Page 6 of 7 FirstFirst 1234567 LastLast
Results 76 to 90 of 95
  1. #76
    Join Date
    Jul 2008
    Location
    near Warragul, Victoria
    Posts
    3,718

    Default pic

    The last pic with the dial indicator , the larger diameter looks to be a reasonably good finish for hot rolled . The brazed carbide tool you are using is not the ideal setup for a learner , it is probably the worst out of the three choices , HSS, carbide insert or brazed carbide. I would get rid of it . I think you would be far better off with a sharp HSS tool or a Aluminium style carbide insert with a sharp edge .

  2. #77
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    1,656

    Default

    I have only just looked at this thread, I had the same problem when I bought my metal lathe over 20 yrs ago, I went through or same hair pulling, turned out to be a roll pin that locks the tool holder. the pin was slightly too small
    allowing the tool holder to move when in use, I replaced it with a tight fitting pin and the problem disappeared, have you checked that nothing is moving it is surprising what a very tiny movement can cause.

  3. #78
    Join Date
    May 2021
    Location
    australia
    Posts
    50

    Default

    Quote Originally Posted by China View Post
    I have only just looked at this thread, I had the same problem when I bought my metal lathe over 20 yrs ago, I went through or same hair pulling, turned out to be a roll pin that locks the tool holder. the pin was slightly too small
    allowing the tool holder to move when in use, I replaced it with a tight fitting pin and the problem disappeared, have you checked that nothing is moving it is surprising what a very tiny movement can cause.


    I'll go over it tomorrow and see what moving slightly



    I have noticed that the tool gets pushed back a little sometimes, but that's from the slack in the cross slide i believe ?

    edit:


    got these to try out as well


    I got these today. Going to have a play around some HSS blanks in a couple of sizes

    a right handed carbide holder with the blade things to go in

    and a few of the brazed carbide tipped ones.

    Also a little finishing stone for HSS and a steel shimming plate.


    I have a 2mm, 3mm and 4mm shimming plate along with various feeler gauge pieces to help where needed.


    199800735_1252972778495824_1838547676655015392_n.jpg

  4. #79
    Join Date
    Jun 2016
    Location
    Sydney
    Posts
    283

    Default You can't

    I was using some degreaser spray as cutting fluid
    Well, that won't work! You need the opposite: a light oil would be a start.

    no idea how to get rid of these marks that are still present.
    There is only one way: do not put them there in the first place. Nothing else works.

    First of all, that steel looks pretty horrible for turning. Some steels are like that, including a lot of bolts. Might be good for something else. Get some free machining steel and see how that goes. Really.

    Check the tightness of the whole saddle: it looks as though it can wobble and let the tool dig in. If the saddle is too light, then you may not be able to prevent to prevent the wobble or chatter which gives those marks. That is a function of the lathe, and small old lathes are often looser than big new ones.

    If you must use that steel, you will need a sharp cow-mouth HSS tip (ie round), a high speed and a very fine cut - both in depth and feed.

    The path to learning is long.

    Cheers
    Roger

  5. #80
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    If you decide to buy carbide, get positive rake tooling. I use CCMT and DCMT. I generally use a .4mm radius insert but I do keep .2mm radius inserts.

  6. #81
    Join Date
    May 2021
    Location
    australia
    Posts
    50

    Default

    here's the latest all put together in a video

    https://www.youtube.com/watch?v=6Byn8lK-rvk

  7. #82
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    The hole in the tool holder should be a neater fit.

    The tool holder should be one piece not two as shown, you really should replace the 4 way.


    Has the compound always been loose as shown before you tightened it?

    Are there 2 small pins at the bottom of the holes that the screws on your crosslide screw into to hold the compound?

  8. #83
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    Yeah, sort out your slide and tool post before you start heading in any other direction.
    Mal at Australian Metalwork Hobbyist has spares and changeover bits, although I’d be tempted to look at a chinesium AXA (250-110/111) size quick change if you have budget for it.

  9. #84
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Mathu,

    Thanks for the video ! I noticed several things. First that tool holder needs to be properly sorted, the way its mounted is not good, too many interfacing layers that will allow movement.

    My top slide is secured into the cross slide in a very similar fashion. The pins that clamp the top slide on mine are machined at an angle that matches the taper at the bottom but do not close into the waist of the groove. This means that when the pinch bolts are tightened the top slide is firmly pulled down onto the top of the cross slide mounting face.

    When parting you should have the cutting/parting point as close to the chuck as is practicable. Whilst using a live centre to support the workpiece is OK, it can jam and break the blade, so if you have to provide support like that, then back the tailstock off just before you finish the cut.

    I made a new tool holder for my Myford lathe and got rid of the expensive QCTP and the four way tool holder in favour of a "Norman" patent one. I also made a similar one for a rear tool post, which I currently use for a parting tool blade.

    It would make a very good learning project for the lathe. I did a write up for it on here.

    https://metalworkforums.com/f303/t20...orman+toolpost
    Best Regards:
    Baron J.

  10. #85
    Join Date
    May 2021
    Location
    australia
    Posts
    50

    Default

    Quote Originally Posted by pipeclay View Post
    The hole in the tool holder should be a neater fit.

    The tool holder should be one piece not two as shown, you really should replace the 4 way.


    Has the compound always been loose as shown before you tightened it?

    Are there 2 small pins at the bottom of the holes that the screws on your crosslide screw into to hold the compound?

    Thank you, Yes there are 2 pins there they are angle cut to fit with the compound slide insert.

    and yeah, when i took it apart i thought i would need another one, perhaps my one is home made 'shrugs' but it's the hole in the middle being too large for the bolt that makes me think i need another.


    Quote Originally Posted by racingtadpole View Post
    Yeah, sort out your slide and tool post before you start heading in any other direction.
    Mal at Australian Metalwork Hobbyist has spares and changeover bits, although I’d be tempted to look at a chinesium AXA (250-110/111) size quick change if you have budget for it.
    Thank you. unsure which way i would go, 4 way post or a quick change due to the ability to change height of the tool with the qctp quite easily. But i've read 4 way is more rugged.



    Quote Originally Posted by BaronJ View Post
    Hi Mathu,

    Thanks for the video ! I noticed several things. First that tool holder needs to be properly sorted, the way its mounted is not good, too many interfacing layers that will allow movement.

    My top slide is secured into the cross slide in a very similar fashion. The pins that clamp the top slide on mine are machined at an angle that matches the taper at the bottom but do not close into the waist of the groove. This means that when the pinch bolts are tightened the top slide is firmly pulled down onto the top of the cross slide mounting face.

    When parting you should have the cutting/parting point as close to the chuck as is practicable. Whilst using a live centre to support the workpiece is OK, it can jam and break the blade, so if you have to provide support like that, then back the tailstock off just before you finish the cut.

    I made a new tool holder for my Myford lathe and got rid of the expensive QCTP and the four way tool holder in favour of a "Norman" patent one. I also made a similar one for a rear tool post, which I currently use for a parting tool blade.

    It would make a very good learning project for the lathe. I did a write up for it on here.

    yep, the pins are there for me as well and act the same way as far as i can tell.

    The parting tool, the point was closer to the surface that i wanted to be flat and not left with that tiny little nipple, that's all. The tail stock support i put in because i just rather have it and not need it than need it and not have it but i agree parting as close as feasible to the chuck is best


    I'll be doing more work tomorrow

    I don't have the coin to get a new post, but i know now that it's a likely cause of my frustrations.

  11. #86
    Join Date
    Nov 2007
    Location
    melbourne australia
    Posts
    3,228

    Default

    Quote Originally Posted by mathuisella View Post
    Thank you. unsure which way i would go, 4 way post or a quick change due to the ability to change height of the tool with the qctp quite easily.
    QCTP every day of the week.
    Chris

  12. #87
    Join Date
    Jun 2007
    Location
    sydney ( st marys )
    Age
    64
    Posts
    4,887

    Default

    If you have a drill press or are able to drill holes accurately and some threading taps you can make your own 4 way post to suit what you want on the lathe, no milling required.

  13. #88
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Quote Originally Posted by BaronJ View Post
    Hi Mathu,
    I made a new tool holder for my Myford lathe and got rid of the expensive QCTP and the four way tool holder in favour of a "Norman" patent one. I also made a similar one for a rear tool post, which I currently use for a parting tool blade.
    It would make a very good learning project for the lathe. I did a write up for it on here.

    https://metalworkforums.com/f303/t20...orman+toolpost
    Best Regards:
    Baron J.

  14. #89
    Join Date
    Jun 2016
    Location
    Sydney
    Posts
    283

    Default Qctp

    My lathe came with a rocker, but I soon swapped a QCTP in place. Never looked back.
    So I bought a second QCTP, for the CNC lathe. Guess what: The tool holders are not strictly compatible between the two!

    Not a problem: a 0.8 mm shim down one or both angled sides on one unit makes it all perfect. For a given value of perfect. But they do work very well for me.

    Cheers
    Roger

  15. #90
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,439

    Default

    Hi Rodger, Guys,

    I'm sure that you know my opinion about QCTP's ! They are great time savers in a production environment and I don't have a problem with that. But for hobbyists use they are an expensive toy !

    I got seduced by people telling me that they were better than sliced bread. To hell with the initial cost of the toolpost and all the tool holders you have to buy to keep up with the Joneses. I don't need or want to spend a small fortune on insert tooling just so that I can save the ten seconds that it takes me to change a tool, or the extra seconds that it takes to reset the tool height after I have just reground a tool.

    OK I'm a hobbyist and I take my time and think about what I'm doing, yes I make mistakes like anybody else ! At least my mistake doesn't cost production.
    Best Regards:
    Baron J.

Page 6 of 7 FirstFirst 1234567 LastLast

Similar Threads

  1. hooray...finished
    By eskimo in forum GENERAL DISCUSSION / OFF TOPIC
    Replies: 18
    Last Post: 5th Nov 2017, 09:48 AM
  2. Repairs finished after a bad day.
    By Mike4 in forum METALWORK GENERAL
    Replies: 0
    Last Post: 12th Jul 2017, 09:56 AM
  3. Advice, tips re. removing duragal for a weld?
    By DoctorWu in forum METALWORK GENERAL
    Replies: 22
    Last Post: 19th Mar 2015, 10:50 PM
  4. Need advice making a small part
    By simonl in forum METALWORK GENERAL
    Replies: 15
    Last Post: 27th Nov 2013, 12:41 PM
  5. Finally Finished My 260
    By kwijibo99 in forum THE HERCUS AREA
    Replies: 8
    Last Post: 16th Apr 2010, 01:53 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •