Using a cats cradle corectly

[woody1Participant @woody1]

Evening all, hope all safe and well,

What would be the method for mounting stock using the titled, I have never used one. I was thinking to centre stock and cradle at the 4 jaw end, loosen two jaws, flip placing the cradle in the steady and snug everything up with hopefully little adjustment needed. I have everything ready just need to tap the holes for the sleave.

Thanks,

Woody.

[woody1Participant @woody1]

[HopperParticipant @hopper]

Sounds like it would work. Set the fingers on your fixed steady while the job and cats cradle/claw is still at the chuck end. Then slide steady along to its working position.

[David George 1Participant @davidgeorge1]

Excuse me but what is a cats cradle in respect to turning on a lathe. I just don't understand what it is as the only cats cradle I know is a piece of string loop round my fingers in my youth.

David

[pgk pgkParticipant @pgkpgk17461]

A fixture to hold a non-circular object in a cage that can rotate within a fixed steady.

Edit.. I suppose one should qualify that further since there may be a circular element on the free end of the workpiece that is off-centre to the chuck. But you get the idea

pgk

Edited By pgk pgk on 14/05/2020 08:39:58

[Phil PParticipant @philp]

People call them by different names, I think this is what is being asked about. I have one for my Pultra but have never needed to use it.

**LINK**

Phil

Edit

Yes I was thinking of the wrong thing PGK, similar principle but you are right I believe.

A bit more info here.

http://www.chaski.org/homemachinist/viewtopic.php?t=77698

 

Edited By Phil P on 14/05/2020 08:37:59

Edited By Phil P on 14/05/2020 08:41:32

Edited By Phil P on 14/05/2020 08:42:09

[woody1Participant @woody1]

Thanks all apologies to I should have explained better. Well I'm going at it, instead of using an long series drill and clamping stock to the cross I am just going to drill end to end. I just put a dti on my tail stock quill fully expecting to spend an hour or so getting it to running true. Ill I'll be dammed! I checked twice with two different indicators with tailstock at different positions along the bed, the is running true, absolute zero both top and side. I should add that the indicator was fixed to bed. How would I go about mounting an indicator in the chuck to ensure its running centre.

Again,

Thanks woody

[woody1Participant @woody1]

Oh I put a dti on my 4jaw chuck body too, I didn't know what to expect really but messing around with the nuts I managed to register 0.001 run out which I think is commendable for a straight bolt on accessory, many thanks to arceuro for a decent product.

[Henry BrownParticipant @henrybrown95529]

Posted by David George 1 on 14/05/2020 08:23:06:

Excuse me but what is a cats cradle in respect to turning on a lathe. I just don't understand what it is as the only cats cradle I know is a piece of string loop round my fingers in my youth.

David

Glad it wasn't only me that was wondering David! Used them years ago but I can't think what they were called. There was a recent thread on here about something similar…

[pgk pgkParticipant @pgkpgk17461]

Posted by woody1 on 14/05/2020 09:47:49:

Oh I put a dti on my 4jaw chuck body too, I didn't know what to expect really but messing around with the nuts I managed to register 0.001 run out which I think is commendable for a straight bolt on accessory, many thanks to arceuro for a decent product.

There are folk on here more qualified with experience than myself. But if wanting to check how thw tailstock quill affcets things I'd have thought some round stock in the tailstock chuck with DTI on bed and run the quill in and out. You still have the issue of flex in that stock and whether the dti stays centred. Or mount the DTI in the chuck and run it along the bed with the quill?
For the 4-jaw you're centring it manually so what may affect it is angulation within the chuck jaws or body. Either centre a decent diameter ground or turned bar and check DTI close to chuck and away. Or just check the chuck face is true and assume/hope the jaws will be too?

pgk

[Brian HParticipant @brianh50089]

Posted by Henry Brown on 14/05/2020 09:48:35:

Posted by David George 1 on 14/05/2020 08:23:06:

Excuse me but what is a cats cradle in respect to turning on a lathe. I just don't understand what it is as the only cats cradle I know is a piece of string loop round my fingers in my youth.

David

Glad it wasn't only me that was wondering David! Used them years ago but I can't think what they were called. There was a recent thread on here about something similar…

Not just you Henry, I always thought that they were called lantern chucks (though why that name is also beyond me!)

Brian

[Neil WyattModerator @neilwyatt]

Paul Lousick posted this image about a year ago:

http://www.model-engineer.co.uk/forums/postings.asp?th=140764

It's possible to mount one on an irregular workpiece for a steady to run on, rather than holding it in a chuck.

They are somewhat hazardous so a screen/guard is certainly advised.

Neil

Edited By Neil Wyatt on 14/05/2020 10:54:53

[DalboyParticipant @dalboy]

Is it something like in this video bot not outboard as he has done

[HopperParticipant @hopper]

That's it. Seems he calls it a spider. Also called a catshead by others. You can also use it to hold long square or hex bar with a fixed steady.

[BazyleParticipant @bazyle]

Just to add to the confusion there is also a version that fits at the rear of the mandrel to support long rods that has the same collection of names.

[Alan Wilkinson 1Participant @alanwilkinson1]

we always called them a spider useed when turning long hexagone or square bar just set them on the bar ajust to run true by the screws then use steady also used on backend of head stock to stop long bars from whipping

[woody1Participant @woody1]

Hi,

A bid disheartened which is all of my own doing. My sleeve was on the thin walled side and flexed so a non starter really, my fixed Steady to, although functional it's a bit heath Robinson and fidely to set up (cannibalised out board head) I have had a nice refresher in indicating stock so not all lost. Before i continue I am going to make a keeper pretty fixed steady. Would the membership think using a centre and faceing each end of the bar would be a good starting point. I just chucked up with sawn ends which are not square.

Thanks.

[pgk pgkParticipant @pgkpgk17461]

I'm not entirely sure i understand that post. I guess the raw square stock won't fit inside your headstock so any set-up is bound to be tedious. I'd probably cut a short length that can be held in the 4-jaw without 'drooping' and then use the simple trick of 4 bits of flat scrap and an elastic band so one can indicate on the inside surfaces (quicker) to get the 4-jaw pretty well centred. Then do the same thing with your cats cradle in the fixed steady wth that trial piece of spare stock before setting things up at their relative distances and finalising indication at the ends and middle with the workpiece and facing it's ends.

pgk

[old martParticipant @oldmart]

Interesting to find out what it is, I only have known them as spiders. Really a crude form of four jaw chuck.

[old martParticipant @oldmart]

Every time I post it doubles up, and some other people have the same problem 

Edited By old mart on 15/05/2020 16:35:06

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