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Ok, I am looking for a way to quickly and reliably drill through mild steel, stainless, and some harder metals. I have tried solid carbide drills to no sucess, but flying shrapnel. Generally drill form 1/2"-1" from 1"to3" deep. I do not have thru spindle coolant so i'm guessing thats why i don't have luck with solid carbide. There are many insert drills available, which i'm sure would be great but they are mainly thru spindle coolant. I found one that uses a special holder which has a fitting attached to it for thru spindle coolant, but the holder is $1,700. I just did a job with 17.5mm holes thru 1-1/4" thick 304 and resorted to HSS drills, man was that boring. I sometimes use carbide endmills and helically interpolate holes, but this doesn't go to quickly in stainless and deep holes also do not work so well. Any ideas?
Yeah. Machining is what it is. Get used to it and bid accordingly. If you are a machinist, why can't you build your own drill holder with coolant adapter for way less than $1700? How do you think machinists years ago drilled stainless steel before most of the modern tool and machine technology came around?
http://www.kirkcon.com/
At the nominal (and mathematically simple) rate of $100/hr shop rate, $1700 will take... uh... 17 hours for break even.
Add in the factor of longer tool life, faster cycle times, better quality holes...
Don't know how many holes you have to do and how often, so you have to answer the question. Is $1700 really expensive?
I've used the Sandvik U-drills in Al and 304SS on both angled and irregular starting surfaces, even without thru coolant successfully. With thru coolant and good rigidity you can go blasting thru the part in unbelievable time...
This calculation implies that every cent of the $100 shop rate is profit. The correct calculation has to be based on the marginal improvement in productivity between doing a job using this tooling compared to doing it by the next best alternate method.Originally Posted by fizzissist
An open mind is a virtue...so long as all the common sense has not leaked out.
I don't know really slowly??? thats why im asking what technology is out there to do this. I didn't lose money on the job, just had the opportunity to make more. I also don't feel like making a cat 40 holder with eccentric that has ports to connect coolant to make thru spindle coolant from a regular flood, using bearings and such. I assume theres something better out there thats what i'm asking. I can't be the only guy in the world without thru spindle coolant, that needs to drill a hole faster than hss can??
Oh ya $1700 is expensive enough for the amount of holes i need to do, especially if im not 100% sure its even gonna work.
We use Iscar Tooling's Sumocham drills. Yes, they are set up for thru spindle, however, we dont use it. With the .656 drill (most commonly used), on mild steel, we push at 24 IPM at 2500rpm on our more rigid machine, (2000rpm/15ipm on the less rigid), and drill through as thick as 3", using nothing but the standard coolant setup.
Pushes our poor 10HP spindle pretty hard, but we've been doing it pretty much nonstop for a good long time with minimal problems.
Typically get 600-800 holes on 2" steel without needing an insert change.
I dont know how well these drills will do on the other materials, but for what we do, they are amazing!
You need to remember, 1700 for the adapter, then how much for a pump? Anything less than 500 psi would be pretty much a waste of time IMO. If you do lots and lots of holes, then yes it's worth it. I've seen 1000psi through spindle drills go 60-100 inches per minute or more through stainless flanges. Took a lot of the 30hp spindle to do it, but very impressive. Holes come out perfect. All they did was drill holes all day every day though.
+1
Did you even calculate the required horsepower requirements for drilling faster? Is your machine capable? It is not only a matter of RPM.
Were you using carbide drills "correctly". Carbide does not like interrupted/intermittent cutting (i.e. pecking). What feed are/were you running? 0.008-0.014" per revolution? The carbide inserted drills I have run from Iscar do not cut springy, curly chips. The chips usually come out as "chunks".
http://www.kirkcon.com/
Ya, i had the rep demo them beside me. With his sugg feed/speed. His conclusion for failure was lack of coolant. Also at $400 a pop for 17.5mm he didn't give me too many tries.
I have a 24 horse motor
Try a spade drill with a peck cycle, it's slow, but you should be able to poke it through. I'd keep the peck light, .025-.05".
I also just finished a job where I drilled 18 11/32 holes through 2.5 T1 plate. About 150 sfm and .001 per rev. Slow, but the drill coasted all the way through.(I know I could have pushed harder, with only 3 parts it really wasn't an issue)
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