McNaughton gear 2nd hand - bit of a gamble

[rsser]

Bought this lot: click (http://www.woodworkforums.com/f221/bowl-centre-saving-system-147507/#post1439018)

Never been persuaded by the value of coring systems but figured if the hollowers were OK and with the handle the buy was fair value and the corer a bonus.

I first learned to hollow under tuition with these hollowers and they performed pretty well. Left a nice finish in shear mode. They should fit the rig.

Having spent the weekend reading up on the corer it's shaping up as a nice challenge. The Mike Mahoney vid provides some useful tips but practice has moved on aways since that was done so robohippy's might be worth acquiring.

The toolgate post sounds like 3/4". First task will be to source a brass bush or two to fit in the 1" ID sleeve on the banjo. The bush should be fairly std from an industrial supplies place but play can't be tolerated with this setup so if that fails it'll be necessary to get the latest toolgate (at a reasonable price!).

The 2nd and 3rd gen toolgates are too high for the banjo on the Vicmarc 175 so coring will have to be done with the outrigger. Some turners have done this but again any play will be an issue.

There appears to be a steep learning curve with this corer but it's more flexible in terms of shapes than the competition. And once mastered it appears that it's 5 minutes' work with a decent sized blank. You end up with useful timber rather than shavings that have to be swept up and disposed of.

The corer blade tips and hollower tips may not be in brilliant condition. The former are apparently high cobalt steel laminated on the knives. Kel McNaughton may be willing to replace them but I'm not holding my breath on that option. One alabaster turner in the US had TC tips brazed on in their place so that suggests another avenue if rehab is required.

We'll see.

[hughie]

Yep a bit steep in the beginning. But dont doubt you will master it with your experience.
I have not heard of any negative reports by those who have mastered it. Infact most swear by them once they get the hang of it.

Of all the corers this one would be my preference as its the most versatile.



The corer blade tips and hollower tips may not be in brilliant condition. The former are apparently high cobalt steel laminated on the knives. Kel McNaughton may be willing to replace them but I'm not holding my breath on that option. One alabaster turner in the US had TC tips brazed on in their place so that suggests another avenue if rehab is required.




If they were mine I would probably go that way, for me the tips are the only let down with this rig.

[Tim the Timber Turner]

I had a saw doctor braze and shape a TC tip onto a worn out McNaughton coring blade.

I think it cost about $40 a few years ago.

It works better than new.:2tsup:

The saw doctor also gave me an old diamond disc that they use to sharpen TC sawblades. I use this to keep it sharp.

Cheers

Tim:)

[rsser]

Thanks for the tips folks.

[bobsreturn2003]

try the original stellite :), a good saw doctor can re tip easily , sharpen with a hand held fine diamond file ,and a new tip will last forever. just need to be carefull not to go too deep :doh:!!!! they are a good tool but i use the oneway set , cheers Bob

[rsser]

IIRC the stellite is original on the Woodcut, not the McNaughton ... but it's worth looking into anyway.

[Tim the Timber Turner]

I think you might have that around the wrong way Ern?.

Woodcut will replace the TC tips on their bowl saver blades (for a fee).

All of my McNaughton blades were hard face tipped when new.

Cheers

Tim:)

[rsser]

Yeah, agree Woodcut will exchange blades once worn but they do appear to be stellite: click (http://www.philirons.co.uk/index.php?option=com_content&view=article&id=47&Itemid=70)

The McNaughton I've bought, acc. to the seller anyway, has a tip topped with high-cobalt steel. It looks to be Mark 1 so it could be 15 years old.

Anyway, we'll see what state they're in and look around for a saw doctor.

[NeilS]

Looks like a good buy there Ern.

You should be able to buy an off-the-shelf liner bushing to adapt to your tool post. Hughie has posted somewhere a supplier of such things.

The tips on my McNaughton corer sharpen nicely on the diamond wheel that you also have, Ern. Keeping a keen edge on the tips I found was essential for mid-powered lathes (below 2HP).

A cradle on the end of the handle (the armbrace style (http://aroundthewoods.com/brace.shtml)) might help with taking the vibrations along the arm instead of the wrist.

[rsser]

Thanks for the tips Neil.

As luck would have it I came by a couple of big lumps of green English Elm recently and they'll make good practice pieces.

[rsser]

Well the kit's arrived and it's a golden oldie alright ;-) But in good nick.

The corer cutting tips are skewed and will have to be reshaped to Vs.

There's lots of play in the toolgate, before sleeving the post to fit the banjo, and if that contributes to binding as I expect, replacing it with the current model is indicated. That's gen 3.

The hollowers are in good shape and will fit the rig.

So the gamble has paid off ... or it would have without the emerging interest in coring dammit :doh:

[robo hippy]

For a sleeve for the tool rest post, I just turned some end grain wood and bored a hole through it.

If you have the old style tips that are beveled out to one side rather than the newer ones which are centered on the blade and proud on both sides, I would get rid of them, or get new tips. Having it centered makes a huge difference, especially if you need to correct your course to the inside of the cut. I have never been able to notice any difference in a square tip or the spear point other than the spear point takes a bigger shaving.

The older Woodcut tips were stellite, and I got mine 5 or more years ago. I had heard that they were using carbide now as well. Not really sure. Mike Hunter, of Hunter tools has retipped some McNaughton tips with small square micro grained carbide tips which have one corner foreward, and the cross section is about 3/8 inch. It works well. Stellite, and Tantung are other cutting steels that work well, are hard, and keep an excellent cutting edge. A piece 3/8 inch wide, and about 3/32 inch thick by 1/2 inch long, and tapered towards the back should work. Silver soldered into place.

robo hippy

[Tim the Timber Turner]

Having it centered makes a huge difference, especially if you need to correct your course to the inside of the cut. I have never been able to notice any difference in a square tip or the spear point other than the spear point takes a bigger shaving.

That reflects exactly, my experience with tip shapes.

Square tip makes it a little easier if you need to take a second bite to open up the cut, this will provide a bit more clearence and help remove the shavings on stringy timber like elm.

Cheers

Tim:)

[rsser]

More 'tips' :wink: Thanks RH and TTTT.

Good idea for sleeving.

What's your take on the effect of lateral play of the blade in the toolgate? There's a heap in this setup. My assumption is that it's to be avoided. There's $200-$300 riding on the answer. I can of course have a play before stumping up for the Mk8 toolgate but I prefer to minimise unwanted variables before starting to learn to use new gear.

Well I've reshaped the corer tips to a V, first on a coarse 3X wheel and then finishing on the #120 diamond wheel. Took the burr off with a Superfine diamond paddle. The edges are as keen as on the parting blade which hasn't been used and which will be left with the skewed cutting edge out of interest.

Jeez, this thing is getting bigger than Ben Hur. Come to think of it, weren't there parting blades involved there too?

[jefferson]

Gidday, Ern.

I'd be extremely reluctant to rely on an outrigger set-up on the VL 175 to assist with any coring work. I've seen a McNaughten in action several times and the strains on the post are extreme.

With the outboard turning attachment, you have (I think) 3 cam locks to engage and go wrong. These attachments seem to be meant for downwards pressure only.

I also wonder whether Vicmarc would support a claim for such use in the event that something went wrong.

Your call as always. Let us know how you get on when coring a large bowl outboard on the VL 175.

BTW - I thought you had a S750 Stubby for bowl work but sold it because your hands couldn't take the pounding. Bet you wish you had it back! :D

[rsser]

We'll see Jeff. There's an Irish turner who's got it to work. The outrigger is a very hefty unit.

Yes, I had an S1000 and the pounding with large pieces was punishing. So I've gone to smaller work and a variety of aids.

[hughie]

Ern have a chat [pm] to John Lucas he makes his own blades for his McNaughton. He's on the forum from time to time, located in the US.

I gather the idea behind all the different points is to gain an advantage in the chip removal. There was a move/idea of using truncated pyramid shape. This gives three cutting faces and therefore smaller chips making it easier for the smaller particles to flow away from the cutting face. But it will be a balance or trade off between ease of cut versus ease of chip removal.

If your thinking of going down the path of fixing tungsten or similar tips to the blades. Drop me a pm with the specs as I have a heap of them [about 1 kilo] I should be able to find something amongst it to suit.


But if all else fails and it proves a bit rough on th the wrists etc. I would be interested in the set should you consider moving it on.

[robo hippy]

There should be a parting blade with a full set of blades. As for how much lateral play in the gate/support fingers, maybe 1/16 of an inch, which I would guess is 1mm or so. Much more than that would be a bit much. With the Mark 8, the large set of coring blades are narrower/thinner than the older blades, and the older ones will not fit in the support fingers.

With extensive use, and a couple of good catches, the blades will get some torque in them. If you put the blade on a table saw and it rocks rather than sitting flat, they can be twisted back into shape. Clamp the handle end in a big vice, and use a big adjustable wrench, or monkey/pipe wrench to twist it back the other direction.

The spear point was a Mike Mahoney innovation. His theory is that it is better for when you are cutting a piece all the way off rather than getting it down most of the way and then breaking it out. This is necessary on end grain cores, and some crotch wood pieces, and some times burl or other very gnarly grained pieces, because if you try to break them out, you can rip the grain out, right through the bottom of the bowl. I agree that it is better to cut these pieces all the way off, or at least as far as you can, but the biggest factor in being able to cut them all the way off is having the cutter at center height. If you have ever tried to remove the4 stub left after you break out a core, you will see that the blade, being extended out a long way off the tool rest will bend down, and be considerable below center. One of the "professional drivers only" situations, if you have a looooooong handle, you can drop the handle a bit, to raise the cutter, and it will cut off fine. The safe way would be to raise the tool rest.

With a single kerf cut, not opening it up any extra, the solid spear point shaving is 1/2 inch or slightly more wide, and the kerf is 3/8 inch wide. My square tipped blades do eject out much more easily than the spear point shavings.

The main reason for opening up the kerf is because the blades do tend to drift as you cut, always migrating to the outside of the cut. Ever notice the burn/rub marks are on the outside bowl, and almost never on the core? This is why you have to bump the tool rest over, or open up the cut some, to allow the blade to slide through. If you don't, the blade will bind in the cut.

robo hippy

[rsser]

Thanks for all the good info and offers.

Getting good info on compatibility of old and new systems is difficult. One of the two Aus retailers told me yesterday that an old std size blade, 6mm thick, would fit the Mk 8 toolgate. robohippy, if you have that toolgate, would you mind measuring that for me?

It seems that given the play tolerance you mention RH that the original toolgate is a waste of time. And maybe trying to match old blades and new toolgate may not be cost-effective.

[NeilS]

There should be a parting blade with a full set of blades.

I have straight parting blades with both my large and standard sets. I haven't found a use for them yet, and don't expect I will ever need both. You would be welcome to my standard straight balde, Ern, although it may not fit in the same gate as your first generation blades.




There was a move/idea of using truncated pyramid shape. This gives three cutting faces and therefore smaller chips making it easier for the smaller particles to flow away from the cutting face. But it will be a balance or trade off between ease of cut versus ease of chip removal.



I'm progressively grinding my spear tips back to square and currently they are ground to that truncated spear point, which I am also finding clears the shavings better than the full spear point. The square grind is also easier to grind, whereas the spear bevel profile is quite complex to replicate.


Gidday, Ern.

I'd be extremely reluctant to rely on an outrigger set-up on the VL 175 to assist with any coring work. I've seen a McNaughten in action several times and the strains on the post are extreme.

These attachments seem to be meant for downwards pressure only.



I use my corer mostly outboard on my Woodfast C1000X as I find it allows unimpeded movement while coring, and for me it is better on the back and other muscle groups and joints after a long coring session.

I do support the outboard cast iron banjo table with a chock of wood to the floor while coring, as an insurance measure. The outboard toolpost on the Woodfast is quite tall yet seems to cope OK with the largest core that I can do from an 18"-19" bowl.


197805...197806


Don't have any experience coring on a VL175, but looking at the Outboard Turning Attachment on the Vicmarc site I would have thought that it would cope OK with the downward thrust which is the primary force transmitted to the toolpost during coring.

[rsser]

Thanks Neil.

Felt like I was trying to put new wine into old wineskins making the Mark 1 setup work; the local retailer just rang to say that they can get a new std corer kit in within a couple of weeks for not an unreasonable amount more than the new toolgate alone. So that's what I've opted for. Cry once. PM has been sent to robohippy.

Looking at web resources on technique, it seems that if properly set up, yes, the main forces are downward and you should just be pushing inward. Probs arise with blunt tips, chip clogging, tool droop, not opening up the outside of the kerf at the entry and not repositioning the toolgate as you get in.

[rsser]

Neil, what's your sense of the effort spent and particular muscle groups strained by coring as against hollowing with a gouge?

[robo hippy]

The only pressure I have on the handle is to pull it very gently towards me which helps keep it on more of an inside course. With the Mark 8, you have a pin to slip in under the blade once you are ready to core, so you won't try to control the handle and blade cutting action, and let the square tube you run it through do all that work.

Here is a short clip of Bill Grumbine coring. He uses an extra long handle. If you are having to wrestle with it, some thing is wrong.

Grumbine workshop - Core It! - YouTube

robo hippy

[robo hippy]

Ern,
Not sure if I got a pm from you or not.

I should have said that the older large set of blades will not fit in the new Mark 8 tool rest. The standard and small set do fit. Now, all of the blades are made from the same thickness stock.

robo hippy

[rsser]

Thanks RH.

Yeah I did PM you but cancelled the query since I'd lost patience with making old work with new.

Have seen that Grumbine vid but thanks; you experts make it look easy but this apprentice has been taking notes :-)

I've sleeved up the toolpost on the old 2nd hand unit just to have a play. This was a bit of a trial in itself; it needed the OD taken down 4 thou and the ID persuaded on with a dead-blow hammer as the post wasn't a true cylinder. I hope his newer gear is better made. Starting to think of him as Kel McNot-on as a big caliper from him a while ago was a DOA.

[NeilS]

Neil, what's your sense of the effort spent and particular muscle groups strained by coring as against hollowing with a gouge?

Ern, you and I are of slight build. With correct technique we can hollow bowls with a gouge for hours with little to no effort. But for me, coring with the McNaughton is altogether different.

To start with, the tool itself is very heavy. You also have to work with it horizontally with a similar hold to that of the Munroe and Woodcut hollowers. The tool itself doesn't need much effort to guide and tends to be self feeding, but there is vibration that travel through the tool. After a session the muscle/joint area that I feel most is my right shoulder.

Both Bill Grumbine and Robo Hippy are substantial men and look like they are waving a fairy wand around...:D... but in my experience it's a tiring tool to use for any length of time.

[robo hippy]

I don't know that I have been called 'substantial' before, but I do have a fair sized 'turning muscle'. Mike Mahoney cuts his personal handles in half. Really, the tool rest is supposed to do all the work, and the tool does pretty much self feed. I generally hold my tools level, with the handle under my fore arm. so it is normal stance for me. There is a real tendency to 'white knuckle grip' the handle, which makes it more tiring, especially if you are holding the handle down rather than letting the cutting action push it up against the top of the tool rest. I had the same sore shoulder for a while till I figured that one out.

robo hippy

[rsser]

Thanks guys. Will suck it and see. Have to work out anyway so this might avoid one morning a week at the gym ;-}

[rsser]

Had the first suck with the Mk I and what a hoot.

Tried the tightest curve blade. Got two cores out of a lump of Norfolk Island Pine (not the best trainer timber). It went through two knots with no drama apart from some rockin' and rollin' and smokin'.

The Mk I gate slides on the toolpost about 20mm so there's no need to reposition the 'banjo' as you get in. More skill needed to steer it though, to avoid the smokin' :D

Jeff, the outrigger coped just fine. As Neil said, the main forces are downwards.

This is wood butchery of the first order :cool:

[jefferson]

Ern,

great to see the outrigger coped fine. Next you'll be coring burls and whatever else we can throw at you!

[robo hippy]

It is difficult to keep the blade on track. The burning is mostly because the blade is drifting, and burn marks are almost always on the bowl, and not the core. Some times you have to bump the tool rest inwards towards the center of the lathe/bowl. Some times you have to open up the kerf a bit. It takes a bit of practice to figure out what is going wrong and how to correct it.

It also helps, if you have one of the circle template things.

23" Layout Template - Woodturners Catalog - Woodworking tools and supplies specializing in woodturning. (http://www.woodturnerscatalog.com/store/Winter_Selldown___23__Layout_Template___layout_template_ws?Args=)

The blade curves are not always spot on, and if you have the template, and lay it over the top of the blade, the blades can be fine tuned. I have my support fingers/gate locked in place, so I can tweak them a tiny bit. Mostly the last little bit at the nose tends to go straight rather than follow the curve. I have always found the small curved blade to be more difficult to core with than the medium curved blade.

robo hippy

[rsser]

Thanks for the tips robo hippy.