Brake disc machining on a 100 year old bench lathe

[@eskeskeskeres]

When knife is in a touch, you should never stop rotation!!

[@geirkleven3936]

The round insert has to much surface area for a brakedisk job, you need something more poity and hopfully sharper than te bangood stuff

[@Rolingmetal]

I'll try the wnmg toolbit that I also got from Banggood.That has 6 rather dull looking pointy bits. It should have less surface area but that will mean that I'll have to advance the cross slide even slower.

[@strib72]

@@Rolingmetal: I don't think so. You'll have less material to remove per revolution. Then you can try to use same speed than the round insert.

[@DolezalPetr]

@@Rolingmetal and for this slow speed use hss, very sharp point on it

[@mikekrening7327]

That round insert is going to take more power and pressure to work properly. For your lathe try something with more of pointed cutter. That will concentrate your power to a smaller point and should cut better and have less deflection. Have fun!

[@Rolingmetal]

I've also bough a toolbit that takes wnmg inserts. They have a sharper point and some negative rake that might not dig in as much as these round inserts seemed to do. I'll see if I can have some fun with that.

[@tectalabyss]

Hi RM. I don't think I have ever seen a round cutter doing Brake work. Only the triangle type. I wouldn't worry about the finish, just the high and low spots/out of round condition caused by heat. To smooth a finish will cause glazing before the pad and rotor wear in together. Has always Liked,Shared and added to Playlists. All my best. Bobby

[@Rolingmetal]

Thanks for the tips. Bobby.

[@frenchriversprings]

When you said I feel defeated I laugh so hard non stop for 5 minutes. Mind you I did take some cannabis 😂

[@DimaProk]

My first time ever seeing metal lathe cutting was when my uncle was turning rotor discs on his mini lathe. I was amazed that you can cut the metal like that and when I look back I'm amazed that he did this on his cheap Harbor Freight 7 x 10 mini lathe! and I guess it worked since I didn't have problem with brakes after that.

[@lv_woodturner3899]

You are brave to try machining brake rotors. Very messy. Good idea to run the shop vac as you machine. Sad about the motor and VFD issues. The carbide edge does not last long. I do not know if cast iron work hardens, but it may be inconsistent density, or hardness from the casting and cooling. Hard inclusions happen. The rust is really touch on the tooling. Perhaps consider grinding off the rust before you machine. Dave.

[@rogerhutchings5811]

Brake discs need a hefty first cut to get under the rust as it will screw the insert up

[@mikekrening7327]

Rolling, don't set your register on a wear surface. Use the center hub to indicate from. I'm referring to the beginning of your video. Have fun!

[@Rolingmetal]

That's hard to do with the chuck jaws in the way and the back of the wheel flange all rusted up. The brakes were not vibrating when braking so they should be reasonable parallel with the wheel flange. I think.

[@Thelemorf]

Exactly, this is what you have to do. Easiest is to have a hub that you mount in the chuck and bolt the disc on that instead of clamping on to the brake disc

[@crazyfeller5704]

Cutting rotors is something I know quite a bit about, but on a dedicated rotor lathe. Literally cut thousands of them for 15 years in my youth. Lathes such as yours, new territory. Couple things about a dedicated rotor lathe. Worn out or new, you will get the same chatter you are experiencing without vibration dampening on the rotor itself. I don’t think the power of your lathe or motor vibration is the biggest issue. Dedicated lathes not much more powerful or ridged. As one of you viewers commented, tie some rubber(overlap about six pieces of inner tube around the cooling fins). The actual straps used are natural rubber about 8 x 10 mm with lead weights attached to them to dampen the vibration. Hopefully this gives you an idea on the amount of rubber to wrap it with. You need something pliable and not rigid. Another thing, dedicated lathes clamp the hub surface on both sides. A poor connection would result in chatter. Not sure if you have a through spindle on your lathe, but a flat, thick, round piece of metal could be used like a draw bar to help secure the rotor to the face of the chuck and prevent the hub from flexing. This should help. If either or both suggestions work, when you flip the rotor to cut the other side, make sure it is spot on. Even the slightest run out will make your brake pedal shake horribly. Learned this the hard way on my own. You can cut a router out of concentricity quite a bit as long as both sides are the same. Cut one side true and not the other and you will know it when you hit the brake pedal. The harmonics are mostly caused by the cutting pressure on the face of the rotor. It begins to flex on the mounting surface(hub)and your bit will dig into the surface. Your power probably won’t be an issue if you can remove the flex and vibration. Essentially you are cutting more material and stalling the lathe when the harmonics/flexing starts. The lathe I used had a very high degree of negative rake and used carbide tooling as well. The cast iron, rust ets would really dull them quickly, but nothing faster than chatter. On the finish of the rotor, some are just pourous and never look good, but will perform fine. Just make sure they are flat on both sides- that is the biggest concern. Good luck!

[@bustednuckles2]

Pay attention to what DM said. I have turned a few thousand rotors in my day also. A couple more things to keep in mind, cast iron can be a bitch to turn anyways but after several thousand heat cycles it does get hard spots in it. if you see any blue spots then throw them away. The surface finish really isn't that critical, being flat and parallel is. If you think about it, you are installing them in a lathe when you put them on the car. The brake pads will polish the surface and "take a set" no matter how bad it looks. You want a sort of semi rough finish anyway. Highly polished rotors won't have enough grab and will increase your stopping distance very greatly. I have actually seen ceramic brake pads polish a set of rotors to a mirror finish and no amount of standing on the brake pedal would stop the car!

[@Rolingmetal]

Thanks for that extensive comment. You gave me inspiration to try again :) I didn't know about that disc brake harmonics issue so I'm definitely going to experiment with some straps. there's no hole through my spindle but I will setup the tail stock maybe that helps. I will try a different pointy bit with some positive rake. But negative rake won't dig in as fast so there is something to be said for that.

[@user-fd4qx2yg9r]

Ерунду научную несёшь

[@emilgabor88]

I Have turned a couples of beak disc . First you need to feed faster . If the disc is hardened you need ceramic insert, But I almost al times i use carbide. I just pressure turn them ( on a large tube, and a bull nose live center) . I have tried to flip the disc but even if you indicat it in sometimes won't work. Basically you Need to machine them in one setup . I have a 560mm swing lathe so I have room.

[@ToreDL87]

I don't mean to be a keyboard machinist, but I guess I will be one today, sorry. Disclaimer: I have nothing against you using a lathe that needs new bearings,worn lathes are in operation every day around the world, and keeps vital industries going. I quite liked the video, and I like how you did your best with what you have, you correctly identified chatter (some can't even do that), I'm subbed and hope that goes at least some way in showing my support, despite what I'm about to say :) That said and out of the way, three things, #1: I haven't touched a lathe a whole lot since attending 3 years of machining school, but have recently bought a 100 year old one and will pick it up soon. That said, the 3 year experience I have on lathe's, was on the most worn out rattling and shaking TOS in probably 30 schools combined. It made the same exact noises as this one, and couldnt get mirror finish even on chrome steel with high nickel content! I was able to get it working well, by setting the cutting tool up with DEAD-ON tool post height setting, with a definitive rake angle. All of a sudden I was getting constant measurements throughout the whole length/width of the workpiece, with just as good surface finish as the others were getting on fancy new Japanese machines. No more sand paper to get that mirror finish. Even the teachers went "wtf". My theory? This configuration puts a sort of pre-load on the worn bearings for the chuck axle, when its spinning, because the cutting tool touches the workpiece with a positive rake angle! And there are ways to do that with round inserts too, sod what the others are saying about "typical banggood quality", work the problem! You can grind the insert with a stone to get a positive rake in it, and then shim the outer end to get some rake on the top side of it as well! If you wanna use the other side to get the full 720 degrees = Flip it, and grind it opposite of what you did before :) #2 3:30 NEVER stop the lathe with cutting tool touching the workpiece just to talk to someone! EVEN if the whole thing is chattering! Chances are you wont get it running again when you start it back up, and that will do more damage than if you just back it up the opposite way of where you were cutting. And then you'll have to disengage cutting tool from workpiece, not a big problem on fancy new Japanese lathes, but with old worn out lathes like yours it's an issue because you wont get the exact same cut even if you memorize dial settings, because the preload the bearings come under is gonna be different, trust me! #3: Use angle grinder with brush disc, get the worst rust off those brake discs before you start machining. The rust, as you correctly theorized, definitely make a number on the cutting tool, because there are high carbon deposits in the rust, brittle, but hard enough to damage the tool steel even at 10rpm, much less 100-200. And also, getting rid of those rust flakes should get you some more balance to go on as well. #4: I'm not a safety nerd or anything (but not planning on dying either of course), but see if you can add a brake to the lathe and an emergency stop, that way you dont have to reach for that elusive stop button that almost always sits too far away in an emergency, and you don't have to wait for the chuck to wind down, and will even reduce wear on cutting tool if you ABSOLUTELY have to stop the lathe with cutting tool still touching the workpiece :)

[@Rolingmetal]

Wow, you really took your time on this one :) No problem, I like getting good feedback. It's the most important reason I started this channel. Learn by doing, instead of watching Abom :)

[@PSUQDPICHQIEIWC]

If you're in a pinch and you need to debark a chunk of nasty cast iron without trashing your tool bits on hard scale or chilled parts of the surface, you might consider chucking it in the lathe and running over it with a grinder or flap disk before taking a proper tool bit to it. It'll make a giant mess, but it helps -- just cover the ways, etc. A slightly rough finish is just fine for a rotor. Small skips and chatter marks won't be an issue. Those defects are tiny compared to the contact area of the pad. The rust print left on the rotor after leaving the car parked for a couple weeks in the winter is going to be more likely to evolve into an uneven wear pattern than small scratch marks.

[@Rolingmetal]

Long time ago I actually fixed up a pair of rust old rotors with an angle grinder and a flapper disk, they lasted long enough for the car to die of other causes :)

[@andrewwilson8317]

When skimming up discs I take a good cut that gets under the surface skin in a single cut with a pointed tool. The pointed tool puts less pressure on the lathe a job and this cuts chatter. Take a deeper cut at a slower cross feed rate. My lathe is from 1933 and is capable as a newer lathe, its better made!

[@Rolingmetal]

Mine is a few years old and was probably never made for such a job. Actually disc brakes probably wern't invented yet back then.

[@zachariasvan3965]

For the fixation of the motor bearings you should use loctite cylindric glue.

[@gh778jk]

Tip on the motor : You can easily run these motors on 80 Hz without damaging them. If you would enlarge the motor pulley to the same extent, you base RPM would be the same (spindle RPM) The advantage is, that you don't have to go so low, in order to achieve lower spindle speeds. Paddy

[@Rolingmetal]

I know, I used to set the upper limit to 100 Hz but now its 80 Hz. But if I get a 6 pole motor I probably have to raise it again. and maybe also move to a smaller pulley groove on the lathe. And a slightly bigger on the motor so I won't slip so easy.

[@freethought2296]

Rotors are usually turned simultaneously on both sides thus reducing harmonic chatter as well as keeping both sides parallel.

[@Rolingmetal]

Mmm, maybe I can make a tool for that.

[@fuzzy1dk]

kzbin.info/www/bejne/i329lKt7YrdjjKs

[@johnfry9010]

Those inserts are probably not rated for cast iron , just had a simalar problem turning a lathe chuck back plate , once I switched to a brazed carbide cutter with a rating of C2 it cut nicely .

[@Rolingmetal]

i read somewhere that cast iron can contain hardened particles that will eat up the insert.

[@amateurdesubaru]

rust is an abrasive I am confirrming to you , never begin a cut or clean pass with the rust , start from fresh meat underneath then go towards the rust

[@Rolingmetal]

I should have taken it of with the angle grider.

[@andrewwilson8317]

You need to clock the disc on its mounting flange,that's the reference face for the disc.

[@Rolingmetal]

too rusty on the inside.

[@matter9]

Don’t know if it’s bad for a vfd, doubt it, but whenever I shut off the power and do some work on the electrics, or even just shutting down for the night, I start the vfd with the mains supply off. With or without an in-line switch the caps drain in a couple of seconds

[@therealspixycat]

The 220 volt account goes via a rectifier to a large capacitor that is used to drive the 3 phases. During the first say 10 seconds a resistor is in series with the capacitor to limit the loading current. Normally a switched power supply is also feed by that same capacitor to drive the vfd logic. So it doesn't matter how or were you power on or of the main supply. Hope this explains it a bit

[@leonadeau2849]

you might try a positive angle triangle insert and a heavy rubber band around the rotor to absorb some vibration

[@kurokami5964]

very late but to cut with a round insert, you need a great feed rate and have a good bite in the material, which cannot be done on that lathe should have used a much more pointy tool the more pointy the tool, the sharper it is and the shallower the cut can be done and for very shallow cuts, aluminum inserts can be used but need to slow down the spindle greatly to avoid burning it you need to take like a minimum of 1mm with such round inserts, and the recommanded speed and feed with a normal amount of material to take(2mm) would need 6 horse power and 610ft-lb torque

[@gregsmith2262]

You don't want a mirror finish on brake disc anyway, as long as it it true. I wouldn't indicate on the disc surface.

[@Rolingmetal]

But it should feel less wavy than old rotors :)

[@wktodd]

You are not going to get enough torque , from a vfd at that speed . You need to get some extra speed reduction from a counter shaft or similar, so that the motor can run closer to 50hz. The real problem you'll have with the brake discs is getting the faces parallel . It is not unusual to cut both faces at the same time with a double edged tool.

[@Rolingmetal]

a counter shaft would be ideal but 99 precent of the time I don't need the slow speeds

[@swanvalleymachineshop]

Brake discs & drums are always a hit & miss affair depending on how many hard spots they have . A hard grade carbide & a big fat rubber ''O' ring like the ones used in concrete stormwater pipes around the outside helps , Cheers .

[@RaysGarage]

Enjoyed the video, My favorite insert is the WNMG-432 try it if you have one and your results might improve but maybe not, I'm no expert just know what works for me. Good luck in the Tool Makers Contest, I'm already doing both American Rotary's contests so I'll sit this one out.

[@Rolingmetal]

Funny, I'm using a WNMG inset o my second attempt to machine a rotor. Worked like a charm :) To bad you don't have time to enter 2 competitions :)

[@therealspixycat]

You need a certain cut depth otherwise you push the material making it much harder. The Rough even cut is may be the best you can achieve. Plus make sure you run the belt on the largest pully disk so that you can run the vfd on the highest frequency

[@Rolingmetal]

Lost of spring passes needed before it stopped cutting material. Made me think the setup or lathe just wasn't rigid enough. I'tt try again with the tailstock in place

[@therealspixycat]

@@Rolingmetal check this kzbin.info/www/bejne/b5LFgpmlmNWkmZI

[@mikekrening7327]

Get the rust off with a flap disc turn your rotor the other way around. Then then indicate the factory surface in. Once you've turned that side and have it concentric to the factory hub. You can flip over and indicate off of the face of the rotor like you did and have a true up face to work from. Don't know if that makes sense... Good luck!

[@DolezalPetr]

you need to support it with tailstock

[@bernardstoddart2532]

Remember a disc can warp so always use your mounting face as a reference and slow down your speed and Save your tools

[@grahameblankley3813]

At about 6-40 the centre pops, another way get a aluminium beer can (Guinness is best) cut top & bottom off can & cut a strip off can, makes excellent shim for any thing loose, my Morris minor car exhaust to manifold leaked wrapped 2 times round joint clamp fitted sealed , hope you or somebody find this useful, from U k.

[@Rolingmetal]

You're comment made me think about the exhaust of my first car. I fixed that with a tin can :)

[@tobiasgertz7800]

"I'd prefer not to screw that up. " Awesome.

[@wktodd]

Brake and clutch discs always harden (cast iron will harden rapidly if heated) . Usually, the hardness is only a fraction of a mm thick so taking a deep initial cut will get the tool under the hardened layer.

[@Rolingmetal]

I used to have a track day car. I've seen some blue disks and glazed pads in my time. A piece of sand paper on a flat surface would do the trick most of the time :)

[@lods7185]

I think You need a Ventilated Brake Rotor Silencer Band. It really helps with the chatter.

[@DavoShed]

I can’t tell exactly from your video but you mention the tool is flat and therefore has no positive rake. If you look closely at the edge of the insert it probably has a small lip all around this lip is the rake angle. A quick look in an old book I have says with a carbide tool the cutting speed for cast iron can be from 200 to 400 feet per minute depending on how long you want the tool to last. So 200 feet per minute at 10” diameter (just a guess as you don’t mention the diameter) = 75 rpm so you need to go slow. If the finish gets better as you move towards the centre where the surface speed is slower then you probably need to use a slower rpm. I’d be surprised if the motor vibration can travel very well along the V belt. I think it comes down to rpm and rigidity. Make the tool overhang as short as you can. Make sure you lock the longitudinal travel. Adjust you cross slide gib as much as you can that still allows smooth movement. That just leaves the head stock bearing. I don’t recall how that works on your lathe. Does it also have adjustment and or end play adjustment? Don’t give up it’s just a test piece. You have nothing to loose and everything to gain if you figure it out.

[@Rolingmetal]

It's totally flat on top no raised edge. I was expecting it to be dished out a bit for some positive rake. But apparently positive rake for carbide is not needed but I sure helps with an underpowered lathe like mine. Anyway I've ordered a box of different looking inserts to do some more tests. I did mention the max diameter. 25.5cm so that's 10 inches. I used this online calculator for the rpm. littlemachineshop.com/reference/cuttingspeeds.php (410 fpm at 10inches = 157rpm. I'm not giving up but I would like to get that vibration problem sorted.

[@DavoShed]

Rolingmetal That is interesting about the rake. That insert might be for a specific material (like cast iron or brass) I think saying carbide doesn’t need positive rake is to simplistic. I have an old booklet with lots of tips and tricks on using carbide tools, both inserts and braised. I’ll scan it for you if you’d like a copy? I’d be trying half that speed if you can. I understand you loose power at slower speeds with your VFD. That’s why old lathes have back gears to deal with low speeds. Carbide tips don’t like very light cuts. Rubbing takes the coating off. I’d be surprised if your motor is causing the vibration. It would be a shame if you spent a lot of effort on that approach if it didn’t help. I’m keen to see what happens. I might go buy an old brake rotor from the wreckers 😀

[@beachcomberbob3496]

Look out for a 'resilient mount' motor (rubber rings mounted on the ends to a separate foot/frame). They are best for a lathe, as they don't transfer vibration to the spindle.

[@Rolingmetal]

Washing-machine rubbers we call them. I actually though about those. I might still try them. How's the money pit coming along?

[@beachcomberbob3496]

@@Rolingmetal I will have a video in the series about the resilient mount motor I've just bought for the Myford. At the moment I'm waiting on shim stock so I can get the apron functioning properly, and I've just had to shell out on the correct main leadscrew - so yes, more money spent, but getting there.

[@TomChame]

Interesting, the vented rotor will make its own harmonic vibrations that you can chase forever and never eliminate. The round inset isn't helping either.

[@Rolingmetal]

thanks, that's something new I learned today :)

[@johndunbar2393]

Another thing to try, is to put something rubber around the outside diameter of the rotor to dampen any vibration. That's probably why the chatter is towards the outside, but goes away as it gets to the center of the rotor, because it's more rigid in the center.

[@Rolingmetal]

I'll try that. together with the tail stock. maybe it works. bicycle inner tube ok?

[@johndunbar2393]

@@Rolingmetal That might work if it's wrapped enough times and tight enough. Another thing would be like a leather belt or something. Or even like a rubber bungee strap with the S hooks at the end. Basically anything that you can tighten down around the circumference of the rotor, but you have to make sure it's tight enough to dampen it completely. Think of like ringing a bell and barely touching it, then think of ringing a bell and grabbing it with your hand. The tighter you can wrap something, the less chance there is of vibration.

[@Rolingmetal]

I like that ringing the bell explanation. I makes sense. I'm going to play in the barn for a while hopefully I'll have a bit more success

[@zbradbell]

The outside is also moving fastest (linear speed) -- I think that will affect chatter

[@timerickson2141]

Get a silencer used for rotors even a bungycord wrapped around the outside radius of the roter will help

[@Rolingmetal]

I will definitely experiment with that. Thanks

[@MrLukealbanese]

Try some Loctite bearing fit glue for the end caps. Loctite 243 should be OK.

[@Rolingmetal]

I though maybe I can fill the bearing seat with some JB weld and the re-machine it to fit the bearing.

[@MrLukealbanese]

@@Rolingmetal hmmmm. Maybe.

[@rossouwdekock9526]

Usually the machines that cut disks cut the disk from both sides to prevent the disk from buckling under the pressure

[@Rolingmetal]

I know, it also keeps things nice and parallel

[@marioruzman4503]

Hi to all , when you trying to resurface brake disc you need to do folowing, 1. All surfaces must be done before you anscrew disc from chuck, that means those two surfaces for breaking and that surface what goes on the shaft of the weel , that way when you breaking, you wont feal that disc is uneven 2. rotation must not be under 100 rpm and feed must be as less as posible ,like 0.05 mm per revolution, and 3. knife for cuttin must be grade K10 for manual sharpening with small radius on the point like 1mm without chip breaking radius , just flat , did like thousends at my home with semi profesional lathe :-)

[@doubleclutch9078]

Way warped, you could do a 70's trip tour on that rotor. To me it looks like a crack in the steel.

[@bookerol]

The most important surface to dial in is the inside mounting surface, that contacts the wheel hub. If the rotor isn't running true to that surface, you will have nothing but trouble down the road. Also, if your wheel hubs aren't running true, your rotor never will be either... the reason on-car lathes came about. You don't really feel rotor warp, but feel the disc thickness variation, that comes from the uneven thickness wear. Usually brake pulsation starts at around a half thousanths (inch) thickness variation. If your rotor surfaces aren't exactly parallel, you will already be past that. Even on dedicated brake lathes, setup can sometimes be troublesome. Most like the rubber band/lead weight dampening straps, but I prefer this type: www.ebay.com/itm/SB9800-AMMCO-Spring-Silencer-Bands-4-Pieces-Brake-Lathe-Rotor-Vented-Assembly/142806199604 Here in the states, it almost isn't economically feasible to turn rotors anymore. The Chinese manufactured rotors are so inexpensive now days. I guess that doesn't equate to good, but people want cheap! Still, on older vintage vehicles, we may have no choice about having new rotors. Fun project, but dialing in that rotor is so important.

[@gh778jk]

I would use HSS rather than carbide, or at least a tool that has a smaller cutting surface. Banggood (or similar) inserts aren't the best choice for a part that needs to be good! Also, as other have said.... think about the surface you indicate from... Cheers Paddy

[@Rolingmetal]

Lathe can't go slow enough for HSS.

[@johnstrange6799]

Good experimentation. How is the newest lathe coming along??

[@Rolingmetal]

I might have learnt a thing or two, who knows. Nothing done with the pdf lathe so far. I might make it someone else his problem.

[@EnglishTurbines]

The overhang distance from rotor surface to the spindle bearing is huge, way too much...I would suggest also that vibration of the motor will be isolated to some degree by the belt drive...That chinese round tip is probably made from cheese and a more conventional pointed tip will work better anyway. Cast iron rotors can get chilled too quick during casting, resulting in hard spots. This is why they are ground, not turned. Fun watching though..

[@Rolingmetal]

The fact the spindle is less then a inch tick probably also doesn't help. But you use what you got got :) The round nose tool wasn't a good idea. No positive rake and too much tool pressure. And the anti wear additives in the rotor really mess up the cutting edge. It was educational, for me, but kinda a failure in the end.

[@EnglishTurbines]

@@Rolingmetal Agreed, we all learn from our experiences usually, engineering in particular.

[@glennmoreland6457]

Check the headstock bearings on that lathe... Plus the main slide & cross slide...

[@Rolingmetal]

The are not perfect , but there isn't much play. But they are suspicious :) If I could have the spindle journals reground I could turn new bearing surfaces from bronze. It's no steel on steel but the bearings in the headstock look removable.

[@bryanbridges2519]

Your lathe will probably handle the job, but the tool has too much contact surface. I have a 5000# lathe that would chatter with that tool in that application. Your not defeated yet, you have just discovered another way that doesnt work. I always enjoy your videos.

[@Rolingmetal]

I like that, another way that doesn't work :) I do have some ccmt inserts with a rather large radius. I think I'll try those.

[@demlotcrew]

Its that insert, you need a more positive rake for that lathe.

[@Rolingmetal]

Zero rake on that insert, some positive rake would help with this low power machine.

[@metalworksmachineshop]

I use a CNMG at 400 RPM. I just posted a rotor turning video this morning.

[@Rolingmetal]

That's more than twice the speed i get with this online calculation. (410fpm and 10 inch = 157 rpm) littlemachineshop.com/reference/cuttingspeeds.php

[@mikediedrich8786]

did you get any vibration when applying the breaks

[@Rolingmetal]

No, threw it away. It was only a test for when I need to machine the brakes on my vintage car.

[@bigbothoee8617]

You need a cutter with a point I litteraly just cut a set yesterday on lathe 80rpm auto feed so slow and deep cut gliding past cast is never a good thing you can hear the tool chatter in your vid

[@Steve_Just_Steve]

Why didn't you try some tool steel with positive rake or brazed carbide? Those china inserts suck. Grab a new belt too.

[@Rolingmetal]

Most of the brazed carbide I have comes from China and it really sucks :) That belt is only a year old but I will inspect it for flaws.

[@martinberggren6033]

You need a more rigid lath. The brakedisks usally vibrates anyway.

[@Rolingmetal]

year harmonic vibration, I just learnend about that. But dedicated disc lathe aren't the mist rigid build machines I think I'll try again with the tailstock

[@wolfitirol8347]

If I do these kind of jobs manually I never like the surface finish but if I use the power feed from the cross slide it gets perfect 😉😉😉 I will never understand why there is so much difference even when I turn the cross slide very carefully...

[@DimaProk]

uneven pressure on the cross slide and not very ridgit machine

[@Rolingmetal]

The spindle speed and tool radius probably also play a role.

[@dragosmates]

First of all you need a far more slower speed for cast iron and you need a lathe with cross power feed and a sturdier lathe. And also you need a triangular insert made especially for cast iron and hard steel. Good luck getting this things

[@miro6138]

You can machine cast iron with good quality HSS, no need for special inserts

[@Rolingmetal]

According to this online calculator I wasn't running to fast. littlemachineshop.com/reference/cuttingspeeds.php 410 fpm and 10 inch = 157 rpm on the outside using carbide

[@Rolingmetal]

Not on this lathe with a 10 inch diameter. I won't be strong enough at the slow speed hss needs.

[@miro6138]

@@Rolingmetal Speed was good, just use insert with smallest corner radius you have and slow feed rate. Bigger the radius, the more force is pushing the work away.

[@rayvasquez7279]

What about using a vibration damper belt?

[@Rolingmetal]

Might help. but the biggest problem was the round tool bit

[@sharpeyedwatcher9724]

Running 50 hertz electric motors at the wrong settings will eventually destroy the motors because the windings overheat.

[@WRFUSINAGENS]

Bom trabalho, parabens

[@Rolingmetal]

Thank you.

[@ldnwholesale8552]

The rotor will have hot spots, which are a lot harder. That will correspond into lathe chatter. Rotors are ground, not machined new. Turning them will never be a great success.

[@tectalabyss]

Hi RM. The comment I made was just my thought's . Not me telling you what to do. my friend.

[@Rolingmetal]

np :)

[@CraftedChannel]

A big rubber band around the OD of the rotor will make all that ringing chatter go away. You can fabricate one from an inner tube or old v belt with connecting elastic segment. Vibration is from the symbol like nature of turning a big thin hard plate. Doubtful it's from the motor. Torque at low rpm always sucks with a vfd. You need more belt reduction so you can turn the motor speed up. VFD setups don't totally escape the torque increasing magic of gear reduction. ;-) VFD's best purpose is fine tuning cutting speeds. Worst purpose is as a substitute for gearing. Maybe I'm trolling the VFD worshipers just a little bit. However, there are endless videos showing torque problems at low speeds.

[@christurnblom4825]

I think you need a capacitor on your motor.

[@Rolingmetal]

No, that for running a 3ph motor on 1ph power

[@christurnblom4825]

@@Rolingmetal OK. I'm no expert on that, it was just a thought.

[@camelblue713]

You need a cutting steel with a small radius.....it will never work with this big one This big radius cutting steel needs pressure

[@Rolingmetal]

My lathe will probably run to fast for a steel tool bit

[@tinker5349]

Well done LOL

[@multiHappyHacker]

Is it safe to run it around 700RPM?

[@Rolingmetal]

Might be a bit much for this old chuck.

[@CarpinteroJesus]

And you still keep buying from bangood, remember you got what you pay for but I guess some people never learn

[@commanderboom206]

Get under the rust

[@Rolingmetal]

For that I would have needed a stronger lathe.

[@spikeypineapple552]

Do yourself a favour, and buy a DCLNR-1616 and a PCLNR-1616. A box of DCMT 11T304 + CNMG 120404 is going to save you hours of messing around. You might not have the power for the cnmgs, but I don't know why you're messing around with high speed and all this different crap when you can 3 boxes of inserts+a holder for under $100

[@Rolingmetal]

I also bought a tool bit that takes wnmg inserts. It has negative rake and should not dig in as easy. Maybe I will experiment with that.

[@spikeypineapple552]

Rolingmetal positive rake dcmt are what most people in industry would start with on a low power machine. WNMG is going to take a lot of HP and induce chatter on a not so rigid machine

[@Rolingmetal]

Yes but it will have less surface contact and the raised edge on the insert should give is some positive rake. Anyway, I'm of to the barn to do some experimenting :)

[@Poksutin]

those single phase motors are a joke :/

[@Poksutin]

@@Rolingmetal true :)

[@user-fd4qx2yg9r]

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