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  1. H

    What have you been doing today?

    love to sure but not with the 150kg lathe and the 600w motor I'm using! I might be able to push it to 2mm but I suspect the motor will stall beyond that.
  2. H

    What have you been doing today?

    I finally ended up finishing and installing the solid tool post mount for the lathe. I should've done this before, I can do roughing passes (S1214) on my bench lathe with 1-1.5mm doc without breaking a sweat.
  3. H

    Changing username

    thanks Shelton, appreciated.
  4. H

    Changing username

    Dear Admin, I would like to change my username to homemachinist if possible, so I can have the same username as my reddit account. It would be much appreciated. Thanks
  5. H

    Adjustable drill.

    You can upload / attach files to this thread. I don't have any specific requirements at this stage but it may be useful to others on this forum as well.
  6. H

    Adjustable drill.

    Do you have a price list somewhere ? I do this as a hobby so probably not going to be able to spend a lot on drill bits of varying sizes, which is why boring bars for anything more than 10-12mm is attractive.
  7. H

    Adjustable drill.

    righto, looking forward to the video when you get it! I've been planning to make one too, might get some time in the shed next week. Great to know that a few YouTubers I watch are close by, Nigel from smallcnclathes channel is based in eastern suburbs as well.
  8. H

    Adjustable drill.

    Hello there from Melbourne 👋 Didn't realise you're from Vic. I enjoy watching your videos, especially ones re. pouring cast iron. Did you end up trying Gotteswinter's flexure design for the boring bar ?
  9. H

    Surface finish banding

    Hopefully the final update on this. I've installed the new leadscrew, the run-out or sag at the middle is about 0.07mm which is better than the original. I adjusted the half nuts to make sure there is no change or deflection when the nuts are closed. This along with the new adjustable brass...
  10. H

    Surface finish banding

    An update on this, got a replacement leadscrew from the manufacturer and it's got a bit of run-out or straightness issue as well. I was surprised to find out that rolled or cut leadscrews have straightness tolerance of 0.015"/ft or ~1mm/metre. Machined ones fare better at 0.2-0.4/metre but are...
  11. H

    Surface finish banding

    It's a good suggestion, will do it once I've installed the replacement leadscrew. Cheers
  12. H

    Surface finish banding

    A quick update for posterity: 1. The whiplash or error is due to a combination of bent leadscrew and incorrect alignment of the bearing block at the far right side. I've adjusted the bearing block to improve the whiplash, also still waiting on the leadscrew replacement. Meanwhile I've made...
  13. H

    Surface finish banding

    Thanks Ken. I'll ask around, but in all likelihood (if it's an hour or more of work) the cost to straighten the leadscrew will be more than what I've paid for a replacement ($100 AUD). It's funny 0.2mm run out doesn't sound like a lot, I expected the saddle gibs to be rigid enough to prevent any...
  14. H

    Surface finish banding

    A few updates (tl;dr still an issue) 1. The leadscrew is bent, 0.2mm radial runout at the middle, which would be pushing the saddle up and down, front and back by a fraction of that. 2. It's hard to tell on straight turning of small stock, but more obvious with steep taper turning because of...
  15. H

    Surface finish banding

    This is a quite promising lead, it could possibly explain the banding if Z move is a bit jerky. It might be possible to measure this as pointed out in the post.
  16. H

    Arduino RPM Application for Sieg Lathes and Mills

    Interesting hack Jenny, nicely done! Arduino is quite capable of doing more than displaying the RPM. Grbl can run gcode on an Arduino and control 3 axes in realtime.
  17. H

    Surface finish banding

    Lots of nice pointers, thanks heaps everyone. That's an especially helpful thread @Ken I Updates: It is an ACME / Metric leadscrew. The thread form is fairly decent, but I suspect it's rolled not precisely ground (not expecting more than 0.01mm accuracy with this). It's good enough for hobby...
  18. H

    Surface finish banding

    Good point Charles. The algorithm for linear motion is pretty similar to Brenseham's where it's a sequence of steps in the dominant axis followed by steps in the other, this repeats until a line for the taper is traced. I'm not sure it's related to that though since the individual steps are very...
  19. H

    Surface finish banding

    > I'm sourcing a 2nd 24V 5A power supply to try the taper turning as Don suggested. Did that and to be extra certain also changed the stepper driver and motor. Same results, clean finish on the straight Z movement for turning but stepped / banding finish with taper turning. It's most likely...
  20. H

    Surface finish banding

    I pulled off the lead screw covers and took a look a the lead screw as it rotates. I think there's a slight bend, or incorrectly rolled leadscrew which is barely noticeable - relative position of the thread root seems to move in (towards bed) and out while the crest seems stationary. Weird, I'm...
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