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View Full Version : Multi centre / eccentric chuck



Oldgreybeard
1st January 2015, 04:56 PM
My "gerry rigged" chucking solution for offset faceplate turning is far from satisfactory, so it looks like a New Year's gift - probably have to be to me from me unless there is a generous benefactor in the wings that I don't know about.

There are 3 possibilities that I am aware of:
Vicmarc Escoulen Eccentric Chuck #3 with 40mm eccentric ball and ball adapter - $561
Robert Sorby RS60 Eccentric Chuck - $520
Vermec Multi Centre Chuck - $235

The Vermec is limited as it does not have eccentric capability - only multi centre.
I beleive that the Vicmarc has far more accurate repeatability in settings, but have not read anything that indicates what the limitations are with the Sorby chuck.

I think I can discount the Vermec chuck as I am particularly interested in the eccentric capability for boxes, finials, long stem goblets and the like.

Is anyone familiar with these chucks and can give me the pros and cons as they see them.

Many thanks

Bob.

mjl09
1st January 2015, 10:26 PM
You havent mentioned the item size you are trying to turn.
eg for pendants there are other options such as the Joyner Pendant chuck (though not sure these are being sold in Australia anymore)

Axminster also do an eccentric chuck - which i believe is also still sold by Craft Supplies (USA)
http://www.axminster.co.uk/axminster-eccentric-spiralling-chuck
http://www.axminster.co.uk/media/downloads/900093_manual.pdf

I have seen Guilio Marcolongo turn both boxes and pepper mills on the Vermec chuck. Given its screw chuck mount for timber - some of this was done using jam chucks held on that screw. You can also rotating the object position on the jam chuck itself or rotate the entire chuck itself in the jaws of the scroll chuck.

As for the Sorby chuck there is a manual on Sorbys website http://www.robert-sorby.co.uk/pdf/RS60.PDF
Also see the projects book http://www.robert-sorby.co.uk/pdf/eccentricchuckprojects.pdf
The adjustment is 0-35 mm - and 5 mm steps are marked within that range. (though settings in between could also be used there is just not a fixed mark currently in place (though the steel could readily be marked with such submarks)

As to the Vicmarc - i havent used it - but its probably worth looking at its manual - if you havent already - to see its options and how it grips timber.
http://www.vicmarc.com/downloads/Vicmarc%20Escoulen%20Manual.pdf


The method of adjustments vary with the chucks and as do the methods in which the timber is held mounted to the chuck.

Sturdee
1st January 2015, 11:02 PM
the Joyner Pendant chuck (though not sure these are being sold in Australia anymore)


No longer sold here but available direct from Ruth Niles (http://nilesbottlestoppers.com/Pendant-chucks.html) who gives great and efficient service. I got the upgrade plate and a better morse taper direct from her last year and no problems with ordering and shipment to me.



The Vermec is limited as it does not have eccentric capability - only multi centre.

Bob.

Bob, if you are interested to have a play with both of them let me know as I have the Joyner and the Vermec chucks.


Peter.

mjl09
1st January 2015, 11:18 PM
There is also one listed on keltons site http://www.kelton.co.nz/Kelton%20Eccentric%20Faceplate.html

chuck1
2nd January 2015, 11:21 AM
When I had a go at the flat lattice I just used a piece of maple/meranti on my screw Centre face plate and friction chucked/jam chucked it.
It needs accurate turning,
The down side is if your doing lots of different centres you will have lots of timber discs pile up.

WoodWriteOz
2nd January 2015, 11:47 AM
The Richard Joyner mandrel is really great for Pendants, Medallions, Earrings etc etc..and with a little ingenuity you can turn 'lattice' style box lids. WH Kloepping has an Excel Spreadsheet which has almost infinite variations, it can be downloaded for free. There are a number of Youtube Videos on the subject from Ed Davidson, Capt Eddie Castelin, Acolyte Turner and one or two others....Regards....George

Oldgreybeard
2nd January 2015, 02:40 PM
There is also one listed on keltons site http://www.kelton.co.nz/Kelton%20Eccentric%20Faceplate.html

Thanks for the links. I had found some of them,but was expecting some more detailed application notes. But from other comments on the internet, most contributors are equally agreived that not one manufacturer has supplied a comprehensive user guide.

For many turners, especially me, off centre and eccentric turning are new and exciting concepts and the new equipment which is available should make these concepts much easier. But from the internet comments, the lack of decent user manuals has perhaps compounded the issue. From the online user manuals, and it appears that these are all that is available, there is no real explanation of anything more than the basic functions - sure there is a brief 'how to', but no explation as to why, when and in what circumstances one would make such settings and what outcome could be expected from the settings.

When you are paying $500 and more for a piece of equipment, I think we deserve more than a basic set of instructions (usually less than 10 pages and offering an explation on how to do a couple of beginner projects - plus adverts for thier optional extras) and a concluding comment such as experiment and enjoy. One manufacture condensed thier user manual into 2 pages!

It is because of the lack of information from the manufacturers and very few videos on the internet that I am seeking advice through this forum. I would not be expecting the projects which I have in mind to fall outside of the Vicmarc recommended 'safe size' of the 3:1 ratio i.e 50mm diameter x maximum 150mm lenght including mounting spigot - if using thier 52 mm cup chuck.

regards

Bob

Oldgreybeard
2nd January 2015, 02:42 PM
No longer sold here but available direct from Ruth Niles (http://nilesbottlestoppers.com/Pendant-chucks.html) who gives great and efficient service. I got the upgrade plate and a better morse taper direct from her last year and no problems with ordering and shipment to me.



Bob, if you are interested to have a play with both of them let me know as I have the Joyner and the Vermec chucks.


Peter.

Thanks Peter, I would like to take you up on the offer to look at the two chucks. Can you PM me with a date/time that is convenient to you.

Bob

mjl09
2nd January 2015, 04:06 PM
Another small one is the Wobble chuck http://www.robert-sorby.co.uk/wobblechuck.htm

I guess part of the reason for the lack of how tos in the instructions is that the possibilities of what can be accomplished through these type of turnings is really only limited by the imagination - in some cases that may not be what was imagined in the first place. Especially when combinations with other techniques such as inside-out turning are utilised.

dogcatcher
2nd January 2015, 06:04 PM
Before Richard Joyner came out with his chuck people were suing Corian to make a similar offset chuck using a PSI Bottle Stopper chuck as the mounting unit. First a 3x3x.5 blank of Corian was drilled and tapped to fit on the PSI bottle stopper chuck, then turned round. Removed and drilled and tapped for an offset hole with the same 3/8 threads. For a pendant, turn first with the center hole, then remove and screw back on the PSI chuck and turn the decorations. These did not have the indexing feature nor as many offset holes on the backing plate.


The Penn State bottle stopper chuck.
http://www.pennstateind.com/store/PK-BS1-MJR.html


Penn State also has an offset chuck. Not sure on this one, looks to be a pen makers chuck, but I am sure with a little jury rigging it will do a lot more. http://www.pennstateind.com/store/CSC600.html

Sturdee
2nd January 2015, 09:29 PM
The Penn State bottle stopper chuck.
http://www.pennstateind.com/store/PK-BS1-MJR.html


Penn State also has an offset chuck. Not sure on this one, looks to be a pen makers chuck, but I am sure with a little jury rigging it will do a lot more. http://www.pennstateind.com/store/CSC600.html

When I was looking for a pendant chuck I looked at both of the ones from PSI but both of the chucks have a thread of 1*8 TPI which is not very common on Australian lathes. Hence I went for the Richard Joyner chuck which uses a MT and the latest version, in addition to the pendant, also has a bottle stopper attachment.

Peter.

mjl09
3rd January 2015, 11:05 AM
Penn State also has an offset chuck. Not sure on this one, looks to be a pen makers chuck, but I am sure with a little jury rigging it will do a lot more. http://www.pennstateind.com/store/CSC600.html

The same type of offset chuck is available in Australia from McJings in either 1“x8tpi or 1“x10tpi
https://mcjing.com.au/categorybrowser.aspx?categoryid=64#OFF-CENTRECHUCKSET

Which for most of us means an adapter is also needed to use either the chuck or multiport adapter
https://mcjing.com.au/categorybrowser.aspx?categoryid=64#CHUCKINSERT

Then in terms of the chuck itself you still need eg a faceplate (or chuck - but thats likely a lot of unbalanced weight ) to mount to the screwthread on the frontface of the chuck to hold onto the timber itself.
https://mcjing.com.au/categorybrowser.aspx?categoryid=63#FACEPLATE

Oldgreybeard
3rd January 2015, 03:02 PM
mjl09, thank you for all the trouble you have gone to in finding all these lnks - it is greatly appreciated.

I should apologise for my last post to you in that I did not finish the last sentence:doh:
The last sentence should have read:
"if using their 52mm cup chuck turning of pieces with a diameter of 140mm and a maximum length of 220mm are possible - depending on the amount of offset and eccentricity."

At this point I am thinking that I should bite the bullet and go with the Vicmarc Escoulen #3. I will wait until CWS return from thier Christmas break and then go down and talk to Jim about the various options that I should include e.g do I need the threaded ball and adapter or not?

Thanks to all who have contributed thier knowledge and assistance.

Bob

DaveTTC
3rd January 2015, 03:12 PM
Can't find the subscibe button but I like the subject and will be back

mjl09
3rd January 2015, 06:48 PM
Just to give an idea of the size of the few things.
Vicmarc 120 and a Teknatool supernova2 for size comparison in the background. The PSI type chuck is shown with both of its chucks fitted with lathe thread adapters (in this case to suit M30x3.5 from the original 1 inch ' x 10TPI of the chucks) and also shown together with a 3 inch faceplate to suit the chuck (neither the adapters or the faceplate were included in the price of the chuck). Back side of the Joyner chuck is being shown at the moment as timber is still double sided taped to the front of it.
335781

Oldgreybeard
4th January 2015, 10:55 AM
I have always told my photography students "If you can't take decent photos with the equipment you have now, spending hundreds of dollars on new equipment will not make a difference"

And now I am about to do the same, only this time with lathe chucks:doh:

I woke early this morning and quietly contemplated my problem and the answer became uncomfortably clear - there was nothing wrong with the equipment I was using. The reality was that I was obviously not doing something right and spending $500+ was not going to help - the same problem would still exist. There are other reasons for considering buying the new chuck, but to get any real advantage from doing so, I need to resolve this issue.

I will use the 'Commissioaire's hat box' to illustrate the problem I have.

335817335818335823335825335826335828
The lid and the base are each turned on 2 axis and these are the same for both. Chris's recommendation is to turn a small spigot to mount the blank in your standard chuck, then hollow out the base, turn the spigot for the lid and the half cove on the outside of the box. That is straight forward - see image 2. The base is then removed from the chuck and turned off centre to produce the profile of the hat - Looking at Image 1 the small finial is the new centre point - offset from the original centre by 12mm (the base is the same profile without the finial)When the profile is completed, the high point of the rim is 4mm higher than the low point on the opposite side of the base. (Image 3).

I won't embarrass myself further by showing my original 'gerry built' offset chuck setup. But I am now working with the Teknatool 150mm face plate and taking advantage of the sliding screw slots to achieve the appropriate degree of offset and turning a recess in the sacrificial block to jam chuck the base using the lid spigot. Up to this point everything works well and I can use an additional screw in one of the single screw holes to ensure that I have a level of repeatability. Remember the lid must be turned to the same offset profile. Only 2 srews have been used for these images - I would use 2 each side to affix the sacrificial block for turning.

Now the problem. Even with a very tight fit of the spigot in the recess i.e. it has to be knocked in, it seems there is always some rotational 'creep' due to the intermittent cutting of wood and air. The wall tickness of the spigot is only 2 mm, so I don't think that double sided tape would have sufficient contact to be effective - I haven't fully tested it yet as I only have carpet tape on hand and that did not work. Maybe I should be using that strawberry jam!:D

The problem manifests itself when turning the lid. Any rotational creep will mean that the grain and colour will not line up when the lid is fitted on the base - or if the grain lines up, the shape of the lid and base will be out of alignment.

I know that I am the problem, so don't feel shy about pointing out my faults. Your help is desparately needed.

Thanks
Bob



Edit - Should have added that i am using an 8mm P & N detail gouge. Cut is predominately a push cut from outside rim to tailstock centre. Tailstock is up except for final cuts to remove T/S dimple.

Skew ChiDAMN!!
4th January 2015, 03:08 PM
Have I got this right?

You're hollowing (turning the inside of) each half, then reverse mounting and using a jam chuck that fits inside each half to turn the outside(s)?

Is the 'length" of the jam chuck sufficient to press up against the flat at the bottom of each recess? Shortening it a mm or so, then using double-sided tape on this flat may mitigate any rotational creep.


I also salvage old VCR heads for use with hot melt glue. I glue it into a recess of some scrap, (leaving a mm or two of the head protruding, so I can later mount it in my chuck jaws) turn the scrap down to a suitable diameter for use as a jam chuck and then flatten the end until the metal face is exposed. ie. I make a wooden tyre around the metal VCR head.

The timber supplies the correct size for a jam fit, while I can also apply a smidgin of hot melt glue to the metal flat. This holds very well... and dismounting simply involves heating the metal to loosen the glue. I place it on a hotplate for a min or so, but others I know use a hot air gun. Horses for courses. I do suggest not trying to extract it from the piece with bare fingers though. Hot, hot, hot!

Some people freeze it instead (throwing the whole job in the freezer!) to make the glue brittle and easy to crack... but I find that in a jam chuck this really doesn't work too well! 'Tis OK for faceplate work, though.

Oldgreybeard
4th January 2015, 05:26 PM
Have I got this right?

You're hollowing (turning the inside of) each half, then reverse mounting and using a jam chuck that fits inside each half to turn the outside(s)?No. I have been turning a recess (see image 6) The recess is esentially the same size as the recess in the lid and fits over the spigot on the base. In many cases a hemisphere is turned when hollowing the lid.
Is the 'length" of the jam chuck sufficient to press up against the flat at the bottom of each recess? Shortening it a mm or so, then using double-sided tape on this flat may mitigate any rotational creep. Is it possible to jam chuck in this manner with curved sides? Is there any brand of double sided tape which is better that I should buy?


I also salvage old VCR heads for use with hot melt glue. I glue it into a recess of some scrap, (leaving a mm or two of the head protruding, so I can later mount it in my chuck jaws) turn the scrap down to a suitable diameter for use as a jam chuck and then flatten the end until the metal face is exposed. ie. I make a wooden tyre around the metal VCR head. Unfortunately I don't have any old VCR heads

The timber supplies the correct size for a jam fit, while I can also apply a smidgin of hot melt glue to the metal flat. This holds very well... and dismounting simply involves heating the metal to loosen the glue. I place it on a hotplate for a min or so, but others I know use a hot air gun. Horses for courses. I do suggest not trying to extract it from the piece with bare fingers though. Hot, hot, hot!

Some people freeze it instead (throwing the whole job in the freezer!) to make the glue brittle and easy to crack... but I find that in a jam chuck this really doesn't work too well! 'Tis OK for faceplate work, though.

Thanks for the comments . Is creating a jamb chuck which fits on the outside of the spigot rather than inside as you suggested the cause of my problem?

Bob

DaveTTC
4th January 2015, 07:01 PM
Bob you really have my grey matter ticking away on this one.

I may have to have a go at something like and see what I come up with


Dave the turning cowboy

turning wood into art

Oldgreybeard
4th January 2015, 07:23 PM
Bob you really have my grey matter ticking away on this one.

I may have to have a go at something like and see what I come up with


Dave the turning cowboy

turning wood into art

Thanks Dave - look forward to what you come up with.
Bob

steamingbill
4th January 2015, 08:09 PM
Hello,

Not really sure that I understand the whole process but decided to toss is a suggestion. Might inspire further ideas.

Can you glue together the bits that are slipping ? and then when you have finished, carefully cut/sand/grind away the sacrificial bit that you dont want, maybe do it carefully by hand ? Then tidy it up. Very tedious and time consuming. There is also that glue chuck trick of putting a piece of paper in the glue between the two wooden pieces ? Still need to tidy the mess afterwards.

Can you somehow use some threaded bar to tighten up the bits that are slipping - i.e. make a slit with a saw to crate some slack then drill and install the threaded bar across it and putnuts in to increase the holding power ? Could apply internal or external pressure ? Need to watch out you do.nt end up damaging the workpiece.

Somehow use some sandpaper between the slipping bits to increase the coefficient of friction and tidy up any dings and scratches by hand afterwards ?

Some sort of expanding mandrel to grip the piece from the inside ?

Bill

wm460
5th September 2015, 02:32 PM
Also see the projects book http://www.robert-sorby.co.uk/pdf/eccentricchuckprojects.pdf
.

I tried this link and When I click on it I get "Sorry, but this page doesn't exist..."

Is there any where else I can get a copy from?

Big Shed
5th September 2015, 02:39 PM
Mr Google is your friend

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CCoQFjADahUKEwjkm_TS-97HAhVm26YKHTpwCf0&url=http%3A%2F%2Fwww.robert-sorby.co.uk%2Fmedia%2Fwysiwyg%2Fproduct_instructions%2Feccentric_chuck_projects.pdf&usg=AFQjCNHH7p7lFAWOLbTNhsdn4ZVXRJ1jkw&sig2=K2gqU57QkOXfW7uKh-zFVg

There also a couple of youtube videos

https://youtu.be/p16qbVqDfTs

https://youtu.be/3a4sj_txPTo

wm460
5th September 2015, 03:03 PM
Thanks for this Fred.:2tsup:
For some reason google let me down.:?


Mr Google is your friend

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CCoQFjADahUKEwjkm_TS-97HAhVm26YKHTpwCf0&url=http%3A%2F%2Fwww.robert-sorby.co.uk%2Fmedia%2Fwysiwyg%2Fproduct_instructions%2Feccentric_chuck_projects.pdf&usg=AFQjCNHH7p7lFAWOLbTNhsdn4ZVXRJ1jkw&sig2=K2gqU57QkOXfW7uKh-zFVg

There also a couple of youtube videos

https://youtu.be/p16qbVqDfTs

https://youtu.be/3a4sj_txPTo