Ball Screw Maintenance on the Emco CNC Mini Lathe
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- čas přidán 2. 08. 2024
- Maintenance on an EMCO PC Turn 50 Mini CNC lathe to resolve issues with the Z-axis, which was not running smoothly. Bearing Ball replacement for the ball nut and some other fixes to improve running characteristics for this axis. Full disassembly process is included.
0:00 Intro
0:51 Lathe Disassambly
5:00 Troubleshooting
7:25 Ball Screw Disassamby
10:27 Broken Bearing Ball Replacement
15:34 Grease Nipple Replacement
17:28 Reassembly
22:19 First Dry Run and Wrap up
Cheers,
Robin - Věda a technologie
very cool video - nice work. It is very much the same as a compact 5.. I am in the process of replacing the existing ball screws with 1204.. I have the hard parts done. (hardest was getting it to fit under the x cross slide. - no major mods)
Thanks! Nice project, I have seen your video with non-circular boring for your modification, very intersting! Keep up the good work.
Mooi werk 😁
14:21 yes. and with this C7 ball screws there must be 1 missing ball in each chain (if you pack them full they will stuck). this also applies to linear rails.
Thanks for the tip!
Interesting
If you need to adjust the gibs again you can do it from below. There is a plastic plug in the sheet metal. Move the z axis to align the screws on the jibs to adjust
Never realized that this would be possible, would save a lot of effort. Thanks for the tip!
@@uptimefab7412 Talked to an old guy who has the manual version of this .machine. He have been doing it 30 years this way
Given the environment in which the bearings exist I feel like rubber sealed would be the obvious choice but the fact that emco decided to go with shielded instead makes me question my knowledge. I highly doubt they did it for cost reasons. Maybe the rubber seals are more likely to get damaged by swarf over time and ultimately the steel shields are actually more protective but that's the only thing I can really think of.
Thanks! Interestingly they also used bearings with a shield on only one side, with the other side open, which can't be reached to lubricate it. So I just went with the double shielded type.
@@uptimefab7412 Yeah that is weird. I guess they figured since the other side was in a sealed area it couldn't be contaminated. Maybe they were planning on making that area greasable which would explain wanting the outside to be shielded and then just never did or changed the design and never changed the bearing type
18:50 i have purchased c3 fk15 and ff15 bearing blocks; the ff15 has metal seals like yours
Thanks for the tip! These look like some nice general use end support bearing blocks. I'll have a look at this if I ever want to replace the bearings on the fixed side (and can't get them out).
Hi Robin:
I have an Emco 5 CNC Lathe, and it seems to be almost the same as yours. Mine is just the lathe without the case or driver that yours has. So I have a GRBL driver board for the Steppers. However in setting it up, the Ball Screw is neither Metric or English units ? Measuring it shows that 10 Revolutions of the Stepper is 9.72 mm !
Is this the same with your Emco CNC ?
Can you tell me how your system handles such odd units ?
Anything you can tell me about setting up an Emco 5 would be greatly appreciated!
Thanks
James
Hi James, good question. I am not sure what the actual gearing ratio on my pulleys is, so I can't calculate the exact steps per revolution. One way to do this is to count teeth on each pulley, but I just measured the output on the axis, similar to what you did. In the SZGH controller you can add any virtual "gearing ratio" to correct the output so it measures the input distance in your program. The virtual ratio has an integer input for the numerator denominator of this ratio, so I just multiplied both by 1000, effectively giving me 3 decimals to fine tune. The x axis is a round number (8 to 1) with 10000 microsteps per rev. The z axis is not with 6440/1000 for 8000 microsteps per rev. Anyway, the numbers are not important really. The only important thing is that it can be adjusted. Hope this helps.
ook fan van wera en knipex zie ik lol
Yes indeed, mooi spul. (het kleine oude Skandia tangetje is ook erg handig)
Interesting video! Did you swap out the Z-axis ballscrew from the original? On my Emco PCTurn it does not look like the same.
Hi, unfortunately I am not aware of the history of this lathe. Maybe a previous owner swapped out some parts. From the lead screw I did not get the feeling that it was not original though, since I did not see any modified parts to accommodate a different design. But I am not sure. Could also be a different "revision" compared to your lathe.
Sir what diameter is the Z-axis ball screw ?
Hi, I cannot measure the diameter under the dust cover, but it should be 8mm. Also dimensions like pitch can be derived from the ball nut. Spec for that is in one of the other comments and also on te website article at uptimefab.com. click "continue reading" under the video link on my website.
@@uptimefab7412 No problem, thank you so much.
Can you please tell me why you remove my questions?
I love your work, it helped me a lot to fix my Emco mini lathe
Hi, I have not removed any questions. Strange... I did get a question yesterday about where to buy the ball nut and when I wanted to answer it, the question was already gone. Sometimes people remove their own comment but I still have the notification, so I thought that was the case. Was that your question? If so, here is the link: store.boschrexroth.com/Linear-Motion-Technology/Screw-drives/Ball-screw-assemblies/Ball-screw-nuts/BALL-NUT_R153223002?cclcl=en_HR#&cartId=ba21b2e4-6c86-4339-bc26-3287e1885d3c&reloaded=true
@@uptimefab7412 Yes that was my questions, thank you. Strange :D Maybe CZcams removed it for some reason. Now i check your other videos and you put link there to the forum for Emco users, Thank you for that too, that is great!
@@NMCFPV CZcams removes a ton of comments lately - if you post a link and are not the video owner, it will be removed. Sometimes it's removed for seemingly no reason
Definitely not a thing they make anymore today.
The lathe indeed has some vintage vibes.