Tool Holder Question

[radar]

Hello everyone!

I have a really (being frank here) stupid question: If an end mill holder can hold an end mill securely with just a little divot in the shank and a grub screw, could not in theory on a small machine (Taig) would a small tool holder connect to the spindle the same way- with a grub screw? Basically, flipping the end mill holder upside down and connecting to the spindle.

It's not quite a quick change tool system, but more like a "not so slow change tool system" idea I had.

Thank you in advance for any input/knowledge imparted!

 

[goldstar31]

I can understand the question but I cannot see why it has arisen. Grub screws ARE quite common and are strong enough to resist the cutting forces- in a spindle. The only thing that comes to mind is whether the design can accept grub screws- which is another question.

In yesterday's correspondence about myfords, I said mine or one of mine had a 'sight glass' being an early one. Transmission of the force to drive the spindle ie 1/3rd or 1/2HP is via a clutch - which is adjusted with a hidden grub screw.
The rest of both machines ie the ML10 as well, has a myriad of grub screws. Oddly, an earlier idiot had a massive jam up and the grub screw holding a leadscrew 20 tooth 20DP gear held whilst that stripped. As another contributor who had a gear box on a ML7 regretted the discontinuance of a brass shear pin.

Does this clear the point/

Norman

 

[radar]

Norman,

I have been trying to devise a way to make tool holders for a Taig that are easier to change out than having to unscrew the cap keeping the collet closed. Something where the tool could already be mounted to the holder.

 

[goldstar31]

Norman,

I have been trying to devise a way to make tool holders for a Taig that are easier to change out than having to unscrew the cap keeping the collet closed. Something where the tool could already be mounted to the holder.

Why not utilise a Morse Taper shank with a large but machinable end?
I have also a number of 2MT blanks with a drilled hole and secured with a grub screw.

You might also consider making a boring head- perhaps to the Thomas design in Model Engineers Workshop Manual using a 'blank' as the basis.

Again, years ago I made up a mini faceplate from one and made 3 different positions for a sweep face milling cutter utilising a stub of a lathe tool.
Not my bright idea but on from Cleeve.

Another useful thing is adjustable 'blank' to take a little slide and lathe tool to do taper shanks.

Sorry- no intention to swamp you but I've done all these things and a lot more over the many years.

The nice thing about it is actually twofold. You get cheap tools and you learn new techniques.

I'm quite ancient( or decrepit) , you know:hDe:

Norman

 

[Blogwitch]

What you are referring to Radar are Weldon shank holders.

This is where the cutter has a flat ground onto it's side and a grub screw holds the cutters in their holders.

If you are not going to be doing heavy cutting they are very easy to make from blank ended Morse tapers, if your machine uses them. Just drill the end out accurately to the size of your cutter and drill and tap for a grub screw on the side of the holder in line with the flat on the side of the cutter.

Just do a search for "Weldon shank cutter holders" and you should get a few hits.

John

 

[goldstar31]

What you are referring to Radar are Weldon shank holders.

This is where the cutter has a flat ground onto it's side and a grub screw holds the cutters in their holders.

If you are not going to be doing heavy cutting they are very easy to make from blank ended Morse tapers, if your machine uses them. Just drill the end out accurately to the size of your cutter and drill and tap for a grub screw on the side of the holder in line with the flat on the side of the cutter.

Just do a search for "Weldon shank cutter holders" and you should get a few hits.

John

Whilst I agree with your comments, my set of blank ends also include other useful tooling as mentioned. Again, I mentioned turret tooling and of course, there are quite a number of my taper tools which hold dies as well and there are stops for chucks and whatever.

NB Hope hospital visit went OK

N

 

[Blogwitch]

Norman,

Just got to wait now for the results while things get much worse each day that goes past.

John

 

[goldstar31]

Obviously, I cannot tick a 'like' but please accept my best wishes. Keep US posted, eh?

N

 

[radar]

I guess here would be a better way to put it: I am trying to make a less annoying to change tool holding system for a Taig mill.

 

[Blogwitch]

Radar,

I got things a little muxed ip, I now realise what you want to do.

It could be done by the method you are proposing, but there is always a BUT.

Your quality of machining would have to be super precise, as any deviation from perfect concentricity would have the tool tip spinning in a circle rather than exactly on centre. This would mean that the cutter would be making larger than stated cuts. Say you were 0.001" out on concentricity at the joint, by the time that error got down to the tip, it could be something like 0.010".

I am not saying it can't be done, as anything is possible with time and money, but rather unlikely with what most people have in their workshops.

I too have gone away from the ER system for mounting in my mill spindle, but they are used elsewhere, and I now use spindle collets for two reasons. The first being to get more throat on my machine, I now have about 3" more, and the second is to eliminate what I was saying before, if there is any error at all in the holding system, then concentricity of the cutter is compromised, and that extra 3" sticking out of the end of my spindle by using an ER system, and I am not saying would, but could cause problems.

Do they do spindle collets for your machine? If so, then that might be your answer. Make up a basic drawbar lifter, and cutter changes can be got down to seconds just by operating one button or lever.

Sorry to dragged you along for so long, but you do have to look at all eventualities.

John

 

[Foozer]

Just got to wait now for the results while things get much worse each day that goes past.

Believe it can be said with univocal voice that we have grown accustom to your presense and having recently lost my own Father to what must needs be, am reminded 'The body corrupts but the message is eternal' . . .

 

[Blogwitch]

Quite correct Foozer.

I have been fighting with all sorts for the last five years or so, and thought I had got on top of it enough to start to get my life back on track. Then something else comes along and kicks you in the dangly bits.

That's life I suppose. I should get the results in a week or so, only then will I know if I can carry on.

John

 

[radar]

Radar,

I got things a little muxed ip, I now realise what you want to do.

It could be done by the method you are proposing, but there is always a BUT.

Your quality of machining would have to be super precise, as any deviation from perfect concentricity would have the tool tip spinning in a circle rather than exactly on centre. This would mean that the cutter would be making larger than stated cuts. Say you were 0.001" out on concentricity at the joint, by the time that error got down to the tip, it could be something like 0.010".

I am not saying it can't be done, as anything is possible with time and money, but rather unlikely with what most people have in their workshops.

I too have gone away from the ER system for mounting in my mill spindle, but they are used elsewhere, and I now use spindle collets for two reasons. The first being to get more throat on my machine, I now have about 3" more, and the second is to eliminate what I was saying before, if there is any error at all in the holding system, then concentricity of the cutter is compromised, and that extra 3" sticking out of the end of my spindle by using an ER system, and I am not saying would, but could cause problems.

Do they do spindle collets for your machine? If so, then that might be your answer. Make up a basic drawbar lifter, and cutter changes can be got down to seconds just by operating one button or lever.

Sorry to dragged you along for so long, but you do have to look at all eventualities.

John

Thank you John!
This is why I like this forum, it's educational.

Taig mills and lathes are a lot like Sherlines and unimats I suppose. They aren't all that large and mostly for small hobby work. I already own a massive milling machine (Lagun FTV-1, all three thousand pounds of it) and a Delta lathe.

I wanted to devise some manner of tool holding system for the smaller machines I would keep at home. If I could adapt the headstock on this thing to use MT3, it would be the Tormach system- since my big mill is already R8 and the tool holders from Tormach would work with either an MT3 or R8 collet (they use the collet to hold the tool holder- wonderful system) and I would have no problem.

However, since I am crunched for space at home I opted for smaller machines.

http://taigtools.com/mmill.html

The way I see it is that they are big enough and rigid enough to make the sundry of small parts large live steam engines would need, and for smaller live steam engines, the whole thing practically. The spindle is ER16, and its hollow.
If I could make a little power drawbar for it I would be fine with that even realistically- but I am kind of at a loss how I would make a small one.

Thank you!

 

[radar]

I even debated if I was to buy a larger mill (X2 type) and was to use the Tormach tooling system I could just leave the collet for the tool holders in there (only uses one specialized collet) and put a lever on top of the machine to raise or lower the draw so I could change out the tool holders.

 

[goldstar31]

As an owner of a Unimat- or correctly a MJ-189, I would suggest that you do two of the following things- once you have forgotten that you have a very different mill.

I would join the Unimat mob or read the books of Rex Tingey and so on. Again, I would go clock and watchmaking for ideas.
After all ER16 isn't a very big maximum size collet.

I once ran a Pultra 10 with 10 millie stuff. Why I sold it, I confess to a mental loss of faculties.
I'd download 'Making the Most of the Unimat' and get ideas. Tingey- he'd be an old fart like me, wrote much of the book for the two round bed bars job but a lot will convert to the Unimat3 and 4- and the Taig. Nice little baby rotary table described but I still suggest that you adopt watch making techniques like using a graver- and on your big lathe as well.

Meanwhile I'm trying to see if a top slide setting 40 degrees off parallel axially gives 16 thous advance using a 1/4" by 40 TPI adjustment.

Well? We all have to dust the grey matter for oneself. NBG here!

Norm

 

[radar]

I think that it would be safe to say that the idea of buying a Taig mill and lathe might have met its end- maybe- depending on something peculiar.

British people here- I have a question:
If I order something from the UK and have it sent to the US, do I have to pay VAT?

 

[goldstar31]

British people here- I have a question:
If I order something from the UK and have it sent to the US, do I have to pay VAT?

If you conduct your business correctly, the answer is 'No' but you should be prepared to pay your own equivalent on receipt of the goods from your Customs.

 

[radar]

If you conduct your business correctly, the answer is 'No' but you should be prepared to pay your own equivalent on receipt of the goods from your Customs.

Crap well that just ruined my joy.

The Taig machines are called Peatol in the UK I believe. It's a 3/4-16 thread on the tip of the spindle- that's it. The internal taper is basically this strange little ER like system the company makes.

 

[goldstar31]

Crap well that just ruined my joy.

A small contribution to the tree that giveth forth food and shelter?

from E.S.Ashcroft then a District Inspector of Taxes, Inland Revenue and Chairman of the Baptist Conference and quoting from the Queran.:hDe:

As for these small lathes, I settled for Unimat clone! This has already been well and truly aired.

Norman

 

[Nick Hulme]

I wanted to devise some manner of tool holding system for the smaller machines I would keep at home!

My small CNC mill has a Coventry Quick Change system fitted and although this is quick and convenient the holders are £60 to £80 each!
My solution was to buy ER11 chucks on 10mm shanks and mount them in the 10mm holder which came with the mill, the 10mm shanks are cut down to allow the chuck head to locate against the holder allowing me to accurately and repeatably use offsets.
I have machined a huge number of jobs, some interesting, many less so and have had no tool holding related issues and changing tools is still quick, probably quicker than with the Coventry Quick-Change system,

- Nick