PDA

View Full Version : WANTED: Tool holders for T2 (I think) quick change toolpost



Jonathan
19-04-2011, 12:14 AM
Hi,

I'm looking for toolholders to fit the quick change toolpost on my lathe. It didn't come with any! The toolpost is 97x97x72mm, so I think it's a T2 since that's the same as the T2 one here:

http://www.chronos.ltd.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2echronos%2el td%2euk%2f&WD=t2s&PN=New%2dT2%2dSize%2dQuick%2dChange%2dToolpost%2dS ystem%2ehtml%23aT2S#aT2S

It looks good, all the surfaces are ground. Quite annoying at the moment I've got the lathe but no way to hold any tools! If it comes to it I'll get one chronos and hope it fits.

Here's a picture:

3960

Thanks in advance.

i2i
19-04-2011, 12:20 PM
have you tried the engineers merchants like cromwell, mscj+j, buck and hickman, ect.

Jonathan
19-04-2011, 12:51 PM
have you tried the engineers merchants like cromwell, mscj+j, buck and hickman, ect.

I've tried J&J and Cromwell - they're 50-70, seems a bit much. I can't find any at buck and hickman, do you know of any others?

M250cnc
19-04-2011, 04:09 PM
I've tried J&J and Cromwell - they're 50-70, seems a bit much. I can't find any at buck and hickman, do you know of any others?

Little lathe cheap parts, big lathe expensive parts

I have various holders the next size down from various manufactures from original to new Chronos types

The newer ones are very flimsy which i only use for small boring tools etc the older beefier types for the bigger tools.

One thing i can say is hardly any fitted correctly which wasn't an issue when manual turning, but when i went cnc those errors were unacceptable and i had to grind the tool post and all the holders, now changing tools i can hold a tolerance of 0.01mm on diameter.

The other place is ebay i still want more so i may make my own in the long term.

Tooling can cost more than the machine, currently i have 26 plus the tools in them + insets = 3 to 4 times the cost of the lathe.

Phil

3962

Jonathan
23-04-2011, 11:07 AM
I got one of the holders from Chronos for 26.95:

3971

It seems to fit well and is 'solid'. Even at that price it's going to cost a fair bit to get enough (though not 26!), and it's going to take a long time to make my own.

There's a version of it here with the proper square bolts:

http://www.rdgtools.co.uk/acatalog/Quickchange_Toolpost__Separate_Tool_Holders_.html

Slightly more expensive but I might get one and compare.

M250cnc
23-04-2011, 11:17 AM
Jonathan that toolpost in the picture is 180 degrees out. :confused:

If you are doing manual then yeah you don't need too many but cnc it takes so long to set them that it is worth it in the long run.

Phil

i2i
23-04-2011, 11:22 AM
it is:heehee:

Jonathan
23-04-2011, 11:23 AM
Jonathan that toolpost in the picture is 180 degrees out. :confused:

Yes it is, didn't matter for what I was doing though! :rolleyes: I realised what I'd done once I'd put the tool in...


If you are doing manual then yeah you don't need too many but cnc it takes so long to set them that it is worth it in the long run.

No doubt I will convert it to CNC soon.

i2i
23-04-2011, 11:25 AM
if you're going to cnc you may want to look over the toolplate idea.

http://www.youtube.com/watch?v=Ehit1ip1LfM

Jonathan
23-04-2011, 11:37 AM
if you're going to cnc you may want to look over the toolplate idea.

The toolplate does look like a good way of doing it, but more awkward to set up and not as many tools. Also limits travel I suppose. Great for small jobs like in the video though. It's a similar concept to what I did with the milling machine here:

http://www.youtube.com/watch?v=4wGDMSiZpyg

I didn't video it but for a different part I clamped a couple of drills to the milling machine table and got it to use them all. Another way to do it would be to mount tools to a rotary table.

I will still want to use the lathe manually when it's converted to CNC.

M250cnc
23-04-2011, 11:50 AM
The toolplate does look like a good way of doing it, but more awkward to set up and not as many tools. Also limits travel I suppose. Great for small jobs like in the video though. It's a similar concept to what I did with the milling machine here:


I will still want to use the lathe manually when it's converted to CNC.

This is what i made for drilling, ground all over and i have different size bushes made for different size drills etc

I had to make one particular holder be perfectly ground as the slots can be surprisingly a long way off.

Agree the toolplate would only suit small parts and be time consuming to set.

Phil
3975

i2i
23-04-2011, 11:55 AM
The trick is to make a toolplate for each job.

Jonathan
23-04-2011, 01:14 PM
This is what i made for drilling, ground all over and i have different size bushes made for different size drills etc

Looks good, you have a surface grinder then? Or are you using a toolpost grinder in the lathe to do it?


I had to make one particular holder be perfectly ground as the slots can be surprisingly a long way off.

I've just been and tested the holder I have with a Mitutoyo 0.0001" DTI. It seems pretty close to me, but then it clearly depends on what you consider close! I took several readings and averaged them...

Measuring on the lower surface, where the tool sits parallel to the bed the width is 18mm and I get a maximum variation of 5.2 thou at the back of the holder, 4.4 in the middle and 4.0 thou nearest the tip (0.132, 0.112,0.102mm respectively). That's going to affect the side rake of the tool by about 0.4 degrees. It's lowest nearest the chuck.

Now measuring on the lower surface parallel to the cross slide over the 98mm length of the holder, so affecting the tool rake angle. I get 6 thou nearest the tailstock (in the corner of the holder), 5.5 thou in the middle and 7.2 thou nearest the chuck (0.152,0.140,0.183mm respectively). That's going to subtract about 0.09 from the back rake angle.

The next thing I measured was the tool centre height repeatability. I zeroed the dial at the front of the holder, near where the tool tip should be. Taking out the holder and replacing it without rotating the toolpost itself I get less than 0.1 thou (0.0025mm), variation (can barely measure it). If I take the holder out, rotate the toolpost around a bit and replace I get a fraction over 0.1 thou (reading between the lines on the dial!). If I take the holder out and put it in a different position in the toolpost I get +-2.5thou (0.064mm) variation in centre height. I think that's pretty good - better than 0.01mm.

If I push and pull hard on the toolpost I can get the centre height to deflect by about 2 thou.

The last thing to measure is how repeatable the holder is moving parallel to the cross slide, i.e. directly affecting the diameter.

Edit: Measured that now and I get 0.3 thou variation, maybe 0.4 ... hard to tell, under 0.01mm.

M250cnc
24-04-2011, 11:51 AM
The trick is to make a toolplate for each job.

Well you could take longer to make the toolplate than to do the job.


Looks good, you have a surface grinder then? Or are you using a toolpost grinder in the lathe to do it?


Thanks, yes i have a Jones & Shipman 540 surface grinder, FYI a toolpost grinder would be used to grind round stock, but i have a cylindrical grinder to do that. :wink:

Any grinding on a lathe is to be done under caution that grinding dust gets everywhere if your not careful, with serious consequences.

Phil

Jonathan
24-04-2011, 11:58 AM
FYI a toolpost grinder would be used to grind round stock,...

Of course, but you can use it for surface grinding. Dress the wheel using the cross slide then fix the work to the faceplate. Also could be used to grind the faceplate.

M250cnc
24-04-2011, 12:10 PM
Of course, but you can use it for surface grinding. Dress the wheel using the cross slide then fix the work to the faceplate. Also could be used to grind the faceplate.

But can you hold the piece to be ground on a magnetic chuck with only light magnetic force so as not to distort the piece to be ground. Then clamp to an angle plate to get it square.

Can you take a CUT of 0.000005" yes that's not a mistake, on the lathe with a toolpost grinder, can you get a part of 6" x 18" flat with a tolerance of 0.0001"

If you can then yes you can do surface grinding on the lathe. :rolleyes:

Phil

Jonathan
24-04-2011, 12:23 PM
But can you hold the piece to be ground on a magnetic chuck with only light magnetic force so as not to distort the piece to be ground. Then clamp to an angle plate to get it square.

Can you take a CUT of 0.000005" yes that's not a mistake, on the lathe with a toolpost grinder, can you get a part of 6" x 18" flat with a tolerance of 0.0001"

If you can then yes you can do surface grinding on the lathe. :rolleyes:


I'm not saying it will be as good as a lathe, of course not. If it was you wouldn't have a surface grinder!

You can take pretty small cuts though. The dials on my lathe are graduated to 0.001", you're cutting a 200th of that so put the top slide at an angle of arcsin(1/200)=0.29 (ok that's tricky to set) to the face. Clearly in practice that method has limitations - if you want to take a reasonable amount off then you're going to run out of travel and have to keep setting it.

There was a surface grinder at school, rarely used but useful when it was. One thing they did with it was to turn the old blades from the power hacksaw into parting tools for the wood lathe.

i2i
24-04-2011, 12:51 PM
[QUOTE=M250cnc;21885]Well you could take longer to make the toolplate than to do the job



obviously this is when he goes to cnc.:tongue:

Jonathan
24-04-2011, 01:00 PM
I will at least make a rear parting tool holder since I use the parting tool on almost every part.

M250cnc
24-04-2011, 02:39 PM
obviously this is when he goes to cnc.:tongue:

Are YOU doing it this way on your CNC lathe ?



I will at least make a rear parting tool holder since I use the parting tool on almost every part.

Good idea, are you gonna grind it. :heehee:

Currently Mach3 cannot use a rear tool. :sad:

You have to get round it by using G51 X-2 then using G50 at the end of the tool to clear it.

Phil

M250cnc
24-04-2011, 02:41 PM
No Content

i2i
24-04-2011, 09:12 PM
Are YOU doing it this way on your CNC lathe ?

On some others have autochangers

Jonathan
07-05-2011, 11:30 AM
Good idea, are you gonna grind it. :heehee:

If neccecary


Currently Mach3 cannot use a rear tool. :sad:

The more I read about Mach3 the more I find it can / can't do!


You have to get round it by using G51 X-2 then using G50 at the end of the tool to clear it.

I'd count that as being able to handle it - only a couple of commands.

I now have a good stash (10) of 'genuine' tool holders:
4002
4003

And plenty of tools to grind and put in them:
4004

Difficult to say how much the holders cost as I got them with lots of other things, very roughly 10 each.