Looking to purchase a new 4 jaw chuck

HI looking around at different options for a 4 Jaw chuck for my ML10 and came across this one from Rotagrip seems to be a great price any one got any opinions on this chuck ?

Hi I have dealt with Rotagrip for around 30 years and found them to be a good supplier,in this time I had 2 X 8 inch,3 jaw chucks both eastern european manufacture ,and various backplates ,soft jaws ,and other tooling .all have given good service.The advantage of this copy of the Burnerd is that the chuck has good overall proportions,less overhang and jaws are narrower and not so clumsy as some of oriental ones.

Is it perhaps a little on the small side, particularly if it is to be the only four jaw available?

Otherwise seems a good choice.

Hi I only have a little Myford ML10, it only has a 3, 5/16 (84mm) center height and the original 4 jaw option was only 4" so I thought it may be an ideal choice.

Edited By Dave Springate on 28/03/2019 18:17:45

I notice the words 'Light Duty' in the description and see the body is only 1 1/8" thick, ie it's on the small side and not a bruiser. Slim chucks can be very handy but I'd prefer something a bit heavier for general purpose use. Depends what you're going to do with the lathe but beware! The usual experience is to plan lots of small work and then find yourself making traction engines...

Dave

This is the other one I was looking at from RDG tools and only slightly bigger in diameter but has a beefier body.

HBM chucks are generally quite chunky so that one is significantly bigger and heavier than the one you first posted.

Personally I find a light duty four jaw nicer to use than its heavy duty brethren. Smaller jaws make it much easier to manoeuvre around projections on part machined workpieces. But I use 8", 200 mm, 4 jaw chucks so everything is rather bigger. Putting things in context its nearly three years since I used my heavy duty one whilst the lighter one comes out to play on regular basis.

Pity you don't have jaw tip width specifications so you can judge what the smallest part you can hold is.

+ 1 for Rotagrip being good folk to deal with.

Clive

If Myford specified the 4" chuck for your model of the ML10 then no doubt that size is the better choice although RDG clearly consider their heavier chuck would be suitable (will it really fit Chinese mini lathes?)

I was interested in Clive Foster's comment which reminded me that on one occasion I had difficulty in gripping a component in the 6" 4J but was subsequently able to do so in a smaller, 5" chuck.

Dave,

Once again as pointed out by SOD it really depends what you intend doing with it. Bearing in mind the size of the lathe and the likelihood of taking 50 thou cuts I doubt the extra 10mm of the HBM and its chunkier construction perhaps greater clamping power will make a great deal of difference on your machine. If you are intending to do big stuff - I have been turning castings on the ML7 that will only just fit in the machine, but they are for a 6" scale traction engine and I have access to bigger and heavier machines to do the really big stuff. Like choosing lathes or mills it's really horses for courses in choosing work holding devices.

Paul.

Dave,

I have a Southbend lathe which has a centre height of 4 1/2" and use a 6" Bernerd chuck similar to the one in your photo. Also have a heavier, chunkier 4-jaw but prefer the slimer one. (I am building a 6" traction engine).  The 115mm version should be perfect for your ML10.

Paul.

Edited By Paul Lousick on 29/03/2019 00:49:41

It very likely is. Don't forget that when actually holding something in the chuck, the jaws may (will) extend out past the chuck body and it is that which will limit the maximum size of chuck you can use rather than the chuck diameter per-se. (Or, conversely, the maximum size of part you can hold in the chuck.)

I had thought about that which is why I was leaning towards the smaller diameter chuck.

I confess to being a little bewildered: I have [and have only ever seen] a 6" version of the genuine Pratt Burnerd 'light duty' Myford-fitting 4-jaw chuck

• Does anyone have a photo of the back of this 115mm copy, please ?
• ... Is it a 'scale model' of the 6" ?

My 4" is designed for front fixing to a backplate ['though it actually lives on the rotary table] and has a solid body.

MichaelG.

One thing with the "lighter" chucks is the jaws are narrower ( easily seen on the two photos above) which I find a big advantage particularly when holding things on an inner edge. Don't think my heavy one had been out of the cupboard for about 7 years which is when I bought my Bison slim chuck.

Looks like "Light Duty" not lightweight as per the hollow backed slim chucks from their e-bay page

I don’t own an ml 10 but if i did i would be happy to buy that chuck , the thin body has advantages like keeping the work as close to the spindle bearings as possible and it keeps the rotating mass as light as possible which may help the spindle bearings on a small machine .

.

Thanks for that, Jason

... makes much more sense now.

MichaelG.

I had a Speed 10 for a while with the ball raced spindle. I'd look for a slim body 5" Burnerd but no bigger. A 4" was recommended and if your ML10 is the plain bearing version, I'd be inclined to not go much above that. Genuine Burnerd 4 jaws with Myford threaded bodies are easy to find on eBay second hand and given how they work, wear, unless horribly excessive, is not a huge problem. Make sure the jaw operating screws aren't cracked though. Replacements are available but it defeats the object of buying secondhand.

There's a Pratt made 4 1/2" chuck on there at the moment which would be ideal. Needs a back plate though.