Z Axis Operations

[Ronno6]

Working with 3/4" 6061 Aluminum,
How much material can I routinely remove per longitudinal pass??

I need to basically turn .730" down to .4375"
How few passes should it take, using a carbide insert tool?

Thanks !

[Gippeto]

I would most likely do three passes...one hogging, one roughing and one finish. But that's with my lathe that I know.

What do you have for a lathe?

Al

[nervoustrigger]

So many variables.  You indicated the material of the workpiece and the type of cutter and the total depth of cut, then there’s also the power of the machine, rigidity of the machine, how well the part is supported, feed rate, etc.  I think the universal answer is to let the machine tell you…if the workpiece chatters or the finish quality is bad, or if the motor is bogging down, back off and take lighter cuts.

[Cody9999]

Not to mention mat'l stick out from the chuck. If your turning a long piece you may have to use a follower rest. Use a little wd40 for cutting fluid.

[Ronno6]

Lathe is a Logan 820 10" swing x 24" bed
Motor is 1/2hp.
Turning RPM 1060
Feed rate 1.91in/min.
2" of material protruding from check jaws.

[Gippeto]

Try .100" depth of cut as a hogging pass @ .006"/rev and see how it goes.

Al

[Ronno6]

I'll give that a shot.
Thanks!

[Ronno6]

Try .100" depth of cut as a hogging pass @ .006"/rev and see how it goes.

Al

Current feed is .0018" /rev.
That'll be quite an increase!

[Rob M]

.5 hp? you could likely run 3-5 hp on that machine.. the cheapest way to do it keep your eyes out for a treadmill in the garbage.. The pwm controller is in there , and the motors generally run 2 hp plus ( sometimes as high as 3.5

[Ronno6]

.5 hp? you could likely run 3-5 hp on that machine.. the cheapest way to do it keep your eyes out for a treadmill in the garbage.. The pwm controller is in there , and the motors generally run 2 hp plus ( sometimes as high as 3.5

.5hp was the motor originally furnished with the Logan 820.
It is likely that more power would just be wasted due to the limitations of the flat belt drive.
As purchased, the lathe was equipped with a 3hp motor, but it was a 3450rpm motor, 2x the speed of the original.
I replaced the motor and set up with the original 2-step pulley drive.
Working excellent so far..........

[Rob M]

ok , as long as all is running well..

[Ronno6]

.5 hp? you could likely run 3-5 hp on that machine.. the cheapest way to do it keep your eyes out for a treadmill in the garbage.. The pwm controller is in there , and the motors generally run 2 hp plus ( sometimes as high as 3.5

Depth of cut and feed rate were no problem,but finish was poor......OK for a hogging pass.
But, as length of the pass is only .25", I leave it on the .0018"/rev setting....takes less time than changinbg
the gears, even with a quick change box.

Much quicker then the sneaking up on it .030" per pass I had been using....

[Gippeto]

The only pass that needs to be pretty is the final one.

My .02 ...roughing is CALLED roughing for a reason...just as "finish pass" seems to me to be self explanatory as well.

My roughing passes look horrible...feed rate cranked up and it almost looks like REAL crappy threads lol.

Al