Author Topic: Better Try and Use It Not Just Look at it  (Read 1312 times)

Offline Twizseven

  • Full Member
  • ****
  • Posts: 275
Better Try and Use It Not Just Look at it
« on: May 29, 2019, 09:17:46 PM »
Having had my nice new mill for a few weeks and gradually assembled tooling for it, I thought I'd better try to use it.
 I need to 'T' nuts to use with my clamp kit from old mill. Cut a couple of lengths of 1" x 3/4" and need to bring down a small amount on two sides prior to making into a 'T'

Mill runs nice and quiet and the power feed on X is great, start it going and just watch.  :) I'm using a 50mm tipped facemill and running at about 360rpm.  The finish leaves a bit to be desired.  :headscratch: It looks a bit scratchy,
but feels pretty smooth.

Ideas?

Colin

Offline pgp001

  • Full Member
  • ****
  • Posts: 649
  • West Yorkshire - UK
Re: Better Try and Use It Not Just Look at it
« Reply #1 on: May 29, 2019, 10:23:21 PM »
It looks like you have it perfectly "trammed" ie it is cutting on both the leading and trailing sides of your face mill.
I like to have mine set with the vertical head just a smidge over so that it only cuts on the leading edge and the trailing side misses the newly cut surface by a couple of tenths of a thou.

In theory this will produce a very slightly concave surface which also depends on the swept radius of the cutter, but for most purposes it will be perfectly adequate.
I know I am now going to get told the error of my ways by the more knowledgeable folks out there, but it works for me.

Phil

Online b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13576
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: Better Try and Use It Not Just Look at it
« Reply #2 on: May 29, 2019, 10:39:18 PM »
Did you use any coolant? That can help the finish a bit. Otherwise looks good.

Bill

Offline Florian Eberhard

  • Full Member
  • ****
  • Posts: 432
Re: Better Try and Use It Not Just Look at it
« Reply #3 on: May 29, 2019, 10:42:05 PM »
Hi Colin

The finish depends on lots of factors:
- Material
- Cutting speed
- Cutter geometry
- Spindle accuracy (actually how good the spindle bearings are adjusted)

The finish you are showing is pretty normal for structural steel (I am guessing that's what it is...?)

Florian

Offline john mills

  • Full Member
  • ****
  • Posts: 116
Re: Better Try and Use It Not Just Look at it
« Reply #4 on: May 29, 2019, 11:23:28 PM »
350 rpm is very slow for a 50mm carbide tipped Dia cutter i would run that at 750rpm on tool steel .for mild steal
could be faster .

Online Jasonb

  • Full Member
  • *****
  • Posts: 6513
  • Surrey, UK
Re: Better Try and Use It Not Just Look at it
« Reply #5 on: May 30, 2019, 07:04:55 AM »
Quality of the insert also plays a big part, if it was a cheapie facemill then tips will be the same, expect to pay more than the head complete for 4 decent inserts.

Offline Twizseven

  • Full Member
  • ****
  • Posts: 275
Re: Better Try and Use It Not Just Look at it
« Reply #6 on: May 30, 2019, 01:02:02 PM »
Jason,

The facemill and inserts were from JB.

I have just spotted that I appear to have 4 tips with a fine radius and two tips without the radius.  I have one more non radius tip so will try the facemill with three non radius tips only and see what finish I get.

I think a visit to Maydown is called for to get some good tips for this and a couple of other tools.

The material is BDMS (080A15).

I was not using coolant.  I have just filled tank with Castrol Hysol T15 but at the moment a few of the segments in the coolant pipe are split and coolant squirts everywhere, notably on the floor.

What is the concensus regarding coolant with tipped tools, I was under the belief that its not the best thing for tipped tools and to just use it if using HSS cutters.

Colin

Offline john mills

  • Full Member
  • ****
  • Posts: 116
Re: Better Try and Use It Not Just Look at it
« Reply #7 on: May 30, 2019, 01:49:45 PM »
on using coolant with these type of cutters ,it does make it give better finish keeping thing cooler letting you use higher mental removal but for it to be of benefit you need plenty of it at good pressure so it gets to the cutting edge.if you just dribble it on it will mostly not get to the cutting edge were it needs to be.the table needs to be
enclosed enough to contain the spray great on cnc machines were the table is enclosed and you can shut the doors
and the coolant can not get out.for smaller low power machines that are open you are only going to get wet
and spread coolant all over the place making a mess.So you are better to leave the coolant off the tips will be
quit happy .The worst thing is a odd dribble that does not constantly cool the tip suddenly quenching hot tips now and then.if the stream is not consistent a strong flow it probably isn't getting to the cutting edge constantly although it might look like it.Better to be dry.I don't like being sprayed with coolant or cleaning up the mess.
if you can contain a strong flow then you can use coolant.but the cutter will be happy without it.

Offline Twizseven

  • Full Member
  • ****
  • Posts: 275
Re: Better Try and Use It Not Just Look at it
« Reply #8 on: May 30, 2019, 09:25:15 PM »
John,

Thank you.  I had heard that it was the heating/cooling that was not beneficial.  Although I have guards on the front and side of the table, there are none on the back, so will forget coolant with tipped cutters.

Colin

Offline gerritv

  • Full Member
  • ****
  • Posts: 542
  • St Catharines, ON
    • Gerrit's Hobbies
Re: Better Try and Use It Not Just Look at it
« Reply #9 on: June 01, 2019, 01:52:09 AM »
I made a copy of the Fog Buster, uses 15 psi pressure on the fluid and air. Spits coolant out, no streams. At a minimum it keeps the work cold. I use this on my lathe, mill and band-saw. It noticeably improves the cut quality for me.

I find this does a great job of cooling as well as adding enough oil to the cutting edge. I usually try to point it directly at the leading edge of the cutter. (I saw an analysis once that indicated this was the optimum way of using oil spray coolant)

Gerrit
Don't confuse activity with progress

Offline Twizseven

  • Full Member
  • ****
  • Posts: 275
Re: Better Try and Use It Not Just Look at it
« Reply #10 on: June 01, 2019, 04:48:58 PM »
I do have something similar but not used it as yet.

Finished a batch of 7 'T'nuts.  Tapping them M12 was a bit of effort.  I must admit drilling them was almost a pleasure.  Lots of power and a decent speed (I use 1400rpm) much easier than on the old mill.
I have another bar waiting to make another batch of 7, but this time will drill and tap them to a smaller size, Most likely 4 @ M8 and 3 @ M5 for holding smaller stuff to the table.

I was wondering whether it is worth oil blacking them, if so, what is the best way to do this.

Colin

Offline gerritv

  • Full Member
  • ****
  • Posts: 542
  • St Catharines, ON
    • Gerrit's Hobbies
Re: Better Try and Use It Not Just Look at it
« Reply #11 on: June 01, 2019, 06:30:17 PM »
I prefer to blue/blacken, mostly for appearance (it just looks right so it must be :-)) . Heat soak at 400-450F for 20 or so minutes. Swil in old engine oil for dark or vegetable oil for lighter colours.
At 450F or so the metal gets to blue colour by itself, the oil just gives it a bit more plus limited rust protection. Quite doable in a regular oven or a toaster oven.

Gerrit
Don't confuse activity with progress

Offline Twizseven

  • Full Member
  • ****
  • Posts: 275
Re: Better Try and Use It Not Just Look at it
« Reply #12 on: June 01, 2019, 08:32:23 PM »
Silly question, but for about the first time ever I have no old oil. I have new oil which is no longer required. I assume this will have the same effect.

Offline gerritv

  • Full Member
  • ****
  • Posts: 542
  • St Catharines, ON
    • Gerrit's Hobbies
Re: Better Try and Use It Not Just Look at it
« Reply #13 on: June 01, 2019, 08:46:06 PM »
I'm sure it will work fine, I just happened to have some used. Not sure if it is a myth or not that using dirty oil is better :-) The soaking at 400-450F should get you plenty of lovely colour.

Gerrit
Don't confuse activity with progress

Offline john mills

  • Full Member
  • ****
  • Posts: 116
Re: Better Try and Use It Not Just Look at it
« Reply #14 on: June 02, 2019, 08:53:07 AM »
I have used the fog mist coolant it was on the first cnc machine i used ,a beaver mill with a ANCA control.
it should be more of a mist  than a a spray .that was nearly 40 years ago it worked ,the machine was mainly cutting hot work die steels did a lot of profiling with ripper cutters shaping with facing cutters and engraving embossing dies.The afternoon and night shifts complained of the mist in the air to breath. Even with plenty of
air circulation
« Last Edit: June 02, 2019, 09:01:27 AM by john mills »