Insert facemilsl, correct use on hardened Steel.

I recently took delivery of some milling cutters that had been stuck in a closed Argos store for over a month. One such item is a used 6 insert 50mm facemill. I used it last night. Not sure if I was using it correctly. I think it originally came from Arc euro tools. I fitted new inserts & checked each insert was touching off & they were. I ran the machine at 1000 rpm at 1st. Then slowed to 800. The material I have mentioned in previous post & is steel. I have no idea of what steel it is other than it is blooming hard. They are Chinese quick change toolholders that I need to take 4mm from the lower face. I have done 4 others in the lathe with a 4 jaw chuck & that was hard going. I tried with a HSS flycutter & it just took the edge off pretty quick.

So now I have the mill I did some work on one. It did cut the material , I took 0.1mm depth per pass. ??? I took a total of 1mm before retiring. The main question is & the inserts were carbide. Is it ok for sparks to come from the cutter. It looked pretty but not sure if this is ok or not. After use I removed & inspected the inserts, which were all perfect. No burrs or chips on any of the 6. The finish was like a mirror. Nearly but very good. I tried it dry & with cutting oil. Either way it was the same. Bonfire night. 

Any input please. Do I need to run faster deeper , ???. I did get 2- 63mm mills too, which looking up are pretty expensive items. One is a 6 cutter one which I believe is marketed by Sandvic. The inserts alone cost an arm. But some members have already said my machine may not be able to handle them. From using the 50mm one I think they may be right.

Steve.

Edited By Steviegtr on 08/05/2020 01:19:34

Hi Steve,

There is a nice cutting speed calculator on the LMS site that may give you some idea of the speeds for various materials. In my experience carbide works best at high speeds, 0.1mm depth of cut sounds too small to me, but you need a rigid setup.

Thor

It did not come from ARC as they don't do that size in 6 insert and don't do any that take teh size 11 inserts

What inserts are you using, they come if different grades some more suitable for hardener steels as your holders are hardened. Once you know what inserts you have go look up the recommended speeds on the makers website so you at least have that part right. You are unlikely to match their feeds and DOC but 0.1mm is just rubbing the insert.

Hardend steel with a 50mm cutter you are probably looking at 80-100m/min speed = 1600-2000rpm with the correct inserts but doubt the machine will handle a feed of 450mm/min. But really comes down to how hard the holders really are and will they or the machine win.

Edited By JasonB on 08/05/2020 08:19:52

I fitted new inserts & checked each insert was touching off & they were.

Unfortunately, if you only checked in one axis (the z?) that is not the only one that requires checking.

No, it is not “OK” for lots of sparking to occur.

Little point in having six inserts, if only one is doing any work.🙂

In this case it may have been an advantage as Stevie will only have blunted one out of the six inserts

A facemill is the wrong tool for machining hardened steel. The inserts are not designed for it. I machine HSS toolbits with standard carbide endmills. The swarf should be coming off red hot. Hardened steel can be turned with ordinary CCMT inserts, but they don't like it. Much better to use CBN inserts.

Andrew

Now i remember why i ground one I modified. It wasn't a great finish but it was a non working surface.

Martin C

I must be getting old and out of date as I would not dream of machining hardened steel with any type of cutter,thats why there are surface grinders to do that work,if the hardened toolholder is case hardened then grind through the case hardening with an angle grinder and then finish off with a milling cutter.

This is the chart I have been using for the face mill inserts, they do give speeds for hardened steels but as I said it needs a specific insert grade. Several of the other makers don't give cutting data for hardened steels for these style of inserts but do as Andrew says for traditional milling cutters

No I have not blunted any of the inserts. I made sure each one scratched the surface. Also watching one of your video's as the cutter works it's way across the work it re-marks the surface the other way. Proving the tram is ok. ??

So from your remarks about origin. I went out into the sun to see if I could make out which inserts are in. I noticed some faint writing on the side of the cutter body. Mag glasses on. It says Iscar, HM90-FP0AP-10. HELI2000.

The inserts maybe wrong as you say. They only say M9. Dark in colour.???. However I do have quite a lot of ones that came with the other stuff I bought. Which maybe correct. HM90 APKT 1003 PDR. If that makes any sense to anyone. I think it maybe Steel & Stainless. See pictures.I also have some Kennametal ones which I cannot identify. The Iscar site shows the cutter but too many settings for my grey cells. I think reading between the lines it was saying 1200rpm & 0.8mm depth of cut. Does that sound right.

From memory of cutting down the holders when the lathe was used. The 1st 2mm of cut was terrible but once below that it was not as bad. So does that indicate they are case hardened. Also do I do as Andrew advises & have a go with the carbide cutters which I do have.

Steve.

Edited By Steviegtr on 08/05/2020 11:50:16

There's hardened steel and then there's hardened steel!

Most of my feed 'n' speed charts list hardened steel, by which they mean around 40-45Rc. I suspect this is roughly wwhere the tool holders will be. On the other hand there's fully hardened steel, in the range 60Rc to 70Rc. The silver steel test piece I turned was ~65Rc.

Andrew

Andrew. When I 1st started doing these I gave one to a friend to do for me. He returned it saying it was too hard & did not want to wreck his cutters. That said, I did do some on the lathe with H.S.S which was all I had at the time. I had to keep sharpening the tip. The only way I can test is with a fine file. I can file them but not as easy as mild steel. ??

Steve.

Nice cutter, but the spec shows it's good for up to 25,198 rpm and 10mm depth of cut (with internal coolant). It's a metal muncher designed for a heavy fast rigid machine with tens of horsepower behind it. Tom Senior never designed a mill for a cutter like that beast. Probably still useful though.

As it won't be possible to drive the cutter as the manufacturer intended, experiment for best results. Which combinations of material, rpm, doc and feed-rate work with a 1/2HP motor and a decently rigid small machine? I doubt anyone knows - it's a suck it and see job.

Dave

Thanks for that Dave. Yes best just to try various speeds & cuts. One thing I have taken from this is the speed for carbide is best high. Might not reach the 28,000 though. I will change the inserts for the Iscar ones as I think they are for steel & not sure about the ones in there at present other than it says M9. In JasonB's chart for a 50mm cutter, what is the Fz mm/t for. It says 0.05- 0.08

Steve.

Chip load; the amount, in millimetres, a tooth cuts per revolution. To get the feedrate multiply the chip load by the number of teeth, 6 in this case.

Andrew

Thanks for that. I thought it was depth of cut. I still have no idea of the answer to that. that. As SOD says suck it & see.

Steve.

Agreed. I think that was the one important measurement that doubleboost avoided measuring, with his noisy chinese facemill? I have my suspicions why.🙂 You don’t show the down-sides of the kit if you want more freebies. Emma did - and hasn’t been ‘invited’ to review anything since reporting the truth about the angle plates she was supplied to review HERE

Yes as I said really depends on just how hard they are.

If any of those insert boxes have a grey colour band with H in in then they would be the best bet to try

May also be worth looking up the spec for your Swizz+tech cutters to see if they give a hardness on them, you can get cutters for hardnesses such as 45, 55 and 65Rc, the higher the number the more they are likely to do the job

NDIY, I did ask on DB's video if he checked the sideways runout as that is the direction the teeth actually cut in but did not get a reply. Bit like when he was clocking the runout of something and had the Dti half way round the side rather than over the highpoint so it did not show as much deflection.

Steve,

I am guessing that 6 insert head (not ARC) is from your eBay hoard on this thread:

**LINK**

That was possibly/probably a good buy.

I think on another thread someone suggested that you consider loading three of six pockets with the carbide inserts - balanced out, which may put less load on your machine.?

Ketan at ARC.

Yes that is correct. it is a Iscar I believe they are made in Israel. Can I do that & use with just 3 inserts. ??