machining a lathe spindle bearing

[@wyliemacbean1157]

Harald, that was awesome. I really liked the last 4-5 minutes and the setup you used, just fantastic. Cheers Wylie

[@jimsvideos7201]

Supporting a boring bar with a steady rest is genius and I wish I'd thought of it.

[@lookcreations]

Interesting bearing set up. Thanks for the link from my video. There are a number of areas for the scraping inside the bearing faces which I am still researching. It seams it is not as straightforward as I had hoped. 👍 All the best Mat

[@Rolingmetal]

Big job for a Emco compact 8. I had a compact 8e a fews ago as my first lathe.

[@stemer1149]

Extremely interesting, particularly the sequence of operations. Would have liked to see the adjustment in the end.

[@HaraldFinster]

Thank you for your kind comment! The final adjustments were done by scraping, and I really did not dare to show my humbling attempts here. I find filming the bearing-scraping process extremely difficult. Even taking stills isn't easy as you have to get light into the confined space of the bearing somehow. MuellerNick has shown the process of a slightly different bearing here: kzbin.info/www/bejne/n3vHaY2tmZ5_Z80

[@stemer1149]

@@HaraldFinster thank you for your reply. I have an old Ehrlicher lathe with tapered bronze bearings as well, they run quite smoothly but I am always at at loss how tight to adjust them. I understand they need approx. 4..6 1/100 mm radial play for the oil but then at last comes the axial bearing at the spindle end and there I am not so sure. Again, thank you for your interesting video.

[@WeCanDoThatBetter]

Tolles Projekt! Welche Multifixgröße hast du denn auf der Maschine?

[@HaraldFinster]

Ich verwende mit dem im Video gezeigten Oberschlitten das Aa System. Außerdem habe ich mir kürzlich einen festen Stahlhalter gebaut, der den leider recht wackeligen Oberschlitten ersetzt. Das gibt mir die Möglichkeit, einen Multifix A zu montieren, den ich auch auf meiner zweiten, größeren Torsa Drehbank nutze.

[@WeCanDoThatBetter]

@@HaraldFinster Ah super, danke für deine Antwort. Hatte fast gedacht, der Stahlhalter wäre größer. Scheint aber ja auf jeden Fall stabil genug zu sein. Ich überlege nämlich gerade einen Aa Multifix anzuschaffen.

[@HaraldFinster]

@@WeCanDoThatBetter Der Aa ist auf alle Fälle ausreichend stabil für eine Maschine dieser Größe. Der Schwachpunkt (zumindest bei der Emco Compact 8) ist der Oberschlitten, insbesondere die unterdimensionierte Klemmung des Oberschlitten-Drehtellers auf dem Planschlitten. Achte darauf, daß noch genügend Höhe zwischen Unterkante der Stahlhalter und der Spindelachse verbleibt. Ich habe meinen Oberschlitten damals abgefräst und "tiefergelegt".

[@WeCanDoThatBetter]

@@HaraldFinster Das ist schonmal super zu hören :) Das mit der Höhe muss ich dann herausfinden, wenn ich einen Stahlhalter habe. Was ein kleiner Nachteil ist und mir noch etwas Kopfzerbrechen bereitet: der Aa klemmt nur bis 12mm Stähle, der einfache Vierfachstahlhalter kann bis 16mm klemmen. Mein Rändelwerkzeug hab ich leider mit 16mm Schaft versehen, entsprechend würde das nicht mehr in die Kasette passen... :)

[@peteraugust5295]

When you put the spindle stock centered on a lathe, why did you not put roller bearings in?

[@HaraldFinster]

I considered this but hadn't the correct roller bearings at hand. Actually I realized your idea using roller bearings later when I converted the lathe to roller bearings and line bored the bearing journals: kzbin.info/www/bejne/gYrPkmWmlpZmorM The (temporary) roller bearing supporting the boring bar sits below the plastic shield.

[@peteraugust5295]

@@HaraldFinster Awesome! Great Work.

[@YOURFISHINGCHANNEL]

Hi , Harald do you know the type of leadscrew for the emco 8? what diameter and pitch? I want to make 1 myself. thanks for the cool video

[@HaraldFinster]

Hi, the pitch is 1.5 mm and the diameter 15 mm. It is a trapezoidal (acme) thread. Feel free to ask if you need more information. All the best Harald

[@Domonkos89]

AMAZING jJOB!

[@Kyokunek]

Any more videos ?? This one is very interresting

[@HaraldFinster]

Thank you for your kind comment and your subscription. I am currently reorganizing my shop - the main job was moving my Thiel milling machine into the basement. This took quite some time but wasn't worth filming. In the near future I will replace the friction bearing of the cross slide by a double row contact bearing. I already did this for the compound slide using my Emco as a "milling machine". (See forum.zerspanungsbude.net/viewtopic.php?f=44&t=24764&hilit=torsa&start=339 for photographs with description in German) The cross slide will be done with the Wohlhaupter boring head on the Thiel. Please be patient.

[@KostyantinKravchenko]

Why not perfect ?

[@HaraldFinster]

I am not entirely happy with my scraping. The friction between the spindle and the bearings could be significantly better with a perfectly scraped pair of bearings. Ideally the spindle should "swim" on a thin ( < 0.01 mm) oil film and not touch the metal of the bearing if it is running above a certain speed. Scraping is still an ongoing learning process for me.

[@mackk123]

@@HaraldFinster scraping is making a comeback.

[@HaraldFinster]

@@mackk123 yes, I agree. I love scraping - just wish I would really master the art. In this particular case I decided to replace the bronze bearings by "modern" angular contact spindle bearings as the results of my first tests turned out really bad. (Chatter when even taking light cuts.) After a long series of tests I blamed the bronze bearings and decided to do the conversion. Unfortunately the conversion did not solve the problem. I am still not sure what is wrong, but I suspect the DIN800 (screw on) mount between the spindle nose and the chuck.