Checking for twist? and tool holders and inserts, Jet BD920W

[djs1234567]

Hi guys,

I am new to the forum and not sure how to get to all members so they can see my post. I hoped I nailed it!


Checking for twist on ways on the Jet lathe?

One of the ways on the bed is wide enough for a 1-2-3 block to sit nicely. the way closet to the operator is about 1/4'' wide and a 1-2-3 block cannot sit on its own without falling off. the question I have is what's the best option to secure the second 1-2-3 block so I can put my level on it and check for twist from one end to the other?

Also,
I had to return my AXA for OXA as you all know that there's overlap and I cannot get to center on work piece as it sits to high. currently, I have 1/2'' indexable grizzly tool holders which are on center with the OXA. To me they seem a bit wide for OXA and not too safe for my taste. if they are safe in your opinion, does anyone know what HSS inserts would fit those grizzly holders? I have you-tubed and google myself out with trying to find and understand indexable tool holder, boring bars, and the cutters for them, there are just too many options, and Grizzly is not much help at all. I did find that they are WCMT 06T304? But not sure if different HSS insert will fit?

pics attached for the tool holders if anyone can help? hope they are self explanatory.
G7039-G7040 are the inserts.



The allen screw that holds the insert on are inserted from the bottom and holds the insert on with an eccentric, or an offset cam on the bottom of the allen screw that wedges the insert against the back of the tool holder.

I am sorry if I am rambling on about nothing, but have so many questions?

I think I am going to be buying 3/8'' indexable and would like to know what products I should be looking at? or in your all opinion should I just get HSS inserts for the tool holder I have now, which I know would be much more rigid and save me a lot of money to say the least?

A.R. Warner seems good and reasonably priced?

I will probably be turning 1018 and 12L14 and A36. Aluminum 6061, 7075, some brass and bronze. If I need to get different cutters that would be fine. It seems like HSS from research would be a good choice? with a positive angle and rake?

Thanks to all of you that read this long boring rambling. Jay

 

[Larry$]

Please take my comments with a grain of salt, I'm no expert, just an opinionated old man.
Small lathes usually are not very powerful or ridged. Inserted carbide tooling generally runs best with enough force to overcome the eased edge that is there to limit chipping. There are inserts made with sharper edges specifically for overcoming shallow cuts on a small lathe, buy those. There are many advantages to HSS tooling. Easy to grind to any required shape, cuts freely requiring less power and less force. Cheap! You can also buy HSS inserts, not cheap. Given the cost to buy a box of 10 name brand inserts and their associated quality tool holders and all the different configurations you will need, you are talking a lot of $$$. Get an 8" bench grinder, G or H Norton wheels a star & a diamond (for shaping the wheel to other than flat) dressers.

 

[Cadillac]

I have a jet 9x20 also and one way to check the ways is to use parrallels. They will fit on the ways and you can check twist. Another way would be just put the level on the carriage and move the carriage back and forth.
As for tool holders and qctp size I have axa qctp on my 9x20. For the most part I use 3/8 tools. I use carbide and hss tooling. If going carbide use ground inserts that are sharp.

 

[markba633csi]

Beginners seem to have more trouble with insert cutting tools than anything else. Do yourself a favor and get a small bench grinder and some HSS toolbits and grind your own tools the traditional way. Or, if you simply must use inserts, try to find some high positive rake types. They give great results on small lathes, comparable to or better than sharp HSS tools.

I have a small lathe also and like to use Kennametal CCGT 3251 style high positive inserts, with a homemade holder
They are diamond-shaped with a hole in the center. You can often find them on Ebay. Two flavors to look for are:
KC5410 for aluminum and other non-ferrous metals, can also be used on steel
KC730 for steel and stainless, can also be used on non-ferrous
-Mark

 

[C-Bag]

Because my 9x20 didn’t come with carbide tooling and I’d always sharpened my drills by hand it was a natural to just always use HSS. But not until I got into Mikey’s thread then started applying the grinds along with finding a stereo microscope did I make true progress. Once you get down in the weeds and get grinding truly straightened out then you can start to unravel the other possible problems. The proof is in the pudding, whether you are cutting a taper or whatever, until you get a proper cut you are spinning in place and accomplishing little.

 

[Larry$]

what's the best option to secure the second 1-2-3 block

Maybe a couple of magnets? End to end "level" doesn't matter. Across the ways will be the twist fixer, maybe. Taking care of twist is one of those things that you should apply the 6 "why" system to. Start at the bottom and work your way up. A 3 leg lathe is a special case and beyond my knowledge of what to do if there is twist. Is what the lathe is fastened to solid? Sheet metal cabinet, over a crack in a concrete floor, wooden work bench, each may cause you problems with changes in time. Since you have an older?? lathe the castings have "settled," most likely. If it is a new Chinese lathe, time may affect the castings as they undergo natural stress relieving. You can either use jack screws or shims to get to level, screws are easier. At any rate the lathe needs to be clamped to it's ridged support so it can neither move up or down. If what it is clamped to isn't stiffer than the lathe it is hard to get the lathe to agree to move. As for the level, how good is good enough? As long as you keep the reference locations exactly the same (mark them) we are down to the sensitivity of the level. How far do you want to chase your tail? I've got a nice Polish made 12" level that I bought when doing machine setup work. 0.0005" in 10", insulating pads to keep the heat of your fingers from causing the metal to move. Needs to sit in the use location long enough to come to a stable internal temperature.

When you have completed, leveling and all is bolted down tight, turn a test bar like shown on lots of videos. Still not perfect enough? check tail stock alignment. Does the quill extend parallel to the bed? Perfection is unattainable, decide what is good enough. This should be a fun hobby.

 

[djs1234567]

Maybe a couple of magnets? End to end "level" doesn't matter. Across the ways will be the twist fixer, maybe. Taking care of twist is one of those things that you should apply the 6 "why" system to. Start at the bottom and work your way up. A 3 leg lathe is a special case and beyond my knowledge of what to do if there is twist. Is what the lathe is fastened to solid? Sheet metal cabinet, over a crack in a concrete floor, wooden work bench, each may cause you problems with changes in time. Since you have an older?? lathe the castings have "settled," most likely. If it is a new Chinese lathe, time may affect the castings as they undergo natural stress relieving. You can either use jack screws or shims to get to level, screws are easier. At any rate the lathe needs to be clamped to it's ridged support so it can neither move up or down. If what it is clamped to isn't stiffer than the lathe it is hard to get the lathe to agree to move. As for the level, how good is good enough? As long as you keep the reference locations exactly the same (mark them) we are down to the sensitivity of the level. How far do you want to chase your tail? I've got a nice Polish made 12" level that I bought when doing machine setup work. 0.0005" in 10", insulating pads to keep the heat of your fingers from causing the metal to move. Needs to sit in the use location long enough to come to a stable internal temperature.

When you have completed, leveling and all is bolted down tight, turn a test bar like shown on lots of videos. Still not perfect enough? check tail stock alignment. Does the quill extend parallel to the bed? Perfection is unattainable, decide what is good enough. This should be a fun hobby.

Wow, what a Lot to digest, thank you. I think the magnet idea was very good. I can get a couple of earth magnets and super glue them into the holes in the bottom of the 1-2-3’s. Far enough in so that they will grab the Ways but not interfere with flatness.
Will be working on it this week.

 

[C-Bag]

Is there a reason you don’t just pull your tool post and set your level on the carriage while you run the carriage down the ways? That’s what I did.

 

[Buffalo21]

I have those Grizzly lathe tools, in certain applications, they work great, in other applications, they are pure crap. The main problems with them are totally proprietary to Grizzly. I’ve looked everywhere, had 3 industrial suppliers, check their sources. There is only one series of insert available, no different grades and over the yrs, the insert quality has been everywhere from excellent to crap, the last batch was pure junk. Not a series of tools, I would recommend to anyone.

 

[djs1234567]

I have those Grizzly lathe tools, in certain applications, they work great, in other applications, they are pure crap. The main problems with them are totally proprietary to Grizzly. I’ve looked everywhere, had 3 industrial suppliers, check their sources. There is only one series of insert available, no different grades and over the yrs, the insert quality has been everywhere from excellent to crap, the last batch was pure junk. Not a series of tools, I would recommend to anyone.

Thanks. Being a new hobby machinist,
I thought I might’ve been overly critical. But now that should tip the scales for me to just put them in the vault don’t bother with them anymore and just get the A.R. Warner 3/8 indexable set. and as one of the reply I received I should just buy some tool blanks and learn grinding and sharpening on my own.
Thanks again