The Home Machinist!

My latest non-machining project ... a tools rack for my lathe.

This will free-up some space in the drawer where all these tools where stored.

Nice! Not only frees up space but probably makes it a lot easier to find what you need without digging around for it. That is one thing that drives me nuts is when you know what you need but have to sort through a couple hundred pounds of other stuff in a drawer or something to get to it.

~GearGeek

Hey Jose,,, Did you make this out of wood? Looks neat-o. Jack of all trades, huh? Hey, I'v got a question,,,I just recieved some lathe tools from Shars yesterday and am kinda stymed. It seems when I set any of them in the tool holder, the cutting tip rests slightly above the work centerline and they will not cut nothing. I lowered the tool holder all the way and still too high! I think I read somewhere in one of the many books I have been reading that ,, the tool tip should be just below the work centerline. Right? They are 3/8" X 3/8" What do you think? Joe r

I've heard both versions.

That the tool must be bellow CL and also above CL, but never have I heard by how much. Logically in my mind, if the tool work best center, then positioning a hair high will counteract for any flexing caused by tool down pressure.

There are several ways to set the tool height.
Some people make a special tool similar to a height gage.
I've seeing many versions.

Using the point of the center in the tail stock is another.
In my lathe one cannot rock the holder like one can with the American style of tool holders, like the ones used in South Bend where the holder seats on a rocker.

Another way is facing the stock until you're sure that it cleans all material.

The one I use mostly is using a six inch flexible scale and softly pinch it against the stock diameter, then eye-ball it until the scale is at right angle to the bed. A square could be used if there are no reference surfaces in the line of sight.

As you explain sounds more like the tool has not been formed correctly.
You may search for Harold's posting on how to grind tools. Better than most books can explain.

Jose Rivera wrote: The one I use mostly is using a six inch flexible scale and softly pinch it against the stock diameter, then eye-ball it until the scale is at right angle to the bed. A square could be used if there are no reference surfaces in the line of sight.

Since it's been mentioned a couple of times in a week.....
Here is a pic of what Jose describes for those who may not understand.

Hey Jose,, I did not explain myself very well. Let me try this way,,, In trying to use the new cutting tools I purchased,,,The tool post on my lathe will not adjust "down" enough to set the tool bit below the C/L of the stock. I can't figure out what I am doing wrong as even at the tool post's lowest position,, The tool tip is still slightly above the C/L of the work piece. The tool post is a Kirkelie brand made in Los Angeles, probably out of business, and built hell for stout. What do you think? I'll include a pic of the setup if that helps. Joe r

It is because the quick change tool holder is for a larger lathe.

You're limited for what I see in the picture to smaller size bits. (Don;t know what size those are, 3/8?)
Now. you have the compound rest set at an angle. It may be the 29.5 degrees needed for threading, but if you would set it at 0 or 90 degrees, you may be able to allow the bottom of the holder to drop bellow the top surface of the compound rest.

Looks to me that is what is stopping the holders from going bellow what you show. You may be bottoming into the corner of the top of the compound rest.

In my Maximat I could not use a brand new set of Aloris knock-offs (China) that where actually of very decent in quality, because I am limited to a .750 tool height using the compound rest.

In order for me to use them, I would had to remove 3/16 off the bottom lip. or remove the compound rest and make a special spacer, thus loosing the conveniences of the compound rest.

Doable but to costly. So I stayed with the type of holder that the lathe came with. Instead, I machined the bottom of my indexable carbide holders in order to bring the tool height withing correct height for my lathe.

http://www.chaski.org/homemachinist/vie ... hp?t=76253

Hey Jose,, well, I ran out to the shop thinking we had figured out another roadblock. The removable part of the tool holder protrudes past the end of the cross slide even when the slide is at o deg. after looking some more, looks like maybe machine about .100" of the bottom of the removable piece is my option. I don't think it will compromise the tool as the is bottom piece is .650" thick. What do you think? Joe r

ilike55s wrote:Hey Jose,, well, I ran out to the shop thinking we had figured out another roadblock. The removable part of the tool holder protrudes past the end of the cross slide even when the slide is at o deg. after looking some more, looks like maybe machine about .100" of the bottom of the removable piece is my option. I don't think it will compromise the tool as the is bottom piece is .650" thick. What do you think? Joe r

Agree with that but consider that the steel block may be to hard to machine in normal ways, specially if all you have are small machines like I do.

You may have to have them grind as much as you need in a shop that had a surface grinder or better yet, a Blanchard grinder, Blanchards are faster material removers thus less expensive to operate.

Measure from the top of the tool bit to the point on the center in your tailstock.
Add as much as you think you can afford to remove and establish a concrete dimension.
Going to a shop with a vague number may cost you more that giving a concrete number.

Glen,

I just had a similar poblem. I purchased tool holders with my lathe and I also purchased a quick change tool post.

The standard tools are to big to fit in the quick change post and on the standard tool post there is not enought adjustment under the tool holder to raise the cutting tool to center height.

So to use the standard tools in the standard tool post I had extend the cutting tool out of the tool holder a fair bit.

So I milled about 7mm of the top of the tool holder. This now allows me to pack the tool hoders up in the standard tool post and they also now fit the quick change tool post.

My propblem was the opposite to what you have but I think the solution is the same in altering the height (milling) of the tool holder or tool in your case

ilike55s wrote: I think I read somewhere in one of the many books I have been reading that ,, the tool tip should be just below the work centerline. Right?

Not in my opinion. Tools should be on center. That's especially true when facing, so you don't chip the tip of your tool, or leave a pip at the center of your part. It gets critical when machining small diameters, too.

Run 'em on center, folks. It's the ideal place for the tool.

Harold

ilike55s,

Just an observation, but from looking at your tool holder and tool bit setup in your pics, you might want to consider another type. If you look at the distance from the center of rotation of your compound to the tip of your tool, you have HUGE overhang which will result in HUGE tool deflection and chatter. Always try to keep the cutting edge as close to the compound as possible for best rigidity.

Glenn