How big can I Drill safely on a Lynx2100LB?

[SND]

How big of an insert drill in 316 Stainless can I get away with in this Doosan Lynx2100LB(8" chuck) what do you guys run in similar size machines?
PDF says 2.5" at about .0052 feed in what looks to be some sort of steel. I'd like to stay in the happy range where I won't greatly overload it or break something, other than hopefully break a chip... I assume I'll run out of Z trust before HP anyway. Can I go up to 2.25" or should I just get a 2"? hole finishes a bit above 2.5" 4.5" deep through holes, 145psi coolant I'll bore the rest. I'll mainly look at sandvik 880's and Iscar DR drills. Not much else available in my area.

thanks

 

[DouglasJRizzo]

I used to work for Doosan. For a Lynx 2100 LB I'd stay at 2" max. The machine can handle slightly more, BUT - you'll be nearing the max limits of Z axis thrust and spindle torque. We ran these tests in the showroom at Pine Brook when I worked there. If it were my machine, I'd keep it to 2" max and then rough/finish bore the rest.

 

[DDoug]

How big of an insert drill in 316 Stainless can I get away with in this Doosan Lynx2100LB(8" chuck) what do you guys run in similar size machines?
PDF says 2.5" at about .0052 feed in what looks to be some sort of steel. I'd like to stay in the happy range where I won't greatly overload it or break something, other than hopefully break a chip... I assume I'll run out of Z trust before HP anyway. Can I go up to 2.25" or should I just get a 2"? hole finishes a bit above 2.5" 4.5" deep through holes, 145psi coolant I'll bore the rest. I'll mainly look at sandvik 880's and Iscar DR drills. Not much else available in my area.

thanks

My concern would be with not having enough thrust to properly pull a chip, stainless might work harden.

 

[SND]

Z trust will surely be the first problem. I'm at 48% pushing a 15/16" 880 at 1300rpm in duplex, .0032" feed, spindle 24%.
Sandvik's got a 50% off on 880 and DS drill bodies and milling cutters for september so I'll probably try something maybe just 1.75".
Right now I poke a 2.38" through but on a manual lathe so its kinda slow but torque is no issue

 

[cnctoolcat]

1.5" diameter is the largest insert drill I have in the shop.

Even on my larger QT28 Mazaks, I just drill 1.5", then go at with a 1" or 1-1/4" boring bar.

A bit longer on cycle sometimes, but easy on the machine and easy on me.

ToolCat Greg

 

[DouglasJRizzo]

1.5" diameter is the largest insert drill I have in the shop.

Even on my larger QT28 Mazaks, I just drill 1.5", then go at with a 1" or 1-1/4" boring bar.

A bit longer on cycle sometimes, but easy on the machine and easy on me.

ToolCat Greg

Same here. My Okuma and Mori can both handle 2" but I really don't like using it, so I do the same, a 1.5" and then a boring cycle.

 

[upthebikes]

Since you’ll be buying new, might as well get an insert drill w/ geo that lets you bore using the same tool (most do, but some do not). I used to do this in 316, 1.25” sumitomo sumidrill for a 2.60 hole and it worked great.

 

[Mtndew]

I'd say that it depends on what drill you use and how much tool pressure it takes to drive it.

The Magic Drills from Kyocera are some of the best indexable drills I've ever seen. They are usually super quiet too.

 

[SND]

I'm just finally getting back to this project and still debating getting a 2" 880, or a Korloy 1.5" at 1/3rd the price.
I did get a 1-5/16 5xd DS20 for a different job, going 6.2" deep and I think Spindle was about 38% and Z around 60% ish in 316, only around 1150rpm and .0035 feed though but cut good.
We don't have much to choose from up here. I couldn't find any reps for Walter anymore, there used to be one but I think they might have pulled out, nothing for Seco, Kyocera or the others, if they got someone they're damn well hidden and clearly don't have a website...

 

[mmurray70]

Last shop I worked at used to run occasional 316 and duplex. I remember the guys running a 2" drill at like 0.002 IPR. Chips would not break but they did come out of hole and it worked fine. Still might be able to use it even if you dont have thrust to use it properly.

If your only going 4.5" deep it shouldnt be too much trouble to bore some of it.

 

[Panza]

A little OT but: At EMO Hannver in 2017 they ran an 80mm insert drill in an NLX2500. The feed was surely not 50thou, but it was breaking the chips.

 

[SND]

I ended up getting the 2" 880 earlier this year, been running it at 900rpm and .0035" feed in 316, runs awesome.
I had some issues with chipping the center insert at first until I realized that the drill was a few thou high, tightened the screws differently in the holder and she quiet right down and Z trust went down.