Part 2 , works 100% better inverted kzfaq.info/get/bejne/g6efrJmWrb_TYo0.html

I designed and built a cutoff tool holder for my Sherline lathe. I designed it to use carbide tooth saw blades. The holder was the easy part; cutting the blade strips was the real challenge, but well worth it, in the end. I don't know if it could be adequately done with a side grinder. I have a steel cutoff saw I built using a '50's era DeWalt RAS, (radial arm saw), as the basis. I basically turned the RAS into a beam saw by anchoring the end of the radial arm, allowing only vertical movement. I also found it necessary to push the saw head, instead of pulling it. The reason was to eliminate problems with blade climb, (think problems associated with climb milling vs conventional milling, only MUCH worse.) So, I have a saw which cuts metal straight, and it was still a difficult to cut a circular saw blade into strips. The key is correct layout. It isn't the cutting, it is cutting them so the carbide tip is in the proper location, vertically. The Sherline is not known for rigidity, so parting is much more easy if the tool is flipped, and parting is done from the back side. When I cut the first set of blades, I screwed up, and didn't account for flipping the blade. I integrated vertical adjustment in the parting tool, but not enough to account for my screw up. I layed out a second blade, and cut the blades correctly. First, know how large the range of adjustment available in YOUR parting tool holder. Second, know where the range starts, and ends. I used the upper margin of the holder, where the balde contacts the holder. If you are parting from the front, use the bottom margin as your starting point. Once you know where the size of the adj range, and its starting point, use the longest rule you have, which is known to be straight. I used a 12" rule on a 7¼" Skil saw blade. I affixed the blade to a backing board, and determined where the center of the blades bore was located. ALL of you layout marks MUST cross the center of the blade. Otherwise, you will have to do twice the layout. Make certain, during layout, the carbide tips are within the adjustment range dimensions. There is a very important 'secret' to making this layout correct. First, you need to understand cutting tooth geometry, specifically rake. Rake is the angle of the cutting tooth, in relation to the cutting path. Think about the tooth either leaning into the cut, (positive rake), leaning back from the cut, (negative rake), or neither leaning in, or back, (neutral rake). If you look at the new steel cutting carbide tooth blades, you will find the carbide teeth have neutral rake. Positive rake will cut metal, but with the aggressive rake, it is effin' squirrelly as hell, and way too dangerous. If you are using a handheld saw, a positive rake tooth will make the saw kick back and eat your forearm, hand, leg or worse. Using a stationary saw, a positive rake tooth will throw material like you've never seen. It'll throw material AND a vise! A neutral rake tooth is absolutely imperative. So, before you start laying out the strips to use as parting blades, grind the carbide tips to a neutral rake profile. It is easier to do BEFORE you cut the strips, as you can use the center point of the blade as a guide for what is a neutral rake. Use a scribe and felt pen/layout dye to mark the neutral line. The second issue of blade prep is the saw kerf. Kerf is the alternating sideways angle of the saw blade teeth. Kerf is necessary to keep a saw blade from binding in the cut. Saw kerf is easily removed by simply bending the blade to achieve zero kerf angle. Once you have neutral tooth rake and zero kerf angle, you can then layout the cut lines for creating the parting blade strips. Roug cutting, that is. Once I rough cut the blade strips, I then found it necessary to flat file the top blade edge. This ensures the parting blade will evenly contact the upper margin of the holder groove, (if you're parting from the front, flat file the bottom blade edge). This sounds like a lot of work, but check the price of carbide tipped parting blades. I got 12 parting blades from a Skil saw blade which could no longer be used for cutting wood. It was either scrap, or a 'nail cutter'. If you could buy parting blades for 10.00, then you'll save 120.00 for the layout prep, layout, and blade finishing. The last thing about using a Skil saw blade is the choice of blade. Saw blades can be found in a variety of blade thicknesses. I chose a medium thickness. I was concerned about using a thin blade; worried about the blade tooth bending under the pressure of parting. I had close to 20 old blades to choose from, as I was a carpenter for 35+ years. When I started, there were no carbide blades, so I use up carbide saw blades until there isn't much carbide left. Cutting nails, screws or brackets is real hard on carbide teeth. If you know a carpenter, or a hobby woodworker, they will likely have a blade they'll give you.You can use a blade with a few missing teeth, just layout the strips to skip those teeth. I used a 7¼" blade, but there is no reason a larger blade couldn't be used. Smaller blades will not yield as many strips, as they will turn out to be too short. After you get you parting blades cut, and finished, take a look at the carbide teeth with a jewelers loupe, and square up the carbide tip sides, face & tip. The more precise you square up the tip, the better parting process will be. If you're inclined to want to save money, and have the time, make yourself some carbide parting blades from a Skil saw blade. Hope this helps someone. GeoD

That is a great idea

Well at least this boy has some imagination to get things done!!! Keep up the good work!!!

Have a direct fit Iscar 21 mm parting blade holder for my Multifix A tool post and made a similar direct fit- one for my little Saupe SD 300 quick change tool post. Parting blades with carbide inserts are available in the same dimensions like the HSS ones from Paulimot and other similar distributors for peanuts. Works like a charm ...

Great idea and thank You for sharing My friend. So I see a very bad lathe chuck run out!!

Where can I get one of those leather snow vises?

Hey nice work!

That's a good idea. Consider getting a vise :)

I have done this before but use discarded blade. You can turn and face with them as well. Parting puts extreme pressures on the machine and ever a 3000lb machine might not like it. Have you experimented with higher rpm's? The nice thing about a lot of mini lathes is rpm control. As you get closer to the center to maintain the same parameters rpm need to be increased. That is what is nice about cnc machines. Some manual machines also have the ability to do this.

Good lord is it worth the effort, and how long will it last??

I guess it worked I fell asleep before the end of the video put me right out

That is a good idea---I cannot buy tungsten carbide parting tools where I live but I can buy cheap tungsten carbide circular saw blades..Well done..

yes yes yes I have made half dozen and special holder for quick change out of aluminium and they work great have not had a a broken one yet .the fact that you he carbide is wider than the metal that holds the carbide gives it auto clearance never had one bind..

Wow that flex!

Perhaps a dumb observation but isn't that cutter upside down?

Without lube aluminum will gall up to the cutting edge and grab the blade. You should really use some lube. WD40 is great lube for aluminum or you can use oil, even used car oil if you're really broke. Also, i didn't see you sharpen the carbide before you used it?

One word. O I L !!!! Hurts to hear a lathe groan like my dog when he is taking a dump.

The the teeth of the circular saw blades have what is called ATB (Alternating Top Bevel) that one is left, one right and one centered. These are OK for parting but really too wide for the mini-lathe. You can use a diamond stone to make them narrower.

what happened to the original blade for that tool holder? my concern would be that lathe has so much run-out in the chuck and deflection in the carriage that that blade you made is going to fold up and create a projectile that will come out at you.

I did this exact thing today! BAm! It works great! Then... I You-tubed it to see if anyone else did it. wa-la!

Sir I have small factory do you have any idea how to pipes cutting fast in a lathe

pour the oil to it bro!

Parting is very demanding on a mini lathe. If everything is right,it can work.

The old foot vice trick. 100% effective, no lost time injuries.

You have to make special holder nice piece of aluminium and dovetail Mill and very easy..you try to hold it any other way no good

great vid. so many haters. you are making good with what you have.

A boss did the tip chip off at the end there? Good video.

Good idea,but the making is a little rustic :-)

que lugar gelado em amigo .qual sua região .boa ideia

If you use carbide, either you keep feeding the coolant or not at all. I think the tip eventually broken because of sudden temperature change. Looks like the carbide itself breaks not the brazing.

Good idea, bad execution. Parting in the lathe is all about rigidity and your setup lacks of rigidity in every possible way. Start by attaching the parting blade as directly as possible to the lathe carriage...I mean, forget about parting blade holder that goes into the standard tool holder, that are too intermediate steps, each one adding flex to the setup. Make a direct parting toolpost (not hard to make one and it makes a huge difference when working in small lathes). Reverse is a good idea since standard way tends to dig the tool in the workpiece and then...crash. Use a lot of oil and a slow turning speed. And last but not least...Parting tools doesn't like misaligned workpieces and I have not seen a single piece running true in your video. Take care of all this advices and you will part pieces like it should.

Just a small critique...You should really turn a diameter first, you are putting to much load on with an intermittent ( initial) cut & it looks like you have too much overhang on your tool post ( the way the tool was bouncing up & down), move your tool post back so the tool is supported by the compound slide body. if you have a saddle lock make sure it is tightened & your tool centred as it looks as though the tool is not at centre height as you adjusted it part way through cut, .. Mild & Stainless steel needs some lubricating even with carbide tip, everything has to be rigid & spot on for parting off on these small lathes.. a very good idea though & well attempted.

could not help to notice, and no one else commented, but the chuck is certainly not true, all the pieces you put in had off set wobble, thus the cutting tool making the stop -go or hit-miss sound, try truing the back-plate or how ever the chuck mounts, like others said the saw blade has both direction of teeth on them, now if you are cutting a solid piece of stock, keep the long point of tooth to the right side, this will let the cut piece drop off with-out any extra tip, if you use the opposite angle it will leave a small tip that you will need to grind off to make flush, looks like it has been a few years since this video, so you probably have found what works better by now, if hope this helps.

meu deus . abraços sou do brasil

Doesn't look like you're on the center of the workpiece

carbide grades there some for wood and for hard steel that you did there is to much work like $5 you could get one . unless your time isn't worth that much spend the $5 last long time

dont you own a vice

That was painful to watch. For a little lathe like that you're better off with HSS that you can sharpen to a razor edge, that blade was dull. It looked like it was above center, making it even harder to cut. It desperately needed lube, any lube, WD40 or even motor oil. Needed more speed and the whole thing was moving due to all of the above factors plus it not being locked down tight enough. High speed, sharp tool, exactly on center and plenty of lube with shallow cuts, you'll see a different result.

مخرطه بداءيه

Why do you go to this aggravation,,,,these parting blades are cheap as snot to buy for your Mini Lathe...