2 inch face mill problems

hi I have an x3 mill recently bought a bangood indexable 50mm face mill, when machining a tool holder down so it would fit in my lathe tool holder the surface finish was Terrible when putting a straight edge over the cut edge it would rock how is this even possible if the cutter was engaged in a full cut the z axis was locked so head couldn’t move, also I have noticed when machining the head cuts twice eg tramming from right to left when the cutter that is not in the work passes over the cut edge it starts cutting again slightly,

Rich

What is the toolholder design?

Is it one with a common insert holder and an interchangeable taper? If yes, investigate the tightness and fit of the joint between the two bits.

Regards

Richard.

Hi Rich it’s this one but r8 drive

I bought one too and had the same poor result. You can see by the worklight how much vibration is caused. I think it is only cutting on one tooth and the whole cutter is riding up on the work.

Looks like its rubbing rather than cutting, what are the inserts like?

Is this the same one that was recently reviewed, on u-toob, for banggood?

Yes same as John doubleboost I bought one off the back off that

From what I have watched on the tube they change to better inserts, the ones provided are not as sharp as they could be.

That's what you'd hope to see. If the "back" of the cutter didn't make any kind of contact, it would suggest your head isn't trammed correctly and you will end up with a slightly concave surface.

It's not possible to conclude anything solid from the comments and video. Opinions perhaps but you'd need to do some more objective / methodical tests to narrow down what's happening. So for instance, to see if all the inserts are cutting, you'd need to examine them and possibly mark them to see if there is any contact. And measure the runout, particularly the axial runout etc with a decent indicator. I think that's one thing John Doubleboost missed out on.

The speeds and feeds are important for these indexable tools. It's not clear if there were any calculations done or if the handles were just being turned. Even without CNC, it's got to be a good idea to set your power feed to the right speed range recommended by the insert manufacturers.

Murray

For reference, for mild steel I would be using 1000rpm and 0.1mm / tooth ie about 500mm / min for a 5 insert cutter. Good idea to use coolant or WD40 even.

Edited By Muzzer on 06/05/2018 20:32:38

Inserts are APMT 1604, both teh supplied four and some from another box give similar results though I will get some better ones when I next order from APT.

First 3 cuts in the video were at 500rpm then after I struggle to change gear with one hand the last cut is 1000rpm, power feed approx 150mm per min on a 4 tip cutter anymore just vibrated too much. The unmachined part of teh cast iron was done with a 40mm 3 insert cutter using TPAN inserts set vertically so zero rake which works a lot better.

I have a similar cutter bought from cskwin2015 on e-bay, and was using it this afternoon without problems. I do not have power feed available, and was using it at 1600 rpm, and approx 50 mm/min, maybe a little faster, one turn of the feed handle every 2-3 secs and 2.5mm per turn. Why such high rpm? Well I had the belts set up for a 6mm cutter and figured the tips could be worked very hard on a CNC machine, so could stand high heats, which meant fast speed if the feeds were low. And I was too lazy to change the belts. The chips came off blue.

I think Jason has it right in suggesting you check for concentricity in the machine. Also, put it cutters down on a flat surface and see if it rocks between 2 cutting tips, that would be a good indicator if one insert was too low and doing all the cutting. Check if the insert is over size, change if it is, but if not, consider complaining to banggood or remedial work with a Dremmel on the tool holder. Shouldn't be needed, but could save the day.

Regards

Richard.

Surely TC inserts are designed to be made to work hard... if you're feeding by hand, up your feed rate so the teeth cut rather than rub, same for aluminium, if you don't have a decent feed rate the cutters ( inc. HSS ) will rub & have aloominum soften & stick to the cutter... plus WD40...just my two penn'orth

George.

Darn right, and true for any cutter, especially with conventional milling. If the feedrate is too low the teeth rub before cutting which wears the cutting edges in short order.

Andrew

I'll give it another go with a higher feed rate but as my other cutters produve a good finish at about 150mm/min and the machine complains above that I have a feeling it is more down to the rigidity of the machine not being able to push the relatively blunt edge of these tips through the work hence the tool riding up over the work.

This is the sort of finish I can get with the 40mm 3 tip tool which is far better than the Bangood gives as similar feeds

Jason,

Can I ask where you get tips for the cutter in the last photo? I have a 32mm end mill with similar tips but one fell out after the screw loosened a bit under the initial vibration on starting a cut and is now lurking somewhere in the workshop. I have been unable to source a replacement - possibly because I have no idea of their acronym - how could one find a CCMT06 without putting the name in?

But.. Surely those tips are horrendously blunt compared to the AMPD1604's where the edge is shaped and thinned to present a chisel edge rather than a scraper.

Regards

Richard

I get them from where I got the holder - Chronos/Glanze 

It is more where the edge meets the face that looks quite blunt on the APMT inserts compared to the TPAN triangles not the actual angle of the cutting edge. Will see if I can get a close up of the two by way of comparison.

Edited By JasonB on 07/05/2018 07:52:09

Could not get a good shot of the edges but these are the triangular inserts

Ah-ha. The web Chronos website has spawned a Glanze site since I bought the holder, knowing TPAN as an acronym means I can now find the inserts. Thanks Jason.

Maybe that's the difference, the inserts I got from cskwin2015 do actually feel quite sharp on their edges. Not quite as sharp as the little ccmt06 lathe tool inserts, but not far off.

Regards

Richard.

I think the edges are too blunt for our machines, they're designed to be ploughed into with a Bridgeport, which would have the rigidity to do that.

The type of cuts you need to take with a hobby machine dictate that you can't go too fast into the work piece or take a cut too deep, it's just the nature of the machine for most of us.

A sharp pointed tool like jasons example show how you could get a far superior finish and real cutting action at low feed rates and cut depths.

Anyone wanna try sharpening the originals and seeing the results?

Michael W

I don’t feel that it is the depth difference between tips - more likely one tooth is cutting on a larger diameter - the one check that doubleboost either forgot about doing, or conveniently ignored.

The tool I bought, which was no good had a supposed morse taper that was of the wrong angle and only gripped at the drawbar end, so chattered in the morse socket. Total carp.