Two issues.... took video footage

[Pcmaker]

I took video footage of the two issues I currently have with my Grizzly 7x12 mini-lathe that I got last monday. This is my first lathe ever.

1st is the graduated collar on the compound slide doesn't turn with the handle. The allen screw is already super tight. I took the compound slide out and cleaned it, didn't see anything out of the ordinary, but this is my first time messing with this

2nd part of the video shows that I'm having problems facing off the work piece. The cutting tool ends up tapering the work piece and doesn't stay square. I've tried different cutting tools, different angles, different work pieces. I've been cutting off .005 to .030. It all ends up the same. with a rounded end of the workpiece.

 

[francist]

Not familiar with the machine so can't help on the dial situation, but as for the facing I would probably:
- rotate the tool post a few degrees or so counter clockwise so that you only cut with the tip and not the side of the triangular insert. Some holders actually present the insert at an angle not parallel with the holder which helps with that, but others don't and you end up dragging on the side of the insert through the cut. The tool post does not have to be oriented exactly 90 degrees to the lathe bed.
- lock your carriage. Not sure if your machine has a carriage lock but here is where it is useful. The tool pressure can cause the carriage to move away from the work as you go through the cut giving a not-square end. If no carriage lock, holding the carriage handwheel with your left hand so it can't move works too. You are ambidextrous, aren't you?
-your centre height on the tool looks ok from here but I can't tell for sure. You've got a bit of nib there which isn't optimum but it also suggests you're not miles out either.

Those are just a couple things I saw right off the bat, you'll get some more feedback from others soon. I gotta get back to work.

-frank

 

[Pcmaker]

A few days ago, I turned the thread dial indicator not knowing what it was and now it's not turning at all. With or without the leadscrew auto feed. Wonder if that could've done something to the carriage. Or maybe I need to push or pull the feed lever more to "lock" the carriage into place? I'll try again tomorrow. It's a Grizzly G8688 7x12

 

[owl]

Well, the indicator dial should have a setscrew, mine is located pretty close to the zero. That is to allow you to loosen the dial and turn it to zero from any position. I suspect that yours is loose. This is not the nut that holds the handle on. If that is the one you have tried without success, I suspect that the hole may not have been tapped to the bottom, and so the setscrew is not gripping the shaft. If so, you could thread it deeper, or just put a bit of brass under the setscrew, and let that grip the shaft. As to your facing, it might be that you have too little angle on the tool, or that the toolholder is not tight on the compound. The former will make cutting very difficult, the latter will allow the cutting edge to rotate slightly, dishing or doming the surface. As to the threading indicator, that is on a single bolt that will allow you to pivot it off the leadscrew to reduce wear, you simply need to pivot it back to contact with the leadscrew and tighten the bolt. It will not rotate when the leadscrew is engaged, for power feeding, just when the feed handle is not engaged. At that point it will rotate, either by turning on the lathe, or by using the handwheel. Hope this helps.

 

[RWanke]

What material are you cutting and what speed are you running at? Sounds fast to me.

 

[Pcmaker]

What material are you cutting and what speed are you running at? Sounds fast to me.

I'm cutting mild steel and I've already tried different angles and different speeds, as well as different cutting tools and cutting off small from .005 all the way up to .030.

Wonder what's going on.

 

[markba633csi]

It's good to practice on cutting aluminum first to get familiar with the basic operations. Steel is harder to work and everything is tougher and takes longer since on a light lathe you have to take lighter cuts.
Also you usually need some lubricant to cut steel

 

[royesses]

There is a half circle spring on the feed screw that fits in the dial (#190) and provides friction to turn the dial with the feed screw but allows you to turn the dial to zero it. This spring may be missing or collapsed. You may need to bend it for more spring tension on the dial. I ordered a half dozen from LMS since my big hands tend to lose small parts. I have 2 of those springs on my feed screw for more friction.

Turn the tool post so only the tip of the tool can cut on the face. It looks like the whole side of the insert is cutting and causing a taper.



Roy

 

[Pcmaker]

I think I have a problem with the carriage moving while I'm facing. I don't have a carriage lock and I pretty much need a mill to make one... I'll figure something out.

There is a half circle spring on the feed screw that fits in the dial (#190) and provides friction to turn the dial with the feed screw but allows you to turn the dial to zero it. This spring may be missing or collapsed. You may need to bend it for more spring tension on the dial. I ordered a half dozen from LMS since my big hands tend to lose small parts. I have 2 of those springs on my feed screw for more friction.

Turn the tool post so only the tip of the tool can cut on the face. It looks like the whole side of the insert is cutting and causing a taper.

View attachment 270235

Roy

Yeah, i saw that half moon spring #190 on the diagram. I had a tough time trying to get #87 on because of it.

I tried different angles and cutting tools to do facing, but they all do the same, even with the very tip of the carbide hitting the face and nothing else.

 

[francist]

This is not meant to be a condescending remark, but is the spindle rotating in the correct direction? (Don't laugh, it happens!)

-frank