attempting a faceplate

[rockmike]

Ive already hit my limitations on my rotary table on a few pieces of work so I decided to build a faceplate to make my 6"rotary an 11" rotary.Of coarse im runnin into problems.This is what ive got done and my issues.

I started with this chunk 12"x12"x1" steel cause it was free

Then I drilled a 1"center hole and some otheres to hold it on the rotary.

I centered my rotary to the quill then I centered the work on the rotary as close as the drilled hole will gwt me.

Heres the 2" hole I cut with the rotary so I can chuck this up in the lathe later to face it off,make some register cuts in it.

Now to my issues.I wanted to make this chunk round on the rotary so when I chuck it up in the lathe ill have it farely close.

But the chatter is horrid working out on the end of this piece,I fear damaging the rotary.I assume the piece is just not ridged enough sitting on paralles to be working out on the end like this.Im thinkin I hit limitations again.

So do I just chuck it up in the lathe and cut my round size into it?Plunge my tool in there to the correct diam. then pull cutter toward me with the crossslide.And just keep working it like that till il all the way through?

Thanks in advance,Mike.

[Mcgyver]

if your lathe can swing it, that's how I'd do it but you'd want to be running about 30 rpm...presumably if the lathe can swing 12+ inches it have speed of 50 rpm or less. i think I'd always go with a single point tool over an end mill if i have the choice, if nothing else for frugality. do you have a faceplate to bolt it to? if so, you're all set up

[rockmike]

I dont have a faceplate for the lathe.But I do have that 2" hole in the middle of this plate,My 3-jaw will be able to grab it from the inside.

Thanks for the advice,Ill turn it as slow as I can.I assume for doing somthing like this, best to use hss over carbide insert type?

[Mcgyver]

carbide will endure a high cutting speed but its brittleness means it dislikes a interrupted cut so i would go with hss. keep in mind the calculated rpm is sort of an ideal thing, the best balance of tool wear and removal rate....if you're turning something at a higher than ideal sfm, it will still work, it'll just really shorten the tool life. in other words, even if you don't have a 30 rpm speed, hss will still work, it just won't last long between resharpening

Plunge my tool in there to the correct diam. then pull cutter toward me with the crossslide.And just keep working it like that till il all the way through?

try it, it may product as much chatter - think of the direction of the cutting force and where support is. might be better to start on the outside and make a series of facing cuts into the right diameter, then turn the OD. The idea is to create a cutting force along the solid radial direction rather than axial which is unsupported....but its a matter of trying it.

btw, chatter can sometimes be solved just buy changing feed and speed; alter things to stop it resonating. In situations like this I've always found reducing the cutting force/beefing up the set up is more likely to work than the increasing feed/speed advise you sometimes hear to reduce chatter, but i guess its a matter of experimentation

[Rusty Marlin]

I dont have a faceplate for the lathe.But I do have that 2" hole in the middle of this plate,My 3-jaw will be able to grab it from the inside.

Thanks for the advice,Ill turn it as slow as I can.I assume for doing somthing like this, best to use hss over carbide insert type?

If its all you have.. try it, but don't be suprised if it squeals something awful. You won't have near enough ridigity. Can you make a plate that is as big as your three jaw can grab to bolt the face plate to? Again, not ideal, but better.

A face plate that you can bolt the one you are makeing to would be the best.

[rockmike]

I dont have a faceplate for the lathe or a piece to make it out of.Im going to chuck it up tonight and try turning it with the lathe and see what happens.Ill let you guys know how it goes.

I really appreciate you guys taking the time to answer my ?'s allowing me to tap into youre experiance and knowledge.
I know a few other machinist friends but its like everything is a damn secret.I ask ?'s and they just give me vage ,general answers to specific ?'s [this is why I seeked out this b.b.,so I could learn ,other than from making mistakes] I understand theres alot variables,its just frustrating trying to get any info,knowledge from them.

[Mcgyver]

well there is always filing......and i don't say that entirely in jest. that piece is way more than I'd choose to file, but its an important metal working technique often overlook.... and it will work. you've experienced what many unfamiliar with shop work don't realize; that metal is not rigid and like any other material will move when forces are applied

[rebel54]

If you have a large bull noise center you could just hold the plate against the chuck with the jaws out but below the cut. Take light cuts, it may slip some but you will be able to cut it this way. Make sure you have the tail stock locked down, its the only thing holding the plate. I done this many times when the plate is to large to turn any other way.

[Al Messer]

And to keep the back gears from sounding like they are about to be have their teeth torn out, put on a HEAVY leather glove on your Left hand and use it as a "brake" on the chuck to keep the work from speeding up between interrupted cuts.

[rockmike]

And to keep the back gears from sounding like they are about to be have their teeth torn out, put on a HEAVY leather glove on your Left hand and use it as a "brake" on the chuck to keep the work from speeding up between interrupted cuts.

Appreciate the input,but theres no way im touching any rotating parts while the machine is runnin. For now Ill treat the machine likes its a pissed off chain saw.I suck at math so I need all my fingures and toes