hello welcome to Enots engineering I'm Alan in today's video we take a look at
parting tools I also review one of Banggoods blade type parting tools
we look at the differences between the tools and see how they perform
so let's go into the workshop and see how we do it
today we're looking at parting off tools
This is the parting off to all that came with my Boxford lathe
the holder has a blade the size of this blade is 3/32" thick and 5/8" width
and you just move it in and out to suit the depth that you're cutting
and you can sharpen this, it's high speed steel so you can sharpen it with the grinding wheel
Now that's one that most of you probably familiar with and the second one I want to look at is
these insert holder parting off tools
this bodies 12mm by 12mm and the parting off tool on this one is 3mm
I have another one here very similar this body is 16mm by 16mm
Its on there and this one's a 2mm parting off tool
now the one I've used the most so far is this one at the back here the 3mm
these two virtually identical except for the thickness of the body
the problem I found with this one is that the tip being 2mm wide
there's very little support underneath the tip
as your parting off if the tip breaks it usually comes down and takes away some of the front
of the 2mm support
that's happened a few times with this tool and I've reformed the shape
I can get away with a small cut or a small depth but if I'm parting a 1" bar off with it
I know I won't get away with it
this one although it's a smaller body compared to the other one
the support under the tip is more and I think it's broke once that caused a tip to dig in
as a tip came down inside the slot it was cutting it then took away some of the support
I've had more success with the 3mm wide one than the 2mm wide one
this is a new parting off tool Lets open this up this is from Banggood
this is the tool holder
16:26 so this is 26mm high to fit a 26mm blade
and the back here this is 16mm high to fit a 16mm tool holder
that's bought separately with this you need to buy the blade that fits the tool holder
in this case it's this SPB 326
that means the 3 is the 3mm wide tip and the 26 is the hight of the blade
so it fits into the holder
sometimes the manufacturer will number them the other way around 263
so you've just got to watch out for that they should still fit
so you need to make sure that you have the right width
you can get these 2mm 3mm
this blade came with 10 tips I've fitted one there's the others
and you can put another insert in this end ready for if you break this one
you just take the out turn it around and replace it in the holder
so what you do it's virtually same as this old type
you put the blade in the holder tighten the three cap heads down to tighten the blade up
and then the tip is just tapped in and held
there's not a cap head or anything to adjust to hold the tip
it's just wedged in to the holder
and I'm hoping if you hit a a hard spot in your material
or it starts to struggle to cut rather than pushing down on the tool
like that it will push the tool further back into the holder so it will tighten up
the problem you get with this type of tool is as you get a load exceeding there on the top
it tends to snap the tool and take away part of the face below
so you lose the support under the tool tip
let's put this in the lathe and see how we go
I fitted the tool holder and the tool into the tool post
set the tool post Square to the Chuck on this edge and here
so I know that the tool is Square to the chuck
I've tightened up the tool post and I've set the tool tip on the center line with the adjuster
and lock that in position
the other thing I've done is bought my compound slide back
so it's not like this
because obviously you've got overhang here and this is overhanging as well
so where the tool would normally be in your tool post
and the cutting tool would be about here
this one is about an inch further out
So make sure that my compound slide is level on the end
so any force on the tool will be pushed down onto the compound slide
and I haven't got this compound slide sticking out giving more leverage
and another thing you might need to do is just check that you haven't got your gib strip too loose
so that this will flex
there's one thing that I'm not too happy about is the amount that this sticks over
I could take 5mm off the back of this tool to pull this in level
so that would bring the tool cutting tool 5mm further in we'll see here we go
so i'll get a piece of steel put that in the lathe
I've set the tool up I've set the speed to around 550 rpm
and I'll just feed that tip in and all I will use is some oil if it needs lubricating
and then what we'll do is we'll change this tool for the other 3mm tool and compare the difference
I've moved the bar out so it's the same distance as it was before with the other tool
so any flexing in the bar or movement in the chuck will still be the same
this tool now is held in the tool holder so it's obviously closer to the tool post
so we'll just see how this one cuts it's a new tip and I'm using the same speed
that's the problem i get with these tool holders for some reason
I was using the same feed same speed it was cutting okay and then all of a sudden just loses it
and I think what it is is that the tool
If you look now this tool on the side profile
you can see that the tool has snapped off just above the support
and in doing that it usually takes some of the support with it
this time it snap off here
my belief is that there's not enough support in this part of the tool holder to support the tool
so when you get pressure on the tool it flexes down on this
and then it will crack because this is not solid enough to support the tool
and this is a 3mm tool all the same as the other one
you have a look at the bar see if the tips embedded in it
you can see here the tip it's dug into the bar and then flexed on the holder and just crack the tip off
and that's the problem I'll get with the two mill and the three mil in the other type of holder
so I'll try this new holder see if I get that problem
I shouldn't do because the new holder has more support under the tool
compared to the other tool
you can see the difference in the support its probably twice as much
and also any force on the tool is forcing the tool because it's at a 45 degree angle
its trying to force the tool back into the holder
so I'm hoping this is a better or will last longer than this type
now if you look closely where the tip was here its rounded off the edge
when this tip broke obviously a majority of it came downwards
rounds off the edge of your tool holder
so the next time you put a tip in there is less surface to hold the tool
and they just keep breaking
I was running that at the same speed it's the same width of tool
setup square within a couple of thou
well it has parted off on the second attempt it's taking twice as long to do it
because I couldn't use the same feed rate that I did on the first one
what I did to this
I ground the face back so that the the tool has a square edge to rest on
I turn the tip round so that's another new cutting tip to the original one
obviously the original one broke off and still it was struggling to get through the bar
I noticed when I put oil on it seemed to stop it cutting
so it doesn't like oil
so whether that is the tip profile is not the same as the other one
I think part of the problem with the tooling is the amount that this sticks out from the holder
if you look there you can't go in much further than that
because this comes up and then you have this part coming out
so you can tighten the tool up but on the blade type you can see
how far in it is compared to the other one
get the two tool holders together and you can see the the left-hand one
it's nearly twice as far out as the right-hand one is
so that means any force on the left hand one has got more leverage and that's probably why these snap off
with this one the blade type is a lot closer to the compound slide so that there is less leverage
so all I'll do on this now is see if I can mill about 5mm off this end
So it comes in further and reduces the leverage on that twist
oh well that's it for today hope that was interesting
hope you enjoyed it and if you did why not subscribe we'll see you next week
on Enots engineering