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Is this Robodrill really 20,000 RPM ? (link to eBay ad)

Perry Harrington said:
IIRC, the top speed is 24k for the high speed spindle. I know 10k is standard. I'd say 20k is a "I don't know what I'm talking about" speed.
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But was 24k available on Robodrills way back in 2004 ?? And didn't that need a separate chiller ?

As an aside, I don't know about you guys, but high speed spindles on a used CNC machine actually lowers the value some to me. My thought is that if previous owner actually ran it at the very high speeds often, that there is much higher likelihood of the spindle bearings crapping out soon after I take ownership of the machine...even with a chiller. Do you guys have the same thoughts in that regard ?
 
for most shops squeezing out every last ounce of cycletime with that kind of rpm is silly while losing the low end torque, not to mention life. IMHO of course.

side note; who in thier right mind would pay anywhere near that price for such a limited, specialized POS?

there is a nice mori for sale in NY with a 20k spindle for same price. I'm still not interested.


I had a choice between requisitioning and 18k rpm mazak with 40HP on a 40taper or a mori with 14k 25 HP for less money. I choose the mori. I have no use for 40HP on a 400mm pallet machine.
 
mkd said:
for most shops squeezing out every last ounce of cycletime with that kind of rpm is silly while losing the low end torque, not to mention life. IMHO of course.

side note; who in thier right mind would pay anywhere near that price for such a limited, specialized POS?

there is a nice mori for sale in NY with a 20k spindle for same price. I'm still not interested.


I had a choice between requisitioning and 18k rpm mazak with 40HP on a 40taper or a mori with 14k 25 HP for less money. I choose the mori. I have no use for 40HP on a 400mm pallet machine.
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I ran into that spec on a quote once myself. I wondered if that is really 40hp and if it is why..:confused:
Gary
 
Perry Harrington said:
IIRC, the top speed is 24k for the high speed spindle. I know 10k is standard. I'd say 20k is a "I don't know what I'm talking about" speed.
Click to expand...
I'm not concerned with "is"....I am concerned with "was"..... 12 years ago.

Occured to me to visit Methods web site in 2004 via archive.org. Couldn't get 2004 to come up, but did bring up Feb 2005......and sure enough 20,000 rpm was an option back then. Interesting the horsepower is the opposite of what one would expect however.....7.5 hp 10K rpm and 5 hp 20K rpm

The brochure raises a new question as it implies the Big Plus spindle was standard by that time.....or does the description really just mean that if you ordered the BP spindle it was available in those two rpm's ?

https://web.archive.org/web/2005052...achine.com/images/products/fanuc/DModelAD.pdf
 
,Further research on Archive.org reveals the Robodrill E models with Fanuc 31i controls were first advertised about Jan 2006. Still 20,000 rpm max but by aprox mid 2006 the 24,000 spindle option was introduced.

Kinda neat that via the Internet archive site one can pinpoint the new models and/or new features down to the month they were first advertised.
 
Philabuster said:
Yes, that is a real spec from Mazak. It takes a lot of power to keep a large spindle turning at that RPM and still take a healthy cut.
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I figured it was a c0ck measuring contest initiated by the marketing dept.
30 hp on a 50 taper is decent; not at all overwhelming, but decent. And I've seen some 100 hp Cincinnati's regularly run to 80% in production aluminum.

i also appreciate the rpm/torque/hp curves that dictate you can transmit more power at higher rpm while keeping torque constant, in the same system.

i found i could barley keep the 25hp loaded with all the high speed g05 control wizardry.
and who would would ever try a 18k rpm 40hp cut with a 40taper??????????? doesn't sound too smart to me,IMHO.
 
mkd said:
and who would would ever try a 18k rpm 40hp cut with a 40taper??????????? doesn't sound too smart to me,IMHO.
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Easy to do with a 2" in aluminum....

I was running a job a couple years ago in my Mori Nh5000 (blocks were 4x6x22) and I had the spindle at 100% with spikes to 150% all day long. Could have used some more power :)
 
I just HAAD to ask that question...:D

yeah, but were you running 18k, maxed out? (thought mori's max out 14k typically) I just can't see myself hammering a new $300k 40taper mill like that.
on the other hand, that's WHY they build em like that and why a business would invest in such a new machine. I'd just go 50 taper for that. 2cents:scratchchin:
 
Higher horsepower spindles also have higher torque, which is needed for fast accel/decel - especially during tool changes - which is an important factor in machine speed.


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