Optimum MH25V

[handlewanker]

Hi, cleaning is one thing but stripping down is another.....not quite in the field of maintenance I would say.

Someone with scant knowledge of mechanical things can do more damage than a simple clean up routine would do.

I got the impression that you did a strip down or part strip down to see how the bits go together for the proposed CNC rebuild…...that is not a routine clean up especially as the machine hasn't actually run yet so a clean up is not even on the horizon.

Perhaps things are different in your part of the World.
Ian.

[DLF]

Hi Ian,

Normally you are right. But I have found swarf mixed with the ACME leadscrew grease. Therefore definetly a full table + saddle disassembly and cleanup was necesary.

And yes, this helped the measurement process needed for the CNC retrofit.

In the end all was good, the bad parts will be replaced under the warranty andd soon I will be able to proceed with reassembly.

A.

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[handlewanker]

Best of luck for the rebuild,...…..I'll be watching to see the results......don't forget when you plan the Z axis stepper motor drive that you also need to take into consideration the extra weight of a power drawbar mechanism.
Ian.

[stuarttaylor00]

I Hope they can sort it out for you, otherwise it pushes you a bit to install linear rails... I have seen a few guys get gibs made but I'm not sure if there are people who can do that locally for you

Thanks for sharing your build, I am watching on with interest, I'm looking at converting a machine in the next 6-8 months. I also want to step it up as you have and get the machine under CNC then move forward from there. I've heard DMM 750w servos direct drive are a good match for a machine of this size/type.

Which controller are you planning to use? I searched for SZGH but found a 3 axis grinding controller, the SZGH 990.

I use a hobby CNC router with Mesa 5i25 and Gecko G540 under LinuxCNC, and find it very powerful and reliable, but a bit more work to set up. I think I will go LinuxCNC on my build.


Keep sharing your progress!

[DLF]

The parts are ordered and will arrive under warranty. So all will be sorted out, I just have to be patient.

When I will make the conversion I will be using Delta 750 W AC servos. X and Y direct drive and the Z with 1:2 reduction. I still have to decide if the reduction is enough to prevent the head from lowering while not powered, or I need a brake.

For the controller I plan to use 5 axis SZGH controller: SZGH-CNC1000MDcb-5 5 Axis CNC Controller For Milling Machining Center

It is actually a 3+2 and I like the option to add a 4th or even a 5th axis in the future (if needed or even possible for this machine). Also it is not clear to me if using the ATC function all 5 axes are available for machining or 1 axis is repurposed for ATC. Therefore considering the price delta between 3 axis and 5 axis versions is not that dramatic I will get the 5 axis one.

BTW: I checked the spindle inside taper concentricity with a dial indicator and is spot on. Could not get the dial needle to move while rotating the spindle by hand. Checked it in 2 places. Could not be happier.

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[Hood]

...
Also it is not clear to me if using the ATC function all 5 axes are available for machining or 1 axis is repurposed for ATC. Therefore considering the price delta between 3 axis and 5 axis versions is not that dramatic I will get the 5 axis one.....

It would depend on how your tool change works. If it requires Step/Direction signals then I think it would use up an axis. If it just needs signals to rotate via relays (for direction) and other standard digital I/O then you would not need to use an axis.

I have a 2 axis lathe controller which I hope to fit soon and although my lathes turret utilises a servo motor for rotation it does not require step/dir signals as I have an indexing servo drive. That means I only need digital I/O to position the turret and thus do not require a 3 axis control.

[DLF]

It would depend on how your tool change works. If it requires Step/Direction signals then I think it would use up an axis. If it just needs signals to rotate via relays (for direction) and other standard digital I/O then you would not need to use an axis.

I have a 2 axis lathe controller which I hope to fit soon and although my lathes turret utilises a servo motor for rotation it does not require step/dir signals as I have an indexing servo drive. That means I only need digital I/O to position the turret and thus do not require a 3 axis control.

Not really sure what signals are needed for the tool changer. The manual is available for download and contains a wealth of information but is written in chinglish and not all chapters are very clear. Therefore the 5 axis version seems to be the safe bet.

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[DLF]

Well... warranty is gone

But central lubrication system mods are progressing just fine. Started today with the Z oil channels. Guideway channels are done. Tomorrow dovetail channel will be milled.

Milling ongoing on a BP clone:
Oil channels
Side oil port

On the other side one of the gib locking holes will be used.

Question: how do I deburr the channel sides without also scoring the guideway surface?

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[DLF]

More milling done today. Added additional channels in the middle of Z guideway oil channels.

And milled the Z gib. After all gibs will be done, I will have them reground.

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[DLF]

A little progress today.

Milled the X axis oil channels. The rear facing dovetail needed a bit more love than usual because 2 horizontal oil channels had to be drilled + 1 vertical. The horizontal ones needed M5 threads to be tapped, especially the bottom one which had to be tapped for the whole length.

M5 grub screws were installed to block the oil pasaages and guide the oil towards the dovetail.

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[atomarc]

Nice looking work Mr...we did just about the same thing on the Grizz.

Much later I happened on a thread on another forum that noted when you machine little slots for oil in the mating surfaces that they should be on a angle to the movement of the slide. The theory is if they're straight, the oil stay in the little trough and merely floats back and forth with the movement of the slide. If they are on an angle, the movement of the slide puts the oil troughs in a shear situation which forces the oil out into the clearance between the parts. I thought that sounded reasonable.

Stuart

[DLF]

Nice looking work Mr...we did just about the same thing on the Grizz.

Much later I happened on a thread on another forum that noted when you machine little slots for oil in the mating surfaces that they should be on a angle to the movement of the slide. The theory is if they're straight, the oil stay in the little trough and merely floats back and forth with the movement of the slide. If they are on an angle, the movement of the slide puts the oil troughs in a shear situation which forces the oil out into the clearance between the parts. I thought that sounded reasonable.

Stuart

Hi Stuart,

I also thought that diagonal channels would force oil better between the sliding surfaces. This is the reason why I have milled the little cross channels.

That being said, the milling is done on a BP clone manual mill located in a small-ish production environment. Therefore the available machine time is limited and milling diagonal channels required a more elaborate set-up which was time consuming (removing vise, clamping in different positions + re-installing and squaring the vise at the end of session). Instead a big vise was already installed and clamping in the vise and milling orthogonality made more sense.

So, no crying over spilled milk. The oil channels are almost done at this point, so no going back possible anymore. How does the oiling worked out for your machine? Are you happy with the solution?

On another thread someone stated his oil pump had enough pressure to lift the table a bit, enough to show on the surface finish when oiling was active during milling. If this is actually true then there would be no problem with oil distribution because oil will be squeezed between the sliding surfaces by the pressure alone. We shall see.

[atomarc]

The only piece oiled on the Grizz is the 'Y' saddle and the oiling system seems to works fine...it's too late for me as well, it's done and it works so no spilled milk here. I just thought it was an interesting concept on the part of the person that posted the theory of the angled oil slots.

Stuart

[DLF]

Oil pump arrived the other day. I just unpacked it and is big. Added a ruller for reference.

4 liter oil reservoir, 140-200 ml/min @17-20bar pressure.

No integrated timer. Just the motor connections, priming button and low level sensor. Control functions will be implemented in the controller.



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[DLF]

Motor housing with the electrical connection block.

I am very pleased with the build quality.



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[DLF]

Made some progress with the oil grooves. Did one side of the Y.



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[handlewanker]

Hi, very many years ago when I worked in a factory I refurbished the slideways on an old belt driven horizontal borer and the oil grooves were cut by hand with a cold chisel using a zig zag pattern all along the length of the slideways.
Ian.

[DLF]

Hi, very many years ago when I worked in a factory I refurbished the slideways on an old belt driven horizontal borer and the oil grooves were cut by hand with a cold chisel using a zig zag pattern all along the length of the slideways.
Ian.

Indeed, the zig zag pattern would have been ideal. I also saw such pattern on some older VMCs.

On a CNC that can be easily milled. Chiseling is beyond my skill level and I do not want to experiment on my machine.

Another approach I saw was milling a big Z or V shape groove along the guideway. I think this solution is the middle ground.

But, because of practical reasons (limited machine time available) I chose the groove pattern shown in my pictures. Might not be the most efficient one, but it was done by others on similar size machines and it works.

If I have to program the pump to start more often then I will just have more way oil consumption. Since I am doing this as a hobby it will not be the end of the world.

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[handlewanker]

As the saying goes....all roads lead to Rome.

[DLF]

As the saying goes....all roads lead to Rome.

True, true...

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