Parting tool holder

[Stuart]

I am in the process of making up some special tool holders for a dikson tool post

I have made these before and the wedge part is well sorted .

So one of these is to take a 5/16 parting  blade , you can buy the half inch ones and the 5/16 are available for the rear post, the rear one will not fit it fouls the top slide .

So out came the measuring equipment the blade is 1.5 mm thick at the top and 1.0 mm at the bottom , now I have measured both my purchased half inch ones the blocks, and the back face is flat no taper so the blade leans over with one side vertical and the other with the total relief showing.


So do I leave a small register at the bottom of 0.25 mm thick to make the blade stand upright with the relief on both sides or not

I need to use this blade in the front position for brass but it will be ok for steel

I have seen the holders for these blades to go in the tool holder but they are to bulky and the stick out is to much

[GailinNM]

I have made tool holders both ways and found for me the best was to put the slot in with no compensating taper or register.  Instead I put a shim in the bottom of the slot that is half the difference in thickness and bend over the ends to lock it in place.  I use different width tools and both the taper type and the "P" type that are tee shaped.  With the shim I can use them them all and I bag the shim with the blade when I change to a different blade.

When installing the blade, I put a piece of stock against the blade and a round rod against that with the whole thing clamped lightly in the mill vice while tightening the blade.  This seats the blade against the back of the slot when using a sliding wedge type blade lock.  If your slot is deep you can also put a flat shim in the tool holder, in addition to the compensating shim, to space the parting tool out near the edge of the tool holder for work near the chuck.
Gail in NM
 

[pgp001]

Here's one I made earlier.



And another



Rest of photo's here.

http://s456.photobucket.com/user/pgp001/library/Model%20Engineering/Various%20Tooling/Rear%20Parting%20Tool%20Holder?sort=3&page=1

If you want the drawings let me know.

Phil

[Stuart]

Thanks Gail for the input

you have answered my question in that the blade needs to be perpendicular with the relief on both sides but as this will only take the 5/16 blade I may still go with a small shoulder at the bottom , but if it does not work or the plant/backyard setup in the east alter the thickness it could be softened and machined off and a shim used as you have said

it does make me think that the setup as provided by the manufacture of the HSS blade holders are making life difficult for people to part off with the poor alignment of the blade I have checked my Myford bought ones from years ago with the W on them and they are all vertical on the face

BTW I do use the Sanvik Q cut system for steel and they are excellent but are to thick for small work

Stuart

[Stuart]

Phil

thanks for the offer I have a proven drawing for the wedge part , but the one I am making is for the front holder and is for the small 5/16 blade . so any tilt without the relief on both side of the blade HSS will cause trouble,

in the case of the blade in question if it was in ( it will not fitt anyway ) any of my holders Myford ones one side would be vertical and the other side would have 0.5 mm side relief that is what I am trying to get rid off


Stuart