chuck help

[christofloffer]

hi folks, i am new to world of turning so bear with me. i have a couple of lathes, one which i picked up for free which is a larger bench top sort (a Woodman i think) and i recently picked up a Hobbymat smaller one. the Hobbymat i just bought came with a chuck but i cant figure it out. i have sussed out how to open and close it (the rear plate spins to adjust the jaws) and how to remove the jaws (rear plate can pull out to allow the jaws to slide) but i cant see any way to lock the jaws or to give it some bite.
i assumed there would be a quick adjustment then a screw somewhere to tighten it up properly. however i cant see anything of the sort.
also i cant see any way to lock up the back plate. it has a couple of allen screws that stop the plate from pulling back and loosening the jaws but they down stop the plate from rotating.
i tried to see if hand tight was enough but as you can guess it is not. it is not helped by the way that as soon as there is nothing to it to push against the spin of the lathe throws the jaws out wide.
the chuck is a WMW Niles DHW 125x4 any help with this would be great as i really want to use the chuck for a few projects.

it also has a hollow spindle but the sizes dont match any tapers i could find. i measured them with a micrometer and the big end measures 15mm/0.591" and the small end (right back at the pulley) is 12.8mm/0.504" but i cant see any info on if that is actually meant to be a taper of if its just a hollow spindle. i was hoping to be able to use a spur drive, i have ordered one which fits in a chuck but a proper taper one would be great.

thanks for reading and any help is really appreciated.

 

[Robbo3]

Lathes & co show no mention of a Woodman lathe.

I thought the Hobbymat was a metal lathe but I see they also do a wood version.

Metal - http://www.lathes.co.uk/hobbymat/
Wood - http://www.lathes.co.uk/hobbymat/page6.html
I note that it doesn't give the thread size of the headstock.

The chuck shown, if it's the same as yours, looks to be a two lever type. Holding one lever still, whilst rotating the other lever & holding the wood in place requires some dexterity (or three hands), but it used to be the norm.

 

[christofloffer]

hi robbo,

the bigger lathe is a woodmen SP 800. it about twice the size of the hobbymat but its pretty coarse. the woodscrew was mangled so a made a spur drive with a bolt/wingnut which was woking well enough but the fixed centre in the tail was being really bad on seasoned timber, got rather smoky. it was free so i cant complain but it was limited for smaller bits.

the hobbymat is the one at the bottom of that link. the chuck looks pretty much the same. which explains a lot as i dont have any levers for it. i can make some though. thanks for that i thought some kind key might be necessary, i hadnt thought of two levers. that really helps, thanks again.

 

[Robbo3]

I call them levers to explain how they work. In reality they are just metal rods that fit in the holes. Often they are oversize with reduced ends. In fact there is a photo showing them in the link.
A dead centre also used to be the norm before live (revolving) centres became affordable. A small splodge of grease eases the friction for a few minutes.

Can't help with the tapers as there are no specs shown & the photos have been distorted to fit the space on the web page. You can download them to view in Windows with a right click & 'save image as'.

I see there are two woodtuning clubs in your general area, one at Bicton, the other at Selattyn.

 

[Phil Pascoe]

Live centres are not expensive, but as ^^ a bit of wax polish or oil of sme kind helps stop the burning.
I suspect your chuck is a cheap metalworking chuck.

 

[christofloffer]

well i found some bar and sorted out the levers. is that all there is to it? i have been trying to get some bits done on it today and its very inconsistent. it seems to be gripping ok but somehow it keeps coming off centre. i was turning the tenon down on the big lathe and first i tried a simple sawn edge flat against the chuck base and quickly saw why that wasnt great. then i started turning the tenon in two steps so that the sawn edge floated in the middle and the turned face was flat on the chuck base. this got things dead on to start with but it keeps on distorting. i had one small pot which almost went perfectly until i got a catch at the last minute and it blew the wall out. every attempt after that i start hollowing out and find that the lip is somehow egg shaped and useless. i dont see why this keeps happening but i must be doing something wrong here or i am missing a step.

as for the dead centre, i am not knocking it in any meaningful way. i just dont like them myself. the live centre seems like a significant improvement. the friction seems worse than it should be, and i tried all sorts from wax to high temperature gear oil but nothing lasts very long and its a pain to keep loosening it off to reapply lubricants. the big lathe will always have its uses but the point of the smaller one is to have a better set up for the things the big lathe fails on. horses for courses.

 

[Robbo3]

Although the chuck pictured isn't a metal turning chuck it's nearly as bad as using one for wood turning. You need to keep tailstock support for as long as possible & when removed take very light cuts with a sharp tool.
It's not the grip of the jaws that stop wobble but the wood pressing on the front face of the jaws. Therefore the wood needs a flat to seat against them & as the jaws are small there isn't a lot of surface area on the faces.

The drawing, courtesy of Chas, shows dovetail jaws in a recess on the left & dovetail jaws on a tenon on the right. The tenon is shorter than the depth of the jaws.