Thread: Two thou bigger at one end !

Originally Posted by simonl

Hi Baron,

Another observation is that because you are not using a "dedicated" milling vice, you may find that the jaws of the vice may slightly lift when tightened. This would also give rise to unrepeatable results. While it may not be relevant with the test you are conducting since you are measuring with the jaws still tight after cutting, if you were to loosen and re-tighten you may well find a different result yet again.

Just a thought.

Simon

Hi Simon,
Yes I've already discovered that the moving jaw lifts a fraction when tightening it up even after tapping the work down it still pushes up a fraction.
Originally when I bought this vice, new sometime in the seventies, I discovered that it rocked ever so slightly. Stan who ran the workshops next door at that time ground the base dead flat for me.

Baron J
Please lets know how the 50mm dia 3 MT Carbide cutter performs in your Mill.
This sounds like the same cutter that I was considering for my Hercus Mill, but did not go ahead because of limitations described.
Coupled with some work, "Anorak Bob" on this forum had accomplished with the same Hercus mill as mine we decided to stay with HSS.
Please lets know how your borrowed cutter performs on heavy cuts on mild steel.
regards
Bruce

Hi Baron,
You may have run the carbide cutter already, but i would suggest just using a 12mm or so HSS endmill and running it over with a 1-2mm overlap. I would think carbide would need more rigidity than you have, especially if you are trying to take a light cut. Carbide doesn't really like really light cuts because it tend to push the material off the workpiece rather than cut it.

Ew

Just a thought

Can you try using a DTI or another dial indicator, or a different setup to verify that the problem is there and it is .002" ? Somewhat like a second opinion Mike

Originally Posted by Abratool

Baron J
Please lets know how the 50mm dia 3 MT Carbide cutter performs in your Mill.
This sounds like the same cutter that I was considering for my Hercus Mill, but did not go ahead because of limitations described.
Coupled with some work, "Anorak Bob" on this forum had accomplished with the same Hercus mill as mine we decided to stay with HSS.
Please lets know how your borrowed cutter performs on heavy cuts on mild steel.
regards
Bruce

Hi Bruce,
The face mill is a "Glanze" 50mm three carbide tip one on a MT3 mandrel.
My mill is rated 1Hp. I ran the cutter at 850 rpm as advised by the guy who loaned it to me and took a 5 thou skim across the top of the jaws. No problems at all.
The surface finish is good and the dial gauge needle just stays still. I'm now quite happy.

You asked about MS. I had bought a chunk of BMS to make a QCTH but it needs squaring up. So I took a 0.5mm cut across the length of it. I'll go and take a photo of the finish later. I'm not unhappy about it but did find that the face mill, whilst is marked 50 mm on the tool, it doesn't cut 50 mm wide. More like 47 mm. So I've got a small edge or ridge on either side.

Originally Posted by morrisman

Just a thought

Can you try using a DTI or another dial indicator, or a different setup to verify that the problem is there and it is .002" ? Somewhat like a second opinion Mike

Too late Mike ! I already did that with the Verdict 0.0001 gauge. Although I don't like using the Verdict. The needle jumps around unless the surface is dead smooth. Most times it isn't.

Originally Posted by Ueee

Hi Baron,
You may have run the carbide cutter already, but i would suggest just using a 12mm or so HSS endmill and running it over with a 1-2mm overlap. I would think carbide would need more rigidity than you have, especially if you are trying to take a light cut. Carbide doesn't really like really light cuts because it tend to push the material off the workpiece rather than cut it.

Ew

Hi Ew,
Yes your right I have already run the face mill over the vice top. I'm now happy about the finish and the parallelism to the table.
See a couple of posts up. I'll take a photo of the piece of BMS that I've skimmed with this cutter. I would appreciate any comments.

Originally Posted by BaronJ

Hi Bruce,
The face mill is a "Glanze" 50mm three carbide tip one on a MT3 mandrel.
My mill is rated 1Hp. I ran the cutter at 850 rpm as advised by the guy who loaned it to me and took a 5 thou skim across the top of the jaws. No problems at all.
The surface finish is good and the dial gauge needle just stays still. I'm now quite happy.

You asked about MS. I had bought a chunk of BMS to make a QCTH but it needs squaring up. So I took a 0.5mm cut across the length of it. I'll go and take a photo of the finish later. I'm not unhappy about it but did find that the face mill, whilst is marked 50 mm on the tool, it doesn't cut 50 mm wide. More like 47 mm. So I've got a small edge or ridge on either side.

Baron J
Thanks for the info.
Because I still think in Imperial, as Im reading about the cut depth my mind is converting 0.5mm to 20thou.
A fairly light cut.
Been looking at those Glanze carbide heads & I was thinking of deeper cut depth say 60 to 100 thou in other words
something for "hogging" metal off quickly. My Hercus mill has a top speed of 1200 rpm, but I think the torque would not be high enough at that speed to cope with what I had in mind.
Understand that this is only hobby & occasional use.
Have used Shapers in the past & always regret selling the machine, I had.
Shapers with a single point low cost HSS Toolbit in my opinion are a wonderful means of removing metal.
It looks like you have corrected your accuracy problem, with the right tool in the mill.
regards
Bruce

Hi Ken,

If you recall you mentioned MDF under the vice.

There are a couple of photos below showing the vice and the covers that I use to protect the table and make cleaning it easier.

I how that this explains things.

Originally Posted by Abratool

Baron J
Thanks for the info.
Because I still think in Imperial, as I'm reading about the cut depth my mind is converting 0.5mm to 20thou.
A fairly light cut.

Yes 20 thou is right. I tend to think in inches then mentally convert to MM.
In fact I owe an apology ! I said in an earlier post that the Glanze didn't quite cut 50mm. It is nearer to 49.5mm. I thought the piece of BMS was 50mm thick, in actual fact its 2" thick. Sorry guys. (

[qoute]
Been looking at those Glanze carbide heads & I was thinking of deeper cut depth say 60 to 100 thou in other words
something for "hogging" metal off quickly. My Hercus mill has a top speed of 1200 rpm, but I think the torque would not be high enough at that speed to cope with what I had in mind.
Understand that this is only hobby & occasional use.
Have used Shapers in the past & always regret selling the machine, I had.
Shapers with a single point low cost HSS Toolbit in my opinion are a wonderful means of removing metal.
It looks like you have corrected your accuracy problem, with the right tool in the mill.
regards
Bruce
[/QUOTE]

I ran the face mill at about 850 rpm because that is what was suggested it would be OK at. I could have taken a deeper cut but then I wanted to take as little of the top of the vice as I could. Its already about 6 mm lower than it originally was when it was new.

I've included some photos of the Glanze and the surface finish from a 1 mm cut across the top of a different piece of BMS. The photo makes the finish look much worse than it really is. I ran the face mill for this job at 1050 rpm and wouldn't like to take a cut much deeper. At least on my machine. It wasn't struggling but I could hear a very faint ticking sound which varies with spindle speed. I suspect a bit of swarf in the gears or something like that. While I remember. I was in low gear 1200 rpm max and in high gear 2600 rpm max with a variable speed 1Hp motor.

BaronJ

Nice cutout job on the mdf. On the original it looked to me that the mdf went all the way under the vice. For a better finish with that type of cutter head, only use one insert. Use it like a fly cutter. There is no possible height difference between multiple inserts.

As to a replacement vice; 'K' body type is ok but the angloc style better. Vertex brand are good and you have dealers over there where Aussies import from.

Ken

I'll be in the market for a 50mm face mill myself soon. From reports, on these smaller machines, the 45 degree face mills are the best option unless you need to mill up to a shoulder.

Just thinking back to your issue, I know you have it worked out now, but another observation/caution to watch out for. I was using my mill last night and when trying to take a cut 4mm wide with a brand new 4mm 4 flute endmill on steel my quill was pushing back up into the head even though it was locked off. At least on mine it has a round knob that locks the quill so its quite difficult to put much pressure on it but I would have hoped that wouldn't be necessary. Anyway, as I was taking a cut I noticed a change in the depth of cut and realised that as I cut across the piece the quill DRO revealed that the quill was being pushed back up into the head.

I'll have to have a closer look at this setup and see if I can improve the lock mechanism, either by increasing the contact that the screw makes with the quill barrel or maybe as a second option switch the round knob out to a lever type knob that allows me to put a bit more torque on it.

These mills are certainly a compromise, but I'm starting to learn my way around them.

Baron J
Thanks for the good info & trials on your carbide cutter.
regards
Bruce

Originally Posted by Toggy

BaronJ

Nice cutout job on the mdf. On the original it looked to me that the mdf went all the way under the vice. For a better finish with that type of cutter head, only use one insert. Use it like a fly cutter. There is no possible height difference between multiple inserts.

As to a replacement vice; 'K' body type is ok but the angloc style better. Vertex brand are good and you have dealers over there where Aussies import from.

Ken

Hi Ken,
Yes I agree with you about using only one insert. This isn't my Facemill so I don't want to mess around with it. I've got a piece of stainless steel this morning. Its about 3" in diameter and 3/4" thick. I've been told that it should be free machining but to throw it out if it hardens when I try to turn it. Its an offcut from a length of bar they got as free issue for a job. It was free to me so no sweat if I have to dump it ! I intend to make another fly cutter with it.

Fine on the vice. I don't know if you have seen the prices that they want for these things over here... Ouch. Its just cost me £150.00 for a Vertex rotary table. Actually the second one. The first one that came had a bent spindle and turned with great difficulty, so it went back. The dealer was very good and sent me an immediate exchange replacement. This one I am happy with, its smooth and no visible backlash. I just have to make some locating bars so that is locks accurately to the mill table in both horizontal and vertical planes. Then I will have to make a tailstock to match it. The list seems to just get bigger. ) ) )