Regrinding carbide inserts

on ebay hey welcome back to my shop today I want to talk about regrind carbide inserts for the lathe I showed this previous in the video where I showed the making of some specialized flyers reading tools and I got quite some feedback about it and for me replying covenants are very valuable process it's rather stupid to do it in a heavy production environment because that would negate the advantage of a carbide insert all being the same but for me doing one-offs prototyping and small quantities rewriting a carbide insert to geometry that helps me a very cheap and fast way to adapt to a job it's and also its rear onion in certain very positive and soft caps geometry helps me with my rather light duty machines so I can hold tight tolerances on my life with really sharp tooling you might say that it's just as good as grinding your own high speed steel tool or a solid carbide or a brave core back to yes kinder the insert has already if I rerun insert most of the work is already done it has clear angles to the bottom and it has also a defined nose radius most of my names are point to or point for in those areas so I don't have to run back myself also my few inserts that I use already have the seven degree clearance to the bottom included so I only have to grind a chip breaker and a top-rate into them so let's look at what we're going to do or what I am going to achieve in this video so let's go okay let's look at these inserts these are CC MTO fake sized inserts and see CMT defines the geometry which is this ad degree rhombus and O six as the size [Music] these are rather small inserts so this is a stock Kyocera finishing inserts I will show the the type number down here and as you can see it has a fancy chip breaker up here and it's all nice centered but when you take a very careful look at the edge here it has a slight radius very very hard to see on camera but you see this the sprite line over here when I tip it up slightly this is the cutting edge radius and this create cutting pressure this is a finishing insert for steel but this insert has a minimum depth of cut of about I think point two millimeters and to make it work otherwise it's just rubbing in creating an awful finish so [Music] this works in a lot of applications very well perfectly fine it's a good insert and I'm by these and I use them I used them for semi roughing and finishing but when it comes to very tight fit or very close fit and - very light cut this doesn't work for me because of the a tree cutting edge radius let's push this out of the way then we have these inserts I have no idea who makes these but I got them in a lot on eBay a few years ago and as you can see they have a chip break a very simple chip breaker ground into them these are actually ground after they have been sintered so this is a this has a razor-sharp cutting edge here and these take 100 of them only a deep cut without a problem but I can't find them none of the tooling suppliers I buy from stocks inserts with such a style of chip breaker I guess they are either specialized insert for aluminum or for very fine finish cuts on steel but that's just my guess and all I use them up I don't have any more of these left in my insert collection so these are out of the game - and then what I do normally when it comes to - very light cut or when I need very low cutting pressure I grind my inserts I take insert to the diamond wheel and freehand let's try to just turn this I grind a very heavy chip breaker into them and at least the cutting edge here sharp so this insert will take a very light cut and exceed very low cutting pressure on the workpiece that's especially interesting when you do long slender parts with a thin diameter otherwise the the cutting pressure will be select apart like crazy and you won't that end up with a cylindrical part but as you can see the hand ground chip break in there is not very defined you could say it's a mess so let's get these out of the way too and this is what I came up now I take them to a surface grinder and I have a little jig set up and I will show you later and I try to recreate something like this the santhi insert up here on used inserts I take the insert and I grind a heavy chip breaker almost parallel to the cutting edge with about five degree angle in this direction and a few degrees of rake in this direction and this works spectacularly they break the chips like crazy because the chip comes down here and hits this hard shoulder where I grind the chip breaker in and this deforms and breaks the chip I have I still have the corner radius in front here which is in this case point four millimeter as it seems which leads to a very nice finish and it's sharp so it works on steel with very light cuts it works an aluminum quite well or perfectly fine it yeah it's it's perfect for my needs and with the setup I have on the surface grinder Hank I can batch these out in no time I can i grind one side I flip it around I grind the other side and I put it away and then I do ten more until I have a box of inserts filled with regrind so let's let's take a look at the surface grinder and how I set it up okay here you can see the setup I have my my big grinding wise with the sign base and 25 millimeters small grinding wise clamp in it the small wise is set at 5 degrees in this direction and you will see in a second why in the and the small wise I have a normal see CMT turning tool clamp which holds the insert that I want to grind and as the tool as an angle of roughly 1 degree tilted down on the insert side like this welcome I will come to that also in a second so that's the setup and the wisest align parallel to the magnetic to the magnetic Chuck of the surface grinder or the rear rail of it so let's get another closer and look what we're doing here this side of the insert is already ground and I turn I flipped insert arounds to grant the other side what we're going to do is we have a straight diamond wheel and a 5 degree tilt in this direction will create a chip breaker a very heavy trip break and this will also remove the cutting edge radius I also tilted the the tool holder one degree down on the insert side so the chip breaker gets deeper to the rear end of the insert and that leads to better trip control the chip wants to flow to the back end of the insert instead of getting pushed into the work and might try to scratch up the work so that's the reason for this angle here I would say we just grind one and then we talk about I have my my dust collector hooked up to the surface grinder s were grinding carbide okay let's flip the in circle around and grunt the second thought [Music] okay a few minutes of work and I ended up with this seven reground carbide inserts with 0.2 and point four millimeter nose radius and this gives my youth carbide inserts a second life so let's go to lathe and see how they perform in different materials okay this is some mild feel just taking a few cuts to see how they perform okay the last couple depth of cut of two hundredths of a millimeter and and it still took a very defined chip and as heavier depth of cut it produced this nice curled up chip so that seems to work and the surface change is also not too bad let's try something different let's try some seventy seven to something something aluminum 7075 aluminum it does do much in aluminum but why not [Music] yeah that's a surface finish that doesn't leave anything to be to be desired happy with that let's try some brass those three cutting brass [Music] grass also not a problem [Music] and finally trying some grill rod which is a tool steel [Music] [Music] so it pushes a bit of a burr in the drilled route that surface hinge is also perfectly fine even with very light cuts I took a 500-ton lemon deep cut on the surface and it's still as good as it gets seems like I found a good procedure to to regrind my cdm-t inserts in a very useful geometry that works on all the common shirts that appear in my shop in all seriousness most of my materials are steel and steel and in the recent time I do a little bit of titanium and I think this geometry of this inserts now works very well especially for the small parts I did in the recent time without having to buy very specialized inserts that I meet that I need about once a few months and or horrible expenses so thank you all for watching and the next time

Channel: Stefan Gotteswinter

Views: 96,758

Rating: 4.9005146 out of 5

Keywords: carbide insert, insert, wendeplatte, wendeschneidplatte, lathe, surface grinder, t&c grinder, flachschleifmaschine, hartmetall, drehbank, grinding, carbide inserts, carbide, stefan gotteswinter

Id: UUVvgcvlbBs

Length: 15min 57sec (957 seconds)

Published: Wed Aug 16 2017