Turned items are not looking good …

Turned items are not looking good …

Home Forums Beginners questions Turned items are not looking good …

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  • #96381
    wavering
    Participant
      @wavering

      I have a Harrison lathe which has defintely got a bus pass and probably a free TV licence too

      No matter how carefully I turn things it looks like rats have been gnawing at it. As far as I can see there are 3 possible explanations

      1. I don't know what I am doing

      2. The tools are blunt

      3. The lathe is knackered

      Or all three

      Any suggestions as to the best way forward?

      Bob

      #6293
      wavering
      Participant
        @wavering
        #96387
        Russell Eberhardt
        Participant
          @russelleberhardt48058
          Posted by wavering on 15/08/2012 15:29:10:

          I have a Harrison lathe which has defintely got a bus pass and probably a free TV licence too

          No matter how carefully I turn things it looks like rats have been gnawing at it. As far as I can see there are 3 possible explanations

          1. I don't know what I am doing

          2. The tools are blunt

          3. The lathe is knackered

          Or all three

          Any suggestions as to the best way forward?

          Bob


          The age shouldn't be a problem I started with a lathe about 100 years old. If it's knackered you can fix it/get round it.

          Your numbered points:

          1. Fixed by asking here.

          2. Try rubbing the cutting edge across the back of your fingernail. If it won't produce fine shavings sharpen it.

          3. Make sure there isn't any play in the headstock bearings they should be tight enough so that without the drive connected if you spin the chuck by hand it won't do more than one or two revolutions before stopping. Make sure the gibs are tight enough. Is there any possibility of the tool movine in the toolpost or vibrating? Keep the tool tip as close to the toolpost as you can. Does the lathe vibrate much when in drive?

          Hope that gives you something to look at as a start.

          Russell.

          #96394
          wavering
          Participant
            @wavering
            Posted by Russell Eberhardt on 15/08/2012 16:31:22:

            The age shouldn't be a problem I started with a lathe about 100 years old. If it's knackered you can fix it/get round it.

            OK

            Try rubbing the cutting edge across the back of your fingernail. If it won't produce fine shavings sharpen it.

            Pased that test

            Make sure there isn't any play in the headstock bearings they should be tight enough so that without the drive connected if you spin the chuck by hand it won't do more than one or two revolutions before stopping.

            Feels OK on that test too

            Make sure the gibs are tight enough.

            Er … waht are gibs?

            Is there any possibility of the tool movine in the toolpost or vibrating?

            No but I think the tool was too low – have added a shim and now a bit better

            Keep the tool tip as close to the toolpost as you can.

            Noted

            Does the lathe vibrate much when in drive?

            No, it is fine

            Not familiar with this site so hope this post looks OK. Thanks for your help Russell

            I have photographed a pic (Photo 1) of my best efforts done a few minutes ago. How does that look?

            Bob

            #96395
            Neil Greenaway
            Participant
              @neilgreenaway71611

              Hi There,

              On my Harrison L5 I once experienced really ppor surface finish all of a sudden – the locking ring nut had vibrated loose at the back of the taper roller bearing at the front og the headstock and left excessive play – I made up a C-ring pin spanner and adjusted the locking ring nut and never had a problem after this. I had to remove the lid from the headstock of course and resealed the lid upon refitting with hylomar.

              Hope this might help.

              Neil

              #96396
              wavering
              Participant
                @wavering
                Posted by Neil Greenaway on 15/08/2012 18:09:03:I had to remove the lid from the headstock of course

                Is there an idiots guide to doing this anywhere, Neil? Or is this best left to competent people?

                Bob

                #96397
                Nathan Sharpe
                Participant
                  @nathansharpe19746

                  Hi Bob, If you need a handbook/partslist go to http://www.lathes.co.uk. Tony has quite a bit of info onsite

                  and sells a handbook for the L5. My own L5 is about 1960 vintage and works well, they are pretty bombproof if looked after . All the above advice is good but keep asking questions until you/we solve the problems. It sounds to me like you are cutting below centre and light cuts. Set the tool height by removing the chuck, fitting a good sharp centre in the headstock spindle and setting the tool to the point of the centre. Once you,ve done that and before removing the centre make a height gauge to sit on the bedways for future tool setting. It need not be anything fancy but must be accurate.

                  Nathan.

                  #96398
                  wavering
                  Participant
                    @wavering
                    Posted by Nathan Sharpe on 15/08/2012 19:01:26:

                    Hi Bob, If you need a handbook/partslist go to http://www.lathes.co.uk. Tony has quite a bit of info onsite and sells a handbook for the L5.

                    Thank you – it seems I do have an L5

                    It sounds to me like you are cutting below centre and light cuts.

                    Yes, I did mention that I added a shim and now is dead centre. Yes, re light cuts, I assumed that a light cut would give a better finish?! Presumably the answer to that is "no"

                    Nathan, this is my best so far … is this what lead you to conclude I was cutting low and light?

                    Bob

                    #96401
                    Neil Greenaway
                    Participant
                      @neilgreenaway71611

                      Hi Bob,

                      I had a couple of different L5 manuals and I cannot remember them being that much help with carrying out fine adjustments. From memory on the lid of the headstock there are 6 or 8 cap head screws and I simply removed all of these and gently prized the lid off – you may have to cut the sealant to get it started to lift off. If you move the backgear lever into a central position it should release the spindle for free movement. At the right hand side of the headstock gearbox (ie the front end) you should see the bearing housing – should be a woven mesh filter on the top to strain the oil as it runs into the bearings. On the spindle just at the back of the taper roller bearings you will see a steel ring with about 4 holes radial round the OD – on my lathe these had been tightened with a hammer/punch – I managed to clean it up a bit and thats where the pin spanner came in – I tightened the nut until the bearings were tight to turn the spindle, and then backed it off a little bit at a time until the bearings were free but firm in running, and also smooth running too. I then refitted the lid – from memory I ran the lathe a short while under power but without sealant to make sure the bearings were OK. Then I sealed the lid up but didnt tighten the screws completely until 24 hours passed.

                      On the cross slide you should have a large chrome plated screw with a large pan type head – this screw head fit into a slot in the end of a tapered gib. advancing the screw into the cross slide tightens the gib, removing it slackens the gib. adjust it until the cross slide is moving smoothly but not too tight and not too slack.

                      I had bought the lathe and learned a lot by trial and error, but also found books like The Amateurs Lathe and using the small lathe very helpful.

                      Hope this helps,

                      Neil

                      #96402
                      Neil Greenaway
                      Participant
                        @neilgreenaway71611

                        Hi Bob,

                        If you face off the end of a bar do you get a pip left in the centre – if so your tool is set low – the diameter of the pip being twice the distance that your tool is below centre.

                        Neil

                        #96405
                        Nathan Sharpe
                        Participant
                          @nathansharpe19746

                          Hi Bob, Yes that photo is the one but I also wonder if your speed is too low. It,s also possible that you have a bit nasty metal in the chuck ! As Neil said you won,t get fine tuning info from the handbook but you will get speeds/ feeds/tool geometry and exploded drawings showing how things go together .

                          What are you cutting with and are you sure its sharp enough? The finish looks as though material is being torn out not cut . Resharpen and try again, we,ve all had to do that and it helps to gain experience .

                          Nathan.

                          .

                          #96406
                          wavering
                          Participant
                            @wavering
                            Posted by Neil Greenaway on 15/08/2012 19:38:40:

                            If you face off the end of a bar do you get a pip left in the centre – if so your tool is set low – the diameter of the pip being twice the distance that your tool is below centre.

                            No, I have got it right now – see my post above with pic in it

                            Regards

                            Bob

                            #96408
                            David Littlewood
                            Participant
                              @davidlittlewood51847

                              Bob,

                              Two things that haven't been mentioned are the type of tool you are using and the depth of cut. For example, if you use a carbide tipped tool and try to take a very fine cut you maye get a poor result as there is a tendency for the tool tip to rub. I find I can get down to about half a thou before this starts happening, but if the tool is just slightly above centre height this will happen sooner – and this isn't as easy to spot by the centre pip method. See what happens with cuts at various depths; if it gets worse for deeper cuts then it is more likely to be a bearing issue.

                              You will also find a great resource for advice on Harrison lathes on the Yahoo Harrison lathe group: http://groups.yahoo.com/group/harrisonlathe/

                              David

                              Edited By David Littlewood on 15/08/2012 20:03:38

                              #96411
                              wavering
                              Participant
                                @wavering

                                Posted by David Littlewood on 15/08/2012 20:00:38:

                                Two things that haven't been mentioned are the type of tool you are using and the depth of cut.

                                I think you have hit the nail on the head there. I was hoping for an excuse to buy a new lathe but I think this is a case of pilot error rather than machine error …

                                I will extend my range of tools, sharpen them and get them at the right height and report back in due course

                                Thank you everybody for your comments

                                Bob

                                #96422
                                mgj
                                Participant
                                  @mgj

                                  I think I would look at the chuck as well. I don't think that has been mentioned, and if it has a bus pass, or not been looked after, the jaws may not be holding correctly.

                                  Give the lathe a tune up (it probably deserves it), sharpen all and ensure you support the work properly too, with minimum overhang. But before despairing, mount a job in another chuck/collet/faceplate/4 jaw, and see. Culprit could easily be a dodgy 3 jaw.

                                  #96426
                                  steamdave
                                  Participant
                                    @steamdave

                                    Bob

                                    Are you a member of the Yahoo Groups Harrison Lathe group? If not, I suggest you join.

                                    http://groups.yahoo.com/group/harrisonlathe/?yguid=133995445

                                    Dave

                                    The Emerald Isle

                                    #96431
                                    Anonymous

                                      One thing that hasn't been explicitly mentioned is the material type. Some steels (EN1A) turn like a dream, others (EN3B) can be a pig if the feeds and speeds are wrong. It can also depend upon where the steel was sourced; all suppliers are not equal.

                                      Best Regards,

                                      Andrew

                                      #96432
                                      Ady1
                                      Participant
                                        @ady1

                                        I will keep it simple

                                         

                                        You're just not trying

                                        You're not observing the cut

                                        You're not listening to the cut

                                         

                                        Get it sorted

                                         

                                        Get back to us in 12 months, after you've cut bucketloads of swarf

                                         

                                        Don't look to anyone else, this one is yours.

                                        A Harrison lathe is a major bit of kit

                                        Edited By Ady1 on 16/08/2012 00:33:06

                                        #96433
                                        Ady1
                                        Participant
                                          @ady1

                                          Oka-y

                                          I'll take a couple of steps back (after falling out of the pub tonite)

                                           

                                          How come you have a Harrison and you don't know what you're doing?

                                          Edited By Ady1 on 16/08/2012 00:40:33

                                          #96435
                                          Ady1
                                          Participant
                                            @ady1

                                            It's no different from women

                                            How much can you learn from a book???

                                             

                                            Dive in there and enjoy

                                             

                                            My own Myford unit is 1944 btw

                                            Edited By Ady1 on 16/08/2012 01:06:57

                                            #96439
                                            Springbok
                                            Participant
                                              @springbok

                                              Hi I have been sitting back and watching this one, looking at the pics the 2 large bits of kit in what would look like a old school workshop, would also say that they are 3 phase. why the travel steady lying on the floor.
                                              I would certainly go along with 1 and 2. as the lathe has far to much swarf around it to contribute to the example shown.

                                              Bob.

                                              #96444
                                              John Stevenson 1
                                              Participant
                                                @johnstevenson1
                                                Posted by Ady1 on 16/08/2012 00:37:51:

                                                Oka-y

                                                I'll take a couple of steps back (after falling out of the pub tonite)

                                                How come you have a Harrison and you don't know what you're doing?

                                                .

                                                How come people own Audi's and can't drive ?

                                                How come people answer questions on this forum and can't sort thier own problems out ?

                                                Answers on the back of a £20 note please.

                                                John S.

                                                #96448
                                                wavering
                                                Participant
                                                  @wavering
                                                  Posted by John Stevenson on 16/08/2012 09:16:45:

                                                  Posted by Ady1 on 16/08/2012 00:37:51:

                                                  Oka-y

                                                  I'll take a couple of steps back (after falling out of the pub tonite)

                                                  How come you have a Harrison and you don't know what you're doing?

                                                  .

                                                  How come people own Audi's and can't drive ?

                                                  How come people answer questions on this forum and can't sort thier own problems out ?

                                                  Answers on the back of a £20 note please.

                                                  John S.


                                                  John

                                                  How did you know I have an Audi?

                                                  Anyway, the problem is the 3-Jaw chuck. It looks like it has been excessively tightened and the outer jaws are bent out sort of if you follow me

                                                  So, does anybody know where in the Manchester area I could get this sorted?

                                                  Thanks everybody, this is a great forum

                                                  Bob

                                                  #96509
                                                  Nathan Sharpe
                                                  Participant
                                                    @nathansharpe19746

                                                    Hi Bob, Just as a follow up to what you were told was not in the handbook, on page 13a are the instructions to adjust the clutch, the HEADSTOCK bearings and saddle,cross slide and top slide. There are several pages of recommended lathe practice for turning between centres,faceplate and chuck work,taper turning screw cutting and tool geometry. In my view it,s worth every penny it cost. I doubt that you can learn it all from the book but it,s somewhere to start the process. Those who say there is no info in them must only have looked at pictures!!

                                                    Nathan.

                                                    #96677
                                                    wavering
                                                    Participant
                                                      @wavering
                                                      Posted by Springbok on 16/08/2012 01:40:30:

                                                      Hi I have been sitting back and watching this one, looking at the pics the 2 large bits of kit in what would look like a old school workshop, would also say that they are 3 phase. why the travel steady lying on the floor.

                                                      Well, it is NOT a school it is the basement of my house. And, yes, I do have a three phase supply. As for the steady lying on the floor it is there because that is where I put it when I finished using it

                                                      wavering

                                                      Edited By wavering on 19/08/2012 20:43:07

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