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PARTING OFF HOLDER ( dickson style for ALGRA tool post.) (june 07... )
The professional brand ALGRA has made a super PRO quick change too post but there is no parting off blade holder available in the catalog, so I am gonna make my own one! The main bit is about 80 * 35 * 20 mm, and it comes off a rusty bit of steel!! check out the Aeny's band saw working on that....
another cut to make the gross dimensions as closer as possible to the wanted dimensions (70 x 22 x 40 mm)
to make it parallel I made few passes on the mill with the lovable OCTOMILL face mill.... achieve a full true parallel piece is a difficul job, I leave to you how to do it!!!have fun!
I give yop some tips!! The first thing to do ius to get two parallel sides, and then clamp the piece by the parallel sides and machine each of the 4 remaining faces by turning them into the vice avery pass..... ù next photo shows you the completed "parallel true" bit. I think I am gonna start buy some already true block, because I am tired to spend hours to get cubes and parallels from crap bits of metal all bended and not true!!! ahahahh
right, now that I have got a perfect parallel I can start the REAL machining. Today I am gonna make the main slot that will be the clamping surface for the ALGRA toolpost pulling piston.. the hitachi roughing 16mm end mill is the best friend I have to remove lot of material in a single pass. I am machining 10 mm deep and 16mm wide!! single pass!! cool. I just don0't know how long will be the mill life.... doing this way!!
once that the main center slot is created I move on the right and then left side to make the slot bigger, but I leave a 0.5mm clearance from the final dimension because I am gonna get the final pass with a carbide 8mm endmill, to achieve a super smooth finish!!! (not shown in photos)
once that the end mill 8mm has made finished the final cut I start working with the woodruff (aka T SLOT) cutter , to get the t slot on both sides. I used a 22.5 x 4mm cutter I thought was carbide tipped and I applyed 60m/min speedd but after two slots the sharpness of the tool isn't anymore good.. what is the problem? are these stupid cutters able to manage few slots, or every slot you do.. you need a new cutter ????? anyway...
the main slot on my parting off blade holder is ready. now I go home! next time I will made the slideways!!
NExt step is to start machining the blade slot. the hitachi 16mm Co mill make the first gross slot.. and the Cobalt 10mm end mill finish the slot with precise machining..
Since the parting blades are made with a +15 -15 degress top and bottom surface I must machine the bottom of the parting holder with a -15° angle.. check out how I have clamped the vice to get a 15° inclination!!! cool, maybe crazy!! the 4mm end mill make the slot just easy as cutting butter!!!!!then...
back with the roughing mill to make the two slots which are room for the clamping system.. The blade must be pushed downwards and pulled towards the parting off holder body. These two slots will be used to screw on the two clamps (I will made them later on)
After the roughing cut, I got the perfect cut with the 3mm endmill, and in the following photo I am drilling prior tapping M4.
right..... taps are made... I love my Dormer taps!!!
now I need to machine the hardest step .-..... I need to create the V slots !!!! I have made many calculations to get the perfect matching Slots but at the end of the job I finally ended up to machine them "EYE" mode....probably because some of my MATH calcs were not right!!! anyway, this photo shows you the first cut of the V slots..
this is the end of the work! nice and clean smooth surface.... matched perfectly on the ALGRA toolpost body.
This is the result of few days of machining...to make the piece more perfect I have polished the Vslot surfaces and I have rounded all the edges with files and handwork!!
The task is completed once I have tapped and installed the central threated bar that allow the holder to get the right height on the lathe turret, by turning the knob.
as shown in the previous photo I have completed the two small blocks that holds the blade in place The following photos shows the fully finished parting off ALGRA QCTP holder!! cool stuff at rulezman workshop this time!!!
top view
kit view, I have got a 2mm blade from SECO and a 4mm SANDVIK blade, all of them off ebay... the inserts are good grade, most of them for medium to finish applications.
here we are !!! the holder is attached at the ALGRA tool post! perfect match!
side view
top view
well done dave!!job complited, keep it turning :)
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