New Mill – Starter Tooling

[Ron LadenParticipant @ronladen17547]

I also got some time today on the flycutter I am making, despite having a sick lathe at the moment I did manage to turn the body. I then gave a bit of thought to the best way to produce the 20 degree angle for the tool mount. I was going to go with a 10mm end mill (the largest I have) but thought that across 40mm diameter that would be a lot of back and forth with each cut.

So I decided to flycut it using the boring head, I set it up at 20 degrees in the vice and took 0.5mm cuts. It worked a treat and the bonus was that each pass of the cutter covered the full diameter. I dont know how they are normally set up and cut but that was my take on it.

[Ron LadenParticipant @ronladen17547]

A new weapon for the armoury, finished the flycutter, well apart from blacking it. Something very satisfying about making tooling.

[Ketan SwaliParticipant @ketanswali79440]

Looks Good Ron,

Thanks for the plug with the tool bit logo. Just make sure to turn the logo bit side around so that it is inside… in contact with the grub screws in this particular case…. so that the correct side is facing out for the purpose of fly cutting.

Ketan at ARC

[Ron LadenParticipant @ronladen17547]

Posted by Ketan Swali on 09/12/2018 10:19:03:

Looks Good Ron,

Thanks for the plug with the tool bit logo. Just make sure to turn the logo bit side around so that it is inside… in contact with the grub screws in this particular case…. so that the correct side is facing out for the purpose of fly cutting.

Ketan at ARC

Well spotted Ketan, picture below with tool in correct orientation, well it is Sunday morning..

[Paul KempParticipant @paulkemp46892]

Ron,

Nice job.

Incidentally I noticed the diamond wheel dresser can be got from Chronos for about £8.

Paul.

[Ron LadenParticipant @ronladen17547]

First job of 2019, managed to get the T slots cut in the rotary table plate. It started out well enough but at the end of the 2nd – start of the 3rd slot the tool started to lose its edge. I have not used a T slot cutter before and it was a new HSS one but I could feel it just wasnt cutting as well. The 4th slot was quite hard work and I almost stalled the mill but just managed to avoid it. Anyway they are now cut and time to move on to making some fittings for the plate centre.

[Mark Elen 1Participant @markelen1]

Hi Ron,

Your plate looks great. Keep posting the updates, I’m interested to see how you get on with it.

Happy New Year

Cheers

Mark

[Anonymous]

Nice looking sub-table, but there's summat wrong with a new tool that struggles after 4 short T-slots. Are you sure it was HSS and not cheesium?

Andrew

[Ron LadenParticipant @ronladen17547]

Posted by Andrew Johnston on 01/01/2019 16:39:38:

Nice looking sub-table, but there's summat wrong with a new tool that struggles after 4 short T-slots. Are you sure it was HSS and not cheesium?

Andrew

I thought that too and it isnt an Ebay cheapie, bought it from where I buy all of my mill tools so a bit disappointed really.

Ron

[JasonBModerator @jasonb]

But don't you usually buy the "premium" range?

Edited By JasonB on 01/01/2019 16:53:22

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 01/01/2019 16:53:06:

But don't you usually buy the "premium" range?

Edited By JasonB on 01/01/2019 16:53:22

I do, but I dont think they do T slot cutters in Premium or do they, cant see them in the catalogue or on the website.

[Anonymous]

Is the sub-table steel or aluminium?

Andrew

[JasonBModerator @jasonb]

No they only do the ones you have.

[Ron LadenParticipant @ronladen17547]

Posted by Andrew Johnston on 01/01/2019 17:06:27:

Is the sub-table steel or aluminium?

Andrew

6082 Andrew

[BazyleParticipant @bazyle]

Since you have left it square, a good decision, you could put some tapped holes in the corners for clamping big bits. They do say one of the biggest problems with rotary tables is that they are never big enough for the clamps.

[Ron LadenParticipant @ronladen17547]

Posted by Bazyle on 01/01/2019 17:17:50:

Since you have left it square, a good decision, you could put some tapped holes in the corners for clamping big bits. They do say one of the biggest problems with rotary tables is that they are never big enough for the clamps.

Thanks Bazyle, I was going to make it circular but then thought of just putting a radius on the corners, then that seemed a waste of usable space, in the end I just knocked the corners off. It does of course reduce the rearward travel towards the column but it is not that much.

Ron

[Ron LadenParticipant @ronladen17547]

It would seem that T slot cutters are a real mixed bag, the one I have is HSS and maybe I was just unlucky. Having had a bit of a search I see HSS cutters similar size to mine at £50-£60 each mine was £13 so either some suppliers are racking up the prices or there is a real difference in quality..?

I have a job coming up in the future where I will need a dovetail cutter, the job is in steel and at the moment I am thinking carbide providing it wont break the bank. I would have thought HSS would be fine but how much do you need to pay for a good one, seems a bit of a gamble.

Ron

 

Edited By Ron Laden on 02/01/2019 08:26:28

[Ron LadenParticipant @ronladen17547]

The poor performance of the cutter could have been of my own making of course. The material was 6082 and the cutter 8mm deep and 16mm diameter. I ran it at 500 rpm, was that too fast..? Problem was, I couldnt run it any slower as the mill hesitated at 400 rpm and even at 500 I almost stalled the mill at one point. I did try it a bit faster but that just didnt feel right and made no difference. I used WD40 and kept clearing the build up of swarf but as the job progressed the cutter certainly felt as if it had lost its edge.

[JasonBModerator @jasonb]

Ron, how deep did you go with the initial 8mm slot, you can reduce the load on the cutter if you mill that first all the way to the bottom of the slot or even a little beyond. Book speed for ali would be about 1500rpm but that would be on a big rigid machine.

They do need a bit of welly behind them, think what it would be like using a 16mm dia cutter to make an 8mm deep pass, that's quite a lot for a small machine.

[Ron LadenParticipant @ronladen17547]

Posted by JasonB on 02/01/2019 09:03:51:

Ron, how deep did you go with the initial 8mm slot, you can reduce the load on the cutter if you mill that first all the way to the bottom of the slot or even a little beyond. Book speed for ali would be about 1500rpm but that would be on a big rigid machine.

They do need a bit of welly behind them, think what it would be like using a 16mm dia cutter to make an 8mm deep pass, that's quite a lot for a small machine.

Thanks Jason, thats probably where I went wrong, I only went 6mm deep with the 8mm slot. Stupid me, from what you say I can now see that had I gone full depth the T cutter would have only had to take out the sides, I was asking it to cut out a 8mm x 16mm slot in one pass.

Ron

[John HaineParticipant @johnhaine32865]

Another trick is to cut the initial slot, maybe a little deeper than the final dovetail depth; then use a hacksaw guided by the bottom of the slot to cut to the full depth of the dovetail so that the sharp corners of the tool don't have to work so hard (or at all). That reduces the power required and also minimises the wear on the teeth tips.

[Anonymous]

Posted by Ron Laden on 02/01/2019 09:22:28:

Thanks Jason, thats probably where I went wrong, I only went 6mm deep with the 8mm slot. Stupid me, from what you say I can now see that had I gone full depth the T cutter would have only had to take out the sides, I was asking it to cut out a 8mm x 16mm slot in one pass.

Oh dear, there's still a lot to learn! Still, the cutter shouldn't have gone blunt working in 6082. Look at an industrial mill and, as John says, the central slot will be slightly deeper than the T-slot. One, it relieves the centre of the T-slot cutter and two, it provides clearance if a clamping stud sticks out slightly from the bottom of a T-nut.

Andrew

[SillyOldDufferModerator @sillyoldduffer]

Posted by Ron Laden on 02/01/2019 08:47:33:

The poor performance of the cutter could have been of my own making of course.

…

Certainly that's been my experience! When I started home metalwork seemed all my tools were made of Cheesium. Drills, hacksaw blades and HSS lathe tools had short lives. Then something strange happened – the tools all miraculously improved. Gradually at first but now they last much longer.

I put the improvement mostly down to gaining experience and taking advice. Cack-handed learners can and do ruin good tools. Some things that changed:

1. Prefer known materials to unidentified scrap
2. Understood better the properties of the materials. Steel, Brass, Aluminium, Cast-iron are not the same and they come in a bewildering variety of alloys with very different properties.
3. 'Let the tool do the work'. This is actually complicated and there's a feel to it. Very light cuts and very heavy cuts are both bad. Depth of cut, cutting speed and feed rate matter. And what's possible is probably limited by a hobby machine, making this a skill. My mistake was being too gentle. Rubbing heats up tools and blunts them. In contrast, when a proper cut is taken much of the heat is carried away by the swarf.
4. Clear swarf enthusiastically. Chopping swarf under the edge murders tools!
5. Cooling and lubrication. HSS and carbide are different. For many small jobs with Carbide I don't bother. HSS benefits more. There is a range of jobs where dabbing and splashing help. For heavy work like cutting T-slots I use flood cooling: it removes heat and swarf efficiently. Aluminium needs special care because it has a low melting point and can stick to the tool.
6. Fitting the tool to the job. Very cheap tools may not be much good, top range tools are far too expensive. Finding the balance is tricky. I don't see much point in wasting money on tools that will last longer than I do! Others have good reasons for investing solid cash in high-end machines and tooling.

It would be an interesting experiment for Ron to repeat the job with a new cutter from the same source. I suspect Ron's second attempt would leave the cutter in better condition, simply because Ron learned so much from his first attempt, perhaps without realising it.

I'm a great believer in theory and book learning but there's no substitute for actually doing it!

Dave

 

Edited By SillyOldDuffer on 02/01/2019 10:18:55

[Ron LadenParticipant @ronladen17547]

Posted by Andrew Johnston on 02/01/2019 10:13:49:

Posted by Ron Laden on 02/01/2019 09:22:28:

Thanks Jason, thats probably where I went wrong, I only went 6mm deep with the 8mm slot. Stupid me, from what you say I can now see that had I gone full depth the T cutter would have only had to take out the sides, I was asking it to cut out a 8mm x 16mm slot in one pass.

Oh dear, there's still a lot to learn! Still, the cutter shouldn't have gone blunt working in 6082. Look at an industrial mill and, as John says, the central slot will be slightly deeper than the T-slot. One, it relieves the centre of the T-slot cutter and two, it provides clearance if a clamping stud sticks out slightly from the bottom of a T-nut.

Andrew

There is still a lot to learn Andrew, just annoyed with myself when I dont think things through, I would like to think that I usually do but I obviously didnt in this case.

Ron.

[Ron LadenParticipant @ronladen17547]

Posted by SillyOldDuffer on 02/01/2019 10:18:15:

Posted by Ron Laden on 02/01/2019 08:47:33:

The poor performance of the cutter could have been of my own making of course.

…

It would be an interesting experiment for Ron to repeat the job with a new cutter from the same source. I suspect Ron's second attempt would leave the cutter in better condition, simply because Ron learned so much from his first attempt, perhaps without realising it.

I'm a great believer in theory and book learning but there's no substitute for actually doing it!

Dave

Edited By SillyOldDuffer on 02/01/2019 10:18:55

Dave,

I will do a test with the same tool, I have just looked at it and it maybe ok, I was just asking too much of it.

Ron

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