Mini Lathe Heavy Machining In Steel - It Can Be Done
2024 ж. 14 Мам.
101 706 Рет қаралды
G'day everyone,
I have been bit busy as of recent, so the next project may have to wait a week or so. For this weeks video I wanted to show you the progress that I have made in learning to use a new set of DCGT inserts that I bought a few months back. They are made for turning aluminum, but the sharp rake and cutting edge makes them perfect for cutting steel, if you are careful. In this video I will turn down some 1214 steel, and show you the incredible cuts that I can take with this mini lathe.
Lathe - Sieg c3 7x14 mini Metal Lathe
Timestamps
0:00 - Intro
1:17 - DCGT Inserts
2:50 - 1mm DOC
3:28 - 1.5mm DOC
4:28 - 2mm DOC
5:16 - 2.5mm DOC
6:09 - 3mm DOC
6:57 - Conclusion
#minilathe #machining #MiniLatheHeavyMachining
The mini lathe is a great starting point for learning about machine rigidity. I believe your content has helped a lot of folks deal with the short comings of entry level machines as proven in this video. Thanks again for sharing, Cheers
It gives the user a better understanding as a big lathe wont show it as well
I am impressed over this small lathe; it performs much better than I expected. Good video.
Amazing results!
That tool holder storage is an awesome and smart idea
A 3 mm depth of cut out of a Mini Lather is absolutely ASTOUNDING!
On stainless maybe
@@smashyrashy what kind of stainless? Do you know what your talking about at all???
Absolutely no it is not. It is totally dependent on the materials. .
@@taxicamel i wasn't talking to you.
@@taxicamel dependant on the materials? Do you know what YOU'RE* talking about at all?
I really like your drawer for yours tools holders.
Very impressive to get that much depth of cut out from a mini lathe. I started using the aluminium inserts on my ancient 1930s benchtop lathe and they are so much better then the regular steel cutting inserts. The best thing about them IMO is not how deep you can go, but how shallow a cut you can take; the regular steel cutting inserts just rub the surface if you try a really fine cut.
That's my experience too. The only downside with them is that they do break relatively easily - interrupted cuts in particular seem to defeat them.
Very true!
@@cooperised Yes they are pretty fragile, as he mentioned in the video if you stall the motor (or make the belts slip as my lathe does) there is a very high chance of chipping the cutting edge off.
If you have failed to machine the correct dimension, then you don't keep single-point turning for .001" or 0.025mm or whatever small amount. Just use a lathe file. This video is NOT the best place to come to learn anything. .
@@taxicamel _"If you have failed to machine the correct dimension, "_ Has nothing to do with this. As an "expert" you should be aware that small lathes simply don't have sufficient power (or rigidity) to take deep cuts. That's fine with HSS, but not so much with conventional inserts which is why they aren't well suited to small lathes. The aluminium inserts do work on small lathes however.
Hey slick design on the rack for your QCTP fittings. Nice space-saving design
Great video content as usual. Cheers
Brilliant work dude that is an impressive depth of cut. Those ccgt inserts are great for a mini lathe owner I use mine a fair bit. 👍
Very impressive for a mini lathe. 👍
Good stuff, you really pushed that there, I can do 1.5 and that’s pushing it. But I prefer carbide myself but sometime need that odd shape HSS so got a load of them for when needed. Good video.
Thanks! Great information!
I tend to use moulded inserts in the manual lathe too. Ground inserts are a bit fragile,. However never a problem in the cnc unless I do something quite daft. The inserts for aluminium certainly make a lathe think it has had a motor transplant. I think if you want the chip to have a chance of breaking, you may need to double the feed and halve the depth of cut. That works for me. Although that long spiral is at least able to be controlled, not like it is a long straight continuous knife edge waiting to bite you.
Thanks, very interesting, and impressive !!
When you talk about your inserts not breaking propperly when you mess up, simply run it in reverse, does the trick every time :). During my apprenticeship the machine in the shop we had mostly used was exactly the same model as the one in the job-school. The difference was that the switch for the direction on the shop machine was the opposite of the normal setup for that machine so if you turned the one in the job school on with the habit built up in the shop you'd run the machine in revers. Took one guy 2 broken inserts and serious confusion from the teacher before the mistake was found
inserts for stainless steel work very well too and they leave a better finish
i'm glad you finally got round to trying the ally inserts. Ever since I tried them on my lathe, I've neved looked back. Addmitedly, My lathe is the "1 size up" from yours(SC4) and it does have the fine feed feature, which is incredible for it, but they're truly amazing for this kind of work. Awesome video as always.
Do you mean Allied?
@@ryanthede4689 Ally, is slang for Aluminium.
@@65cj55 all the years I've been machining I've never heard that. It must just not be a thing people here say. Like face milling vs raster flats
@@ryanthede4689 Us Aussies like shorten words, we even have a Aluminium Boat Building Company called Ally Craft..
Outstanding stuff! I use the ground inserts more than half the time I am cutting on the lathe. When you are experimenting for best surface finish, take a look at different cutting oils. Every machinist has their own favorites, but I have been surprised by how much performance can change with different types. For steel, my current favorite is made by Rigid, but I would recommend you try several. You will find your own favorites quickly.
It's really amazing how much you have gotten out of a Chinese mini lathe. 3 MM cuts are much more than I would ever than I would ever ask out of such a lathe. I would be satisfied with less performance from a Chinese mini lathe. wow I just noticed that I evidently watched this video before.
Good job man
:D nice demonstration!
machine goes brrrr 🤩
I think people worry way too much about "chip breaking" does it even matter for the home machinist? Whenever I get that long curly swarf the cut "feels nice" so surely you're doing something right!? I suppose there is a safety factor to consider. Anyway that's a great DOC for a mini lathe! I did some experimenting with carbide a while ago and my findings match yours, although I didn't dare go all the way to 3mm. It seems carbide likes being pushed, but only if you have the power and rigidity. I was amazed recently at my Cowells lathe taking 1.5mm (total) off a relatively large diameter of steel! Albeit with a very sharp HSS cutter and very slow rate. But still impressive. If you're not familiar with the Cowells lathe it's a tiny micro lathe more suited to watchmaking! Sometimes I wonder if we are too timid with our machines? Great video. 👍
Awesome mate. Im not always too worries about perfect chip breaking, but when this was spitting out 1m long chip strings, that was a bit ridiculous. Cheers
@@artisanmakes Yeh that is a bit crazy. But it does show a good smooth and consistent cutting force if you are able to achieve that! 👌
This is a very interesting video, because most people say you can't do much machining on steel with these mini lathes. this method seems to work pretty good. it shows that mini lathes can machine steel providing a person is patient. which is really all a person can ask since these lathes are hobbyist grade and not professional grade lathes. something that I noticed, is the cuts seemed to get easier and cleaner. the smaller the diameter the stock got. which makes sense since the smaller the diameter. the easier it would be on the lathe and the cutting tool. for me I think they are very suitable for making bushings and other things like that. however I'm curious how they would do on stainless steel. I'm going to have to watch the other video to see what the outcome is.
I've been using my mini lathe for about 4 years now, and have turned stainless, mild and cold rolled steels, bronze, brass, aluminum, plastic, lead, cast iron, and the only thing I failed on was a mystery metal that broke 3 inserts (turned out it was piece of a hydraulic shaft, that was case hardened). I've never done that depth of cut on mine though.
Good job,
Do you think adding another drive belt or 2 for the motor could help with stalling or power delivery?
You can get 8.7”x15.7” lathes for about 800 USD that have 1.5 HP dc motors. With that, along with generally better QC, one of those lathes could really hog material.
Really appreciate these videos! Gives a good perspective on what can be achieved with these little machines. Any chance of a link to the inserts you use? Cheers lad.
I would like to know where did he get carbide inserts for 1$
Most likely Banggood or similar site
Nice 👍
Great. I’d really like to see how a medium / high carbon steel handles those ally inserts!
do u have a suggestion on a quick change tool post for one of the mini lathes 7x14? i got one on amazon an i did get one of the cheaper cause i had just picked the lathe up an dont have a bunch i can dump on accessorys but i didnt expect much from the tool post i got an it will take some work for me to keep it repeatable but my biggest concern is when i was turning some steel in it i noticed the post seems like it was giving alittle but only when cutting, couldn't feel any when not so its not as ridged as the one that came on the lathe so when working with harder materials i'll be switching back to the one that came with the lathe cause it didnt do this but for softer i'll use the quick change post but i really wanted the quick change tool post for adjusting the tool up an down more than for being able to switch them out but since ive gotten it i see the value in being able to just switch between the tools but the little post i got just isnt rigid enough for some of the stuff im going to be doing. mine costed $34 so there was cheaper but also i feel like its a touch smaller that it should be compared to the original post that came on the lathe 175mm is how big the tool post is im not sure how big it should be an it also didnt have a place to engage the little spring loaded catch to help keep the post from turning, i dont know if this is how it suppose to be or if it should have one, this is my first lathe an ive never gotten to mess with one until i got this so i know very little about them but its videos like this that have guided me so far. thanks for sharing.
Have You ever thought of filling the lathe bed with epoxy granite for more rigidity and vibration damping?
Welcome in the big game, its time for 1hp 1500rpm motor!
How about 5hp 2stroke snowblower/ go-kart motor. Added feature have the expansion chamber dump unburnt 2stroke oil out on the part being cut.
@@cobre7717 the bigger the better!
High Speed Steel calls for lower cutting speeds and heavier depth of cuts. I prefer tangential HS tools on my lathe. Originally my lathe came with a 550 W single phase motor, but I bought a three phase 1.5 kW motor and a one - to three phase frequency converter after I discovered the motor to stall when turning with carbide inserts. Since then I've only had a few occasions with belt slipping instead and only turning with HS steel. Downside is an inferior surface finish.
Very cool. I've got to try this insert... :) Any word about brass cutting with this insert? Thanks!
Have to say wow! Are you using 1214 or 12L14? It is still very impressive.
Nice! -but 0.5HP seems to be almost more than what the rigidty of the machine really handles. You'd need better main bearings, a better chuck and a stiffer bed to push it further.... I'd work on that in stead of putting time and money into upgrading the motor :)
Crazy 😳😍
I use ccmt aluminium inserts on my little lathe, they cut a lot better than normal inserts. But yes, crash the machine and the insert is stuffed. But the maximum depth of cut i can get is 0.4mm, and those blondilocks chips is the best I can do. At least they are contrallable rather than a rats nest. But all my cutting is on 4140, dont know how it would go on mild steel. Oh - and I let the magic smoke out of my motor trying to do deeper than 0.4mm cut.
Hey Brendan You describe these Aluminium inserts as DCGC inserts. What is the full code for these inserts.
DCMT’s are a finishing tip. I’m a turner by trade but have a hobby machine in the garage which is pretty much gutless compared to professional machinery. We use WNMG’s or CCMT’s for roughing, and occasionally DNMG’s, but these amateur machines wouldn’t stand a chance under load with any of them.
What is the material for the clamp holder made of?
Genuine RCKLCY inserts 😀
I would recommend using uncoated inserts if possible instead of the yellow coated ones you use. The coating on most carbide inserts makes the cutting edge slightly duller, and the performance benefits from using coatings are not beneficial at the performance level of small machines.
if you bought a 1 HP motor, what would u want rpm to be on the motor data plate????
That was a good assessment of what your tool is capable of doing although there are a couple of factors I think you didn't consider. number one volume of material removed in cubic centimeters per minute the larger the diameter the more material you remove per minute stated in cubic centimeters. Such as 1 mm deep cut on a 50 mm diameter removes more material than a 1mm deep cut removes on a 25mm diameter for the same length of cut. Number two the absence of coolant. Coolant can greatly increase the efficiency of a tool by putting a barrier between the tool in the material also the coolant causes the chip to take the heat of the cut and the chip reacts differently when it's hot rather than when it's cool try these and tell me what you think. my best wishes
Good stuff to think about. I'd love to install a coolant set up one day with this lathe. I use a bit of mineral cutting oil when stuff heats up but its always a bit of a bugger to use when I have the cameras set up. Cheers :)
5:30 Material removal rate is probably why.
I mean yes it can be done, but there are a few things to consider here. 1214 is a free machining steel, which machines like butter compared to 4140. While the mini lathe is managing that depth of cut, the feed rate is really slow and you would be better off taking smaller depths of cut at a faster feedrate. I know my 650kg hobby lathe will happily do 3-4mm DOC at 0.2mm/rev in 1214. A “fullsize” lathe wont just do a 2mm depth of cut, it will go much more. The inserts you are using aren’t brittle per se, they are the same carbide just with super high positive rake and razor sharp edge for machining soft materials. They just don’t hold up because both of those things lead to highly reduced edge strength.
I am aware of this, and material removed wasn't really what I was aiming to demonstrate. I just wanted to see how far I could push the lathe, in light of the new mods and the new insert. I just thought it was neat what this little lathe could do. I even said in the video that this was best case scenario
i like your tool holder.. holder :)
I would look into one of those 750W BLDC sewing machine motors on eBay. They're small and very torqy.
crazy
I have one more question sir! With the new motor for the lathe are you still able to cut threads with the lathe?
I do it by hand, I have a hand crack that connects to the spindle. That is the one downside with my AC motor, with the gearing I have, the lowest I can get is about 400rpm. Although you can get AC motors with VFD controllers to lower the RPM
VERY INFORMATIVE Where do you buy your DCGT aluminium inserts? I can only find them on Ebay China and they will take 6-8 weeks to crawl to Darwin.
Aims industrial if you don't mind swapping your first born.
@@brendanshorter5550 Thats me stuffed - already used it for crab bait
Up graded electric motor ?
wow.
I think to get the chip breaker to work your attacking it from the wrong angle.. Rather than going a deeper cut, I think you need a more aggressive step over.. The chip it just to thin to break. With a thicker cut rather than deeper the chip becomes more brittle and less ribbon like
How many horse power is this lathe?
Is that 1214 or 12L14 ? The chipbreaker is designed for aluminium. I find they break steel chips if you reduce the DOC and increase either feedrate or rpm or both.
The stuff I have at the moment is 1214 grade. Cheers
I'd recommend an AC servo motor, 1 to 1.8 KW. You can get some that go up to 3000 RPM, which would be plenty I feel like for a lathe like this, especially with gearing.
I would use a 6 pole 3 phase motor with vfd. Hz range about from 20 to 200Hz. (400-4000 rpm on the motor)
well it's a lathe kzhead.infoUgkxN9zrzkkhnjUF5PQbuA_B1gYdsfCu9k6z but it wasn't what i would have anticipated. Headstock, tailstock, carriage apron are manufactured from aluminum now not cast iron. The spindle diameter for the bearings is too small allowing for a few play in the spindle so I am using some blue Loctite to take out the play.
can u link ally inserts
Are you pushing manually or by machine? And if automatic what turning speed and what feed rate at what diameter?
I'm feeding it manually, and how much I push it really depends on how much the motor can take. You get a good idea with feeling when the motor is maxing out, so I can't really give you a quantified feed rate. Cheers
do I get a feeling a motor upgrade is in your future?
Very interesting content. Definateley not making any comparisons but you should check out John makes
Are you turning the feed by hand or is it a power feed?
Feed by hand
I swapped my 550w motor for a 6375 170k brushless skateboard motor powered with 24v power supply.
Stupid question - what's the issue with one long chip? Is it just cumbersome to deal with?
A bit late, but one of the risks of a long chip like that is it wrapping around the part - marring the finish - or even getting wrapped around the chuck, spinning around and picking up more long chips like that. A long whip of very thin very sharp steel flying around at hundreds of rpm is dangerous for the operator. If it doesn't pick up like that and instead continuously feeds downward, you may find yourself grabbing sharp steel line when trying to stop your feed too.
If your chips ain't breaking try increase the feed rate . Try 900v/D for your carbide tools for RPM selection .
Thanks, the motor power is the limiting factor in preventing the feedrate increasing here. I've bought some slightly different inserts with a different chilbreaker and that should help. Cheers
@@artisanmakes by the way cool Chanel!
What rpm are you running the lathe at please
about 700 or 800 rpm
you can sharpen it by diamant grind disc
There is a video somewhere on youtube where a guy takes a 25mm depth of cut with a mini lathe if I remember correctly. He’s done loads of modifications to the machine to stack everything in his favour and it did work. However when comparing cuts, depth of cut is far from the only metric. If you want to see how quickly you remove material you should calculate volume of material removed per unit of time. (Inch^3/minute or mm^3/second). Comparing depth of cut while slowing down the spindle and feed is usually not faster than regular roughing strategies because of the compromises involved. Edit: I found the video and I see you found it as well about a month ago. kzhead.info/sun/ZN5wh8esfaSvbI0/bejne.html
I am aware of this, and material removed wasn't really what I was aiming to demonstrate. I just wanted to see how far I could push the lathe, in light of the new mods and the new insert. I just thought it was neat what this little lathe could do. Cheers
@@artisanmakes They are indeed a very good option to use on small lathes. But even on larger ones like the +-300kg lathe I'm using them often on parts that cant be (easily) set up rigidly.
Anyone have an idea of the rigidity difference between this lathe and a 9x20 lathe? I have a 9x20, and I've always assumed it was just a bigger heavier 7x14 with similar rigidity, but now I'm thinking it may be quite a bit more rigid. Not that 3mm doc is bad for a mini lathe, it's incredible.
How heavy is it? The 7x14 weighs below 30kg if I recall correctly.
@@MF175mp oh wow, yeah the 9x20 is much heavier than that. Without the base it's probably around 80 or 90 kg, like 200lbs, and the base adds another 20kg probably. I didn't realize the 7x14 was THAT small. Thanks for the info.
@@jacobmiller6664 I checked and some sites listed it as 38-40kg. But still it's pretty light
Hey did you learn to use the lathe by yourself??
I was taught how to use a lathe, but a lot of the nuances in machining, like turning different materials and fixturing is self taught and is jus learned from experience.
1.5kw 3phase VFD!
what rpm are you turning at ?
It is roughly 8-900rpm
@@artisanmakes thank you
Morning. Hey i have like 8 or 10 boxes of brand new carbide inserts, would you be willing to trade them all for 1 of those lightsabers?
I take normally similar depths of cut on my cnc lathe but the feed I'm using for roughing is like 10x yours. 7,5kW motor, 250x500mm lathe, weight 2500kg
Thats a cute automatic mini lathe
@@yak-machining a lot weight for the small work envelope. Try find a manual 10"x20" or 250x500mm lathe that weighs 2,5 metric tons
How is your answer related to this video?
Bro 3 mm with mini lathe that is crazy
The problem of the fisrt insert its because have a big radius nose, for that reason you cant do deep roughing cuts.
no doubt that is part of it, but ultimately I use these inserts because I get the best results with them on this lathe set up
I mean, it works at low tensile steels, but... buy some industrial quality inserts for steel... on sale it is around 3 - 4 $
I have used proper seco and kyocera inserts to machine stuff on this lathe they don't perform all that much better, given the limitations of the machine
You would be better with ground finishing inserts for steel. The aluminium inserts work but dont last long as the rake angle is too steep. DCMT the M stands for molded, look for DCGT (G stands for ground) finishing inserts for steel. Ground inserts are much sharper and finishing inserts allow less D.O.C. Even stainless is pretty simple them. Less tool pressure. They can be more fragile
Always do the face first, expecially for tailstock...
In my experience chip breakers rarely work...
How much price of mini lathe machinery?
They go for about $6-800 depending on where you live. 7x14 mini lathe
Try squaring the cutter face to the work.
Imagine if they made all your upgrades standard.
Try cutting some D2 or 4140PH, I dare ya 😂
I've turned hss on this lathe and I'm sure it could do annealed 4140, albeit much slower
Well carbide and any other insert for steel are not "sharp" for a good reason
Absolutely, but us hobby users tend to coopt these things even if it's not optimal. And this insert has its advantages over a sharp hss tool. I have seen a few stainless steel inserts that are pretty sharp though :)
I'm really interesting . maybe I can afford.
In America, we machinists call those big wads of chip a bird nest. Atleast where I work.
koenigsegg make a decent small electric motor , maybe try to get one as an upgrade 😈
RISK , can be expensive.
Correction. Depth of cut has nothing to do with the amount of material removed. You could be 2mm into the part while removing less material with an edge of the cutter. To make this test anywhere a curate, you have to compare results with a power feed.
Well yes, you could see that the feedrate was suffering quite a bit at the heavier cuts. I wouldn't take this video too seriously, I was just a bit curious to see how far I could push the lathe. Cheers mate
i say even deeper or higer feed i am a fully educated machinest btw
There is only so much that this lathe could do. Cheers
@@artisanmakes i know . though you could take a lighter pass at higer feed. that should also make you able to use the chip breaker
Respect your equipment. It is not designed for hard work. Invest in a bigger lathe and you will be miles ahead.
Obviously a bigger lathe can cut better. This channel is about taking a $600 mini lathe and pushing the limits to the next level. Its very cool to see the limitations bypassed!
1 or 2 hp??? 5 hp 😏😉😁 is way to go, you may rotate the earth 🌎 😁😆🤣😅
Umm, I don’t understand the need to push your machinery to its limit. Why take the risk of blowing a motor or the electrics? 🤷♂️
I don't understand why people are using these pointy inserts. I understand for small diameters with live center, but in other cases, it should not be used. A square insert would be better.
Dcmt is just convenient. Good clearance and I've gotten the best results from them.
@@artisanmakes If you look at the proper angles for machining, the square insert is the proper one. It turns the cutting/chip/swarf much better over. That pointy one does not have a rear "wall" to turn over the swarf/chips.
It could be like this but dcmt is just the most convenient insert for me, at least with the Inserts have access to. You do you. Cheers