# Preparing for a new lathe



## bluwolf (Oct 4, 2009)

After Will looked at the used lathe for me and we decided it was not a good choice I had already decided I would get a new one. At the risk of sounding like "me too" I had decided on a PM1236.

So I called and talked to Matt. Long story short, they're out of stock. I'm looking at 4 to 6 weeks. I was dissappointed but realized I have a lot to do before the lathe gets here anyway. 

I've gone through all the old threads, not the least of which was Will's thread on his new lathe. But it's tough to keep it all straight. I'm not sure if there are too many variables for this to be a reasonable question. Maybe that's why I've never come across it before on any of the forums I've been on.

If you had a new lathe coming what would your list be to prepare for it? For those that have one, what did you do to prepare for it's arrival. Maybe a better question is, what would you have done differently if you were to do it over? Is it possible to put this in something resembling a checklist? If so, it might be able to help others in the future as well as me right now.

I'll give some examples of my questions. I have a 7x12 lathe. There is nothing from that lathe that will transfer to the 1236. So I need all new tooling. 

The recent thread about insert comparisons helped me to a point. Then I got a headache. From that thread I gathered that CNMG and WNMG were the most common inserts. After that the rest of the designations in the part #s start to blur for me. Is there a reasonably priced set of insert holders/inserts that would get me started for basic turning, facing, boring?

I know the all the lubes will need to be changed after break-in. This assumes that it comes with all the boxes filled in the first place. Will's did and I asked Matt about this. He said sometimes yes, sometimes no. Is there a general consensus on which fluids to use, and how much do you need to have on hand to fill/replace once you have the lathe?

I now realize I could go on and on. So I'll phrase the question like this. What advice would you give someone that would help them or save them a lot of grief if you could do it BEFORE they got the lathe and started making mistakes or forgetting things?

Wow. This is beginning to sound like too vaque a question even to me. Maybe that is why I've never seen the answer before. Feel free to rephrase the question for me. Or tell me what questions I should be asking myself. Any two cents worth will be appreciated.

Thanks,
Mike


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## precisionworks (Oct 4, 2009)

> Is there a reasonably priced set of insert holders/inserts that would get me started for basic turning, facing, boring?


MSC/JL has a special that includes the CNMG-4xx holder plus a CNMG-4xx boring bar plus 10 inserts for $149. Figure that the 10 inserts would cost at lease $50, so you get the holder + boring bar for $100 more, which is a decent price. 

http://www1.mscdirect.com/CGI/NNSRI...rid=15610Pstoreid=1040626Ppagenumber=25Pmode=

The boring bar (A16MCLNR4) is 1" diameter x 12" long with a coolant through hole that accepts a standard air fitting - which is how I use mine.

The turning holder (MCLNR124B) is 3/4" shank - you'll have to mill down the bottom side of the shank so it fits your tool holder block.

I doubt that you currently have a 1" boring bar holder, so add that to the list & you're ready to turn/face/bore. That particular bar + insert needs a starting hole about 1.125" diameter (IIRC). You can buy or make bushings so that smaller bars will fit into the same holder.

A 3/4" boring bar is really handy, as you'll sometimes needed the "smaller" bar. MSC/JL usually has these on sale as well.

I just did an eBay search & could find nothing better than the $149 kit, but that can change on a daily basis.


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## bluwolf (Oct 4, 2009)

Thanks Barry,

I'll show more of my ignorance. In the picture it looks like the boring bar is 3/4" and the insert holder is 1". I'm probably missing something. And can I face with that holder? I've always turned with a RH holder and faced with a LH holder. Now you see how much I've got to learn.

I was gonna be more specific in the first post. But it was already getting too long. One of the reasons for the bigger lathe is to to do a couple of bigger projects. But I also do a good bit of smaller stuff. 

Among other things many here make flashlights. I make pens. I would like to try making some titanium barrels. For their I.D. I would think I would be reaming as opposed to boring? If so, any suggestions?

What type of drill bits work best in harder stuff like ti? How about center drills? I'm sure I've got more questions.....

Mike


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## gadget_lover (Oct 4, 2009)

Congrats on the purchase!

I have to disagree with the thought that the 7x12 tooling will not work for the bigger lathe. It will often work, but will still have limitations similar to when you used them on the 7x12.

For boring small, shallow diameters, the same 3/8 inch shank boring bars will work if you adapt/make/buy a holder for them.

Your 3/8 inch turning tools will fit in a larger tool holder, but the holder will have to ride higher to bring the tool's cutting edge to center height. You will still have similar DOC limitations, but they can be used while waiting for the bigger, stiffer tools to arrive.

I imagine that there will be times when you want to have a small, skinny tool to reach in someplace. But I'm a packrat that keeps old versions of everything.



Daniel


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## precisionworks (Oct 4, 2009)

> In the picture it looks like the boring bar is 3/4" and the insert holder is 1"


The bar in the kit is 1" diameter, and the holder shank is 3/4x3/4.



> I would like to try making some titanium barrels. For their I.D. I would think I would be reaming as opposed to boring?


On a pen barrel, you'll have a small diameter hole that's really long, which is a tough job for a boring bar. Drilling and reaming is probably the easiest way to go.



> What type of drill bits work best in harder stuff like ti? How about center drills?


For hole drilling like this, with a large L/D ratio, solid carbide drills are tough to beat. They are much more rigid than HSS drills, giving less deflection and better accuracy. They can also be fed faster, which is really important in Ti to avoid work hardening. The same applies to solid carbide center drills.


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## darkzero (Oct 4, 2009)

precisionworks said:


> For hole drilling like this, with a large L/D ratio, solid carbide drills are tough to beat. They are much more rigid than HSS drills, giving less deflection and better accuracy. They can also be fed faster, which is really important in Ti to avoid work hardening. The same applies to solid carbide center drills.


 
Sorry to be a bit off topic, but I came across a thread related to drilling Ti this past week. http://www.mmsonline.com/dp/forums/forum_results.cfm?t_id=3188&f_id=99&pub=MMS

The OP states that he heard it was common practice to maintain continuous feed when drilling Ti to avoid having to recut through the areas hardened by the drill point but could not obtain good drill life unless using the peck method. Another poster is saying to use HSS + CO & not harder metals due to their sharp cutting edges? What does the "CO" mean when they are referring to carbide + CO & HSS + CO? Any thoughts on this?

There's also talk about changing the cutting angles on the drill bits. Another poster mentioned Boelube. I did some reading on it & ordered some oil & paste last week. Anyone use this stuff?



BTW, Mike congrats on the PM1236! I can't wait till the day I move up to a bigger lathe.


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## wquiles (Oct 4, 2009)

Mike,

As you know by now, I am pretty "visual" when it comes to machining, so instead of just text, I will post a "few" pictures that I just took for you, of the cutting tools I recommend for the 12x lathe:

1) Phase II BXA Wedge Type Tool Post. On special from Enco with 4-5 holders for $189:
Enco part #: SV890-9637

This post shows how I got it installed in the 12x lathe:
https://www.candlepowerforums.com/posts/2776862&postcount=172


2) For turning/facing, same tip Barry gave you - a CNMG 4xx series tool, like the one I use - this is how I do the bulk of my work on the lathe:













3) For parting, I feel one should have two tools, a carbide insert cut-off tool for metal, and a much sharper one for plastics. After trying several blades/tips for a couple of years, this carbide insert tool is what I have settled on - simply fantastic performance:











4) For parting plastics, this is totally awesome - it is a fine grain, extremely sharp carbide tipped blade:











5) You need at least two boring bars, a "small" one and a "medium" size one. You get to decide that is small/medium, depending on your particular uses/needs. And like Barry said above, spring for the solid carbide - it is definitely worth it. I also have a 12" solid steel boring bar that I used exclusively to do the internal boring on my 1xD's for fitting the FM 4xAA adapters, but if you get the kit Barry mentioned above, you will also get the "large" size boring bar, but you still need the smaller ones. These two are 3/8" and 1/2" - both solid carbide.











5.5) I have a 7/8" solid carbide CNMG 4xx boring bar that I bought on Ebay last Friday, but it has not arrived yet, so I don't have a photo yet - but this is the Ebay listing - this will likely replace the 1/2" solid carbide bar that I showed on top:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390062121229&ssPageName=STRK:MEWNX:IT


6) For internal threading, this tool is the bomb - I have cut over 40 hosts with that same tip, and it is still doing a great job on the 1xD customs that I sell - the top does not even appear to have any wear yet!:
















7) You need a "really" good Chuck for the tailstock. My choice is the Jacobs Ball-bearing Super Chuck, specifically the model 16N, shown here in my old 8x lathe:
Enco part# SV505-8005






This post shows how I got it installed in the 12x lathe:
https://www.candlepowerforums.com/posts/2771970&postcount=129



8) For external threading, you have tons of choices - this is what I use:






I have more lathe tools, but these are the ones I feel are most important/useful 

Will


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## precisionworks (Oct 4, 2009)

> common practice to maintain continuous feed when drilling Ti to avoid having to recut through the areas hardened by the drill point


Ti (and some types of stainless) will harden if the temp at the drill point reaches the hardening temp of the material. The two most common ways to overheat & work harden Ti & SS are to feed too slowly or to run the tool too fast.

Feeding too slowly allows the tool to rub more than it cuts, which generates immense heat. Running too fast does the same thing. The reason to maintain continuous feed to to avoid ever hardening the material. Once you harden Ti or SS, you might as well toss that part in the scrap bin as it is nearly impossible to continue drilling the hole any deeper.



> What does the "CO" mean


That's a common reference to Cobalt, which is added to HSS to increase the tools red hardness. Cobalt is sometimes called M42.



> changing the cutting angles on the drill bits.


Most solid carbide twist drills are 118 degree split point, but 135 degree is also available.


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## darkzero (Oct 4, 2009)

Thanks Barry! :twothumbs


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## unterhausen (Oct 5, 2009)

wquiles said:


> Mike,
> 
> As you know by now, I am pretty "visual" when it comes to machining, so instead of just text, I will post a "few" pictures that I just took for you, of the cutting tools I recommend for the 12x lathe:
> 
> ...



Great post, thanks for the effort. Don't know how I missed this part of the forum before. I'm just getting started with my lathe and suffering from a lack of funds, but at least I'm getting a better idea of what I should buy when it makes sense.
Eric


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## darkzero (Oct 5, 2009)

unterhausen said:


> Don't know how I missed this part of the forum before.


 
Sorry to hear that! :nana: This part of the forum is just as bad if not worse. Because of this sub forum I've spent more this year than any year that I've been here on CPF.


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## bluwolf (Oct 5, 2009)

darkzero said:


> BTW, Mike congrats on the PM1236! I can't wait till the day I move up to a bigger lathe.


 
Thanks. I've been waiting for almost two years. I just got tired of waiting.



precisionworks said:


> On a pen barrel, you'll have a small diameter hole that's really long, which is a tough job for a boring bar. Drilling and reaming is probably the easiest way to go.
> 
> For hole drilling like this, with a large L/D ratio, solid carbide drills are tough to beat. They are much more rigid than HSS drills, giving less deflection and better accuracy. They can also be fed faster, which is really important in Ti to avoid work hardening. The same applies to solid carbide center drills.


 
So much to learn, so little time....



wquiles said:


> Mike,
> 
> As you know by now, I am pretty "visual" when it comes to machining, so instead of just text, I will post a "few" pictures that I just took for you, of the cutting tools I recommend for the 12x lathe:
> 
> ...


 
Visual works very well for me. As usual an awesome job. That helps a lot. But then I've come to expect no less from you.



unterhausen said:


> Great post, thanks for the effort. Don't know how I missed this part of the forum before. I'm just getting started with my lathe and suffering from a lack of funds, but at least I'm getting a better idea of what I should buy when it makes sense.
> Eric


 
Suffering from lack of funds, I know that feeling, or I will VERY shortly. These guys do a great job. I belong to a bunch of these types of forums but these guys are the most helpful by far.

Mike


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## wquiles (Oct 7, 2009)

Mike,

Today I got the 7/8" solid carbide boring bar - it is huge!

Here it is compared to the two that I showed earlier, the 3/8" Solid Carbide from Circle, the 1/2" Solid Carbide from SECO (which you just bought from me), and the new, 7/8" no-brand solid carbide that uses CNMG 4xx inserts (note that I have not adjusted the 7/8" bar yet so it looks way tipped down!):

















My plan is to use the new 7/8" with the "D" custom 1xD's that I make, but I tried today and it "does" fit inside the "C" body as well 


EDIT: I forgot to mention that like the Circle and SECO bars, this no-brand bar also has a coolant through hole 


Will


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## bluwolf (Oct 8, 2009)

Will,

You know I'm never lacking for a stupid question. What is the knurled thing over the end of the new bar?

Mike


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## wquiles (Oct 8, 2009)

bluwolf said:


> Will,
> 
> You know I'm never lacking for a stupid question. What is the knurled thing over the end of the new bar?
> 
> Mike



My father taught me that the only stupid question was the one I did not ask ...

The knurled ring is the back of the Aloris 5C collet holder for the BXA tool post (I posted the special price in the Deals sticky on top of this forum). With the right size/type/shape collet, this 5C holder for the lathe can hold any round, square, or hex diameter bar from anywhere in the 5/64" range (3mm in metric) up to about 1 1/8" (26mm metric). With the right collet you can hold almost anything, plus you can also buy a 5C emergency collet and drill it for anything specific you might have, plus the collet can hold stock much stronger than a drill chuck could 






Will


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## Atlascycle (Oct 8, 2009)

wquiles said:


> My father taught me that the only stupid question was the one I did not ask ...
> 
> The knurled ring is the back of the Aloris 5C collet holder for the BXA tool post (I posted the special price in the Deals sticky on top of this forum). With the right size/type/shape collet, this 5C holder for the lathe can hold any round, square, or hex diameter bar from anywhere in the 5/64" range (3mm in metric) up to about 1 1/8" (26mm metric). With the right collet you can hold almost anything, plus you can also buy a 5C emergency collet and drill it for anything specific you might have, plus the collet can hold stock much stronger than a drill chuck could
> 
> ...



I'll double check with the collets that we have here but i do not think that a 5Ccollet will have a big enough through hole for any thing bigger than 1" Diameter. The working end will hold up to 1.125" but it is only an inch or so deep.

Jason


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## precisionworks (Oct 8, 2009)

> Aloris 5C collet holder for the BXA tool post


You got lucky on that one, Will ... I tried to get the same 33% off on the AXA-5C and it ran up at only 15% off ($140 after discount).

Being both stubborn & cheap, I looked around the web for a while & found that Blue Ridge Machinery has a killer closeout on Dorian, which is interchangeable with (and same quality as) Aloris ... and the price was $75 for the 5C  (The Dorian P/N is D25AXA-36)

They currently have *only* the following items remaining:

D30BXA-1 $29.95
D30BXA-10 $49.95
D30BXA-5 $39.95

http://www.blueridgemachinery.com/bargain_corner/close-out_and_discontinued_items/tool_holders.html


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## wquiles (Oct 8, 2009)

Nice find Barry :thumbsup:


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## unterhausen (Oct 8, 2009)

Which toolpost attachment is this? Is it modified? 



wquiles said:


> Will


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## wquiles (Oct 8, 2009)

unterhausen said:


> Which toolpost attachment is this? Is it modified?



It has been a while, but I think the kit (blade holder, blade and inserts) was Enco's part #SV891-6964. You then use a standard tool holder to clamp the blade holder.

One of my pending projects is still to make my own, combined tool holder and cut-off blade holder into a single piece, much like Dorian's:






I already bought the steel for it, just waiting for "time" to work on it 

Will


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## precisionworks (Oct 16, 2009)

My Dorian 5C collet holder arrived today ... but would not go low enough to bring a boring bar tip to center, so it got modified.







Notice the notch in the lower right corner of the holder. With the notch, the holder just clears the compound slide.






The holder is so hard it cannot be milled, even with carbide, so the relief notch was ground in on the surface grinder.






The sharp edges left from grinding were chamfer ground to 45 degrees to match the factory chamfers.


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## wquiles (Oct 17, 2009)

Looks awesome - nice job!


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## Atlascycle (Oct 17, 2009)

Barry, 
Mind if I ask why use a boring head in the lathe?


Jason


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## precisionworks (Oct 17, 2009)

> why use a boring head in the lathe?



I find that it's so much easier to get a fine finish in the lathe than it is in the mill. My mill does not have power down feed, where the lathe does have power feed going toward of away from the chuck. Also, the larger boring heads get really unbalanced when the bar is way off to the side for a big bore.

The head shown is the smallest one I have, an Everede TenthSet that takes a WCGT-2 trigon insert. The TenthSet heads are awesome when you need to sneak up on a critical bore dimension. The cross slide is used to rough away most of the material, and then the boring head screw is used for the last few thousandths. With this TenthSet head, each quarter turn of the screw opens the bore .0001".

Most of my larger boring heads are Kennametal Erickson TenthSet, all purchased on eBay. Like the Everede, the shanks are most often 3/4" straight, although some are 1" straight.


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## Atlascycle (Oct 17, 2009)

That looks like a nice little boring head.


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## Greebe (Nov 3, 2009)

I would caution you buying one of these lathes. Here is why.

I have one of these lathes. Overall I really like it but it does have one major problem.

Since day one it leaks oil like crazy. Every gear box that has oil leaks very bad. The headstock leaks onto the motor, the feedbox leaks onto the chip pan, and the apron leaks onto the chip pan as well.

The feedbox leaks so stinking bad that I have to top it up regularly. Then I end up with fluid all over the chip pan which then contaminates my coolant.

It kind of pi$$es me off to pay $3500 for a new machine and have it leaking like an old car with a cracked block.

I contacted Matt about this several times and all he said was that that was a common problem and that I should tear the whole thing down and replace all the seals. Right....., maybe I should get a discount for having to rebuild a brand new lathe.

Just something to consider.


Greebe


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## wquiles (Nov 3, 2009)

Greebe,

As I posted in my own thread, mine does not leak like yours, nor the other owners who have gotten the lathe in the last 10 months that I have exchange email with. 

Remember that this lathe is basically the same as the Grizzly Gunsmith lathe, and several other ones - all made in the same factory. One of our own here in the forums had the Grizzly lathe, and he found not only a crack on the main bed, but also developed really loud noises in the main gearbox, so it is always possible for any of them to be messed up and fail to be caught during the quality check (assuming they have one!). 

You are the first PM1236 owner that I have heard has this problem, but as I said, maybe yours was just not put together properly at the factory - a true lemon. Sorry to hear about your troubles.

Will


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## Greebe (Nov 3, 2009)

Yep I know what you mean. I know a guy who had a the Grizzly RF45 milling machine that the head leaked on it badly. They offered to pay shipping back to them to exchange the Milling machine and shipp him a new one for free. He didn't want to go through all that trouble so he just shipped the head back and they payed shipping both ways and sent him a new one. 

That is the kind of service I expect. Granted I do not want to crate up the machine and send it back, but some sort of an offer to make it right would be nice.

Greebe

P.S. -- Other than this issue I really like this machine!!!


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## bluwolf (Nov 4, 2009)

Greebe,

I'm sorry to hear about your issues with the 1236. But that wouldn't be enough to keep me from oredering one. It seems I've heard that all the brands have this issue on a lathe here and there from time to time.

I'm not making light of your problems and I hope you can work something out with Matt. There are at least a few people here with PM lathes and a couple of us about to have them. I'm sure we'd all like to hear that you were able to resolve this problem. I know I would like to have a warm and fuzzy feeling about service after the sale.

Mike


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## cmacclel (Nov 23, 2009)

precisionworks said:


> The holder is so hard it cannot be milled, even with carbide, so the relief notch was ground in on the surface grinder.




I milled mine  With a 3/8 Hanita Carbide Rougher.

Mac


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## precisionworks (Nov 23, 2009)

> I milled mine  With a 3/8 Hanita Carbide Rougher.


What brand holder, Mac? Dorian, Aloris, or Best of China Moon :nana:


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## cmacclel (Nov 23, 2009)

precisionworks said:


> What brand holder, Mac? Dorian, Aloris, or Best of China Moon :nana:




Dorian


https://www.candlepowerforums.com/threads/224350



Mac


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## Greebe (Dec 22, 2009)

Just wanted to follow up on My PM1236 problems. I have got the leaking under control with some help from Matt.

I wanted to say that he has been very good to deal with and that my original comment about my dissatisfaction was premature. The machine is a very nice piece of equipment and Matt has gone out of his way to help get me squared away. 

In fact I just bought another machine from him this afternoon as I have been quite impressed with how he handled all of this.

Thanks Matt 
Greebe


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## wquiles (Dec 22, 2009)

:twothumbs


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## bluwolf (Dec 23, 2009)

Greebe said:


> Just wanted to follow up on My PM1236 problems. I have got the leaking under control with some help from Matt.
> Thanks Matt
> Greebe


 
Greebe,
Happy to hear it turned out well for both of you. I'm actually expecting my PM1236 today. 

In the meantime, I had a problem with my old Jet mill and got some help from Matt. Thought you might find it interesting.

https://www.candlepowerforums.com/threads/253093

BTW, you said you ordered a new machine. What did you get?

Mike


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## alexmin (Dec 27, 2009)

precisionworks said:


> MSC/JL has a special that includes the CNMG-4xx holder plus a CNMG-4xx boring bar plus 10 inserts for $149. Figure that the 10 inserts would cost at lease $50, so you get the holder + boring bar for $100 more, which is a decent price.



So far I could find a special on CNMG-4xx holders + inserts here for around $100 but these holders have 1" shank. 
http://www1.mscdirect.com/CGI/NNPDFF?PMCTLG=04&PMPAGE=1

Should I get a holder for my QCTP that can take 1" shank or look for 5/8" shank tool holders?


Edited: I did some research and looks like there is no such thing as tool holder that takes 1" shank. The BXA size holder would be too weak if it had 1"x1" pocket. Am I right?
Since I don't have a mill I'll have to grind off most steel off the holder on my belt grinder and then finish on my surface grinder.


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## StrikerDown (Dec 27, 2009)

WQ engineering makes one 
but I hear they are really behind on production! ;-)


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## precisionworks (Dec 27, 2009)

> WQ engineering makes one



They do nice work. Just a small company in Texas, run by an Electrical Engineer turned machinist


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## gadget_lover (Dec 27, 2009)

OK, I'm missing something.

If you mill down a 1 inch shank to only 1/2 inch, don't you lose all of the advantages of the larger tool? 

I'd be more inclined to buy a tool that used the slightly smaller CNMG insert ( a CNMG-3 or even "2") with a shaft that fits the tool post.

Now if I get a terrific buy on the larger tool, that might change the story.

Daniel


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## wquiles (Dec 27, 2009)

You guys are way too kind - I am still a beguiner and mostly a hack 





gadget_lover said:


> Now if I get a terrific buy on the larger tool, that might change the story.


That is exactly the point - the 43x stuff on Ebay is super cheap: This is the same exact 43x kit that I got some time last year => CNMG 432 holder plus 10 inserts for $35 plus shipping 


And here is one that is "only" 3/4" shank - a lot closer to 5/8":
3/4" shank CNMG432 holder for $40 plus shipping


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## alexmin (Dec 27, 2009)

Will,

your second link is to generic Asian made holder.
Shouldn't I go for a brand name holder? 
Asian tools used to have problems with heat treating. I understand that it is important for a toolholder to be heat treated properly so it is not too soft or too hard and brittle.


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## darkzero (Dec 27, 2009)

alexmin said:


> So far I could find a special on CNMG-4xx holders + inserts here for around $100 but these holders have 1" shank.
> http://www1.mscdirect.com/CGI/NNPDFF?PMCTLG=04&PMPAGE=1
> 
> Should I get a holder for my QCTP that can take 1" shank or look for 5/8" shank tool holders?
> ...


 
You can get the Aloris oversized holder (P/N: BXA-1S) that accepts 3/4" shank & get this: LMT FETTE MCLNR 12-4C. It's the same coolant fed CNMG 4XX holder that Will has except with a 3/4" shank. For $50 for the whole kit that's a steal! I know nothing about that vendor though. 

Travers is the only one I know that sells the Aloris oversized holders but they cost just over $80 ea! I'm sure there are other places that carry them, Dorian & DTM also make oversized BXA holders. Never seen the Dorians listed anywhere but Mike @ PrecisionSpin (the guy on ebay who has the remaining DTM stock) has plenty of the oversized BXA holders (P/N: H75-2EA).

There's also the same holder that Will has on ebay right now but it has a 1" shank. LMT FETTE MCLNR 16-4D.

I'm trying to stay away from tooling that I have to mill so I ordered a Dorian MCLNR 10-4B which has a 5/8" shank & accepts CNMG 4XX (P/N: 50116 $50.30). Very few manufacturers make CNMG 4XX (MCLN) holders with a 5/8" shank. I have other Dorian holders & QCTP so this was my "_first choice_".

If price is a concern it would probably be best to just get the 3/4" LMT LETTE holder & mill the shank. If you don't care about the coolant feed on the holder get the Dorian. That LMT LETTE holder that Will has looks very nice though!

Will, have you used the coolant feature on it? I'm almost regretting ordering the Dorian but I know I will probably never use that feature but that's not say that I still want it.


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## darkzero (Dec 27, 2009)

wquiles said:


> That is exactly the point - the 43x stuff on Ebay is super cheap: This is the same exact 43x kit that I got some time last year => CNMG 432 holder plus 10 inserts for $35 plus shipping


 
Holy crap that is cheap (never mind my ebay link)! :twothumbs


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## unterhausen (Dec 28, 2009)

IIRC, the BXA standard boring bar holder will hold a 1" boring bar if you take the sleeve out. The bxa toolholder/boring bar holder will only hold a 1/2" boring bar. I milled one or the toolholders out to 3/4" without much pain. That wouldn't work for a boring bar though.


The MSC deal has 20 inserts, a 3/4" shank toolholder and a 1" boring bar. It's order # ER84285477If you can't get it with that order number, go to the msc web site, click on special offers, select metalworking and go to page 26.

I figure that the cheapest I can get those inserts from MSC is $5, and that makes the tools cost me $50, but we all have to pick our own rationalizations.


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## alexmin (Dec 28, 2009)

Guys,

I understand that CNMG 4XX is good for Al and steel. How is CNMG 4XX for turning stainless steel or plastic?
Do you use different inserts?


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## precisionworks (Dec 28, 2009)

> Do you use different inserts?


Almost every shape & size insert, whether for lathe or mill, can be had in a grade, profile, and coating to cut everything from butter soft to ultra hard.

Substrate refers to the type of material that is used. Some are soft & tough, others hard & brittle, with a bunch between those two extremes. If using an uncoated insert, the substrate cutting edge is the tool point.

Coatings are the primary reason that inserts today work so well, and can machine a wide variety of materials. With a coated insert, only the coating (just a few microns thick) touches the material, and the substrate supports the coated edge. There are as many coatings as stars in the sky ... OK, there are more coatings 

Even though all inserts have a primary shape (round, square, triangle, etc.), that shape is often modified for specific materials. Look closely at this first shape, pretty typical for general (medium) steel machining:







Then notice how that shape is modified with a polished rake face, high positive geometry, and sharp (no lip) corner points:







Those are both CNMG-432, but using different substrates, different coatings, and far different geometries.


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## alexmin (Dec 30, 2009)

Thanks Barry.

What do you recommend for turning small diameter(0.5" or less) stainless steel with only one end supported. (Like a cap for a fountain pen) 

Description on many CNMG type inserts says something like "... use on large diameter, well supported pieces, rigid lathe etc." It has to do with negative rake angle. Right?

I assume CNMG is not very good insert for turning thin wall 1/2" stainless tube that sticks out 2"


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## precisionworks (Dec 30, 2009)

Alex,

None of the negative inserts will do what you want - but a positive insert will do that easily. There are a zillion ANSI-ISO shapes in positive, but try to find those that are popular & readily available on eBay. The TC*M*T (molded) and the TC*G*T (ground) are two popular triangles, while the CCMT (or CCGT) are an 80 degree diamond. Lathe Inserts (Curtis) has a decent selection in CCMT & CCGT, with good pricing. EBay has dozens of listings for both the triangle & the diamond.

Both shapes generate low cutting forces, unlike a negative insert (CNMG, WNMG, etc.) Stainless is tough enough to turn when both ends are supported, but a positive insert will work as long as cuts are not really aggressive.


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## alexmin (Jan 14, 2010)

wquiles said:


> Will



What is this insert nomenclature?


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## wquiles (Jan 14, 2010)

alexmin said:


> What is this insert nomenclature?



That is my SECO Snap-Tap Internal Threading Toolholder, which uses custom threading inserts from SECO.

The toolholder part # is: SNR000625-60-16 (5/8" shank)

The Insert parts# is: 16NR AG55 CP500 (TPI range 48-8)

Will


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