DRO for the Myford ML7

[John Baguley]

I've spent the last two afternoons fitting the DRO kit to the ML7 and it was all pretty straightforward and everything fitted as it should. There is one thing that I'm not happy about but I'll mention that later.

The first bit fitted was a length of aluminium extrusion which is mounted to the saddle using a couple of brackets bolted on using the existing bolt holes used to hold the rear saddle clamp.

The Z axis scale mounting was the next to go on and that simply bolts to three of the existing threaded holes in the back of the bed using three brackets. I believe these tapped holes were meant to fit a taper turning attachment. Needless to say, you can't fit this kit if you do have the taper attachment fitted and want to keep it.

The mounting has a slot milled in it to take the magnetic strip which simply sticks in place with double sided tape. A thin stainless steel strip goes over this to protect it and an aluminium cover goes over the lot to keep swarf out.

The read head is mounted to the previously fitted aluminium extrusion using a couple of brackets.

On to the X axis now and this is perhaps where the faint hearted should look away as it involves drilling and machining the cross slide casting!

The first job is to drill and tap two holes in the end of the cross slide casting to bolt on an aluminium extension piece. This enables the magnetic scale to extend back behind the cross slide.

I only just had enough headroom on the mill to do this and the mill head was right at the top of it's travel.

The extension piece was then bolted on.

Next, a 10mm wide by 1.8mm deep slot has to be milled into the underside of the cross slide to take the nagnetic scale.

I found that the scale was actually 10.2mm wide so had to widen my initial slot slightly. Once again, the magnetic strip is stuck in place with double sided tape and a thin stainless cover stuck over that.

The slot for the scale doesn't actually need to be this long but I just made it the same length as the magnetic strip.

After refitting the cross slide to the lathe the next job was to fit the read head, again to the aluminium extrusion using one bracket.

Finally, the disply was mounted on the wall behind the lathe, all the cables connected up and it all worked first time

Fortunately, I didn't need to move any of the stuff that was already behind the lathe as I have a couple of racks etc. for my tooling that I didn't really want to move.

As usual, the cables for the scales were miles too long so the excess is just hanging down behind the lathe stand. I may shorten them but that would probably invalidate any warranty.

So, what don't I like about it?  The cross slide scale does not read the full travel of the cross slide. As you wind the cross slide out, the scale loses contact with the read head after about 3 inches and consequently the DRO stops reading. On my lathe at least the cross slide has another 1.75" of travel before the feed screw disengages from the nut. I can see this being a problem when turning large diameters and the cross slide is towards the end of it's travel as I won't be able to use the DRO for measurement.

The magnetic scale is plenty long enough to read the total movement but it needs to be moved further back by about 2 inches so it remains in contact with the read head. in other words, the aluminium extension bolted to the back of the cross slide needs to be a lot longer. Whether this does become a problem remains to be seen. If it does then I will make a new longer extension piece and move the magnetic scale further back (if it will come unstuck again!)

Apart from that, I'm very happy with the kit.

John

[silverfox]

John

It has a lovely facility where you can set up the system to change tohe settings so whatever tool you use it will awlays be set to thr toip position of every other tool ( hope that makes sense)

However i have not fathomed it out yet, so if you crack it, can you put up a step by step guide on how to do it. Whenever i follow the book it goes all pear shaped!!

[John Baguley]

Aug 4, 2021 18:45:10 GMT silverfox said:

However i have not fathomed it out yet, so if you crack it, can you put up a step by step guide on how to do it. Whenever i follow the book it goes all pear shaped!!

I haven't even looked at the instructions yet! I did use it tonight to make a new blowdown fitting for a chap at the club and realised that the X axis is reading backwards so I'll have to read the instructions to see how to reverse it. I hope that it's more understandable than the one that came with the mill DRO!

I watch quite a lot of machinists on YouTube and I'm sure 'This Old Tony' did a video on using tool offsets on the lathe. It will be for a different DRO but I would think that they all work in a similar way.

I'm not sure if it is a facility that I would use very often but I will try and learn how to use it.

John

[simplyloco]

Aug 4, 2021 21:27:13 GMT John Baguley said:

Aug 4, 2021 18:45:10 GMT silverfox said:

However i have not fathomed it out yet, so if you crack it, can you put up a step by step guide on how to do it. Whenever i follow the book it goes all pear shaped!!

I haven't even looked at the instructions yet! I did use it tonight to make a new blowdown fitting for a chap at the club and realised that the X axis is reading backwards so I'll have to read the instructions to see how to reverse it. I hope that it's more understandable than the one that came with the mill DRO!

I watch quite a lot of machinists on YouTube and I'm sure 'This Old Tony' did a video on using tool offsets on the lathe. It will be for a different DRO but I would think that they all work in a similar way.

I'm not sure if it is a facility that I would use very often but I will try and learn how to use it.

John

I have an Easson DRO, and I have to say that the two most useful features are R/D and measuring  the depth to a shoulder which makes my multi bed stop  redundant.  I didn't need the handbook for these!

[millman]

I purchased the M Dro setup a couple of years ago and the only complaint I have is that I have absolutely no idea how to program in the tool offsets. I can do it for one tool but have no idea how to save the setting. I have read the instructions but they just don’t make any sense to me. My only other gripe is that there appears to be no battery backup, if the power goes off all your settings are lost. If anyone knows how to set and store the tools can they please share their knowledge?

[John Baguley]

When I get chance I will have a play with the tool offsets and see if I can fathom it out.

John

[John Baguley]

I'm having a go at entering the tool offsets today. It was all going well until I got to using the Tool Library. I entered the offsets for Tool 1 ok but the method described in the manual for moving to Tool 2 does not work as stated! It says to press the Down Arrow key, then 2 and finally enter. When you do that, it comes up with tool 50! If you enter Tool 1 again, it goes to Tool 25! You can then select the tools by repeatably pressing the Up Arrow key but that doesn't sound right. I shall investigate further. Maybe I'm doing something wrong.

I am wondering if doing it the way the manual says selects a Tool Bank (of 25 tools each) and then you have to select the required tool using the Up Arrow key. If that's the case then it's a bit of a faff.

This is for the MDC700 console by the way.

John

Edit - The Tool Recall doesn't seem to work either. If you recall Tool 1 it comes up with Tool 25 and recalling Tool 2 comes up with Tool 50. I think I will get in touch with MDRO and see what they have to say.

[Gary L]

Aug 6, 2021 14:09:41 GMT John Baguley said:

I'm having a go at entering the tool offsets today. It was all going well until I got to using the Tool Library. I entered the offsets for Tool 1 ok but the method described in the manual for moving to Tool 2 does not work as stated! It says to press the Down Arrow key, then 2 and finally enter. When you do that, it comes up with tool 50! If you enter Tool 1 again, it goes to Tool 25! You can then select the tools by repeatably pressing the Up Arrow key but that doesn't sound right. I shall investigate further. Maybe I'm doing something wrong.

I am wondering if doing it the way the manual says selects a Tool Bank (of 25 tools each) and then you have to select the required tool using the Up Arrow key. If that's the case then it's a bit of a faff.

This is for the MDC700 console by the way.

John

Edit - The Tool Recall doesn't seem to work either. If you recall Tool 1 it comes up with Tool 25 and recalling Tool 2 comes up with Tool 50. I think I will get in touch with MDRO and see what they have to say.

[rant]
Easily the worst part of a DRO is the console manual. I have two DROs, both different, but alike in that one respect. I don't suppose the UK market is very great these days, but you would think the OEMs would go to the small extra expense of translating their Chinglish into a language we Occidentals could understand, if only for the US market which must be significantly greater.

I've tried to understand the Tool Offsets on my mill and my lathe, but utterly failed to make sense of either. Needless to say, they are both different, which is all I have managed to glean.

The kit is very versatile, it is such a pity the functions are buried deep in this incomprehensible word soup.

With China being such a centralised state, it is a further pity that nobody has sent out an insruction to standardise the user interface on these boxes. Training staff must be a nightmare in a production setting.
[/rant]

Gary

[John Baguley]

Yes, the manual for my Sinpo DRO that I bought direct from China for the mill is pretty grim although I think that I have managed to sort out most of the functions or at least those that I have so far used.

The manuals that came with the M-DRO console look pretty reasonable though and have probably been produced by M-DRO themselves. It does make me wonder though if anyone has actually checked them to see if they are correct. Neither the 'Tool Store' or the 'Tool Recall' functions work as described. I can get the Tool Store to work by using a slightly different method but no luck with the Tool Recall. It may be that there is a software problem in my unit but it seems a bit worrying that no one else has managed to get the Tool functions to work.

I've searched online and on YouTube but cannot find anything useful about the MDC700 console but plenty of videos on problems with other types!

In the meantime I've emailed M-DRO about the problem and am waiting for a response.

John

[John Baguley]

Well, I have had a reply from Jo at M-DRO and it would seem that the Tool Library only works correctly when you are in metric mode! No mention of this in the manual

I've just been in the workshop and tried it and that is indeed the case. Set the dimensions to mm and it all works as it should. This means that all of your tool offsets have to be input in mm.

I'll get on now and finish my 'How to use the Tool Library' guide.

John

[John Baguley]

Several members have expressed an interest in how to use the Tool Library feature in the DRO and how to enter tool offsets. Now that I've got it to work I'll try and explain it as best I can. Note that this is specifically for the M-DRO MDC700 console and will be different for any others. The general principles will be the same though.

Note that the Tool Library function will only work correctly in metric mode i.e. the measurement system must be set to mm. It will not work in Imperial mode as I found out the hard way!

If you use a quick change tool post like I do then you will no doubt have umpteen tool holders with different tools in them ( I must have about 25) and all the tool tips will be in a different position relative to the holders. What the Tool Library function does is to allow you to input the differences between the various tool positions and then recall this whenever you swap a tool. I doubt if it's something I will use very much but will be very useful for mass production work involving several changes of tool.

Note that you must not alter the position of the tool post or topslide when using the Tool Library otherwise everything will go pear shaped!

Firstly, you need to pick a tool that will become your reference tool and all the other tools will have the X and Z positions relative to this tool measured and entered into the library. Probably use something like a favourite facing and turning tool that you use all the time.

The position of the cutting edge of this tool needs to be set to zero relative to some surface on the lathe. I used a dial indicator with a flat foot to do this but if you want to spend £100 or so you can get a fancy tool setting gauge but it's basically the same thing. You could also use a length of bar in the chuck that you have faced and turned. That would enable you to measure the X and Z positions at the same time for each tool but perhaps not as accurate as the indicator. Using the indicator I had to first measure all of the X offsets of the tools and then reset the indicator to measure the Z offsets.

The indicator (or bar) is set up in the lathe and the tip of the reference tool (Tool 1) wound in towards the indicator until the indicator reads zero (or the tool touches the bar). I set it so that the indicator went round about 1 ½ times to the zero to ensure that there was some pressure on the foot.

Ensure that the DRO is in Absolute mode, Radius mode and metric mode and zero the X axis.

Take out Tool 1 and put in Tool 2. Again wind in the tool until the indicator reads zero but this time make a note of the X reading on the DRO, in this case 7.142mm. This reading is the offset of Tool 2 relative to Tool 1.

Repeat for Tool 3 and for as many tools as you want to set up making a note of the X axis reading for each tool.

Reposition the indicator so that you can measure the Z axis position of the tools.

Put Tool 1 back in and wind the tool in until the indicator reads zero again.

Zero the Z axis on the DRO.

Replace Tool 1 with Tool 2 and again wind in until the indicator reads zero. Make a note of the Z axis reading on the DRO, in this case -0.380mm

Repeat for all the tools.

You now have a list of all the tool offsets relative to Tool 1 and these need to be entered into the Tool Library.

Make sure that you are in metric mode!

The Tool Library locks itself every time that you switch the DRO off so it needs to be unlocked. If you try to use it without unlocking the display says 'tl_close'

Unlock the library by pressing the '±' button five times. The display will then say 'tl_open'

Open the Tool Library by pressing the 'Tool Store' button. The display will show 'Tool 1' and the X and Z readings for that tool. Make sure that both X and Z are set to zero. If they are not then select each axis and zero out. Press 'Enter' to save.

Now move to Tool 2 by pressing the 'Down Arrow' button. The display will ask you which tool you wish to select.

Enter the tool number e.g. 2 and press 'Enter' The display will show Tool 2 and it's X and Z position. Enter the X and Z readings from your list that you made earlier. In my case X was 7.14mm and Z was -0.380mm.

* Note that to enter a negative offset you need to use the '±' button. Enter the offset as normal but when the number is flashing press the '±' button. This will change the value to a negative one. Then press 'enter' *

Note that I made a mistake when entering the Z axis reading - it should have been -0.380!

Now step to Tool 3 and repeat the process. For Tool 3 the X reading was 3.125mm and the Z was 0.210mm

Repeat this for all the tools that you want to use.

Exit the Tool Library by pressing 'Tool Store' button again.

You have now entered the tool offsets for all your tools and are ready to use them.

You call up the tools by pressing the 'Recall' button followed by the tool number, then 'Enter' and then pressing 'Recall' again. It doesn't seem to display which tool you have selected though.

If the X and Z readings on the DRO are first set to zero then when you call up a tool it will display the offsets that you put in earlier.

Note that you cannot reset the X and Z axis to zero or enter a value for them once Tool 2, or 3 etc. are called up. If you need to reset the X and Z axis to zero or enter a position during a machining operation then you must select Tool 1. I suppose that is logical as if you alter the zero reference when using anything other than Tool 1 then all the tool offsets will be affected.

I think that is about it and hope that you can make sense of it all.

John

[jackrae]

An excellent presentation of "how to do it" so many thanks for resolving the issue
Will I use it - probably not - too much faff and if the QCTP slips for any reason it's back to square 1

[John Baguley]

Thanks Jack,

I probably won't use it either but if it helps someone else who does want to use it then it's been worthwhile.

I'm a little puzzled why it will only work in metric mode. I presume it must be a software issue. The software must be written around the metric mode and the imperial dimensions are just a conversion that only works on certain features.

I haven't tried the Zero Datum Memory yet. I wonder if that might only work in metric as well?

John

[millman]

Thanks very much for all that information John, I was trying to input the offsets in inch mode, never gave it a thought to try in metric. I was waiting until I could visit their stand at an exhibition and get a demonstration of how to do it but now that is not going to happen due to COVID. I shall have a play with a couple of tools tonight and see if I can get mine working.

[John Baguley]

Aug 10, 2021 15:50:43 GMT millman said:

Thanks very much for all that information John, I was trying to input the offsets in inch mode, never gave it a thought to try in metric.

It never occurred to me either! I just assumed that it would work in both

John

[silverfox]

John

an old dog has learnt a new trick!!!

Will play about tomorrow with mine..

One question if you have tried it

If you are using imp as your go to measurement. i can see that setting up the library in metric

Now using tool 1 the datum tool in metric mode which was X=0, Y=0 the offset for tool 2 would be for example X=25.4, Y=25.4

you go to lbrary and change to tool 2

Can you go back to metric once change and if you move X and Y 1inch each would the new reading be 0,0 putting the tool 2 tip where the tool 1 datum point is?

hope all that makes sense

And thanks for the detailed work through

Ron

[John Baguley]

Hi Ron,

Yes, once you have selected the tool then you can change to imperial and use that for your measurement system. If you set Tool 1 to zero in X and Z and then change to Tool 2 you can move Tool 2 to the zero point of Tool 1 by moving the X and Z axis by the amount of the offset. It's only for inputting the offsets and selecting the tool that you need to be in metric mode.

One thing that I realised tonight whilst playing - You will need to input a negative offset at times which I hadn't tried before. I assumed that you would do that by pressing the '-' button before entering the figures but no, that doesn't work.

You have to put in the dimension and then change it to a negative value by pressing the '±' button. The manual does sort of mention this when describing how to use the SDM function.

John

[silverfox]

John

Apologies for not getting back sooner ,but have had the BiL staying with us. As a result..not much time in workshop

Will have a play in the next day or so.

Ron

[John Baguley]

No problem Ron. Let me know if you have any problems

I've been using the DRO all the time since I fitted it and it is proving to be very useful.

John

[jasonb]

How well does it work in actual use?

Although the tools can be set as shown in static use will they actually cut to that as there will be a certain amount of force pushing the tool away from the work which depending on the wear and adjustment of the machine may not put the tip of the tool where the DRO thinks it is. This could also vary depending on whether a light or heavy cut is taken.

As I see it there is also the problem of having to redo all your tools if you need to reposition the topslide or the toolpost as there is no way to index them back to the exact same position.