Originally Posted by twocik  Thank you!! Yes any tips, help would be greatly appreciated.
For 6061 you use a cutting speed of 200?
I notice when I move the carriage by hand slowly toward the chuck, at 600 rpms I get a nice finish. Now when I put it on auto feed, it comes out very groovy and not polish looking at all.
1. When engaged does that mean the clutch lever is toward me or away
- On - rubber pushing on the belt?
- Off - rubber off of the belt?
Basically which way is on and which way is off?
(The I'm using is the 9 x 20 Harbor Freight.)
"I have a DC motor now"
So you made the upgraded, did you do it yourself?
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I got a better look at your pics, first things you need to do is make yourself a new compound rest mounting I think you maybe even be able to buy them through LMS now. That will make big difference, Second you need bring your tool into the post as close a possible the more ridgid the better, the chip breaker on the tool you are using indicates that you are using a facing and not a turning tool(its odd either way), lookin down onto the tool you should have a narrow steep left shoulder and broader shallower right the chip breaker should be near parallel to the work piece, although it may not have one at all. Your speed was too fast, and your are heat treating your tool tip which indicates you are rubing more then cutting, you may need to regrind the tool gently and keep it cool untill you are past that the heat treatment. Your grooving indicates that your feed is to aggresive, which means your tool isnt right/ bad angle/or sharp, I would expect that kind of find finish on a piece of 1045 shaft steel.
Also you have to remember if you are not using coolant that your tip will expand as it heats so agresive cuts should be avoided untill you have a good base cut, with a rough cut like that you will hit high spots creating even more heat.
I use a CS of 200 for most of the alum I do(i do mostly sand cast with some bar stock), typically I don't know for sure what the material is so I play it safe which seems to work well for me, its not a die hard rule, if I have finish problems which I often do I typically start to change the speed both up and down and see if it matters. Tool angle is critical with HSS, its not as forgiving as carbide in that right, also making sure you are on center, and of course sharp.
As for when you have the autofeed engaged(and not the screw cutting) that entirely depends upon your feed rate per revolution typically the slower you go the better the finish. Also with a finishing tool, you dish out the tip more then a roughing tool, I don't concern myself with finish on any alum I do, but cast iron I do, there I provide a very braod radius on the tip maybe near half of the tool bit but that is a different animal. So I can't help you much with fine finish on alum I just use a regular turning tool. Also how are are your chips breaking off? you might need to touch up the tool with some grinding wheel on the top to provide better chip clearance.
I suspect there is a problem with your clutch, can you provide a pic? with the lever towards you the clutch is disengaged, with it away the clutch is engaged. There is not any question when its in and when its out, mine stops and does not turn, as it should. The grizzly manual is decent try downloading that and see if gives a clearer picture, I would have to actually look at mine to determine which way the wheels bind up, if memory serves the belt is engaged from the bottom but don't hold it to me. Sorry I have not made it home yet to look, I had to babysit a friends forklift today.
Variable speed yes and no, the lathe I have at work which is a piece of scrap iron with a chuck, has a variable speed motor. My 9x20(same lathe as yours) is still stock but I do have the motor and control(90 VDC 1 HP) to put on, when I get some time I will it should be straigh forward as the motors are nearly the same size maybe a mounting or belt issue, if its not possible with the DC I have a metric 3 phase I will through on instead which is the same frame size(DC would be more fitting for this application). At this point use the machine untill you are comfortable then worry about upgrading, I have not used mine at home all that much( I got it third hand about 3 months ago) I currently use my shaper more then anything, so I have be careful about my HSS tool statements as they are ground different, I still refer to drawings when I have to grind new tools esp the lathe.
Chris