Author Topic: What Speed Do You Spin At?  (Read 22743 times)

Offline bodrighywood

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Re: What Speed Do You Spin At?
« Reply #30 on: May 30, 2014, 08:58:28 AM »
Since this thread started I have been looking at my speed to see what I tend to use and find that like Nick I am rarely if ever over 1000 on faceplate work and spindle work depends a lot on the wood as well as the size. As a lot of the wood  I use is potentially likely to split etc I use even lower speeds. Yesterday I was roughing out at 300 for one piece. The top speed on both my lathes is only about 2000 anyway and it is rare that I go the flat out speeds.

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Offline edbanger

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Re: What Speed Do You Spin At?
« Reply #31 on: May 30, 2014, 10:29:50 AM »
Sergio

I think that you are correct, people should be taught to run the lathe as slow as possible and to have sharp tools and master good tooling techniques. Since I started this post I've been checking my turning speeds and I find that I work well under 500rpm once the wood is balanced, dependent on the size of the piece the range is from 200rpm to 400rpm. I only use the faster speed for buffing.

We should all promote turning at the lowest speed possible this would make things much safer should something decide to depart from the lathe unexpectedly.

This has turned out to be an interesting post and the feedback from everybody has been first class.

Ed

Offline Graham

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Re: What Speed Do You Spin At?
« Reply #32 on: May 30, 2014, 03:09:52 PM »

 I find that I work well under 500rpm once the wood is balanced, dependent on the size of the piece the range is from 200rpm to 400rpm. I only use the faster speed for buffing.
That does seem VERY slow. I must give it a try and see.
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Offline seventhdevil

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Re: What Speed Do You Spin At?
« Reply #33 on: May 30, 2014, 04:21:26 PM »
that sounds too slow for many purposes.

my skittle production at that speed would take ages. one set might be finished in a days work at that speed rather than the 1500-2000 i currently make them at and one set takes 2-3 hours.

as many people have already stated it's probably what were are comfortable (or used to) turning at which is best. diameter does have an impact and will slow it down immensely.

the walnut i have on the lathe at the moment is running at 250 and is 28" across. i'll be turning the speed up as fast as the lathe and balance of the blank will let me when i start again as it is simply what i like to do. others will feel differently and have a slower or higher speed that they use.


Offline The Bowler Hatted Turner

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Re: What Speed Do You Spin At?
« Reply #34 on: May 30, 2014, 05:12:02 PM »
 
        "We should all promote turning at the lowest speed possible this would make things much safer."

DEFINITELY NOT !! There are too many people making up rules and regulations and making spurious claims about the safety of this and that. I do not usually use the term amateur regarding woodturning, preferring to say hobby turners as not all hobby turners are amateur but it should be remembered that there are 2 types of turner. Hobby and professional. But some of the claims here are obviously amateur. We all have different ways of doing or achieving an end product, sometimes the professional turners differ in their opinions but that is no reason to promote a method. I was taught to turn at the highest speed I can comfortably work at and as a production turner you will not last in your job long by turning at slower speeds. At the moment there is no chart available that can properly tell you safe turning speeds, think why this is for a moment, bearing in mind that if H&S feel there is a need one would have been produced before now. Turning speed is subjective, in as much as each and every piece of wood is different therefore each and every piece of wood that is mounted on the lathe should be......wait for it..........risk assessed. This does not mean rheams of paper with different gradings and hollow sounding results, what this means is you mount the piece on the machine, whilst you are doing this you are looking at it, feeling the weight and looking for defects you are looking to see which side is heavier as this will affect balance you are touching it to feel the moisture present and how loose the bark is. You are doing all this in a split second or two when first handling the wood.  This is called experience, it is not something that you can read from a chart, to some extent can be taught but the best way of learning all about it is to ......experience it. This experience will take the form of things like reducing speed to prevent chatter on a bowl or thin spindle but it must be weighed up with, in my case, the need to earn a living in a reasonable time for each job.
     There is no easy answer to this all I will say is what we used to say in the forces.....get some in!

Offline TWiG

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Re: What Speed Do You Spin At?
« Reply #35 on: May 30, 2014, 06:31:03 PM »
just started turning a 30"x 6" chainsaw cut walnut that weighs 70kg and started it down at the 60's. just got up to 250 near round.
How did you get that to the lathe and mounted ?   I have access to very large wood and it is always tempting to go BIG but my lathe can cope with what I can get to it and mount  ( 30kg max ) and this is plenty I find and do not make large bowls very often ,as I find they do not sell that well , and do not intend to change lathe just to go big . I have seen articles where turners have a chain hoist system over their lathes , but this would also require special tooling and a big shed !! Would be nice to see some pics of a bowl that size though !

Offline Paul Hannaby

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Re: What Speed Do You Spin At?
« Reply #36 on: May 30, 2014, 08:18:02 PM »
Plucking figures out of the air for maximum or minimum speeds for any particular object doesn't really convey any meaningful information because, as we all know, the speed of rotation is a function of diameter.

To give an example, I haven't turned anything at below 3000 rpm today tells you very little but if I add I was turning pens with a maximum diameter of 3/4" it then means something.

The chart that everyone seems to be avoiding like the plague is based on the arbitrary cutting speed for wood being around 25 feet per second. Obviously that is going to vary a little depending on what is being worked but as a rule of thumb, at least it gives a baseline and if the proviso of balance, vibration and security of mount is added I don't see a problem with using it as a rule of thumb. Where things go wrong is when only half the information is passed on or the safety factors are ignored.

Offline Derwent Woodturning club

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Re: What Speed Do You Spin At?
« Reply #37 on: May 30, 2014, 08:41:29 PM »
I thought everyone might be interested in a web page I came across some years ago. I think it covers the topic of lathe speeds very well, covering many of the aspects already mentioned but conveniently on one 'page'.
http://www.docgreenwoodturner.com/lathespeed.html
Regards,
Derwent Woodturning Club

Offline Bryan Milham

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Re: What Speed Do You Spin At?
« Reply #38 on: May 30, 2014, 09:50:57 PM »
I've just come in from hollowing a couple of vessels from a log of Eucalyptus (still don't like the stuff but a neighbour took his tree down and asked 'Could you... ' - so I'm turning it.)

Anyway it was fairly ovate and well out of balance, so I started at under 200 RPM, well below any vibration level, 400 ish to finish rounding it and once well balanced about 800 to shape the outer and hollow it. No great speeds for a bit of timber only 5" finished diameter but it was all I needed to do the job on green wood. And I had some wonderful ribbons flying.

One thing I have noticed about speed. I have a very acutely sharpened Skew (well several of them), I measured one at a 23º included angle and kept at a razors edge. I find at high speeds it cuts very poorly, in fact it prefers to skate over the wood. It's much happier around 2000 even on small diameters (lace bobbin sizes).

Any Idea why it skates at high RPMs?
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Offline seventhdevil

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Re: What Speed Do You Spin At?
« Reply #39 on: May 31, 2014, 01:47:38 AM »

Quote
just started turning a 30"x 6" chainsaw cut walnut that weighs 70kg and started it down at the 60's. just got up to 250 near round.

Quote
How did you get that to the lathe and mounted ?   I have access to very large wood and it is always tempting to go BIG but my lathe can cope with what I can get to it and mount  ( 30kg max ) and this is plenty I find and do not make large bowls very often ,as I find they do not sell that well , and do not intend to change lathe just to go big . I have seen articles where turners have a chain hoist system over their lathes , but this would also require special tooling and a big shed !! Would be nice to see some pics of a bowl that size though !


how did i get it on the lathe, i lifted it on...

i've no huge shed for engine hoists and other pulleys or lifting devices, it's a 20'x14' shop that is chock full of wood and machinery so no space left for fancy lifting gear.

what can i say i'm 6'3" and 17stone of mostly muscle but i don't think i could lift a heavier weight.

the roughing out is finished and the bowl at the moment though admittedly sopping wet still weighs 23kg i've cored it and should get another 2 from that.

i'll see about getting pictures on here but last time i tried nothing happened.

Offline TWiG

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Re: What Speed Do You Spin At?
« Reply #40 on: May 31, 2014, 06:17:00 AM »




what can i say i'm 6'3" and 17stone of mostly muscle but i don't think i could lift a heavier weight.

        Ah that explains how then !!    Still it is probably not easy getting the face plate and headstock threads to marry up though !!  I do not know if like me you cut the blank with a chainsaw as accurately as you can and shape the outside a bit as well ... saves time   !!  My shed is only 7x6 so you would not fit in it  !!..ha ha .....      Terry...

Offline edbanger

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Re: What Speed Do You Spin At?
« Reply #41 on: May 31, 2014, 07:17:05 AM »
Paul H a point well made a statement needs facts, I did not know that the arbitrary cutting speed for wood was around 25 feet per second so that something that I've learnt, and give me something tangible to work with

Paul (DWC) thank you for the link that also helps, how to explain to someone turning speeds.

Bowler - Your right also once you have learnt the skills required go as fast as you like and if your production turning a slow speed would be a waste of time. But if when we started driving we just got in a car and put our foot to the floor without learning any control .......only one thing is likely too happen :) but if your a professional racing car driver that a different matter and I think that wood turning is the same except you have not got the steel safety cage around you :) :)


Offline seventhdevil

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Re: What Speed Do You Spin At?
« Reply #42 on: May 31, 2014, 10:01:45 AM »




what can i say i'm 6'3" and 17stone of mostly muscle but i don't think i could lift a heavier weight.

        Ah that explains how then !!    Still it is probably not easy getting the face plate and headstock threads to marry up though !!  I do not know if like me you cut the blank with a chainsaw as accurately as you can and shape the outside a bit as well ... saves time   !!  My shed is only 7x6 so you would not fit in it  !!..ha ha .....      Terry...

i did use a lever to get it on to the spindle and it was about seven sided with a chainsaw when i mounted it..

7x6 is about the space i have to use in the workshop that isn't cluttered with wood or machinery.

Offline TWiG

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Re: What Speed Do You Spin At?
« Reply #43 on: May 31, 2014, 02:10:17 PM »
I feel  , 7x6 is small but mine is dedicated uncluttered turning space though , however it soon gets knee deep in shavings though ! Most of my work is fairly large hollow forms and I may start with a 20 kg lump , but end up with something that only weighs a kilo or 2 so lots to clear up ,but green wood so cuts nice and very little dust .

Offline woodndesign

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Re: What Speed Do You Spin At?
« Reply #44 on: June 03, 2014, 12:03:16 AM »

Ed, back to your question, on reflection of the automatic ... pulley the belt is on, the most average 8" flatwork and 2>3" spindle the Mystro normally remains at the middle range, on checking I'm most surprised at it being 916rpm, much like Pete found under the 1000, my next increment is 1483rpm... the other speed are used to reflect the varied shapes and sizes.

I do wonder as why when this post related to lathe speed, with all of us being a singular body as Turners, that the distinction of 2 types ...  Hobby and Professional has been raised ... just which is it that is being Amateur.

David
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