Lathe tooling

[[486]]

I kinda like negative rake triangular ****, got a lot of inserts for it so I buy holders for them in 33x size
I don't really like the c-shape inserts, especially in positive rake since you only get two corners instead of six
if you buy **** from aliexpress you'll figure out the metric crossovers on insert size pretty quick

if you're going with insert tooling, if you buy all the same shank size they usually have the same height in the tool post, so if you run across one of the four sided toolposts that doesn't take the quick change holders they're a good solid option
there's a whole tray of brazed carbide toolbits in the first picture sitting on the cross slide, those work well enough, and you can sharpen them with a normal bench grinder wheel, just gotta push real hard
you can sharpen your inserts too, but they usually get broken to the point where there ain't room to sharpen them without getting into the holder

dunno man, it's really one of them deals where you just gotta figure out your own way
you can always braze chunks of broken carbide onto bits of normal steel and shape them on the grinder to do what you want done, for wierder ****

I really need to start digging out all the perfectly usable inserts this place throws out and shipping them to you guys

even the broken ****'s worth keeping at 8+ bucks a pound

 

[bad zuki]

I kinda like negative rake triangular ****, got a lot of inserts for it so I buy holders for them in 33x size
I don't really like the c-shape inserts, especially in positive rake since you only get two corners instead of six
if you buy **** from aliexpress you'll figure out the metric crossovers on insert size pretty quick

Are you using negative rake tool holders or tooling itself. I just learned that that is a thing...

if you're going with insert tooling, if you buy all the same shank size they usually have the same height in the tool post, so if you run across one of the four sided toolposts that doesn't take the quick change holders they're a good solid option

Okay. I've got a 4 sided on on the Hendy and it works really good. 1 side for face, 1 for part, 1 for right hand, 1 for left.

there's a whole tray of brazed carbide toolbits in the first picture sitting on the cross slide, those work well enough, and you can sharpen them with a normal bench grinder wheel, just gotta push real hard
you can sharpen your inserts too, but they usually get broken to the point where there ain't room to sharpen them without getting into the holder

dunno man, it's really one of them deals where you just gotta figure out your own way
you can always braze chunks of broken carbide onto bits of normal steel and shape them on the grinder to do what you want done, for wierder ****

Yeah, I appreciate the board's input though. I need to get a bench grinder next.

 

[posford]

there's a whole tray of brazed carbide toolbits in the first picture sitting on the cross slide, those work well enough, and you can sharpen them with a normal bench grinder wheel, just gotta push real hard

You're not wrong, but you're not right. **** that **** all over. I'd rather hand grind HSS blanks before ****ing with old **** brazed carbide.

even the broken ****'s worth keeping at 8+ bucks a pound

Yeah thats not how that works here.

 

[[486]]

Are you using negative rake tool holders or tooling itself. I just learned that that is a thing...
Okay. I've got a 4 sided on on the Hendy and it works really good. 1 side for face, 1 for part, 1 for right hand, 1 for left.

negative rake insert holders take negative rake (square edge relief) inserts
positive rake insert holders take positive rake inserts
the relief angle is all set by the insert holder

with the negative rake inserts you can flip them over and use the other side, but in my hamfisted use I usually smash the whole corner off so I ruin two "edges" at once

Yeah thats not how that works here.

what, they get mad at people that raid the scrap bin?
I know al-ox ain't technically kosher for grinding carbide, but it works good enough that I've never bothered mounting up the one si-carb wheel that I've got hung on the pegboard
I rather like grinding carbide rather than ****ing around with hss, I feel kinda awkward getting hss glowing red on the grinder wheel where carbide doesn't seem to care much (do not quench-cool hot carbide though)

I need to get a bench grinder next.

get any 3600 rpm motor from an old frost-broken shallow well pump (because they have a threaded shaft) and stick a wheel on it
screw it to a bench with plumbers' tape if it doesn't have feet, and use a block of wood screwed to the bench as your tool rest

the chinkanese bench grinders severely lack horsepower and the good single phase baldors are always $300 even when used

 

[[486]]

oh right forgot about the tool post thing

Might could be a good idea to grab the one off the hendey before selling it, if it is reasonably sized for the new lathe.
guy you're selling it to will probably run out and buy a quick change post anyways, they're just stupid money to my mind.

 

[bad zuki]

oh right forgot about the tool post thing

Might could be a good idea to grab the one off the hendey before selling it, if it is reasonably sized for the new lathe.
guy you're selling it to will probably run out and buy a quick change post anyways, they're just stupid money to my mind.

I’m keeping the Hendy, it’s too cute to sell and I use it quite a bit for small jobs. With that said, all the bits are golden coast specials, are holding on for dear life, and most of them are chipped.

This old dog is the one being adopted by a buddy. Roughly 1890’s, with really good tolerances.

the negative rake inserts you can flip them over and use the other side, but in my hamfisted use I usually smash the whole corner off so I ruin two "edges" at once

There is a running joke that I could break Thor's hammer by setting it down. Things will be broken regardless of how easy I am on it. But good to know.

Are the single sided carbides cheaper then the double sided ones?

 

[[486]]

Are the single sided carbides cheaper then the double sided ones?

no
in fact the positive rake ones seem to sell for a bit more money secondhand since common "parrot-wisdom" has it that homeowner machines don't have enough rigidity/HP to run negative rake tooling

 

[cj3a]

I like these stuff from Aloris

Universal Tool Holder #20 CXA-20

Universal Tool Holder #20 CXA-20

www.aloris.com

And

Turning Holder for Carbide Triangular Inserts CXA-12N

 

[cj3a]

Another good one

Combination Turning & Facing Holder CXA-16

Combination Turning & Facing Holder CXA-16

www.aloris.com

 

[[486]]

while I've cut dovetails in a few of my insert holders to have a similar effect, I don't really like that since it is less useful than a tool holder in a "normal" QC block

can't extend it out for clearance shenanigans, just have the one position being fully 'necked in'

 

[bdkw1]

Positive rake is for aluminum and plastic.

 

[[486]]

and too much positive rake will pull rather than pushing, it's all a balancing act
though you can reduce your top rake by putting the **** below centerline, can't really increase it without grinding
like threading pvc pipe with chasers intended for stainless, it just grabs and digs in instead of taking a normal sized bite (example provided for m92)

Oh right, I've got a couple boxes of inserts that have a really high top rake angle formed into them, while the clearance angle is still negative rake geometry
they're not the most common, but they're out there

 

[bad zuki]

Welp, I don’t have to worry about tooling for a while. The rotophase ate the new lathes motor for breakfast. Was fun while it lasted.

Either that or it’s a fed motor and didn’t want to work on the “not a cannon” after I pulled it out of the weeds

 

[bad zuki]

Well, it’s a Christmas miracle, the sob decided to choose life. New converter ordered anyway, I’m not chancing it again!

 

[ORTitan]

You may know this already. If you use a VFD with that old motor and you turn it down to decrease speed it can really test those old windings in the motor. I have cooked an old Bridgeport motor that way.

 

[bad zuki]

I think I’m just going to run a vevor converter and hook it to an outlet so I can run anything 3 phase out of it,

 

[cj3a]

I set up a panel powered by the phase converter and ran all my 3 phase loads off of it. I bought all of my electrical parts off of eBay. I got the factory part numbers out of the grainger catalog and used that in the eBay search.

 

[bgaidan]

Welp, I don’t have to worry about tooling for a while. The rotophase ate the new lathes motor for breakfast. Was fun while it lasted.

Well, it’s a Christmas miracle, the sob decided to choose life. New converter ordered anyway, I’m not chancing it again!

What exactly were you running on the first try? A rotary? In theory, that should be better than a VFD for that old motor.

Are you sure the motor is wired for 230 and not 460? A lot of the stuff I've picked up from industrial places has been 460....except my big Monarch that was like 580v and needed a transplant.

 

[bad zuki]

What exactly were you running on the first try? A rotary? In theory, that should be better than a VFD for that old motor.

Are you sure the motor is wired for 230 and not 460? A lot of the stuff I've picked up from industrial places has been 460....except my big Monarch that was like 580v and needed a transplant.

The lathe came out of a 240v 3phase building, supposedly. And the seller is gonna verify tomorrow. The rotophase is a hodgepodge of leftovers throw together, but it throws out ~260v on the ghost phase.

It’s a 24v dc transformer setup to run an Otis elevator 120v dc generator backwards. Then flip the switch and it kicks over the line voltage and spins up.

The guy who built it passed away in January. He was saving it to make a 120v dc system for the old drill press. He always says it needed a bit of load on the high leg to help break in the motor. The lathe ran better than my ability and really can remove some metal. But turned it off to reposition the tool post and it wouldn’t turn on. I took the belt cover off to check and spun it a bit and it worked perfectly fine.

 

[Firstram]

Welp, I don’t have to worry about tooling for a while. The rotophase ate the new lathes motor for breakfast. Was fun while it lasted.

It didn’t kill your motor but, you have waaay too much stick out on that tool! You want to keep everything as short as possible.

 

[arse_sidewards]

You want to keep everything as short as possible.

No **** but sometimes you gotta make do.

 

[[486]]

another vote for "fix your RPC, chink inverters just die"
they're simple machines, and you can easily make them pushbutton start/stop with only a couple old contactors

 

[Firstram]

No **** but sometimes you gotta make do.

Lantern tool posts are incredibly versatile for reaching into a tight spot! That’s not a tight spot

 

[bad zuki]

It didn’t kill your motor but, you have waaay too much stick out on that tool! You want to keep everything as short as possible.

Noted. I need to take a few intros to lathes classes.

another vote for "fix your RPC, chink inverters just die"
they're simple machines, and you can easily make them pushbutton start/stop with only a couple old contactors

Let me get my propane torch out and heat the bearings up and maybe it will light. Took 30 minutes earlier today.

 

[[486]]

Let me get my propane torch out and heat the bearings up and maybe it will light. Took 30 minutes earlier today.

wut

your rpc is probably not a simple machine like it should be
take it apart and put it together in a way that makes sense rather than the old farmer ******ation that it probably is

 

[bgaidan]

The lathe came out of a 240v 3phase building, supposedly. And the seller is gonna verify tomorrow. The rotophase is a hodgepodge of leftovers throw together, but it throws out ~260v on the ghost phase.

It’s a 24v dc transformer setup to run an Otis elevator 120v dc generator backwards. Then flip the switch and it kicks over the line voltage and spins up.

The guy who built it passed away in January. He was saving it to make a 120v dc system for the old drill press. He always says it needed a bit of load on the high leg to help break in the motor. The lathe ran better than my ability and really can remove some metal. But turned it off to reposition the tool post and it wouldn’t turn on. I took the belt cover off to check and spun it a bit and it worked perfectly fine.

I'm not following the build there, but 260v isn't horrible if that's voltage from the wild leg to either of the other two legs. Is that with it idling or with with the lathe load on it?

 

[bad zuki]

wut

your rpc is probably not a simple machine like it should be
take it apart and put it together in a way that makes sense rather than the old farmer ******ation that it probably is

It is not a simple machine. I’d like it to be push button.

The oil bath bearings are cold, the little propane torch helps it get to an operating rpm that allows the line voltage to kick the 3 phase over. I need a higher voltage transformer to spin the dc side faster. I think.

I'm not following the build there, but 260v isn't horrible if that's voltage from the wild leg to either of the other two legs. Is that with it idling or with with the lathe load on it?

IIRC, it was with a light Bridgeport load on it, but it’s been a while since I’ve looked at it. Never had anything big enough to load it.

 

[[486]]

what the **** lol

add balance caps to flavor

turn that dynamotor into a stupid stick welder or whatever

 

[arse_sidewards]

The oil bath bearings are cold, the little propane torch helps it get to an operating rpm that allows the line voltage to kick the 3 phase over. I need a higher voltage transformer to spin the dc side faster. I think.

You need a 120v motor and a clutched pulley as your starter.

 

[[486]]

You need a 120v motor and a clutched pulley as your starter.

and flywheels
and a tesla turbine

ooh ooh ooh you know those magnet thingies you put on fuel lines to align chakras? some of them too, on all the ground wires