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View Full Version : First time using a lathe need a little advice



airsoftmode
01-23-2007, 10:21 AM
Hi guys, i just got a lathe from cummins tools its the 399.00 version and I have 2 questions. First i machined my first hilt and polished it out on the lathe using 0000 steel wool, and while the result is very smooth it is a gun metal color closer to the color of the steel wool rather than the bright silver color im trying to achieve, therefore my question is how i might achieve the bright silver color with my hilt. Also, i want to machine a pomell that starts at 1.5in and tapers to .5in smoothly, how can i achieve this with my lathe. O finally whats the best parting tool to use, should i get the bladeholder replacable style or the solid tool.

xwingband
01-23-2007, 11:06 AM
I don't have a lathe but I believe you can get an angle rather easily by just manually turning the dials. Like if the taper was 1 inch long that'd be easy you move both the length and depth of the cutting the same. Basic geometry you'd have to figure out.

Also with a lathe polishing should be easy you can use the sandpaper while it's on there. If not plain old hand polishing which you should do anyway is possible. Get up to something like 2000 grit at least them use a metal polish to get the nice mirrored look.

I'll let other with a lathe chime in, so don't take my word as gospel.

Jonitus
01-23-2007, 12:00 PM
Don't use steel wool to polish. It's two dissimilar metals, which gives you the dark color. You need wet/dry sandpaper, in grits from 600 to 2000 to polish on a lathe (at least, it's what I used on my MSH sabers in the gallery). Lots of water with a touch of soap for lubrication, and clean the sandpaper regularly.

When you get done with the wet sanding, a few good rounds with some Mothers mag and aluminum polish will really bring out that look you want.

Also, when polishing, you can use a bit higher speed because you're not putting much load on the aluminum. I machine aluminum at 600 rpm, but polish at about 1000.

Do-Clo
01-23-2007, 12:26 PM
I use a scotch bright pad to polish the parts that I make. I find that it gives a nice shine and a smooth finish. Swipe one from the wife or pick up some at the store.(don't tell the wife where her new pad went :shock: )

vadeblade
01-23-2007, 01:08 PM
Hi,

I had a cummins mini-lathe too. I like pictures so i will provide some with my instructions.

1. Back the Compound Rest all the way back untill you see the hex screw underneath. Loosen the hex screw but do NOT unscew completely. Just make it loose. Now the Compound Rest should be able to rotate.

http://www.geocities.com/projectstm/temp/CompoundRest.jpg

2. Work out the Angle needed to get the diameter you need for your pommel.

http://www.geocities.com/projectstm/temp/makinganglecut.jpg

(note: i did not pay attention in high school math class and it was a long time ago. so i have no clue as to what the formula is to get the angle needed. anyone have it?)

3. Use the really crappy angle marks on the Compound rest to set your angle. Lock the angle down by tightening the hex screw. Move the Compound rest back to where the tool can cut into the metal.

4. Start shaving off the metal starting at the corner closest to the desired diameter.

http://www.geocities.com/projectstm/temp/makinganglecut2.jpg

Here is my lathe making four pommels. Notice in the right side of the picture, my compound rest is set at an angle. Personal preferrence - I removed the backsplash because it gets in the way of turning the handle when making angled cuts like these.

http://www.geocities.com/projectstm/images/making4pummels.JPG

vadeblade
01-23-2007, 01:31 PM
ohh, on polishing. I use steel wool to get the rough burs out. Then I switch to wet/dry sandpaper working from 300 to 1500 grit. Personal preferrence again - The mini-lathe is prone to rust with the smallest amount of moisture. To avoid this I use synthetic motor oil as a lubricant instead of water when polishing. I sometimes finish off with a polishing compound on a clean shop rag. All done at high RPM since there is no load on the lathe when polishing.

Tenric Starkindler
01-23-2007, 07:20 PM
in H.S. metal shop in order to put a shine on either steel or aluminum rods (or other round stock) I waould just set the blade for 1-2mm cut and shave off a hair's breadth by hand. IF you have a steady hand it can look just about as good as the other polishing methods (by which I mean not a mirror shine, but failry close.).

airsoftmode
01-24-2007, 08:01 AM
Awesome, thanks guys answered both my questions, but now as far as parting tools go ive seen two kinds and im not sure which to buy. I could either get the one that comes blith blades that attatch to the tool holder, or i could got with a solid parting tool ground out of tool steel. Which works best, according to the website the solid tool can take twice the torque, although since im working with aluminum im not sure if this matters much.

Jonitus
01-24-2007, 08:12 AM
To figure the angle, you'd use the tangent function.

If "x" represents the angle of interest, then the tangent of that angle is the ratio of the opposite over the adjacent.

The adjacent (a) is parallel to the lathe and the opposite (o) is perpendicular. So, "x" is equal to:

TAN (o/a)

vadeblade
01-24-2007, 10:01 AM
For parting tools my personal recommendation is the blade type that goes into a parting tool holder. This type:
http://www.geocities.com/projectstm/temp/blade_partingtool.jpg


True this one can take more torque
http://www.geocities.com/projectstm/temp/HSS_partingtool.jpg
But the problem is that the mini-lathe sometimes can't. In my experience, no matter how much cutting oil I used, and with the lightest touch feeding the tool into the aluminum, the cutting tool above still managed to trash my work. The issue is the large surface area of the cutting face.


On most of my projects though, i save myself the trouble of using a parting tool. The piece was usually cut about 1/8 of an inch longer than what I want the end product to be before mounting it to the lathe. Then I just faced off 1/16 of an inch from both ends. This results in a mirror finish on both ends.

Strydur
01-24-2007, 11:07 AM
I agree..I have never had much luck with the parting tools.

Ryma Mara
01-27-2007, 02:39 PM
polished it out on the lathe using 0000 steel wool, and while the result is very smooth it is a gun metal color closer to the color of the steel wool.

Intresting, Did you use any water or anything when you did that?

I would like to give that a try on my mhs

xwingband
01-27-2007, 03:00 PM
polished it out on the lathe using 0000 steel wool, and while the result is very smooth it is a gun metal color closer to the color of the steel wool.

Intresting, Did you use any water or anything when you did that?

I would like to give that a try on my mhs

He used a lathe... I don't think you have one. So that tidbit is virtually useless. Having a spinning piece of metal in front of you is a lot different from going at it by hand.

Ryma Mara
01-27-2007, 03:10 PM
We got a drill and a modifyied pice of metal and that works, VT did his that way and it turned out kick butt. so did you use any water or anything?

vortextwist
01-27-2007, 04:10 PM
he was talkin about using steel wool on it.

I made this to attach to my drill. It's a 3/8 bolt with 2 3/8 nuts inside an 1/2 inch electrical tubeing. then I took a piece of tims blade that we cut off and drilled and but a bolt through. pit it into the blade holder and sand away,. Works pretty awsome. I just wish it was nice outside so I could do it there. kind of tough to do in the bathroom sink.
http://i74.photobucket.com/albums/i259/vortextwist/newlightsabers.jpg

Lord Maul
01-28-2007, 12:07 AM
wow, talk about ingenious... great work man :shock: :D just don't push too hard, you could break the shaft :(

darthdan
01-28-2007, 05:37 AM
just don't push too hard, you could break the shaft

http://i113.photobucket.com/albums/n237/huskerbrewdad/Smilies/whistling.giftrying...my best...not to comment...

vortextwist
01-28-2007, 09:37 AM
ya we don't want any broken shafts. I will show some pics of my posished hilt today sometime.