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27th July 2020, 08:15 PM #1
Tungsten Carbide Tipped Turning Tools
I had better begin by explaining that I have little idea about wood turning and I am probably the least qualified person on the Forum to speak of such things. Having got my disclaimer out of the way I will briefly show what I have finished with or nearly finished with as I have still to varnish the handles and I have yet to try them.
P1060279 (Medium).JPG
Before too many of you have a W*F moment, let me explaining my motivation and reasoning behind this. Could I make up turning chisels for a song that worked well? Not a cheap set that turned up their collective noses at the first sign of anything harder than Camphor Laurel.
I realised that I could buy the carbide inserts at quite cheap prices. In fact I bought a total of twelve cutters on three separate occasions for total of A$45.62 including freight. Admittedly of these cutters five were the same round cutter. The square cutters had different radii and one was smaller. The two cutters that look like they were produced by the Renault car company are different as one comes to a sharp point and the other has a very slightly rounded nose.
Have I got a suitable selection of cutters? I absolutely have no idea, but I am sure you blokes will tell me. In fact I am relying on it.
I had a few bits of round bar lying around. Ok, I suppose they were stashed in my Steptoe hoard. Some was 16mm and some was 12mm. I cut the square bar from some flat plate, which was about 16mm too. That was going to be a problem for fitting the handle so I solved it by drilling and tapping some 12mm rod into the ends. Much easier to deal with.
As I pointed out at the start, I have no idea what I'm doing and in fact I have never physically handled one of this type of turning tool and only seen them in pix. I surmised that the tungsten cutter has little inherent strength and needs to be supported on the steel body of the tool with just enough clearance to allow cutting to take place.
This means cutting the bar stock along this principle:
P1060186 (Medium).JPG
Not too difficult for the square cutters. The initial cut is made with a thin cutting disc mounted in an angle grinder. A little careful filing and the cutter will sit against a shoulder. One of the square cutters has a little more movement than I would ideally have liked, but I can probably live with it.
After cutting the initial rebate I filed and ground away until I was ready to polish up the sharp end or rather the part that received the sharp end. The hole is drilled and tapped to receive the holding screw.
P1060201 (Medium).JPGP1060202 (Medium).JPG
The screws were an issue I had not reckoned on. The round cutters all came with their own screw but the others did not. I reasoned that I would only be using one round cutter at a time so I could share the other screws among the square and "Renault" cutters. Not the case as the holes were not the same size!. I went to a nut and bolt specialist ( I nearly said a screw specialist, but I just know how that would have been interpreted) and he ended up giving me five screws (apparently they were 5c each) which were not quite right and I would have to modify. Actually SWMBO was going to Toowoomba and did the shopping for me. I am thinking of upgrading her status and
asking her to make some more significant purchases. It would appear her buying power is better than mine.
The shoulder of the head had to be corrected to suit the cutter profile and the diameter of the head was ground down to a smaller diameter. The only real problem was holding these tiny screws but that was solved by making a holder out of rod and tapping yet another thread.
Screw head too big:
P1060219 (Medium).JPG
The head ground down to suit:
P1060222 (Medium).JPG
The holder:
P1060220 (Medium).JPG
The round cutters were more of an issue. If I had continued to use a grinding stone, I would have been there until Christmas. I tried a Dremel and a pneumatic die grinder. Hopeless. So I revisited the problem and drilled a hole first and then cut the waste away.
P1060191 (Medium).JPGP1060190 (Medium).JPGP1060193 (Medium).JPGP1060197 (Medium).JPG
If the round cutters were more difficult, the Renault cutters were a real pain. I realised I would have to cut a large rebate and then cut a small piece of flat bar to the replicate the shape.
P1060231 (Medium).JPGP1060232 (Medium).JPG
Then the vee shaped bit had to be fixed in place. They were difficult to hold in place being so small. The first one I welded ok, I think, but the second one was a disaster and fell off because I ground away all the weld. Then I tried gluing with epoxy, but I think the old glue I used had gone off. In any event the offending part fell off so I ended up tapping and screwing in place, but I had two goes at that too, which is why the shaft is a little bit shorter than it's mate! I think it will be ok as this cutter looks as though it will only be for delicate work. Come to think of it I don't do much of that so it will probably last for ever.
Nearly there, but I will continue shortly as I have lost the lot before now.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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27th July 2020 08:15 PM # ADSGoogle Adsense Advertisement
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27th July 2020, 09:01 PM #2
Paul,
I’m confused for the reason of why,
But then I do know you like too tinker an save a few pennies(I hope you appreciate me going imperial there [emoji6]).
An I guess there is some wood turning coming up,
You do realise wood turning can be highly addictive with no none cure!!
My only advice would make sure you have zero play with the fit of the cutters an screws, there is a reason they are counter fitted.
If they are loose you will have a dangerous situation of Tool chatter.
Not what you need trying to learn how to use a lathe.
Cheers Matt.
.
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27th July 2020, 09:18 PM #3.
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Not just a "no-movement fit", but the screws should accurately match apply the counter sink (CS) to provide even pressure all the way down the CS. You can check this with some blue grease.
If this is not done the load will not be even and it can stress and break the cutter. This happens when you least desire it.
I have a couple that I have used on timber and find the TC tips work better if the are touched up a bit on a diamond wheel.
Also while they last a long time it helps to be able to touch them up from time to time.
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27th July 2020, 11:08 PM #4
Bob and Matt
Thank you for the additional information.
The pix were accumulated over quite a period of time so I had to go searching for some of them. This is the steel I began with:
P1060185 (Medium).JPG
The ferrules started life as hexagon shaped compression fittings. Initially I only had stainless steel, but later on the scrap bin yielded brass as well. The principle is the same. Cut off the hexagon points with a thin cutting disc in an angle grinder and then rotate the fitting against the bench grinder. Finally they are buffed on a fibre wheel. there were basically two sizes. Some I drilled out to enlarge the hole for the shaft. The inside of the fitting is threaded and originally I had hoped to wind them on to the timber, but that proved impractical. Consequently they are mainly an interference fit. One ended up a little loose and that got the epoxy treatment.
P1060228 (Medium).JPG
These are the steps for the brass ferrule. One more than the stainless, but still faster because of the material:
P1060273 (Medium).JPG
The two "Renault" bits are very similar at a casual glance so the sharp one got a stainless ferrule and the blunt one a brass ferrule. Simple. More difficult will be the different radii on the square cutters as I can hardly tell them apart without putting a small rule across them.
P1060255 (Medium).JPGP1060257 (Medium).JPGP1060260 (Medium).JPGP1060261 (Medium).JPG
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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27th July 2020, 11:19 PM #5
Matt
Really the main use for the lathe is making up handles for the turning tools.
Not quite true as I have to re-handle some butchers steels for knife sets that have to be made over the next few months. However it is true to say that I already had plenty of turning tools to do that. It was something of an exercise. In fact I found three more tools that only required handles, which also happened to be already made so I will have to post some pix of those too. I have always been very wary of skew chisels, but during this process I became more familiar with them.
Fortunately my addictive nature is in recession.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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28th July 2020, 09:43 AM #6
This is a great thread Paul, and will follow it with interest. I have neither the turning background to comment on the application and suitability, nor the metal working background to critique your technique. I expect I will learn a whole lot in following along though.
Actually SWMBO was going to Toowoomba and did the shopping for me. I am thinking of upgrading her status and asking her to make some more significant purchases. It would appear her buying power is better than mine.
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28th July 2020, 10:41 AM #7.
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Another thing to watch out for is the bevel angle on some of these MW TC tips. Most MW turning carbide tips are designed to cut with the point and at most ~1mm either side of the point and their bevel angles can be a tad extreme for wood turning. Using these on the flat can cause probs. Again a diamond wheel can be used to reduce the angle and make the bits more useful. I mounted a $10 diamond wheel on the side of my CBN wheel like this. It's a thin wheel so most of the back of teh diamond wheel is supported by a 10 mm thick disc of steel. Mostly I use it to touch up TIG welding tips.
TP2.jpg
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28th July 2020, 03:44 PM #8
Bob
The tips I am using are intended for woodwork not metalwork.
I quickly googled this:
Tungsten carbide truning tools..png
It was literally the first item that came up and replicates what I was trying to achieve except that this uses a single handle and interchangeable shafts. It is the Banggood site. Initially I thought I had miscalculated on my price saving as it appeared to be about $32 including freight (but not 10% GST) and then I realised it was for the handle and a single shaft. Phew. I'm still quids in to perpetuate Matt's imperial theme.
The tips are very fragile compared to the metal equivalents.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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28th July 2020, 07:09 PM #9
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28th July 2020, 08:59 PM #10
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29th July 2020, 12:31 PM #11
The chisels received their first coat of varnish and need to be rubbed back for more: Just a seal coat really.
P1060314 (Medium).JPG
So, a little bit more detail (or you can just scroll to the finish or even unsubscribe). The shafts for these were cut out from plate and so a little on the rough side, but I wanted to compare a square shaft with the round. Tallowwood on the left and Forest Red Gum on the right. I am reminded of a fabulous, albeit a bit dated, (understandably for something 50 years old) old Pommie comedy program from the sixties about two tailors called "Never mind the quality. Feel the width."
NEVER MIND THE QUALITY - FEEL THE WIDTH! - YouTube
P1060301 (Medium).JPGP1060302 (Medium).JPGP1060303 (Medium).JPG
These three have the 16mm round shaft. Tallowwood on the left and Forest Red Gum for the other two.
P1060304 (Medium).JPGP1060305 (Medium).JPGP1060306 (Medium).JPG
This shows a bit better the difficulty with the "Renault" cutter and why one shaft is so much shorter because of several attempt to achieve a satisfactory fit. The support plate is welded on the left but secured with small bolts on the right. The shafts are 12mm. Both handles in Forest Red Gum
P1060307 (Medium).JPGP1060309 (Medium).JPGP1060310 (Medium).JPG
This one is by itself really only because of the handle which is Bull Oak. Not a defect free specimen unfortunately and my intention was to fill them with resin, but I have decided to let it be with warts and all.
P1060312 (Medium).JPGP1060313 (Medium).JPG
These are the other high carbon tools I referenced before. I have recently become more adventurous with skew chisels, I find a lot of use for the heavy parting type tool (for forming the cut for the ferrules as an example) and am a big fan of the scrapers, which is testimony to my lack of skill!
P1060298 (Medium).JPGP1060299 (Medium).JPG
Here they all are together
P1060315 (Medium).JPG
And the question you probably were all afraid to ask, being the sensitive souls I know you are, did I need so many turning tool? Would four have sufficed? Absolutely not ! Did I need more?
P1060300 (Medium).JPG
Probably not really.
One aspect that I realise was very seriously raised was, I think, a result of my comment that one cutter was able to spin. That may have been misunderstood, although it was quite right to be queried. I had better explain this as it was not loose so that it wobbled. It was loose because it was not butting properly against the shoulder of the shaft. As I tightened the screw it gripped the cutter and moved it off square to the shaft. You can just see it in this enlarged pic.
P1060302 (Medium) (2).JPG
All the other cutters sit tight on the shaft except for one which I know I have to revisit and is the issue raised by Bob and Matt. One last comment is that all the handles are different in shape. I am not good a replicating the patterns so I don't try. Besides which I have come to realise that if the tools are sitting in a tray or a rack (I am going to have to make up one of those) the tool is easier to identify if the handles are different.
One more last comment ( ) the carbon steel tools are relatively robust and can stand my storage system seen two pix above, but the tungsten carbide cutters are brittle and need some protection. This is my solution:
P1060316.jpg
Cut off fingers from old leather work gloves. It is best to do this with the gloves off the hand.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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29th July 2020, 01:13 PM #12
Paul, I feel sorry for you, as the slope is steep and you are at the precipice!
Good looking tools, be warned TC tool bits break, spectacularly. Were a full face shield when using them. Also, if the tool bit doesn't break, the shafts will bend, DAMIKT!Pat
Work is a necessary evil to be avoided. Mark Twain
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29th July 2020, 06:20 PM #13
Pat
Thanks for the warning. I will use a face shield with them.
I hope the shafts on these won't bend: Certainly not the 16mm square and round versions and as they are all in steel I am keeping my fingers crossed. I may have to revise my technique if that looks like becoming a possibility. Are the commercial versions made of steel or aluminium? I have considered that I may continue to use a traditional roughing gouge to get my square stock to a cylinder. To date I have only ever turned between centres and have not ventured into the deep and dark pit of bowl making.
Regards
PaulBushmiller;
"Power tends to corrupt. Absolute power corrupts, absolutely!"
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29th July 2020, 09:00 PM #14
Hello Paul, the one's that have bent are steel and bend at the junction on the cut away for the tooling.
I do admit to testing the limits of the tools with hollowing Sydney Blue Gum and horrible Grey Box Burl.Pat
Work is a necessary evil to be avoided. Mark Twain
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