First Impressions with Lathe

I just got through my fist work session with the big girl and it's pretty enjoyable to operate the big 16". I am working on that backplate for the three jaw chuck so it's a cast iron part and after the folks here sorted me out I was making chips...er...a...sort of a heavy sand! Seems like it is a little too easy to push the lathe to a point where the belt slips off and then no power. Maybe a blessing in disguise since I am pretty green?

About the best depth per cut I could manage was .01 at 80 RPM spindle speed. Anymore and the belt would slip off the position. I was using the auto feed too at about .012 per revolution. That was all good for about an hour, then I decided to stop and post and see what wisdom or encouragement might be shared... plus I needed a rest.

I made my first HSS 3/8" cutter too in the form of a right hand cutting tool. Pretty long process since my grinding wheels are pretty fouled up and I couldn't find the dressing tool. Is there an old school way to dress them? It probably took me an hour to make that one tool!

I am pleased with how it performed for the first 12-15 1 inch passes or so but then the work piece started to look gummed up and not clean grooves like I started out with. How long should I expect the cutter to remain optimal in cast? I took a few pictures as I was getting close to being done.

I rigged up a shop vac to try and collect as much stuff as I could.


I tried to get some picures of the chips flying but it didnt work.


Here's the general setup. Working this close to the headstock there isnt a lot of room.IO had to slide lantern off center to get the room.


Here's how the passes were starting to look at the end. I will sharpen the tool before I begin again. I am sure the tool wasn't perfect but I was really pleased with the geometry.


more picture in next post...

Here is the tool after the hour or so of use.



Another look at how little clearance there is. Cutter is in front of the part but check that saddle...almost out of runway!


Here's why am taking any and all advice! LOL Look at the part I need to make and the blank I have to turn down!

You should be able to take more material off, the belt probably old and lost its tension. You would do better with a composite belt or a multirib automotive belt. Cast iron is abrasive due to the carbides in it. Here you would do better with a carbide tool. Try to set the cutting tool edge is close to center of the compound as possible. That will give you the best rigidity and minimum chatter.

Tom

Kevin T said:

Here's why am taking any and all advice! LOL Look at the part I need to make and the blank I have to turn down!
View attachment 284183

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That’s ...I have smaller chuck backs for sale.
Ted
[email protected]

SBLatheman said:

That’s ...I have smaller chuck backs for sale.
Ted
[email protected]

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I have been waiting for you to come through for me since I got into this lathe thing! LOL

What do you have? I need a 2 3/8"-6 TPI ... around 6" max diameter. I only found this 10" diameter one where the rest of the dimensions were close the original Skinner Chuck Dims. The 8" was too feeble everywhere else....but just think how dialed in I will be with cast!!!

Kevin T said:

I have been waiting for you to come through for me since I got into this lathe thing! LOL

What do you have? I need a 2 3/8"-6 TPI ... around 6" max diameter. I only found this 10" diameter one where the rest of the dimensions were close the original Skinner Chuck Dims. The 8" was too feeble everywhere else....but just think how dialed in I will be with cast!!!

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When you, or anybody, needs something South Bend, I’m just an email away
I don’t have every part, but quite a few...

Send me an email and I will check my chuck backs for your best option.
Ted
[email protected]

Looks like you're doing OK for being a bit "new" at it. And besides, having fun is what its all about, right? Cast iron will chew up tool bits no matter what, you can always touch it up with an oil stone or whet stone. I keep several around for just that reason, after the rough grinding is done. Like someone else said, maybe get some practice in with the old belt then switch to a serpentine belt.

Turn the compound to 30º or so (instead of 90º) and you should be able to pick up more "room". Also, you should keep that backplate and convert it to a face plate. Some cast iron is poor quality and will cut like that. You might try making your cutter's edge a sharper angle.

I'm not exactly sure what that material is for those particular back plates, but I don't consider it just cast iron. I cut cast iron pretty well. But those back plates are like cast iron mixed with concrete, lol.

I used a 3/4" brazed carbide cutting tool when cutting mine, spear tip shaped, like what you got going on. I don't make the point real sharpe though, just slightly blunt, or rounded can stop the work from looking like your cutting threads, or an Elvis Presley record, lol. Pretty sure spindle speed I had was 160 rpm. Couldn't tell you what feed rate, but on the slow side. I think I managed .002" a pass.

The material doesn't really cut like the cast iron I know, It's like a cast iron, heat treated steel combo. Even drilling and tapping, the threads aren't as pretty as cast iron.

For grinding your cutting tools. White AO grinding wheels for hss. Green silcon for carbide.

The buying never ends, i know, lol. But in your online travels, look for used bulk cutting tools. Though used, a good bunch will already be sharpened and ready to rock, with a variety of cutting shapes, angles. Just an example:
Lot Of 29 Lathe Cutting Tool Bits With Carbide Tips Mostly 1/2” and 5/8” USA | eBay

And as you get more squared away with tool holders, try to get capacity size to atleast 5/8". Just like machines, big and heavier is usually more rigid and stable, which makes better cuts.

Cast iron can be nasty stuff to turn and with HSS tool bits it does not like high speeds. For what you're attempting I'd suggest you might want to be using the back gears to get the spindle speed down.

Also if you're making a chuck mount plate and you'd like to get on with life you don't have to reduce the OD of the plate all the way down. Just cut enough off the face to give you the pilot diameter you need to match the chuck back and leave the OD of the new plate too large. It won't hurt anything and it sounds like it would save you some frustration.

Dobermann said:

Cast iron can be nasty stuff to turn and with HSS tool bits it does not like high speeds. For what you're attempting I'd suggest you might want to be using the back gears to get the spindle speed down.

Also if you're making a chuck mount plate and you'd like to get on with life you don't have to reduce the OD of the plate all the way down. Just cut enough off the face to give you the pilot diameter you need to match the chuck back and leave the OD of the new plate too large. It won't hurt anything and it sounds like it would save you some frustration.

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Oh yes back gears for sure to see that 80 RPM, I can try to bump that up too.
Great idea to just turn down a step. I would not have thought of this on my own. I was trying to copy the original!

One note about slipping belts, wouldn't hurt to try some belt dressing.

PMc

SLK001 said:

Turn the compound to 30º or so (instead of 90º) and you should be able to pick up more "room". Also, you should keep that backplate and convert it to a face plate. Some cast iron is poor quality and will cut like that. You might try making your cutter's edge a sharper angle.

Click to expand...

I reached out to Ted so if he has a suitable backplate that is a better match I will definately convert this one to a faceplate! Great idea thanks!

texasgunsmith said:

I'm not exactly sure what that material is for those particular back plates, but I don't consider it just cast iron. I cut cast iron pretty well. But those back plates are like cast iron mixed with concrete, lol.

I used a 3/4" brazed carbide cutting tool when cutting mine, spear tip shaped, like what you got going on. I don't make the point real sharpe though, just slightly blunt, or rounded can stop the work from looking like your cutting threads, or an Elvis Presley record, lol. Pretty sure spindle speed I had was 160 rpm. Couldn't tell you what feed rate, but on the slow side. I think I managed .002" a pass.

The material doesn't really cut like the cast iron I know, It's like a cast iron, heat treated steel combo. Even drilling and tapping, the threads aren't as pretty as cast iron.

For grinding your cutting tools. White AO grinding wheels for hss. Green silcon for carbide.

The buying never ends, i know, lol. But in your online travels, look for used bulk cutting tools. Though used, a good bunch will already be sharpened and ready to rock, with a variety of cutting shapes, angles. Just an example:
Lot Of 29 Lathe Cutting Tool Bits With Carbide Tips Mostly 1/2” and 5/8” USA | eBay

And as you get more squared away with tool holders, try to get capacity size to atleast 5/8". Just like machines, big and heavier is usually more rigid and stable, which makes better cuts.

Click to expand...

Yes I was going to end up with some bigger holders because I have a lot of 1/2" blanks but I was just usin what I had....

I also was just using the grinding wheels that came with the basic craftsman and ryobi 6" grinders I had laying around. I dont have anything setup as a dedicated tool grinder so I am light in this area. What do you guys like for a tool grinder? I have a pedastal that I can mount one on but I dont know what to look for. I know I want to be able to attach a vacuum to it to help keep the dust down in the garage but what represents a good value that can also grind the bigger bits? I'd rather not spend 800 bucks on one!

Get the tool post in the center of the top slide and choke up on the holder to get a better finish, and more room as someone already said. Less overhang is always better.

Looks like Ted has come through with a nice looking chuck back that I can use! Much less work! So I'll do a clean up pass on this OD and maybe break a few sharp edges and stow my "new faceplate" away until it's needed! I already have a cherry Southbend 16" faceplate but having one I can customize is probably good for down the road.

Took off the grinder request. I think it needs a separate thread somewhere.

Kevin T said:

Looks like Ted has come through with a nice looking chuck back that I can use! Much less work! So I'll do a clean up pass on this OD and maybe break a few sharp edges and stow my "new faceplate" away until it's needed! I already have a cherry Southbend 16" faceplate but having one I can customize is probably good for down the road. Grinder recommendations anyone?

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Lots and lots of options, and way of doing things. Could have a dedicated bench or pedestal grinder, as is, or even one which you could fancy up with small table and miter gauge.

If you really want to do more on a lathe, there are countless pitch, rake, and chip breaker cutting angles that need to be ground, for what cut, for what material, what speed, what finish and so on.

You're kind of land locked in your location, so I don't know what's available there as used or vintage. Or what shipping from state side is like. But now that you're thoroughly sucked in, lol, there are a great many styles and variations of tool grinding machines. Purchase and rebuild costs pretty low.

If you're grinding blanks, it'll take time, even with optimal grinding wheels. There's some with water cooling.

I went the vintage route. I paid $150 for mine. I put new spindle bearings, a new link belt, wiring, small parts, etc. prolly a few hundred into the build. Maybe another $400 into a whole variety wheels. The real cost again, being time. Got close to a year in it. Thread link for anyone interested:
Hammond Machinery Builders, Tool Grinder Model CB-77

texasgunsmith said:

Lots and lots of options, and way of doing things. Could have a dedicated bench or pedestal grinder, as is, or even one which you could fancy up with small table and miter gauge.

If you really want to do more on a lathe, there are countless pitch, rake, and chip breaker cutting angles that need to be ground, for what cut, for what material, what speed, what finish and so on.

You're kind of land locked in your location, so I don't know what's available there as used or vintage. Or what shipping from state side is like. But now that you're thoroughly sucked in, lol, there are a great many styles and variations of tool grinding machines. Purchase and rebuild costs pretty low.

If you're grinding blanks, it'll take time, even with optimal grinding wheels. There's some with water cooling.

I went the vintage route. I paid $150 for mine. I put new spindle bearings, a new link belt, wiring, small parts, etc. prolly a few hundred into the build. Maybe another $400 into a whole variety wheels. The real cost again, being time. Got close to a year in it. Thread link for anyone interested:
Hammond Machinery Builders, Tool Grinder Model CB-77

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Oh wow that is really sweet. Shipping here sucks but some people gouge a lot more than others so I just ahve to keep my eyes peeled. This place is a total desert for any industrial stuff.

Some pics to clear up my good name! LOL I sharpened the cutter and put a slight radius on the end and cleaned up the edge in that cast part, so it can be stored until needed. Really nice finish. Machining that material wasn't too bad, but definately is messy! Didn't really try any different speeds or anything, just ran the 80 rpm with the back gear and a feed per inch about .005 per revolution.

id go even more radius.
increase depth of cut and feed rate.

cast is fun.