turning with a 3 hp lathe advice

hpe · Apr 8, 2020

hi i have a denford cyclone with a 2.2kw (3hp) motor . i need a bit advice on technique.
i have an issue when boring
i have a part made from aluminium that has a 54mm hole in it 40mm deep.
my boring bit has a 16mm shank and needs a 20mm hole
so rightly or wrongly i first bored 10mm drill bit
then used a 20mm slot mill to drill to 20mm
then the boring bar to edge it out to 54mm

it does struggle a bit with the 20mm slot mill in the tool holder and seems a long winded way to do it.

i have seen some ceratizit ecocut tools which your can drill with then use it to bore out the diameter .

but for 40mm deep i would need 18mm cutter @2.25d length and im not sure of the hp requirement to use this tool .

any suggestions on a better technique or tool would be appreciated.
i only turn aluminium

regards

Hbjj · Apr 11, 2020

Skip the (slot mill)
And use the traditional tool for making holes...
A drill bit

Gordon Heaton · Apr 11, 2020

Drill from the start with a 1" or larger twist drill. Don't worry about center drilling or stepping up. Then bore to size with a 1" boring bar.

Limy Sami · Apr 11, 2020

Gordon Heaton said:
Drill from the start with a 1" or larger twist drill. Don't worry about center drilling or stepping up. Then bore to size with a 1" boring bar.

I doubt that lathe has the gonads to push a 1'' drill from solid

Link removed as it did not work - google that lathe and get to Denfords site where you will find the spec

gbent · Apr 11, 2020

If the machine can't push a 1" drill in aluminum with a 3 hp spindle they must be chinese shop vac horsepower. It is possible if it is a variable speed motor the OP may have to find the directions to make sure the chosen speed is in the speed range of the motor where it develops full horsepower.

Jersey John · Apr 11, 2020

Personally I find it a little strange the 3HP/2.2Kw is struggling.

What's the belt type and drive layout?

John :typing:

Limy Sami · Apr 11, 2020

Badly sharpened drill ? - or even worn to a taper, hence jamming???

Mind you, some Alu can be a surprising power hog.

GregSY · Apr 11, 2020

3HP is a lot of power.

I'm assuming you are looking to do this with a sort of 'production rate' requirement? Because if you are doing just one or two, what's the big deal? Never understood why people have such a hard time defining their need...it makes big difference to the solution.

thermite · Apr 11, 2020

GregSY said:
3HP is a lot of power.

Get real. The AB5/S is SEVEN HP and it's only a column drill. Mind - the sort of column drill for the job, too...

I'm assuming you are looking to do this with a sort of 'production rate' requirement? Because if you are doing just one or two, what's the big deal? Never understood why people have such a hard time defining their need...it makes big difference to the solution.

To be fair, he listed the most important factoid:

"I only work Aluminum"

Worked to keep ME from being the least bit interested in his silly little "problem" didn't it?

How's THAT for "efficient communications"?

johnoder · Apr 11, 2020

Gee - I wonder how they ever got ANYTHING done in the olden days - when 3 HP was just right for a 20" Hendey - about 100 years ago

thermite · Apr 11, 2020

johnoder said:
Gee - I wonder how they ever got ANYTHING done in the olden days - when 3 HP was just right for a 20" Hendey - about 100 years ago

"Patience", and high-carbon-steel tooling, John.

Skilled workman might earn a whole US Dollar. A day. Not hour.
Mind.. it WAS still a "gold" dollar until ..what? 1931?

NOW? We want to see 5 HP, 10 HP ... or better on stuff that really SUCKS... such as a common "Shop Vac", no time to use a broom...

eKretz · Apr 11, 2020

Less cutting speed too. Lots of parasitic drag just spinning a heavy spindle at high speeds.

Gordon Heaton · Apr 11, 2020

thermite said:
. . .We want to see 5 HP, 10 HP ... or better on stuff that really SUCKS... such as a common "Shop Vac". . .

Yeah, but the shop vac uses cold fusion. The only way to get that kind of HP from a typical 120V circuit.

thermite · Apr 11, 2020

Gordon Heaton said:
Yeah, but the shop vac uses cold fusion. The only way to get that kind of HP from a typical 120V circuit.

Meahh.. may pretend to RUN on "cold" fusion. Same s**t as "broken promises" ain't it?

But they hafta SELL "6.6 peak HP" on "hot" gullibility!

Those old motors, BTW? More akin to a Brabant "HP" than a Morgan.

dian · Apr 12, 2020

"ceratizit ecocut": so does someone have experience with this or similar? are they some kind of propietary viper insert? hpe, is there a price list somewhere?

thermite · Apr 12, 2020

dian said:
"ceratizit ecocut": so does someone have experience with this or similar? are they some kind of propietary viper insert? hpe, is there a price list somewhere?

Google finds 'em.

Ceratizit \ EcoCut

The ADVERTISING COPY reads well.

If they were "magical", I wudda thot' there wudda been PM members already braggin' on 'em.

Not just "wish-wondering" off an advert....

??

hpe · Apr 14, 2020

i should have explained its a mach3 conversion ex collage machine . 3hp motor is run from a vfd no gearbox . 20hz to 80hz approx 600 to 2200 rpm .i have machined some pulleys to change to 190-760 rpm but not fitted them yet .

not sure what the % of power loss is at the lower hz settings
the eco cut is just a tool you can plunge into stock with and the geometry lets you bore out the hole ,i presume other manufacturers have a similar multi function tool
i make small batches custom of stuff from home as a hobby .
im the guy at home with cnc mill and lathe in the garage

cheers

thermite · Apr 14, 2020

hpe said:
not sure what the % of power loss is at the lower hz settings

Only a major OEM has the dyno and such to "know", but a handy rule of thumb is that yah figure the need of double the HP for electronic variable speed over geared or belted.

Dee Cee no loss below "base" or nominal nameplate RPM, loses out to VFD above it.

VFD loses out to Dee Cee at low RPM, shines best above it.

So the stepless variable handiness isn't "free", either approach.

Even so, with pushing large drills, it's also the need of the "push", not just the rotation, that eats a great deal of power.

A major maker of spades, run with high-pressure coolant, advised that even my 7 HP AB5/S drillpress would run out of balls at over an inch and a half with their goods. The 7 HP Cazeneuve lathe much the same.

So I went with tooling-up with legacy MT arsed helical twist, mostly.. BUT
As most of my LARGER holes are shallow, laid-in "annular" cutters as well.

And the abilty to mount my Chandler-Duplex boring and FACING heads on the DP.

Which is what I might need for your described tasking, as I'm presuming blind hole, and FLAT bottomed as well?

To my benefit, I ain't hardly ever in anything bearing even the slightest resemblance to a "hurry"!

YMMV on that part, so tippy-toe-ing about with a Chandler-Duplex or similar boring head with facing capability is prolly not in the time budget?

Peter from Holland · Apr 14, 2020

On a typical VDF the torx stays about the same (till netfrequency that is)
Half the motorspeed is same torx so half the power
If you run full motorspeed but mecanicly change to half speed on the spindle power stays the same so torx dubbles

Peter

DennisCA · Apr 14, 2020

Maybe a rotabroach would be useful for boring larger holes? It's hollow so it leaves a plug, less material to shift, less HP required...

turning with a 3 hp lathe advice

Plastic

Cast Iron

Titanium

Diamond

Diamond

Stainless

Diamond

Diamond

Diamond

Diamond

Attachments

Diamond

Diamond; Mod Squad

Titanium

Diamond

Titanium

Diamond

Plastic

Diamond

Diamond

Hot Rolled

Similar threads