What's new
What's new
By:
Advanced search…

Search results

  1. G

    bridge straight edge out of steel

    I found this paper on low temperature creep of steel, abstract only. Kind of technical, I do not really understand the implications of it. Here is a short excerpt "Small plastic and creep strains in eight austenitic steels and a low-alloy steel were measured in the temperature range from 4 to...
  2. G

    bridge straight edge out of steel

    Denis, I am not a metallurgist but here is a theory of mine. You can have a beam that has a very high compressive stress on one side, neutral in the center and high tensile stress on the other side, the part ends up dead flat after scraping. There is no easy way to know what kind of stresses are...
  3. G

    Possible types of steel for this bushing plus alternative recommendations

    DOM, I bought a chunk years ago to repair a PTO post hole digger, the local steel supply shop sold it by the inch, the guy in back sent me up to the office to get a price before he would cut it off. I am glad he did because I bought just the length I needed instead of "just give me a foot or so...
  4. G

    Possible types of steel for this bushing plus alternative recommendations

    I think it depends a lot on what kind of equipment your friend has. I have a old manual lathe that can drill a 7/8 diameter hole 2 or 3 inches deep in steel but it would be annoying and take awhile, guessing 1/2 hr each. I might end up using a couple of different cutting tools to get there. I am...
  5. G

    Possible types of steel for this bushing plus alternative recommendations

    I would be tempted to buy the bushings you indicated that are a little long, this way you have stock that already has a thru hole and outside diameter, your friend just needs to part it off. I have modified pins and bushings from tractor supply a couple of times. They also sell steel shafting...
  6. G

    Why is HSS tool set above center

    Thanks for that info on hone, I learn something new every day
  7. G

    Why is HSS tool set above center

    I did not realize going above center was recommended for carbide for strait OD turning. Are you suggesting modifying or regrinding carbide inserts, I have tried this a few times with some sucess. Not sure what you mean by hone, is this wearing and dulling of the tool cutting edge? I agree...
  8. G

    Why is HSS tool set above center

    Yes let's assume the cross slide is horizontal. I guess 50 or 100 years ago there was a state of the art factory with a row of brand new SB lathes turning out barrels or shafts all day long. The lathes had been properly installed and leveled. The SB factory Rep said you will get best production...
  9. G

    Why is HSS tool set above center

    I am no expert on carbide but I think its edge is generally more blunt, "the angle of keenness" (from the SB page in my first post), between the front relief and top rake. This is recommended as 60 degrees for HSS cutting steel. Some examples I have seen of carbide are more like 75 to 80...
  10. G

    Why is HSS tool set above center

    Peter, I am not sure if you are asking a question or just making a comment about SB. Assuming the former, here is fig 15 and 16 from the Herco book that shows how changing the height affects the front clearance and back rake angles. I think this chart is true regardless of what kind of lathe or...
  11. G

    Why is HSS tool set above center

    I am not sure 5 degrees above center is the best description by itself but the page from the book in my first post has a sketch that I think shows what the 5 degrees means. A line from the tip of the tool thru the center of rotation will be 5 degrees above the horizontal. This amounts to...
  12. G

    Cross Slide TPI

    Sometimes the thread on the lathe may be in a diameter that is uncommon today. You can use the next size larger size and buy or make the new nut.
  13. G

    Wanted: SB Heavy 10 apron rack pinion gear/shaft

    My gears look about the same as yours, I am going to adjust the fit of my used gears by installing bushings for the shaft and shim under the rack. There is a number on the end of mine, I did not realize t was a size so thanks for that.
  14. G

    Cast Iron Plate

    Rubber from inner tubes may be about the right stiffness but in my limited experience can vary a lot in thickness. Might be worse than nothing.
  15. G

    SCREW TAP BROKEN

    I have had reasonable luck with wilton tap extractor tool, there are little fingers that go into the tap flutes.
  16. G

    Why is HSS tool set above center

    Excellent points. I have seen those effects before but had not considered the effect of cutting height. Seems obvious in hindsight.
  17. G

    Why is HSS tool set above center

    My 56th rev of the SB book "How to run a lathe" states to set the HSS tool bit 5 degrees above center for normal straight turning of mild steel. Grind the bit with sufficient front clearance. My question is who came up with this and why 5 degrees? I suspect there is some science and logic behind...
  18. G

    SB 13 inch cross feed screw

    The screws are different
  19. G

    South Bend model B ,carriage

    On my SB 9" there is nothing holding the front down except weight and the cutting force should be down also. I guess if it lifts a little, the pinion gear will hit the rack.
  20. G

    Cincinnati 16" Shaper for sale on FB in Buffalo

    I got my 7" SB with vise and cabinet for free years ago, still use it occasionally.

ABOUT PRACTICAL MACHINIST

With more than 10.6 million unique visitors over the last year, Practical Machinist is the most visited site for metalworking professionals. Practical Machinist is the easiest way to learn new techniques, get answers quickly and discuss common challenges with your peers. Register for the world’s largest manufacturing technology forum for free today to stay in the know.

Learn more about us.

STAY CONNECTED

Facebook Instagram YouTube LinkedIn Pinterest Twitter Tiktok

Register Become a forum member. Register today.

Sign Up Sign up for our e-newsletter.

© 2024 Copyright Practicalmachinist.com. All Rights reserved.

Back
Top