Cutter selection and set up on lathe

[Creativechipper]

I am getting ready to cut some aluminum as a 1st cut ever.
So I have a few questions:
Why does my compound slide have grooves and a big area that my cross slide and tool rest will never be able to travel, due to a hole and plug on the compound that mates to the cross slide base?
What sort of angles should my QCTP and cross slide be at for a facing cut?
I have a selection of Hss tools and not sure on orientation and choice of tool?
I mounted one up and took a guess at position but not sure?

Let me know what you think.

Thanks for the guidance!!

 

[ttabbal]

I think you're getting terms mixed up, so let's start there.. The part with the QCTP mounted on it is the compound. The part the compound sits on is the cross slide. Your cross slide is like mine, and has T-slots on it. Under the compound you will find 2 bolts. Loosen them a little and you can slide the compound anywhere on the cross slide and rotate it. You can also remove it.

For a facing cut, you want to lock the compound and have the tool pointing at the side you want to face. To lock the compound, look at the Allen screws on the side of it. The one without a nut is the lock. Snug it up, it doesn't need to be super tight.

For normal turning, most of the bits pictured don't look great. Ignore the oddly shaped HSS in the last picture for now. They are special use grinds. The lower HSS looks like it might work, though the top rake is a bit light for aluminum. The top HSS in that picture looks like a threading bit to me.

I have no experience with brazed carbide, so I can't say on those.

Start with light cuts of about 0.010" and see how it goes.

You should consider learning to grind. There's a sticky at the top of the beginner forum where you can ask for models and get all sorts of information about it. There's no way to tell from the pictures how well ground and honed those bits are.

What lathe is it? It looks a lot like my PM1127.

 

[Creativechipper]

weiss250f, 10x30
I can rotate my compound but it swivels on a nipple. So I cant slide it up and down the slots that its bolts are in.
I have taken it all the way off, maybe I am missing something here?

 

[Cadillac]

Here's acouple tips
Your qctp has two sides to mount the tool holders. One side of the dovetails should face the chuck and the other farthest from the operator or closest to centerline of lathe. Your tool should always be exactly level with center of lathe or a touch lower. I also have a lathe with a similar cross slide. Mine has a pin though with two corresponding holes in the top slide. Those mounting positions should give you the ability to use the capability or size of the machine.
To answer your question put a tool holder in the front dovetail of qctp. Use the tool in your first picture with the cut on the right side. Mount in tool holder with cutter facing towards center of lathe. Your tool will be perpendicular to the chuck. That's the best way to face a part. The tools you picture have a chip breaker ground in them. Should work very well. Although you want to work from the OD to the center with that tool. Watch some YouTube videos some are very resourceful. Good luck

 

[Creativechipper]

heres a pic under the compound

 

[Creativechipper]

So for cutter placement and alignment, more like this?

 

[Cadillac]

Yes my top slide is the same so you should be able to put your compound slide mount in either hole and bolt it down. And yes that's how your tool should be oriented for facing. I'd use the tool in your first picture before that one. Just make sure either way that the tip of tool is touching work and the back of tool is a hair away so the back of tool is not dragging on work piece.

 

[Creativechipper]

The cutter in which image?
Image #3843 with the left and right cutters?

 

[Creativechipper]

Here's another couple angles with a different hss tool

I know there must be an optimal position vs the positions I have?

What is a good position for the cutter?
I have watched a lot of videos but its so hard to see the angle and exact type of tool to cut ratio. Then my cutters don't look quite like the ones I have seen either..hmm

 

[francist]

You should be able to do something with the last cutting tool you've shown, but play with the angles a bit. More like this




You can also come at it with more of an angle (I tend to this way, myself) like this

This second method is only good for the facing cut though, you need to reposition for the turning cut otherwise you drag the back corner.

What you should be noticing though, is that it's only the tip of the tool that contacts the work. Not the flat faces of the grind. Even though the angles can be used to advantage, they are not so critical for your purposes right now. The main thing is don't drag on the whole face of the cutting edge.

-frank