings. That DRO has paid for itself over and over. I can't imagine doing this job by relying on micrometer dial readings. On very small parts, backlash makes it impossible to make identical cuts. I'm happy with how it turned out after a rocky start, but I thank you all for steering me in the right direction. Now it's on to the next challenge. Doing this to make a living would drive me crazy. As a hobby, it gives me great pleasure as a learning challenge. I may be odd; I get more pleasure from making things than watching TV; sure wish I had more years to look forward to.

[whateg0]

... I get more pleasure from making things than watching TV; sure wish I had more years to look forward to.

I disconnected cable several years ago and don't have an antenna. I have a 50" TV in the living room that probably hasn't been turned on in 4 years.

Dave

[John Hasler]

I have a 21" TV in the living room that hasn't been turned on in this century.

[LIALLEGHENY]

TV's make nice post it boards.

[LIALLEGHENY]

Also a good place to tape up your blueprints.

[Mr Ron]

The only time I turn on the TV is when I go to bed. It helps me fall asleep quickly.