Making a Fly Cutter From 4140 Chromoly
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- Опубліковано 14 чер 2024
- G'day everyone,
In this video I will be making an improved fly cutter from some 4140 steel. Fly cutters are a good tool to use to face large pieces of metal and leave it with a good surface finish and it is one of my most used tools.
The replacement will be made form 4140 steel which is higher tensile strength and more resistant to corrosion. I will also make a new tool holder to hold some CCGT inserts that I bought.
Timestamps
0:00 - Intro
2:06 - Machining The Main Body
6:26 - Machining The Tool Holder
8:26 - Testing The Fly Cutter and Inserts
#machining #diy - Наука та технологія
G,day everyone. Just wanted to clarify a point that I might not have explained well in the video. I have regularly used aluminium cutting inserts in my fly cutters in the past and have used them to cut steel with excellent results. They can definitely machine steel. As some people have pointed out, a larger nose radius will probably get us a better surface finish, and these inserts do come in a larger nose radius which I might end up trying. With that said, the DCGT inserts that I use have a smaller nose radius than this and still get better surface finishes, so I don’t think that is the issue here. Overall, these are still weird inserts and sometimes these import tools are too god to be true. Cheers
at this point it probably would make sence to upgreade to a sc4 or sc6, they are really at least 2 stps above the sc2
or one of those portable metal bandsaws
we see you struggeling with both in all your videos
Since you haven't mentioned what the nose radius you are using is, I have to wonder if you are reading the carbide names wrong...
CCGT 1st C = 80° included angle. 2nd C = 7° Relief angle, G = Tolerance (there's a chart for that but both are the same), T = with hole & single sided cutter.
DCGT D = 55° included angle. C = 7° Relief angle, G = Tolerance (there's a chart for that but both are the same), T = with hole & single sided cutter...
I use DCGT inserts, DCGT070202, DCGT070204, & DCGT070208, the final 2 numbers (02, 04, 08) are the nose radius, 0.2mm, 0.4mm, & 0.8mm respectively. I hope this helps.
Good choice on the 4140, I used to work for tooling company that mainly made indexable mill and lathe tools and 4140 was our goto material for most of the tools we made. We usually started with annealed material, machined out the rough blanks, heat treated to 40-44 HRc, and finish machining/grinding.
I think the difference in the inserts will be the tip radius. Using the round insert sort of validates that. As with HSS tooling on the lathe, a larger tip readius will give smoother cuts. You are making me try 4140 again, my first effort resulted in a ruined cutter.
As far as cutting it on the wrong side, BEEN THERE DONE THAT. I just ordered a milling machine and it will be my first one. I made my fly cutters on a small lathe and it was difficult at best even without making the mistake of cutting it on the wrong side. I plan to make a new Fly cutter in a couple of weeks since my mill gets delivered this week and it's going to take me a bit to get it setup.
Had me worried if we were to see some hacksaw action 🎬
Thanks for sharing
Cheers
Try dressing the insert corner with a fine diamond hone to smooth and soften the nose radius. My guess is that you are seeing, how to describe this, randomish grabby point cutting along the cutting edge leading to irregular surface finish.
I have the same experience. Really sharp inserts provide a more dull surface, while the standard inserts leave a glossy surface. The latter rub heavily on the workpiece with their rather blunt cutting edges and polish it to a shine. On my very light machines I cannot remove 0.02 mm with the standard blunt inserts, they then rub on the workpiece without removing material. For precision work if necessary, I give my inserts a sharp cutting edge on my diamond grinding wheel. With a piece of scotch brite or something similar, I'll apply the gloss later. A disadvantage of such really sharp inserts is that the edge crumbles even more easily, so it is not always a good solution, and HSS is an option then.
I think its a good idea to have the slot sized for hss blanks just in case anyway
Looks like a great addition to the tool kit thanks for sharing.
Another brilliantly done tool
You could make another insert holder on the opposite end of that rod for the button insert for finishing maybe. Just take it out, flip it around, and do a second pass without having to worry about changing inserts
Maybe don't use the same rod, as making the holder that thin will weaken it lots. Make a second holder though just for the finishing passes.
I got a battery powered portable bandsaw at work last year. It was a total game changer. Makes quick work of just about anything metal.
shhh quite down.. the hacksaw is the best part 😉
Blackgates engineering here in the UK do a set of castings for a nifty bench power saw 🙂
Nice build.
Your devices are really modern! Great work.
I hear ya mate. My better half and I have moved back to West Auckland from South Australia into this, oh lets be kind and call it a summer, summer. Never seen so much rain! The muggy weather from the rain is killing us too, coming from a pretty dry climate, it's tough to get used to again. However, really interesting video again fella.
Excellent job.
Nice work mate.
Leaving a recess for the grub screws also removes the chance of them leaving a burr that may make moving/adjusting the tool holder part difficult. Though against CrV tool steel that may not be much of an issue in the first place. Nice clean build :)
Nice work. Very neat fly cutter build.
Well, I'm sold on button inserts.
I have diamond honed some inserts to get a finer edge for use on soft materials. Tedious, but it does work.
Nice Work
I got also some CCGT china inserts with a badly ground edge radius leaving also a rought (but shiny) surface in aluminium. The radius is more like a flat. Regrinding it on a verry fine diamond stone helps.
If you lap the faces of those inserts down you can get better finish and durabilty....just relap as needed. Long time usage out of one insert. Also, the tip of the cutter will be a little beefier for longevity and finish. They really do much better for steel after that. Lap with diamond stone. Thank you for the videos...enjoyed
Gday, you really can’t beat a fly cutter finish, in my 3” fly cutter I use Drillpro brand dcmt inserts off eBay, they leave a nice finish, my local steel supplier mainly only stocks 4140 in bar stock, I don’t have a major rust problem with any of homemade tooling, I don’t use cold blue just a simple spray of wd40, great job as always mate, cheers
@Ronix good looking set
Heya, probably a lot of these around but some ideas about surface finish issues, even considering your experience with similar ish inserts.
1. too small nose radius - 0.8 or 1.2 for polished aluminum inserts will work better.
2. chipped insert? pretty strong interrupted cut, be surprised if cheap aliexpress aluminum inserts are the appropriate carbide grade.
3. Very high effective rake - grabbing into the material and setup not rigid enough to cope with - especially w/ gummy mild steel.
4. Feed/DOC too small - rubbing
5. non-polished/coated inserts have rounded cutting edges which effectively burnish material as they cut, polished aluminum inserts dont.
6. tram issue (?) rubbing on the backpass
Nice work! The 4140 should definitely give you a long lasting tool.
My experience with carbide leaving a bad finish is usually due to it not being pushed hard enough. I.e doing a deeper DOC.
Fair enough, interesting to hear your experience with it. Cheers
Also corner rounds. Larger the fillet the better the surface finish, but higher tool pressure
Maybe also needs the fly cutter holder being balanced
That true and also the insert is too sharp, you need a larger radius at the insert
Still doesn’t explain why my DCGT aluminium inserts with the shape rake and smaller nose radius leaves good finishes but these don’t.
did a beaver chew that 4140 into 2 pieces?
In Australia we have drop bears that'll do that
Olá amigo incrível seu trabalho, e muito útil e bem feito!!!
Love ya show ya goofy m8te from Australia 😆
Would have been nice to cut the fly cutter with a fly cutter! 😄
I am so happy that there are folks like you working with affordable machines so you can demonstrate for the masses rather than a smaller segment.
Should there be cutting at the trailing end? I'm thinking the spindle needs a bit of trimming. Can that machine's tram be adjusted?
I think you might do better using the other corner of the insert. And if you can get the trailing edge parallel to the work it could work as a wiper and give you a better finish.
I just made a 2 insert dovetail cutter made from 4140. The finish is good enough and more attributed to the runout.
Do swap to a link belt as soon as possible or a dual pulley setup as you’ll get so much more turning power from your large
"while I got close, I didn't get anywhere close…" words are hard.
Eh, the old video ended there, the latter half was done about a month later. Nothing more than that
@@artisanmakes oh, I hope I didn't make you feel bad. I was being genuine when I said words are hard.
Haha not at all. Cheers
We'll, don't I feel silly. Nice video. 😅
Wow, that finish with the button insert is amazing. I need to try it. The sharp edges of the inserts meant for aluminium will chip easy with interrupted cuts since they're uncoated. dcgt will work well, why not continue using the button insert (rcmt ?)
I’ve never had much issue with uncoated sharp inserts breaking on me whether it be this or DCGT a long as I keep the depth of cut light. It’s mostly stalling the mill that ends up breaking them. I definitely am thinking about sticking with the round RDMT inserts, I just have to keep the cuts light due to the cutting forces. Cheers
Napisz proszę jakich obrotów użyłeś , od miesiąca posiadam własna frezarkę i właśnie się uczę
Bardzo mi się podoba Twoja praca
Pick the insert with larger nose radius. Those look way too sharp nosed. Try to see if 1.2 or 1.6mm nose radius is available or bigger.
I've seen button inserts hog out a lot of material. I was surprised to see the finish you got with it in the fly cutter.
Hehe I might need a bigger machine before I can hog material with round inserts :)
Hello
Thank you very much for sharing your videos and your art with us.
Ihave a question!?
Can you say me please how much must cut this place that the screws are?
Best regards sina
Von Österreich 🇦🇹
Long Shot... I've started using a fly cutter to cut the nail nick in the slip joint knives I'm building. The trouble I'm having is I can't seem to find any guides on what geometry to grind into the lathe tool to make those 1/2 moon slick nail nicks. Any ideas? All thoughts are gratefully received. I'm trial and erroring at the moment and it's more error than anything else =) Love your videos, very inspiring and encouraging.
the geometry and coating make a HUGE difference as im sure you know. those inserts will be great for aluminum, but not the 4140.
I’ve used aluminium specific inserts for steel for years. They aren’t finishing inserts but they can get you great finishes, as I showed the video. For whatever reason these specific aluminium inserts just won’t work. Cheers
Curious to know what the out of balance is like on this. Have you mounted it horizontally in a bearing to see?
Goedkoop wort duurkoop.
The difference between a CCGT and CCMT inserts is CCGT inserts cut material CCMT tips are blunt and rip material off and burnish the surface but you need a minimum depth of cut of the tip radius and a feed of 25 to 75% of the radius per rev to get a smooth finish.
A 20mm diameter piece of 4140 should be spinning at approx 1800 rpm. Using a CCMT09T304 insert the minimum depth of cut should be 0.4mm and a feed of 0.3mm/rev roughing and 0.15/rev finishing and you will get a mirror finish. If your machine can not achieve this then stick to CCGT06T302 type tools and adjust the feed and speed to match the tip rad.
Could you maybe do a complete hour long shop tour? 🤭
The insert looks like a 2 radius. Meant for roughing - -try a 1 radius which would be more suitable for mirror like finishes.
Those inserts like you said are made for aluminum, I tried those same inserts in steel and had similar finishes on a 2 inch face mill, but when I used them only on aluminum I got a nice mirror finish.
Maybe, but as I said in the video I have used DCGT aluminium cutting inserts for steel in my fly cutters and they net great results, which is why I was surprised that these CCGT inserts didn’t work.
@@artisanmakes probably because they have such a sharp raked cutting angle.
That still wouldn’t explain why the same geometry DCGT inserts work but these don’t
That particular insert being for aluminum may have steel in the coating. Conversely, a lot of the inserts used for steel have aluminum in the coating. AlTiN and AlCrN being 2 more common coatings for cutting inserts designed for steel. The reason behind it is to stop the chip from welding itself to the insert while cutting. The insert is still carbide, so it WILL cut, but looking at the finish, there is some smearing going on.
Do you have some shoptour video?
What do you think would be the maximum diameter for a fly cutter for your mill?
Hi, you refer to the steel not chosen for the body as "carbon steel". Is this a shorthand for high carbon steel or low carbon steel? Later you refer to the metal for the tool holder as "steel". Is this different from "carbon steel"?
Shouldn't the grub screws be on the other side to push the cutting tool onto centre line?
You wouldn’t really have the space to have them on the other side
The reason that aluminum insert isn't leaving a glossy or shiny surfaces is: the edge is too sharp, a slightly radical cutting edge will create the necessary to leave at glazed/shiny surface behind.
Maybe but the fact remains that I have used aluminium inserts for years to machine steel and have gotten excellent surface finishes from them, as I showed in the b roll in the video. For whatever reason this specific batch of inserts wouldn’t work. Cheers
⭐🙂👍
Interesting that I design a flycutter then literally the next video you put up is making another flycutter xD
I went down a similar route to 'We can do that better' and designed one that takes a ccmt insert directly utilising the 100 degree edge to try and get more use out of the scrap inserts from lathe tooling
The 100° edge works really great on fly cutters for me! Finish is great. A Bonus is that it creates much less burr than sharper corners, because the material ist cut "from the top" rather than pushed over the work piece edge leaving a burr. And you can reuse your old inserts.
@@schrauberhugo2594 reusing the old inserts was the main idea. Remember someone saying it in a video a few years ago and thinking it was a good idea, then promptly forgetting 😂
@@SimJackson Joe Pie has a great video about fly cutting, there I got the idea from. Although he uses hss, but with a huge radius and angle.
Surprised that you find carbide produces better surface finish than HSS given your smaller sized machines; do you polish the edges after grinding the tools? Also, the difference between branded HSS and generic Chinese is like comparing a long distance journey in a Fiat or a Mercedes: they’ll both get you there but one gives a more pleasurable experience.
Please tell me how many degrees it tilts
I think your insert may just be too sharp. Looks like very small corner rad, maybe try grinding a bigger radius on one corner and try ‘‘em again?
Small radius for this size insert, but bigger radius than my finishing DCMT inserts. Cheers
With the tiny corner radius of the aluminum inserts you need to feed very slowly. The button insert has a ridiculous corner radius and will therefore create a much mor even surface. Cutting loads need to be considered with high corner radius inserts however.
The corner radius on this is still larger than most of my finishing inserts, the scale is a bit hard to judge but these inserts are roughly double the size of my regular inserts. Cheers
The corner radius on this is still larger than most of my finishing inserts, the scale is a bit hard to judge but these inserts are roughly double the size of my regular inserts. Cheers
i think the finish quality has to do with the carbide nose radius, larger is better.
For sure, but there is something that is not quite right with these inserts. Even compared to smaller radius CNMG that I use in my boring bars, these don't work as well.
@@artisanmakes maybe they only work well on aluminum.
@@artisanmakes You should try some with a larger corner radius for aluminium, 08 should be fine.
As I said in the video I’ve used DCGT inserts made for aluminium that yield great surface finishes in steel and have smaller nose radius than what these have.
Try with RDKW inserts.
Not too familiar with those inserts, what would be the advantage over the RDMT inserts that I use? Cheers
Why did you remove the part from a secure and inline setup from the hole making process to then tap the part when there is no alignment for the tapping process? Just drill the hole, tap the hole then move to the next hole.
Easier for me to film
Those inserts were meant for aluminum I'm almost certain. Might want to double check, I may be wrong. Great video!
I they are made for aluminium but I’ve used these types of inserts for steel for many years, as seen in the b roll fly cutter footage. You have to be careful but they do work. It just happens that these particular inserts don’t work as well as other similar ones
@@artisanmakes My bad, I just seen your comment below. I'm surprised you've had any luck with the finishing style aluminum inserts on steel. I've tried in the past and it usually just breaks the tip but maybe I'm doing something different. Either way, I really like the video and the tool, very nice job!
No worries, the hood up much better than I would expect. They do wear out faster than normal inserts, but I can get a few hours out of one insert. Cheers
What state are you from?
@9:53 "And whilst I got close, I didn't get anywhere close" 🤔
Hehe. It’s actually a second edit. Everything after 10 minutes that was filmed a few weeks later since I wasn’t happy with it.
Would their be any benefit to Balancing a fly cutter?
Quinn at blondihacks made one a while back. From memory there was a bit more made to her fly cutter so it might make sense to balance it when they get heavier. But in my experience, I haven’t had any issues.
@@artisanmakes Thankyou :)
What was the material you cut with the new flycutter with the aluminium cutting inserts? In my experience those cheap aluminium cutting inserts really only work well on aluminium. When used on steel that sharp edge immediately gets slighly damaged (look under microscope) and you get a bad surface finish. So if you were tryinh steel that could be a problem?
Looks to be a piece of hot rolled steel, which is what I intend to machine. I would agree with that, but I got such amazing results with similar DCGT aluminium cutting inserts and they lasted longer than I expected too. Cheers
Looks like head or column are out of tram
Comparing the finish of those single point carbide cutters with their minimal radius to your Button (360 deg. round) cutters is unfair. Actually no, .... it's more than unfair; It's illogical! On the up side, I still enjoyed the video.😉
Wakodahatchee Chris
Definitely unfair, but it was more of a troubleshooting effort to see if I had a problem with the inserts of the fly cutter itself. Cheers
Why cut the bottom at 10 deg, this will just add imbalance, the cutting point is well below the body so clearance is not a problem. I have just finished making one myself, and what I did was just put the slot at an angle and did not mill a complete flat for all the holding screws, but just a small one for each screw. I used a purchased lathe tool with a diamond insert rather than making one and the finish was as good as the round insert you were using.
For me the angle helped simplify the tool holder geometry. I've never had much of an issue with imbalance, so overall it made it easier for me. Cheers
Ha, no hacksaw for the 4140
You need to upgrade from the garbage machinery. It would make your life so much easier and your work would come out a lot better. Even it’s just a small jump in size.
This is just a hobby, I simply don’t have the space or budget for that. Plus I like my machinery.
The price you pay for imports is quality control. You probably just had bad luck.
I find the nose radius of those CCGT inserts needs to be at least 0.4 or more for a good finish. I'm not sure why that is? Probably something to do with the chips?
Anyway, nice work again buddy. 👍
Thanks for the info. This is my first time using CCGT inserts. I had a look at the specs and these are 0.8mm node radius, which is a good indicator that the issue is with the inserts themselves
Try scraping the bottom of the ice cream bowl with the pointy tip of a steak knife. Then the tip of a spoon. Then the side of the spoon. You will see the difference a larger radius makes, and you get to eat ice cream 🍨
I don’t quite understand the analogy, the nose radius on this is larger than most of my finishing inserts?
@@artisanmakes Oh, You must have got a bad batch then. Maybe they aren't hard enough?
Not sure, I’m no lathe insert-ologist but sometimes these Chinese inserts just don’t work. Cheers
I don’t understand why anyone would bother with inserts in a fly cutter in a home shop on a small machine. Quality high speed steel is cheaper, has worked exceptionally well for years and holds up better on interrupted cuts.
Just my thoughts and doesn’t reflect on your work, which is very good.
If it works best for you I’d say use hss. For me I seem to get better and more consistent results with some types of carbide. Cheers
I know you know what youre doing, but I highly recommend ditching the inserts you use when cutting steel on your lathe. Youre really overpowering the machine. The machine will cut much more freely with well ground HSS tools or even the polished inserts you used for your fly cutter. The fact that we regularly see things moving and shaking on the lathe is a good indicator of the value in switching out your tools to something more appropriate for such a small machine
Put it simply I get better results from carbide than I do with HSS with this lathe. I used to use hss exclusively but with the ac motor drive I have found that the lathe works best with carbide inserts. Cheers
Might want to work on your grinding then. Not trying to troll you but its pretty obvious from the cuts that things are not right.
Oh for sure, this lathe needed a rebuild. As I mentioned in the video 4140 tore up the v belts which is resulting in that wobble, but the lathe mounts also need replacing too. With that said I do push this lathe beyond what is reasonable to see what it can do. Cheers
@@artisanmakes why would ac make a difference? Every lathe is ac. I think its possible you should revisit your hss grinds. The surface finishes and lathe moving around in your videos demonstrate the failures of the carbide tooling. If you cant get better MRR and finishes with hss then then the issue is the grinds arent optimizes and warrants further research and practice.
This lathe was originally dc, most small bench top lathes are. I replaced that motor with an ac that directly drives the lathe spindle. It’s more powerful but it fixes the speed at around 900 rpm. It’s an imperfect set up but it works. Only downside is the rpm is a bit high for hss but at allows me to push the lathe with carbide, at least when im not turning 4140. Cheers
8:48 try using an insert designed for the material you intend to mill. Using an insert designed for machining aluminium is of course not going to leave a superb finish on steel..
As I said in the video, I have used these aluminium cutting inserts for steel for years, especially in DCGT they can yield great finishes. For whatever reason the CCGT inserts just wouldn’t work. Cheers
You have bad surface quality on lathe machine, because this cheap machines have low rigidity. This plates are very sensitive for rigidity. Deep stripes can tell about:
1. Bad bearings in spindle
2. Bad contact between tool-post with compound rest, or between compound rest and cross-slide, or (most often) between cross-slide and ways of your machine.
Can’t argue with that, this machine is being pushed well beyond what it was intended to to. I am happy with the results that I can get from it, especially in 4140, but it is in need for a rebuild sometime soon. Cheers
Lol those polished inserts are for Al
You can use these for steel in lighter machines. They don’t last as long but that’s a trade off that you have to work with on these machines.
@@artisanmakes They love aluminum on my Tormach. Anything other than AL, I get the same results as you