Can you guess
what that sound was? What about that one? I'll give you a hint. So this came in the mail. I was curious to try one because there's a lot of people
recommending this type of blade. These are sometimes called T-type blades because their profile looks like a T, but I
believe they're actually P-type blades. P for parallel, T
for tapered. Supposedly they make parting-off easier because of their concave top
and wall clearance, which is all embedded
in their geometry. This particular blade has 8% cobalt, so the tip should last a little longer
than the plain HSS blades. And if you remember, in the last video I mentioned how my straight blade liked to jump off of the tool holder. And that for harder materials,
like stainless, I was much more successful
using that thin blade. It's just less tool pressure during the cuts. That means I need a proper tool holder
for that blade... so why not make it suitable
for both blades? This is the only piece of stock I have that's big enough
for the new tool holder. I'm pretty sure it's A36, cold rolled, and I'm aware it might not be
the best choice in terms of wear resistance,
but it might be just right to try out this
different type of tool holder. The first step
is often squaring the stock. This is no exception, but I haven't had much success
fly cutting this type of material. I find A36 to be a bit gummy
and the surface finish isn't always great, so I guess this time I'll try
this massive face mill that was sent to me by mistake. I know this is too big for my mill, but how could I not try it? Specially after the arbor for my mill showing up
at my door 2 weeks later, also by mistake. Yeah, she didn't buy it either. But don't you worry, I'll be hiding behind
two concrete walls feeding with a stick. Humm, the surface finish
is actually pretty good. I'll finish squaring the stock
using only one insert in the face mill. It's like having one big heavy fly cutter and that mass really seems
to make a difference. But when I'm about to finish I realize the block is too big and will leave the tool overhanging a bit too much. But the block needs
to have a certain width, so I take a few measurements
and the most I can cut off is 10 millimeters. Milling that is an option, but that would be a waste of material. I think I'll try to make
that cut in the bandsaw. Avoiding the vice pinching the blade
is the tricky part here, so before that can happen, I'm sticking a shim in the slot
and flipping the part. Then I can finish the cut
until both parts are separated. Next, I'll fly cut the last face which is now rough
from the bandsaw cut. Now it's time to cut
the dove tail. This is the first time I'll be doing
something like that, so I'm taking another holder as a reference. I don't want to overcomplicate this, but I want to get the dimension right. So I take a couple of endmills
and rest their shanks against the angled faces. That angle is 60 degrees. Now I can use an adjustable parallel
to take up the remaining space. Back at the mill, I start by roughing
a channel for the dove tail. Then, with the finishing endmill,
that channel is taken to size. From that point, we can focus on cutting
both sides of the dove tail. As I'm approaching
the final dimension, I start to take measurements
using a second adjustable parallel. This allows me to track the progress and keep the reference
of the final dimension on the first. As soon as I can squeeze
that between the endmills, I know I'm there. Now we need to create some clearance for the solid tool post mount. And this is the perfect time
to chamfer the edges on this face. Finally, some deburring
in the dove tail is complete. The next feature is critical
for the success of this tool and that's how we'll hold the blade. I want to have it trapped in a way
that it can't move in any direction, so I know I need to start with a slot. The question is,
where's that going to be? The short answer is: anywhere as long as the tip
is right on center with the spindle axis. But the longer version requires
a deeper analysis of the problem. First of all, I need that slot
to be as low as possible in the tool holder. Then I have two blades
to support: the P-type and the straight one, and I'll be mostly parting steel. That means each blade should have
some back rake, probably five to seven degrees. For the straight one,
that's easy, it's a matter of grinding
that in the blade. In fact, that's already done. But the P-type is not meant
to have the top ground, so that means we need to rest
the blade on an angle. Now let's think
about tool height. The straight blade will always have
the tip in a lower position - that's because of the back rake grinding. That means the tool holder
will have to go up. Also, since the blade
will be on an angle, stick out will matter and the more retracted the blade is, the higher the tool holder
needs to be adjusted. So I think that with a straight blade
on a 5 degree angle, as retracted as possible, I can safely mark the location
for the slot. And just to be on the safe side, I've given 2mm of clearance to the top of the tool post. That's to make sure
there's still full support if I need to move the tool holder up a little bit more. In theory, this blade position
will support the 2 types of blades, with some room for adjustment at the top
and a lot at the bottom. Now that we know where
the slot's gonna be, we need to set up the part
in the milling machine. The easiest way to make this slot
on a 5 degree angle is to clamp the part directly
to the table using a square and an angle block to set the angle. But the indicator doesn't lie, and the table's front face
isn't exactly square to the Y axis. Nothing a couple of taps
in the right place can't fix. There you go. I'm going to mill this down
by 3 millimeters, that'll be enough to
take the straight blade, which is only 1.5, and the P2, which is 3/32nds. That's roughly 2.4 millimeters. I did look for the 1/6ths blade,
which is a P1, but couldn't find any place online where shipping to me
was available. That's why I'm still using
the old blade. As for the height of the slot,
I'm oversizing it on purpose. I need at least one extra millimeter
that my slitting saw will take. Maybe a little bit more. This 4mm endmill
creates extra clearance for the top of the P-type blade. But while we're here,
let's finish the slot. Holding the blade... There's a couple of ways
to make that happen, but remember when I said
I wanted to clamp it so it couldn't move
in any direction? This is it, and I might ruin
this part right now. So here's the deal. I'm going to split this in two parts, the main body and the blade clamp. The clamp will be held by 4 screws that I need to tap as close
as possible to the wall of the slot. That is, without breaking through. I think it will be easier
if I do it at this stage, so here it goes. Spot drill. Tap drill. Clearance drill for the counterbore, counterbore, chamfer and tap M5. Next, let's cut this
in the bandsaw. Fingers crossed it
will make a straight cut. This might not be making
much sense to you right now, but I'll explain in a few seconds. First, let's split
the clamping part. Oh boy, that's gonna hurt. I think I need to make
some arbors for my saws. And just like that, we have now two parts to address. Starting with the clamp, I'm holding it in the vice
in a 5 degree angle. That way I can clean up the finish
from the slitting saw cut. Then I clamp the part on its side
with the help of the angle block and do the same to the bandsaw blade finish. One last dance and we bring back
the dove tail cutter. Back on the main body I clean up the new face
from the split until the shortest blade is pinched just by resting
the clamp in place. The P-type blade is half inch high, or 12.7 millimeters, while the straight blade is 13 millimeters. I'm going to try to make this work
for a range of blades, something like 12 to 13.5 millimeters. The key for this is milling
this face a little bit more so that a step is left on the part. That step, and the fact the screws
are on the opposite side will make the clamp be a clamp. Yup. I don't think the blades
will go anywhere. This big tab of metal. Although it could be completely removed, I'm going to keep it. I'm just going to make it shorter
to align with the clamp. I think it will be helpful
to keep the tool holder up on the bench. Chamfering all the edges on this face is just a matter of adding
a shim as thick as the height of the step between the clamp
and the body... and chamfer away. What I'm about to do next
is a risky nice to have. I'm not sure if this is going
to render this tool useless. Let's just hope not. This big chamfer on the front will allow for better visibility of the blade while it's cutting. I'm kind of concerned
because it can actually weaken the tool, but I'll try to account for that. Now let's address the elephant
in the workshop. The weird bandsaw cut. As you know, I had lots of problems
parting off with this lathe. There was chatter, and worse than that, the tools were constantly digging
in and crashing the lathe. What you're seeing here
is me parting off a small piece of 1045. I did it, but took almost an hour... very frustrating. In some clips like these, I actually saw my compound flexing, so I replaced it with a solid mount. That compound is now
carefully stored. I didn't throw it away. And that change alone
made things so much better, but there's something I saw
on another YouTube channel that I couldn't resist trying. I mean the Spring Part-off Tool Holder
from Winky's Workshop. That made so much sense to me! To resolve the parting problems found on a small lathe like mine. Don't get me wrong,
I'm a big fan of rigidity, but... what if! And yeah, I know my tool holder
looks very different, but functionally it's just the same. I hope. A big thanks to Winky
for sharing this tool with all of us. And now you get why
the back of the tool holder is partially split
from the front. And also why the same has to be done
to the top, so it can actually flex. But a sharp split will be more prone
to crack or break. That's why we'll add a big radius
to the flexing point. And here we go again. Close your eyes and cover your ears. Ok, I was hoping
this wouldn't happen... and I don't have a slitting saw
that's small enough to take this last bit without biting
the wall of the hole on the other side. So I guess I'm left to cut this by hand. Finally I'm able to break through, and I'm quick to jump
into making the threaded hole for the height adjuster. I'm very close to the end
and I want to try this so badly. But in order to do that, I need the knurled wheel that sets the height of the tool. So let's clean up
this piece of 4140. I decided to go with 4140
because it resists better to rust, and that's what I want from this knurled surface. Knurling is a tedious process, at least for me anyway, and this time I'm preparing
for the future. What I mean by that is
that I'll be knurling a longer piece of stock than I actually need for this tool. That way I'll have a leftover piece
that I can use later if or when I need it. I think the knurled came out OK, but I've done better with mild steel. Also this took more time as 4140
is a lot more harder to deform. Maybe a scissor type tool
would have helped... I don't know. I didn't apply a lot of pressure
on each pass because this bump type tool
is not very good for the spindle bearings. Threading the end of a rod
provides a good way to hold a part like this, otherwise we wouldn't have a good way
to face it on both sides. Well, the knurling works. With the wheel finished, I'm going to add
one last screw to the tool. This screw will act
as a flexing limiter. Winky mentions this helps
preventing the blade going under the nub at the end - that is when parting
off solid stock. I think it makes sense to have
a way to adjust... Oh NO! No, no, no, no, no, no... C'mon! I was right at the end...
and I mean right at the end. OK, think! What are
the options now? I could leave it like that
and drill another hole. Hmm... no. I could use a nut
and weld it to the tap... but that can leave some marks
on the tool. Still, no. Let's try something else. OK... this will not work. I guess I need to drill it. This is an HSS tap with 5% cobalt so I have to use carbide. I'm going to start with this 3
millimeter endmill, this one should be good up
to 65 Rockwell. I'm doing this very very slowly, the last thing I want is to break
the endmill in there. Hmm, this doesn't feel right. But it might have been enough
to create a flat spot for my spot drill. Let's try it, again, very slowly. This thing feels hard,
but the spot drill is cutting. I have 18mm to go, I just hope I don't break
anything else. And if that wasn't hard
enough, at the end, the tip of the tap broke
in small pieces that found their way into the slot. Removing them was a nightmare because they started to dig
into the metal as soon as I tried to push them out. Eventually I managed to remove them. But what do you do
with a 4mm hole now? Well, going up one size
is kind of obvious, but I'm afraid I'll find
some leftovers of the HSS tap in there. But I also don't want to go to M6, so let's try opening this up to 4.2 and see how that feels. Everything went well, M5 it is. And with that done,
the only thing left to do is make this tool feel nicer and better looking. Here is the finished AXA tool holder. I think it looks pretty cool. Basically the blade is held on the front which is partially split from the back. A second slot, parallel to the top, leaves only this portion
right here connecting the front to the back. And that will allow
for this whole part to flex. The blade is clamped
with four screws from the bottom and the way the clamping works guarantees the blade
is always pushed upwards. That means the top of the blade
should never sit sideways because it registers against the tool holder. You can see that clearly
in this shot, you can even see how the blade
is correctly tapering down both along the head and foot. Then we have the last screw
we added to the tool to control how much flexing
should be allowed. And that's it, enough with the talking,
let's test it. Unbelievable. Let's try power feeding. Now I want a thin shim,
let's say half of a millimeter. Pretty close! And looks like the tool
is not digging into either side. This thing is totally
a game changer for me. I want to try it more aggressively. Wow, this just wants to cut. What a difference from before! Let's try faster, 500 rpm. Did you see how fast those ships
were being ejected? That's just insane. I also tried 1045
and the tool cuts about the same. So next let's go straight
to 4140. Wait, did you see that? That's a lot of flexing,
but nothing looks broken, so let's continue. I think the problem is
the blade. 4140 is harder and because of that, requires
more tool pressure to cut. Having a wide blade
doesn't help. I'm going to change to the other one
and we'll continue the cut. Much better now. The feedback of the tool
is just excellent. It's really easy
to control the cut. You know what? Let's see how much it flexes
with the DTI. Goes between 0 and 1 thousand,
maybe one and a half. It's like it's self adjusting
and adapting to the cut. Or maybe that's just vibration,
I don't know. Shall we try stainless? Stainless is not difficult if the tool is engaged
and the feed is constant. Going slow and interrupting
the cut, that's asking for trouble. The example of that
is this shot with power feed. To be honest, I still feel kind of nervous
parting stainless using power feed. You never know, things
can go south all of a sudden and I think hand feeding
is just safer. Having said that,
let's increase the feed rate and see what the indicator tells us. For one, the tool definitely flexes
more with stainless. I don't know if you noticed it, but there's a moment where it most certainly would crash if it was a rigid tool, but instead it readjusted
and continued the cut. I think if I had to describe
this tool with one word, that word would be forgiving. I've lost the count of the times
this tool saved the lathe from crashing during the tests. But we're not done yet. I want to try this on aluminum. I guess there's not much to say
about that. Cuts like a hot knife. I'm amazed with this whole transformation, both in the machine and in myself. Parting off was something
that worried me every time I had to do it and now... Now I'm confident I'm able to do it. Of course I'm not going
to push it hard all the time. If I did, it was just to show you
what this is capable of. And I'm sure there's a lot of you
with bigger lathes, and even with lathes like mine,
that don't have any problems
parting off stock. But I had. And now I have
something that works. I will not bother trying
to improve it any further, it just works. I think the solid tool post
mount also plays a role in making this tool successful. Rigidity must exist
in the right places to allow the flexing happening
where and when it should. But you tell me why you think
this works so well. Dare I say almost as good
as a rear tool post?
