Learning to lathe [things]

Thanks Will - I tried the Little Machine link again, and now its working for me. I will study it all!

I was hoping to learn the correct gear settings for the tailcap threads in the body. I think its a 1mm thread but I may be quite wrong!

So do you cut the host body radially with a small diameter rightangled 60 degree tool or use an indexable tool holder such as Glanze or Sandvik?

cheers!


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The minis I have cut down have been done using a .040 inch parting tool. I know the minis are 28 threads per inch (TPI) I have not done any of the C or D mags, so - I don't know what the TPI is

Fred,

If you can't alter your set-up the only option left is to indicate it in. Get yourself a good test indicator that measures to .0002 or .0001 ten thousands(if you have'nt already). I know they're expensive, but very precise.

I like your lathe, by the way. Can you post a picture of the entire machine?

The first thing you need to do, plasmaman, is get a set of thread guages. Then when you are duplicating a thread there is much less guesswork. Just measure the thread you will be duplicating and go from there.

For the changegear settings, there is a diagram on the side of the 7x10 that has the popular sizes. You can also use the web appplication at http://www.tanj.com/cgi-bin/tpi.cgi to get a list of possible gears for various threads. If you search this forum you should find some good threading info.

Try the "Common dimensions reference" at https://www.candlepowerforums.com/threads/51647 for the MAG threads.

See the "Silly Newbie Tricks" for some more threading info. https://www.candlepowerforums.com/threads/54273 A quick search shows that around post 130 is some real good info about using the compound, though there is a lot of good info in that thread for newbies of all ages.

Daniel

will said:

The minis I have cut down have been done using a .040 inch parting tool. I know the minis are 28 threads per inch (TPI) I have not done any of the C or D mags, so - I don't know what the TPI is

Click to expand...

The C mag threads are different on each end. The bezel end has a finer pitch than the tailcap.

Daniel

Thanks Daniel - just what I was looking for!

Sometimes the obvious is not always that obvious.

Mind you, I've never worked with a mill at all, so my only introduction to one is through my reading. As you know, my lathe has some limited milling capabilities, as the headstock can be moved vertically.

The tapered slots that I did on the 18650 battery tube, and posted pics of in post 130, are an example.

However, as I proceeded to correct my major mistake of the battery tube, i.e., uneven lengths for the slots, I noticed that the surface quality of the slots was sporadically poor. It looked as though one side of the groove was being gauged, while the other half looked fine.

I decided to do some testing, to see if the different RPMs and depths of cut would make a difference. Here's a test piece:



As you can see, in the middle of the photo is the problem that I was encountering, while just to the left of that is a very shallow cut done at high RPMs. I thought I had figured it out, but then I took a close look at the first completed head, which had been polished a bit:



When looking at those grooves, it was rather obvious that the problem was not gauging within the grooves, but smearing of the chips onto one side of the groove. They just optically appeared to be gauges.

Finally, I had one more thing to check on a test piece: I wanted to test the groove's appearance when the depth of cut was uniform along the length of the cut; so I eliminated the taper and just did some normal grooves:



As you look at that photo, the end closest to the camera was the end of the piece that was held in a collet in the dividing head. My normal method for making the grooves was to start the milling of the groove close to the collet and to move the piece toward me. However, as you can see in the photo above, there was one groove that was cut in the opposite direction, i.e., the piece was moved into the end mill and toward the collet and dividing head.

Bingo!

I had been improperly moving the piece in relation to the ball nose end mill; the part should move toward the mill, which is rotating CCW in the spindle, or toward the operator.

So back to the second iteration, but this time with the proper feed of the part to the end mill:

At this stage, I'm very pleased with the outcome--the grooves are much, much smoother than my previous attempts, and the lengths of the grooves are now identical in length.

Lessons learned: Read the books more carefully. And, there's nothing like hands-on experimenting.

I have an ENCO 7x10 mini-lathe that I bought used off EBAY about 7 years ago. I use it a lot for both wood and metal ( aluminum ). I had some problems facing certain parts and parting off pieces. I would get too much chatter even at the slowest speeds. Different lubs, different tools - nothing seemed to fix the problem. I checked the spindle bearings a number of times for looseness, they seemed fine, no movement that I could measure. There was also a harmonic vibration at 600 rpm and around 1200 of so. I decided last week to order new spindle bearings and countershaft bearings. I replaced them this past weekend and I now have a lathe that finally works like it should. The facing now comes out with no chatter and parting works fine.

The hardest part of replacing the bearings, they are all pressed on the shafts and pressed into the housing. A big hammer gets them off. I pressed the new ones on in a big vise, then tapped the outer race into the housing with a piece of brass. Not and easy fix, but worth it

Fred,
Most impressive. When you have your lathe in 'Milling Mode', what is the maximum RPM you can turn the small ball end mills?

Anglepoise said:

Fred,
Most impressive. When you have your lathe in 'Milling Mode', what is the maximum RPM you can turn the small ball end mills?

Click to expand...

David,

The Wahli has a variable speed spindle--the lowest RPM when threading is 50 RPM, the top speed for turning (milling) is 3,000 RPM.

Pretty scary, actually, when you are standing next to it. :sweat:

Thanks,
That looks like a very nice lathe and I now see that the spindle goes up and down for a bit of milling. Very nice looking lathe. And 3,000 rpm is just right for the small stuff.

Putting the pieces together--finally.

Found a little unexpected time to do some more lathe work today, so I wanted to put the tapered groove pieces together to see if I liked the overall look.

Close-up of the head:




Close-up of the seam:




View from the rear:




Overall view on its side:



And standing up:



Personally, I like it, although there is room for improvement. Still to be done are the split ring holes, and I think I might like something at the bottom of the light, but I'm not sure what. Have to see what the split ring holes leave for real estate to play with.

So, what do you think of it?

I really like the head. Looks very good. Now the body needs some rings or something at the far end. Things look a little bare where the tapering just tapers off.

Outstanding design Fred...and the machining looks perfect too.

Very, very cool.

Thanks for sharing,

TB

It looks quite impressive. Is that the aluminum or the titanium version? The pictures really show it off well.

Daniel

Fred, that is SWEEEEEEET!!!!! :twothumbs Now, you do remember my address don`t you? What? :duck:


Ken

kenster said:

Fred, that is SWEEEEEEET!!!!! :twothumbs Now, you do remember my address don`t you? What? :duck:


Ken

Click to expand...

Ken, that's great of you to offer to polish the light for me! Of course I have your address, I'll send it along promptly. :lolsign:

Very impressive

Great work PF- love the precision and repeatability of those tapers.
It looks fabulous- what's your plan for the guts?

ICUDoc said:

Great work PF- love the precision and repeatability of those tapers.
It looks fabulous- what's your plan for the guts?

Click to expand...

David,

The guts call for a USW0H P4 emitter with a Khatod reflector and an AR-coated lens. The driver will be either a NG750 or an LD0^3 at 800 mA. There will be a brass converter module holding the driver and the LED. The battery will be an 18650.

This is 6061Al, not Titanium, so I was thinking of having it EN plated, but if I'm going to get anything anodized before too long, I might go for black ano, as I like the looks of this: