Thread: HM 52 or similar Face Mill Cast Iron

Just curious if any one has been using a 100 or125 face mill runnng SEKT inserts on their machine.

Holder is KM12 type

If so what results are you getting?

What depth of cut are you achieving?

Are you feeding above 100 mm/ min?

What RPM are you running ?

Are you using SEKT or SEHT inserts?

Thank you.

75 mill face with sekt on the BM30 and result was crap....have not tried it since....I put it down to faulty inserts from Banggood...

Thank you for the reply, I have 100 plus face width that I am currently machining with a 80mm face mill , depth of cut varies between .5 and 2.5,mm.

Have squared the head as best I can.

Really looking to see if any one has been able to achieve an exceptable finish with minimal step if any, between the two cuts, and also what type of tip life are you getting from the cutting tips.

Dont really want to buy a 100 mill cutter and arbor if good results can't be achieved.
I would class a .05mm or less step as good and .07mm step or less as okay.

While I am not going to be mean much help here , your question reminds me of the time back in the ETSA apprentice training centre wher one of the instructors got tired of us taking smallish cuts with the big face mills.

So as a demo he set up on the big Mazak mill the biggest face mill he could find and set the machine for the fastest speed and fastest feed and let it rip. Well there were blue hot chips the size of your finger nail flying all over the place not to mention people dashin around trying to avoid getting hit by the them or stopping them going down the front of your shirt.

Cheers

A facemill that big is going to be a struggle in that size machine you will be a lot better off with a flycutter.

Originally Posted by pipeclay

Thank you for the reply, I have 100 plus face width that I am currently machining with a 80mm face mill , depth of cut varies between .5 and 2.5,mm.

Have squared the head as best I can.

Really looking to see if any one has been able to achieve an acceptable finish with minimal step if any, between the two cuts, and also what type of tip life are you getting from the cutting tips.

Don’t really want to buy a 100 mill cutter and arbor if good results can't be achieved.
I would class a .05mm or less step as good and .07mm step or less as okay.

Hi Pipeclay,

My go to tool for that sort of work is a fly cutter ! I'm sure you have seen pictures of the ones I make.

New_Flycutter-2.JPG New_Flycutter-1.JPG

This one is a 20 mm thick 75 mm diameter disc on a 20 mm shaft.
Your mill is heavier than my little BF20 so a larger diameter would cut full width.

I do have a 60 mm insert face cutter but it is really too big for my mill and the finish is rubbish !

Interesting flycutter.
Apparently some euromills have as acccessories heavy discs to be attached to the spindle when facemills are in use That increases the inertia of the rotating mass to thereby smooth the cutting, reduce chatter and reduce vibration in the drivetrain.

Hi Guys,

The rationale behind the design of my fly cutter was first, rigidity, 20 mm is the biggest diameter that I can hold in my tool collet on an MT3 arbour. Second was balance. A hole just big enough to hold a 6 mm square of HSS tool steel with a 2 BA grub screw. I've spun this at the maximum speed of my mill, 2200 rpm with no noticeable vibration at all. Third tool deflection, a 1 mm depth of cut is possible but my mill struggles with that. As far as bulk metal removal is concerned 0.5 mm or about 25 thou is comfortable, but a 2 thou finishing cut leaves a mirror like surface on most materials except plastics, where it looks like it needs a shave.

I've also made a couple of small ones, mainly for producing a flat bottomed hole and a dovetail or two.

Originally Posted by BaronJ

Hi Guys,

The rationale behind the design of my fly cutter was first, rigidity, 20 mm is the biggest diameter that I can hold in my tool collet on an MT3 arbour. Second was balance. A hole just big enough to hold a 6 mm square of HSS tool steel with a 2 BA grub screw. I've spun this at the maximum speed of my mill, 2200 rpm with no noticeable vibration at all. Third tool deflection, a 1 mm depth of cut is possible but my mill struggles with that. As far as bulk metal removal is concerned 0.5 mm or about 25 thou is comfortable, but a 2 thou finishing cut leaves a mirror like surface on most materials except plastics, where it looks like it needs a shave.

I've also made a couple of small ones, mainly for producing a flat bottomed hole and a dovetail or two.

Hi Baron,
I loved this posting because of your references to 'mm' , 'thou', '2BA', .
Us colonials can be quite adept at manipulating units, but your reference to BA threads; well I have to ask.
Aussie manufacturing, up until about 1975, was pretty much BSW, BSF, and for small stuff, BA. I have a box full of 5BA screws and sets of BA taps. I even have the number drills for the tapping sizes.
The US car makers particularly, introduced Unified threads. My old Vauxhalls had UNC/UNF threads, so I guess Britain had a mix of BSW/BSF/UNC/UNF. I had a 1961 Humber which used BSW/BSF threads.
So is the BSW/BSF thread forms still widely available in the UK or has the UK gone Metric because of the EU/ECM. And, what is the status of BA threads?

I would be interested to hear your comments on this subject.
regards,
rumpfy

Originally Posted by rumpfy

Hi Baron,
I loved this posting because of your references to 'mm' , 'thou', '2BA', .
Us colonials can be quite adept at manipulating units, but your reference to BA threads; well I have to ask.
Aussie manufacturing, up until about 1975, was pretty much BSW, BSF, and for small stuff, BA. I have a box full of 5BA screws and sets of BA taps. I even have the number drills for the tapping sizes.
The US car makers particularly, introduced Unified threads. My old Vauxhalls had UNC/UNF threads, so I guess Britain had a mix of BSW/BSF/UNC/UNF. I had a 1961 Humber which used BSW/BSF threads.
So is the BSW/BSF thread forms still widely available in the UK or has the UK gone Metric because of the EU/ECM. And, what is the status of BA threads?

I would be interested to hear your comments on this subject.
regards,
rumpfy

Hi Runpfy,

I haven't been called a "Colonial" for a very long time .

Yes all the thread forms that you mention are still around ! My use of BA threads was simply because I have some quantity of them and at one time quite involved in electrical engineering.

I was in fact looking at a box of taps the other day sorting out the different threads. I keep picking up odd ones at various places that I visit now and again. Mainly because old or damaged taps and cutters are good tool steel that can be pressed into service for other purposes.

Engineering firms today don't even bother sharpening cutting tools anymore, they just throw them into the scrap metal bin. A scrap yard that I frequent has an 8 ton skip almost full to the brim with carbide inserts, cutters and the like.

Thank you for the replies.

The job could be performed with the use of a fly cutter, but the time it would take and the number of cuts required would not be realistic at present.

Currently around .125"/3mm of material needs to be removed from each face.( roughing )
The use of a fly cutter would probably be feasible for a finish cut.

The 80 mm cutter is performing well the only limitation on this machine is a reduction in feed is required above 2 mm depth of cut.

Hi Pipeclay, Guys,

Yes I understand where you are coming from. I found that feed was important as well ! The sweet spot for me seems to be around 350 rpm and 40 - 50 mm a minute at 15 to 20 thou DOC in steel. Cast iron is about half that feed rate at about 20 - 25 mm. A carbide insert fares much better ( a carbide parting insert in place of the HSS )
but it makes bloody hot chips.

Originally Posted by pipeclay

Thank you for the reply, I have 100 plus face width that I am currently machining with a 80mm face mill , depth of cut varies between .5 and 2.5,mm.

Have squared the head as best I can.

Really looking to see if any one has been able to achieve an exceptable finish with minimal step if any, between the two cuts, and also what type of tip life are you getting from the cutting tips.

Dont really want to buy a 100 mill cutter and arbor if good results can't be achieved.
I would class a .05mm or less step as good and .07mm step or less as okay.

I just went looking for a photo from late last year when I machined my larger cast iron bandsaw bed, but can't seem to find it.
I know I sent some to Peter (Bollie) showing him the wear and the finished job.

I never got any step between passes using my 75mm facemill, I could see the pattern, but couldn't feel it. From memory I had to do 4 passes. As for depth I was trying to take as little as possible off, I think I ended up a little over 1mm.

Found them

Another one