flexible toolrest

discussion of the niceties of turning on a bow, bungee or pole lathe.

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flexible toolrest

Postby roosstoi » Wed Nov 06, 2013 10:33 pm

we tried to build a toolrest which can be used as well for turning bowls as "regular" for turning lenghts objects.
Although the blog is written in German I think the pictures speak for themselves.

http://roosstoi.blogspot.de/2013/11/da-stoi-jetzt-ist-es-doch-schneller.html?m=1

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Re: flexible toolrest

Postby jrccaim » Fri Nov 08, 2013 4:20 am

Ausgezeichnet, Herr Rosstooi! ! Ich werde sofort kopieren.

Escellent. Brilliant! I will copy it at once.
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Re: flexible toolrest

Postby roosstoi » Sun Nov 10, 2013 4:44 pm

another weekend another Solution
http://roosstoi.blogspot.de/2013/11/da-stoi-so-funktioniert-wohl-die.html?m=1

we changed the headstock (or is it the tailstock?) and worked on the
toolrest. Now the toolrest, when turned, can slide under
the headstocks metal part


btw. the bowl is made of fresh aspen

have fun with the pictures
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Re: flexible toolrest

Postby SeanHellman » Sun Nov 10, 2013 9:51 pm

Great photos, and I like the way you have made the tool rest especially how it attaches to the bed of the lathe. I was a bit mystified why you want a tool rest like you have made until I saw your second post. You are using normal electric lathe turning tools? If using gouges etc, the nearer the tool rest to the bowl the better, so a good solution. I personally have never used gouges only hook tools to turn bowls with, so it is not important that the tool rest is so near the work.
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Re: flexible toolrest

Postby roosstoi » Mon Nov 11, 2013 3:58 pm

If I am talking of "we" its also Mathias Baumann, an examined cabinetmaker and carpenter with whom I have to fight every weekend for the right way to go.....

usually we did not use electric lathe turning tools, but as we were not satisfied with our results on bowls, we tried out several variations in many ways, also with our hook tools.
I think one reason is that I am not patient enough for making the sharp edge, which especially with the hook tools is very boring to me. This was one main reason why I turned to the Tormek system because even a sharpening Dummy like me can reach a sharp edge in no time compared with the method by hand. But Tormek is useless on hook tools ;-((

Anyway, the hook tools we forged were definitely not satisfying at all. So I took one of my favorit books -the katalogue of DICTUM ;-((, it allways becomes expensive when I grab for this one - and ordered a smaller gouge than I had before.
What arrived was not only a smaller version of my own KIRSCHEN tool but it also had a very different form of the edge, not straight but round, and it worked at once fine with the spindle lathe

So the next step was the new forming of the toolrest and again the new gouge worked fine even with the bowls and our "bad" hook tools at least helped us to make the final cuts underneath the mandrell.

Working very much with scouts at home and offering workshops at our annual scouting camp site my wish was to have a lathe that can fulfill both opportunities so I am not forced to use a "removal truck" when going to a camp, at least an "all in one" lathe with as less a compromise as possible, otherwise I would again rather have the two lathes with me.

So, like allways, we have a solution for the toolrest and the tailstock, but it goes on:
the next issues are

what did we do wrong by forging or while sharpening our hook tools
how can a smaller - just by looking at the space needed while working not the transporting size - or different pole
work the same way.
The treadle must be constructed in another way, because with this new toolrest some other standing positions but in the right angle are possible, and its not funny to stand right next to the treadle and have to push it.

So, I dont know If we find solutions for every issue, but we like to think about it, discuss it and find a way through the problems at least by try and error, but because most of the products being out of wood, our ideas can at least become firewood, which we allway are in need of.
Last edited by roosstoi on Sun Nov 17, 2013 5:35 pm, edited 2 times in total.
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Re: flexible toolrest

Postby gavin » Mon Nov 11, 2013 5:49 pm

roosstoi wrote:what did we wrong by forging or while sharpening our hook tools

Have you bought a Sjante Djarv or Ben Orford hook tool? They will work and you can model your next one on that. Whether you put bevel inside or outside makes a difference to ease of sharpening - I'd go for outside bevel to start with.
roosstoi wrote:how can a smaller - just by looking at the space needed while working not the transporting size - or different pole
work the same way.

To make a bowl lathe you need a lot of inertia i.e. weight else the whole thing wobbles as the work spins. Instead of weight you can have it fixed to walls and floor very tightly. As I gather your needs are portable, fixing tightly won't work for you. Spindle lathes need less inertia to prevent wobble. I would go for a slot-log pattern like this, which will work for both spindle and bowl turning.
Image
roosstoi wrote:The threadle must be constructed in another way, because with this new toolrest some other standing positions but in the right angle are possible, and its not funny to stand right next to the threadle and have to push it.

The treadle ( note there is no 'H' in the word) is the plank or frame you push with your foot. The drive-strap or string is led or passed VERTICALLY with a bowl lathe from end of treadle to spring and it goes thru the lathe bed. With a spindle lathe, the string leads DIAGONALLY over the lathe bed.
Like this:
1-Bob Fleet slot-log lathe.jpg
1-Bob Fleet slot-log lathe.jpg (67.43 KiB) Viewed 12715 times

If the string were led THROUGH the lathe bed and the treadle pulled back 40 cm or so, the pull would be VERTICAL and so useful for bowl turning.
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Re: flexible toolrest

Postby roosstoi » Wed Nov 13, 2013 8:48 pm

Thank you Gavin for your hints,

we will start with the tools first. We had all our bevels inside, we will change this the next time.
For our hook tools we had the small round grinding stone fixed in the big drill and could by this way sharpen our hooks inside bevel.
But I can also imagine that the cutting could work better if the bevel is outside.

Today we made two more gouges, with round "corners". Without having hardened them, they both already worked fine when tried out even without a handle.
For these gouges Mathias made a sharpening tool, which works fine on the Tormek.
Foto 1.JPG
Tool which enables sharpening of the the gouges edge including fixing the angle AND with the possibility of sliding and turning the gouge
Foto 1.JPG (94.55 KiB) Viewed 12658 times
Attachments
Foto 3.JPG
top of the gouge 10mm steel the second was 5 mm steel, here I think it is clear what I mean when speaking of "round" corners.
Foto 3.JPG (78.88 KiB) Viewed 12658 times
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Re: flexible toolrest

Postby jrccaim » Sat Nov 16, 2013 5:35 am

Rosstoi, love your bent tailstock. As you point out it allows the rest to clear the bowl. Neat post on your blog! I will go back to it.

Gavin points out that bowl lathes must be massive. Upon reflection I would like to suggest the following amendment: the mass of the lathe must far exceed the weight of the rough stock -- the piece you intend to turn. On my polecat, held down by a workmate I doubt I could do a 25mm diameter bowl; not much of a bowl. On my "summet" lathe, about ten times that. maybe a 750 mm bowl. Ah, but there is a way around this one. Just pile extra weight on the lathe. For this purpose I would use (and have used) big logs. The heavier, the better. However, there is an even better way. Construction sites often afford you a bunch of I-bar cutoffs, steel, much denser than wood. Or both! wood and I-bar! It is no disgrace to use I-bar, it's just adding mass. It might help if you design the lathe to take this treatment. Ultimate diameter of bowl is of course limited by your center height. If you do huge bowls professionally as Robin Wood does you will indeed need a huge massive lathe. It is all Sir Isaac Newton: Action = reaction. So you cut 1 mm of the piece. The lathe deflects roughly as mass of piece/mass of lathe (there are other factors). So if the lathe mass is 10 times the mass of the piece the lathe will move away 0.1 mm. Not exact. What you really want is a factor of 100. Or better. This is why a toolroom lathe weighs a ton or so. For a 1 Kg piece the deflection is 1 /1000 but furthermore the lathe is bolted to a concrete floor. Bolting to a concrete floor is not really bodgering but I for one will not blame you if you do.

Re tools. Hook tools in particular. It is not very hard to make a hook tool. It is extremely difficult to sharpen one. Once you put in the hook on the forge you are done. You can grind an edge before you bend it ( recommend this) but as soon as you get it into the forge your beautiful edge is distorted. Vergangen. Ask me how I know. So you quench and temper and now you have to sharpen the b*** thing. Getting the edge to where it works is a via crucis, the way of the cross. You will at once perceive that your sharpening gizmo must sort of match the curvature of the hook. The bigger the radius the easier it is, but it is still a bear. I do 5mm radius hooks. ( I work miniature in winter, and here Winter is). They are not just a bear, they are a saber-tooth tiger. But eventually... you get it. Advice. Do not do this all at once. Takes me me weeks to get an edge on a hook. Do a few minutes or as much as you can take each day. Of course you can buy a professionally made hook; but I enjoy making my own tools as much as I enjoy bodgering. Once you finally get a decent edge all you have to do is touch it up. I am still working on my 200 mm hook! Made it two years ago. And I use diamond hones!

Re gouges. Yes, a commercial power lathe gouge can be used to do pole lathe turning. You will have two problems to overcome. One is that commercial gouges are much too hard for our purposes. They are made for our powered brethren. The motor makes up for a dull edge. The hardness is so that the edge won't dull right away, and can be touched up on a powered grinder. Mass market, you see. The other problem is that the bevels are not really the ticket for pole lathes; too steep. But again if you hone the edge you can do it; I use a wet grinder, a TSO (Tormek-shaped object). Enough posts on this subject to give an elephant indigestion, see Tools topic. I suppose you could retemper. I have done this with Chinese chisels with excellent results. And since so many tools these days come from China, maybe it would work, but I have no experience with turning tools. Beware. Alloy steel. Rules for hardening and tempering of tool steel may not apply. Ordinary carpenters' gouges work just as well as power-lathe tools and are much cheaper. In fact the bevels (25-30 deg) are more like what we want. We cannot turn a pole lathe at 3000 RPM! Still have to hone them, though.If it cuts your fingernail it may just be sharp enough.

Fun topic. Thank you Rosstoi!
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Re: flexible toolrest

Postby roosstoi » Sat Nov 16, 2013 9:00 am

thank you JRC, Gavin and Sean for for your advices, they are all very welcome and I'll try my very best.

I added a google translation gadget to my blogs, although I think
the results are terrible.
Now.... back to work its Saturday and thus roosstoi time (roosstoi is bavarian for horse barn or a stable)
Last edited by roosstoi on Sun Dec 08, 2013 6:44 pm, edited 1 time in total.
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Re: flexible toolrest

Postby jrccaim » Wed Dec 04, 2013 5:00 am

Hello Rosstoi. I agree that the Gooogle translation gadgets are awful. But perhaps better than nothing for those who cannot read German :). Now what I really wanted to say is about the gouge you show in your last picture; I did not observe it carefully enough last time. If you will look at it carefully (it shows up clearly in the picture without any enlargement) you will observe striations, very small grooves, that run longways, parallel to the long axis of the tool. These are grinder marks. That tool has been ground, but never honed and still less polished. Observe the very steep bevel, about 60 deg. This is standard stuff for power lathes. I do not like it for a pole lathe although I use it sometimes. Since I do, I use a wet grinder, a Tormek-Shaped-Object (TSO) to get the striations out. I use the grit-changing stone to get a finer grit. I have built myself a gouge-honing jig (see the "wet grinder" subject elsewhere in this forum), because both the Tormek and its jigs are extremely expensive, at least in the USA. Although beautifully made. To put a polish, a mirror edge, on these things is extremely difficult. Although I suppose it would suffice to put a mirror edge on the first few mm of the gouge. My Japanese waterstones will not even scratch my power-lathe gouge. I conclude it is alloy steel, with half the periodic table added to the steel. Chrome, Vanadium, and Tungsten for all I know. It is extremely hard. So I find it impossible to polish it. So far. This winter I intend to conduct some experiments with valve-grinding paste and the leather wheel on my TSO. Valve-grinding paste is used to seat the valves in gasoline or diesel motors; it is very hard, probably carbide. The "polishing compounds" recommended by the wet-grinder manufacturers are probably pumice (volcanic dust). Useless.

Thanks for letting me know what "rosstoi" actually means. I should have guessed the first part -- ross meaning "horse," but the toi part would have eluded me :), but then I do not pretend to even begin to understand Bayrisch :)
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Re: flexible toolrest

Postby roosstoi » Sun Dec 08, 2013 6:40 pm

Hello JRC
As you live in Alaska I can tell you that our heavily forrested area at the east side of Bavaria is sometimes called the Bavarian Sibiria, last weekend we got our 20 cm of snow on the hills.
You´re absolutely right, our edges are far from being perfect or even being good. We are working on too many subjects the same time in the very moment AND in most cases looking back to the weekend from the Sunday´s point of view I must admit, that we at least did work on other things than we had in mind on Friday ;-)). Allways the same, but our workshop is our recreation place and so our interests are wobbling towards this and that and back again....
So the edge thing is on our to-do list the follwing weeks BUT first
I want to finish the bridge
I want to clean the area from "junk" wood and shift it into firewood before snow stays for months

BUT the trees are already cut and brought home for the future bowl turning.....

Now the Bavarian roosstoi thing, don´t divide the word into rooss and toi, the line is between roos and stoi
You´re right that "ross" would be an old German word for horse, but in Bavaria we speak it with a long "o" and a warm but short "s"
And "stoi" is for Stall, stable
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Re: flexible toolrest

Postby jrccaim » Sat Dec 14, 2013 5:55 am

roosstoi wrote:Hello JRC
As you live in Alaska I can tell you that our heavily forrested area at the east side of Bavaria is sometimes called the Bavarian Sibiria, last weekend we got our 20 cm of snow on the hills.


All I have is 32 cm! But fear not, it is supposed to dump 30 cm on us tonight :) It is awful skiing, there was a melt and then a refreeze and the snow is like iron.

roosstoi wrote:You´re absolutely right, our edges are far from being perfect or even being good. We are working on too many subjects the same time in the very moment AND in most cases looking back to the weekend from the Sunday´s point of view I must admit, that we at least did work on other things than we had in mind on Friday ;-)). Allways the same, but our workshop is our recreation place and so our interests are wobbling towards this and that and back again....
So the edge thing is on our to-do list the follwing weeks BUT first...


I have but one suggestion here. These commercial tools are very, very, hard. I cannot do an edge in a morning. I creep up on it. Turn a little, sharpen a little. A Tormek-Shaped Object (TSO) wet grindstone helps a lot but I really go for mirror edge; I find it takes me weeks. I'd rather take weeks than go crazy trying to do it in a day. I find that for that final polish a diamond stone is the thing, a very fine diamond. In Germany, at least, watchmakers use some stuff called Diamantenpulver, or diamond dust. They mix it with very light oil and use it to polish parts. I cannot find such a thing in Alaska or even the Internet. It does take some practice to do a gouge. You must constantly rotate the gouge, or you will put put a flat on it. Not good. .

roosstoi wrote:I want to finish the bridge ...

Now the Bavarian roosstoi thing, don´t divide the word into rooss and toi, the line is between roos and stoi
You´re right that "ross" would be an old German word for horse, but in Bavaria we speak it with a long "o" and a warm but short "s"
And "stoi" is for Stall, stable


Ah! My knowledge of Bayrisch is very meager. I Love to learn more. I can do a fair job on Hochdeutsch, but my Bavarian friends defeated me by speaking Bayrisch! I was lost. Still am. BTW there was once a tractor maker (maybe still is) called Fendt. They made a tractor called the Dieselross, or diesel horse, and that's where I learned the Ross word!

Blick immer aufwaerts, nie zurueck! Keep on turning.
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Re: flexible toolrest

Postby neilyeag » Tue Sep 23, 2014 5:28 am

The treadle ( note there is no 'H' in the word) is the plank or frame you push with your foot. The drive-strap or string is led or passed VERTICALLY with a bowl lathe from end of treadle to spring and it goes thru the lathe bed. With a spindle lathe, the string leads DIAGONALLY over the lathe bed.
Like this:
1-Bob Fleet slot-log lathe.jpg

If the string were led THROUGH the lathe bed and the treadle pulled back 40 cm or so, the pull would be VERTICAL and so useful for bowl turning.


Gavin, is placing the drive strap through the frame for bowls, more of a preference or is there indeed a practical advantage? I have see pictures of both ways. If an advantage, then should one switch back and forth between over the frame for spindles and then when doing bowls through the frame? The way I designed my current treadle, it seems to work fine "over" but if I pull it back to go "through" it just seems like it is just not right?

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