jordhandson
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£10 bargain! i reakon you could cut it down to fit a smaller blae holder, yes it will become one ended but a lot easier than what I am going through. plus you do not have the blade holder anyway. depends on your lathe tool post size I guess
thanks that might come in hand dont forget pics if you make your own holdersThat what I thought I have a dickinson quick change on the lathe and I am at the mo saving all the offcuts left from the forklift tine, I have been whatching a few vids to see if I can make some holders so figured make one the the tang thing.
Bye the way if anyone after a tang holder the seller has another one list see here
https://www.ebay.co.uk/itm/CNC-Parting-tool-Iscar-Tang-Grip/283709247783?
will dothanks that might come in hand dont forget pics if you make your own holders
Cheers Hood if you have any pics of your holder that would be handyInteresting that these blades say 35-3, would have thought they would say 32-3. Maybe they are od ball sized.
Will have to look and see if I have a pic of mine to see what it says.
Ok not very clear as I had to zoom in on a screenshot but it definitely says 32-3.
View attachment 270616
Aye, as long as you are making your own blade holder up it will be fine, if not then it won't fit in a 32 holder unless you modify it.
Use a well pointed darning needle with the eye cut off so you get a bt of parallel metal in the chuck to set the point ... Slip a mirror in at the tailstock side to see the points match . Did you stone the parting tool edge after grinding it ..it helps if you do.I am 99% sure it is at the right height, Good shout though about milling the bottom though.
I think it is more that the blade has a slight angle on it as the blade holder dont sit 100% square in the QCTP holder
I will have to raid the mrs sewing box for a darning needle!Use a well pointed darning needle with the eye cut off so you get a bt of parallel metal in the chuck to set the point ... Slip a mirror in at the tailstock side to see the points match . Did you stone the parting tool edge after grinding it ..it helps if you do.
What you said about it stopping the chuck ...... sounds like it has grabbed into the metal . Did you lock the saddle so there is no chance of any saddle movement ?
Hmm ..... besides tightening the gibs properly so it is tight /hard to move the slide , set the cutter parallel to the chuck face , if it's not parallel you are trying to cut at an angle & are liable to break the knife or try to bend it.
To set it parallel I've found I need take the part out the chuck , open the jaws as wide as I can without dropping them out . Slacken off the tool post so it rotates freely.
Then slip a quality precision round bar/rod or key steel bar or a precision square ground tool bar on the bottom jaw so it touches the chuck face .
Now gently advance the carriage till the side of the parting knife blade starts to touch the round bar it's now in parallel . This is assuming you have turned a couple of test bars to make sure th tailstock is centered to give you a parallel bar instead of a traffic cone shaped rod .
Even getting to t e stage of being able to turn a proper parallel rod test piece took me several attempt , for at the time I didn't know about the mini molehill problem as well as not yet discovering how far it was out from the stamped in alignment marks on the tail stock slide .
I now have made three test bars of 6 ,12 & 18 inch lengths . If I want a decent job I'll reset the tailstock using a roller bearing advanced to the tailstock end to get as little run out as possible and checking it with a DTI for run out . ( it sometimes involves re stetting the tail stock gibs too depending where the tailstock is positioned for work on the ways . .. It changes over the length of the ways , as I don't have an accurate inverted Vee on the ways to keep it in true . My bed is flat & had a couple of thou wear towards the chuck end .
That's one of the best ways I know of for getting the cutter parallel to the chuck and at right angles to the work piece .
If parting much more than an inch I found that making the cut almost twice as wide in stages as the parting blade , it stops you picking up swarf and causing problems . Aluminium & copper are problematic for this as they have a soft swarf .so widen the parting slot in 150 thou deep stages . If your clever when you grind your blade angle it ever so slightly so there is a leading point on the cutting edge , . then if you've set the height well you'll get it cleanly parted to whichever side you've made the lead in . Handy if you're turning small parts that are hard to hold and remove any spigot left when the metal is parted .
Gently tighten it then retighten it properly and check it again with a torch from under the chuck at the back , if you've moved out of square /true a triangle of light will show . When you use other tools, set them up in a similar manner so the index graduations are at 90 . you can always of set them a degree or so after once you proved parallel. When you put the parting tool or any other tool back on untill you get to kno your lathe & have proved it's accurate again recheck just incase the QCTP ot the cutting tool has rotated slightly . ( see below )
Silly to ask this ..have you checked that the mating surfaces of the QCTP and the top of the slide are actually flat and haven't been pulled through like a very flat mini mole hill . If you find that's the case you'll have to file & scrape the lathe surface to get it flat again otherwise the QCTP tends to try and rotates about the anchor bolt .. guess how I know & how many parting tool blades I broke before I worked out what the problem was ( five ).
PS ..pent a small fortune replacing all 32 clamping Allen screws in all eight of my QCTP tool holders .. the original ones must have been made of lead .. I sheared a couple off early on & also ripped some Allen key holes out so it was round & like a bin bag before the tool piece was sufficiently tight in the holder .
Is there not a risk of unscrewing the chuck when you do this?Hello, to stir things up a bit, I use the Eccentric Engineering parting off tool in a Dickson toolpost. I have a Boxford STS metric lathe and run it in reverse when parting off.
https://www.eccentricengineering.com.au/products/for-front-or-rear-inverted-parting-tool
Not if the parting tool is upside down as you are running the spindle the same direction as you would with it at the front.Is there not a risk of unscrewing the chuck when you do this?
I can see that if he’s using a rear toolpost, but he’s using a Dickson style which suggests that it’s a front mounted one.Not if the parting tool is upside down as you are running the spindle the same direction as you would with it at the front.
Edit
Oh maybe I read the quoted text wrong. Yes if it is an upside down tool at the front then if using a screwed chuck you would need to take care.
Aye, not sure what it is. When I saw an upside down tool I automatically presumed it was a rear post being used but possibly not. If not then if a screwed chuck care would be needed.I can see that if he’s using a rear toolpost, but he’s using a Dickson style which suggests that it’s a front mounted one.
Or am I being really dumb today?