The Big Ugly Tool

Re: The Big Ugly Tool

terry quiram

Will MAPP gas get hit enough? What is the spelling of the hard steel and where did you get it?

Re: The Big Ugly Tool

robo hippy

Randal said that MAPP torches 'may' do it, but a regular torch is much better. I have a link up on the 'see more' part. Tantung is the metal, which is cast, not technically 'steel'.

robo hippy

Re: The Big Ugly Tool

John C Lucas

MAPP gas will get hot enough to silver solder. Its heating a piece of metal that large that is the problem. If you place the steel on two fire bricks placed.at.an angle to form an L it should work. I heated some large metal the other day and it works just fine

Re: The Big Ugly Tool

Ron Bauer

Reed, Where do you get the tantung and what grade do you use? I saw your 2012 posting in Sawmill Creek but the link to the vendor is broken. TIA. Ron.

Re: The Big Ugly Tool

Dave Paine

Thanks, nice video. I may have to look for some Tantung. Not as common these days due to the proliferation of carbide.

I am very interested in the McNaughton experiment.

I have a used McNaughton system. The knife which is used the most has been ground back so not as wide as the 3/8in original.

I am thinking about grinding off the thin HSS then drilling and tapping to mount a triangular carbide insert, 3/8in wide. I have been wondering if I should arrange the insert with the point forward. Your Tantung experiment has a straight full width edge. Now you have me wondering which orientation may work best.

Any suggestions?

Re: The Big Ugly Tool

Barry Irby

I loaned my McNaughton system to an acquaintance. He ground them from the top in stead of the front and ground away all of the carbide. I was flummoxed. Posted the disaster here and Mike Hunter stepped up and offered to install carbide cutters. (Thanks Mike) He put diamond shaped cutters on them with the narrow tip pointing forward. What a blessing. They work very well, better than new. My only regret is I wish the cutters were slightly wider. I have not measured them, but if they were a 1/32 or 1/16 wider the blades would have a little more room.

(My history with the system has been somewhat fraught with difficulties, but that's another story.)

The new McNaughtons...

Brian Roberts

are made with the cutters pointed rather than flat....If I am not mistaken.

They wer originally straight (perpendicular to the shaft) and I believe they switched for a reason.

Those who have used both may know more?

Re: The Big Ugly Tool

Dick Coers

Too much heat in my opinion. That pry bar video shows it WAY past cherry red. He was up in the range where brazing would have worked.

Re: The Big Ugly Tool

Ron Bauer

Dave, I replaced the original McNaughton cutters with 3/8" round carbide cutters. They are mounted with a screw. I have cored a lot of stuff and they seem to work very well. They afford enough clearance that there is no binding in the kerf. If one thinks that the amount of "work" that the cutter is doing is related to the amount of edge that is engaged in the wood then a straight cutter (like the originals) would be preferred. A round cutter would be a close second. I would not presume to know more than the manufacturer but I would not put a diamond shaped cutter on my knives. In the event you borrow from the metal turning world make sure you get one meant for aluminum as they are "sharper" than the ones for metal. Ron.

Re: The new McNaughtons...

Dave Paine

My set is older. A couple of the knives have the original grind. Straight angle like a skew. If I recall Mike Mahoney recommended the pointed triangle shape of the present grind. I have not used these knives so no experience on the difference.

The knives I have used have been reground to be pointed on both sides.

Re: The Big Ugly Tool

robo hippy

I sent a McNaughton blade to Mike Hunter, the carbide guy (hope Mike is his first name, but it's been a while), and he put a square tip on one, with the corner pointing straight forward. It worked okay, but not great. I am doing more work on the McNaughton blades to see if I can make my own because the curves on the McNaughton blades are not true, which is why they drift. I do like the way the tantung cuts much better than what ever it is that Kel has on them. I do prefer a square tip rather than the diamond or spear point.

robo hippy

Re: The new McNaughtons...

robo hippy

I do talk about this in my old video on using the McNaughton, which is up on You Tube. The first cutter heads on the McNaughton were angles slightly across, with a wing on the outside, and the inside surface flush with the curve of the blade. At Mike's suggestion, Kel went to a spear point with the wings of the cutter centering on the blade. A huge improvement. I prefer a square across cutter, more similar to the Woodcut or Oneway (don't like the chip cutter tip point on Oneway at all, square works better). The idea of the spear point was that it made it easier to cut a blank all the way off rather than breaking off a 1 or so inch tenon because you can rip right through some bottoms especially with end grain or crotch figures. The biggest problem with doing that is that by the time you get almost to dead center, the cutter is way below center. There is a lot of down pressure on the cutter when it is engaged, so you need to start out above center. If you have done enough of them, you can feel it. That solves the cutting the blank totally off. Raise the tool rest a bit, or use the long handle, and slightly raise the tip/lower the handle: Master Class here... The standard set of blades are about 3/8 inch wide, and I think the large set are about 7/16 or so. You need room on both sides to keep it from binding, just like you do if you are going to any depth with a parting tool. The last inch or so of all the blades tend to go straight rather than follow the curve, which is why they always drift to the outside. Put them on a circle template to see. Most of the time it is visible to the eye. It doesn't make much difference in coring a small bowl, but if you are reaching out 6 inches or so, it makes for more course corrections.

robo hippy

Re: The Big Ugly Tool

robo hippy

We did try brazing, and on the 3/4 inch wide pieces, it just didn't work. The pry bar is a hardened steel, so maybe it needed to be hotter. If he had a rose bud tip, that might have helped too, but I can only grind the stuff.

robo hippy

Re: The Big Ugly Tool

Dick Coers

Unless he would turn down the pressures, a rosebud would have taken that pry bar too hot, too fast. There are lots of different braze alloys just like silver solder and solder. There are easy flow braze alloys for carbide attachment that almost flow at the same temp of silver solder.

Re: The Big Ugly Tool

Barry Irby

I have not done anywhere near as much coring as Reed and my relationship with my McNaughton set has been trying at best. Soon after I got them I realized they were not bent consistently. The curves were irregular/lumpy and the cutters were ground straight ac cross. I sent them back to who ever the US Rep was and instead of fairing the curves he reground the cutters to a diamond point. Did not discuss it with me, just did it. A friend and I worked on the curves and got them MUCH better. I was surprised at how soft the steel was. Way too easy to bend in my opinion. Then I loaned them out and the guy ground the carbide off the top. When they came back, they looked like they had been dragged behind a car. As I mentioned above, Mike Hunter repaired them. The whole episode has shaken my faith in Automaton and I have not bought any more knives.

The knives woudl be easy to make if you have the ability to install the carbide cutters.

Re: The Big Ugly Tool

robo hippy

Getting the perfect arc of a circle is the difficult part. I figure I either have to buy cylinders and cut rings, or but strips and bend them. My manufacturer (same one who makes my robo rests) says that standard practice is to bend it longer than needed, then trim off the end because it is difficult to bend that last little bit. I did have some carbide tips brazed onto the ends of some of the blades, and they were totally wrong, I broke one off, and the blade appears to be a cast metal of some sort. The newer black blades are more like cold rolled, but I don't really know. I tried every point configuration I could think of, and the square across works best. A square bit on the end needs to be tapered towards the back, just like Oneway and Woodcut.

When loaning tools, I use the old mantra of 'You bend it you mend it. You break it you buy it.' I apply that to myself too...

robo hippy

Your source of Tantung??

Ron Bauer

What is your source of the tantung and what grade do you use?

Re: Your source of Tantung??

robo hippy

There is a link in the 'show more' section right below the title in the clip. I have no idea of which grade it is, and wasn't aware that there are different grades. I need to send the clip to them and ask that question. A finer grained version would be good.

robo hippy

MAPP

Ralph Lindberg

"old" MAPP would certainly do the trick, I haven't tried "new" MAPP, but it does produce a cooler flame then the old stuff

I still have bottles of the old stuff, carefully marked for special projects only

Re: Your source of Tantung??

Dave Paine

I think Tantung has only one "grade". Often stated as Tantung G.

Tantung is a cobalt cast alloy. The hardness of e.g. tungsten carbide but without being brittle. Can produce a fine edge like HSS, but much harder, so longer lasting. Can be ground/sharpened with CBN wheel - just not easy.

Very high red hardness, so it keeps it hardness even if red hot. Hence not easy to grind/sharpen.

Tantung, Stellite, CPM76 were popular cast alloys for insert and tooling before tungsten carbide took over the insert market.

In addition to VR/Wesson, try EBay.

Re: The Big Ugly Tool

Bob Macgregor

In grind and use, how does the Big Ugly Tool differ from an Oland tool?

Re: The Big Ugly Tool

robo hippy

Well, both are scrapers, and you can grind the nose any way you want, though the most common I have seen for both is some where between ) or a half circle. The Oland tool, those that I have seen, are generally a 3/8 half round bit in a metal rod. Most of the Big Ugly tools are 3/4, but I prefer 1 inch wide. Use is pretty much the same, they are scrapers. The Tantung keeps a cutting edge much longer between sharpenings. It keeps the edge almost as long as carbide, but is easily sharpened on standard grinding wheels. I would think that you could put tantung on a bit, especially if the bit is half round stock.

robo hippy

The original Oland tools used cutters...

JamieDonaldson

...that were most often 3/16" and some larger at 1/4." They were square high alloy bits ground as round nose scrapers held in drill rod shafts, and I still occasionally use the angled tool for hollowing since taking my first turning class with Knud in 1986.