2 inch face mill problems

Just editing some video but what I have found confirms that not all inserts were cutting and that a hobby bench top machine just can't take feed rates that the Bridgeport and above can. Stay tooned!

I do think ridgidity of the machine does have a big part to play and the noise off the gear train on the mill is horrendous in some cutting situations

Rich

I run a couple of face mills on my Bridgeport, a 40mm and a 50mm with three and five teeth respectively. Both use a triangular 16mm tip. Being a tight wad I buy TPUN160308 turning tips and grind them by hand on a diamond wheel. They cut well give a good finish and last well between touching up the cutting edge. Much more cost effective than designated TPKN milling tips.

.

With due deference to Muzzer; I shall simply mention 'Angels and Pins' and will say no more.

MichaelG.

So I put the arbor into the MT3 spindle and tightened it up and then went to mount the cutter and got the feeling that the 22mm bore was not that close a fit on the arbor compared with say a gear cutter or slitting saw. Dusted off the micrometer and the arbor measured 21.97mm dia, luckily uncle Ketan had sent me a dial bore gauge for the articles so set that up to read zero between the micrometer when they were at 22mm and poked it into the cutter read 22.06mm. So 0.09mm play which is confirmed by the first part of the video. Also clocked arbor at 0.0005" or just over 0.01mm tir.

I then fitted the cutter to the arbor and got about 0.1mm tir shown on the second part of the vid which confirms the above. Finally loosened the screw a bit and tapped the cutter true but it moved a bit when tightened, could have spent longer getting it about right but just over 0.01mm was good enough for this test. last part of video.

Edited By JasonB on 07/05/2018 11:13:45

Edited By JasonB on 08/09/2018 20:25:28

I've got one of these Banggod cutters but haven't used it in anger yet after having read everyone else's experiences.

The insert height originally varied by 16 thou which I managed to decrease to about 8 by swapping/changing the inserts. I have a good quality 3mt arbor which fits my Mitsubishi face mill snugly but is a 'loose' fit on the Banggood job like Jason found.

When I bought it I also got some inserts for aluminium, these are razor sharp as the now dried blood on them testifies and also the height difference is now down to 1 1/2 thou. I'm tempted to try these on steel and see what happens (I use the aluminium turning inserts on mild steel and they work a treat).

If i can find my camera battery charger I'll post a pic later.

Paul

Hi Jason,

Thanks for the videos, I have the same experience as you when it comes to 50mm face mills. Mine uses triangular inserts with positive rake, and like Chris I use cheap TPUN inserts that work fairly well. I don't take as deep cuts as you and use a fairly slow manual feed or else the overload protection is tripped.

Thor

OK Gents,

Very un scientific test on a piece of rusty black bar.

Left hand side was the inserts for aluminium, 10 thou depth of cut at 1000 rpm, hand fed. Any more than 10 thou and the vibration was awful and you could tell it was cutting unevenly by the sound. What I wasn't expectiong was the right hand side, same speed feed and depth but with inserts for steel. The faster you fed it the better it seemed to like it, even at a 40 thou depth of cut. It sounded fine but I know that the cutting teeth vary in height.(BTW my mill is a RF30)

The steel inserts were APMT1604PDER-M2. I didn't get the inserts with the facemill but I noticed that there seem to be two flavours available, both in grade VP15-TF. One is -M2 and the other -H2. From what I can find the H2 is for medium to heavy cutting and the M2 is for medium to light, they certainly seem to have a sharpish edge to them.

Maybe you have it, HasBean. The steel -M2 side looks not too sad at all.

Regards

Richard.

I am not clear on what inserts Richard was using. If it is a TP** insert there will be very little rake on the cutting face and will require extra force to get the inserts to cut. The APMT inserts pictured appear to have a rounded cutting edge appropriate for higher horsepower rigid machines. The APMT insert also has a dimensional tolerance of +-.005". The inserts with that large a variation can not be expected to equally share the cutting load. APKT inserts have a tolerance of +-.0005" if I remember correctly. That would be a much better choice. For low horsepower machines the APKT inserts intended for aluminum work quite well in steel and the cutting forces are reduced. I am using BG APKT inserts for aluminum in my 1 1/2" face mill and am extremely pleased with the results. My 4" face mill uses SEHT inserts. Lots of top rake. I highly recommend face mills using hat insert.

As I said earlier the triangular inserts are held vertically so zero rake but they need a lot less effort than the fcaemill to remove a similar amount of metal and give a better finish.

Hasbean, looks like you have it cutting well on the right side. I have noticed that in all the videos I have seen of these facemills they all seem to have a slightly different insert so this may be why some people get a good result and others poor, just need to find the one that works! Your narrower width workpiece will have required less power from the machine than if it were the full width of the cutter which may be another factor.

I have to confess I have no idea what inserts came with my cutter apart from the fact they were AMPT1604's. The insert box does not give any further indication (pot luck I got good ones, I think - it is typical of many of the Chinese inserts). Getting the right designation means it's possible to get the right ones again in the future - though not necessarily direct from China.

Regards,

Richard.

My 50 mm face cutter was sold to me with tips with a chip breaker, but when I went for new tips I was told to get them plain, without the chip breaker, they are 16 mm triangle. Being new to milling machines at the time of the initial purchase I asked about cutting speed, depth of cut, and feed rate, the answer was, put on about 1 mm DOC, 900 rpm, and crank like hell.

Ian S C

I've got one of those Chinese cutters, I mounted it on MT2 shank (blank end arbor turned to fit) and run it on my Centec. At 1000 rpm, 0.030" depth of cut and 0.002" tooth load it produces a mirror finish on steel and doesn't seem to cause the machine any distress. The backs of the inserts don't seem to sit down flat, but it works, so who cares?

I think you’re right Michael, it’s asking quite a lot of some desk top mills. If you also consider that some folks extend the quill as well it can’t be the most rigid of setups. I have a VMC which is a fairly solid machine for its size but it’s never occurred to me to get a face mill. I’m only a hobbyist though and I get a nice finish with a Flycutter.

I got my genuine Korloy (Korean) 50mm face mill from a UK shop on ebay IIRC - unused but under half price. Then I got a couple of packs of APMT1604 coated (for steel) and APGT1604 (uncoated for loominum) inserts also from ebay. I went for Mitsubishi branded parts and as far as I can tell that's what they are.

Proper inserts must be used by the billion out there, given the range and volume of stuff they churn out. so it's hardly surprising that some make their way onto the market. I stick with Korloy, Mitsubishi, Taegutec etc and if you shop around they cost around £2 per insert inc P&P. Aliexpress is also a good source for inserts, both turning and milling. Good prices and generally pukka parts.

Murray

I treated myself to a couple of sets of new inserts, ordered yesterday and they arrived today so gave them a try out this evening.

The Grey (PVD Coated) ones are a General purpose insert for steel, stainless, exotics and cast iron with a 0.4mm corner radius and made by YG-1. The edges of these feel noticably sharper than the two types of Bangood inserts. The other ones are by Korloy and are a high rake non-ferrous insert with polished finish again with the 0.4mm corner radius. These are sharper still as you would expect with a ground and polished finish

I clocked the holder to within 0.02mm and then put the same bit of cast iron into the vice, 1000rpm and about 125mm per min feed, 1.0mm DOC with teh general purpose inserts and it went through without stalling the machine with a much better finish. This is not good quality iron ( old multi gym weight) so there is some grain but no signs of the torn surface I got before and no vibration from the mill.

Next up a bit of 1.25" steel which cut at the same parameters gave a reasonable finish, think I marked it up a bit winding back out but a bit more time playing about with feeds and speeds should have it cutting well but don't think the X3 will take much more in the way of deeper cuts or higher chip loading. Andrew will be pleased that the chips were coming off blue.

Finally a piece of HE30 - 6082 with the non-ferrous tips, 1250rpm and 200mm/min feed, splash of paraffin and a very nice cut would easily have handled more.

So if your bangood facemill is no good try it with some better quality inserts as you don't really know what you are getting from them. but I suppose that is what to expect for dirt cheap, the eight new inserts cost me more then the arbor, facemill C/W 4 inserts and an extra box of ten inserts.

J

Just how it should be.

Also matches the colour of the language if a chip goes down your shirt front.

The theory is that most of the energy supplied by the motor goes into deformation of the chips so even with 500W (one electric fire bar) the chips ought to get pretty hot.

Andrew

Tips look good Jason where did you get them from ?, thanks for the help

Nice, viscious-looking inserts, the uncoated ones. But they don't look as I'd expect from an ISO-compatible APKT insert - also interested to know where you got them. That geometry has the 90 degree corner and a "wiper" edge to give a flat (axial) surface when used to face off.

This is what Korloy APKT160404PDFR MA-H01 look like from Cutwel. The H-01 suffix denotes Korloy's non-ferrous grade. Cutwel sells them for £8.40 inc vat (each) and even with 30% off that is pretty expensive. As mentioned, I get mine from ebay, Aliexpress etc.

Incidentally, these inserts are capable of almost 16mm of axial DOC, so they can be used for roughing and finishing external vertical faces. Arguably, you are losing much of the insert's capability if you only make shallow facing passes with them. You can get smaller holders that take one or two of these inserts - down to under 10mm, if you use the smaller APKT11 insert. Then they become usable for slotting and pocketing. Same problem though - very intermittent, noisy cutting.

Murray

Here's a single insert, 16mm dia cutter doing its thing in loominum. It's actually a Mitsubishi BAP300-series holder but the insert is very similar to the APKT style. Because it has only one tooth, the feed rate and MRR is fairly low, despite running at 6000rpm. I've gone over to solid carbide cutters now, as you can shift a lot more swarf in the same time. Perhaps this kind of cutter is best for production volumes, where you actually wear out cutters over a relatively short period of time and the costs add up. Forgive the silly title but this was the first ever metal I cut on the CNC machine.

Edited By Muzzer on 09/05/2018 22:27:03