Grayson lathe parts

[Nev WhitehurstParticipant @nevwhitehurst53938]

Hi all , I am after any tooling for a Grayson lathe from gears to chucks , I only have a 4 jaw chuck which came with the lathe and as being a raw beginner it takes me ages to adjust the 4 jaw chuck so the work piece runs true , I am based in Wolverhampton West Midlands if anyone could help me out I would greatly appreciate it . Thank you

[duncan webster 1Participant @duncanwebster1]

Details of headstock nose are here. It claims to be same tread as MLY/S7, but without the parallel register. A photo would help. No doubt someone out there has a drawing of the Myford setup

[Clive Brown 1Participant @clivebrown1]

The 3 1/2″ Grayson lathe can use gears from the Myford ML7 / S7, which are readily available. Myfords use a keyway system. For the Grayson, you will need to drill a 1/16″ dia. hole to suit the Grayson dowel pin system. Ignore the keyway.

By all means acquire a 3-jaw chuck, very convenient but you may have trouble sourcing a suitable backplate. The thread is similar to a Myford but the register diameter is smaller, 1 1/8″ vs. 1 1/4″ IIRC. It’s perfectly possible to machine one though, but as a fairly demanding exercise. Blanks are available commercially.

For your existing 4-jaw, a very useful accessory to help truing a workpiece is a second chuck key to be used in conjunction with the other one. Again a DIY exercise, of turning, drilling and filing. Mild steel is plenty good enough. Practice is also a great help.

PS. I wonder if a Myford backplate could be pressed into service with a spacer ring loctited into the over-large register diameter.

[Nev WhitehurstParticipant @nevwhitehurst53938]

Thank you for the information Duncan

[Roderick JenkinsParticipant @roderickjenkins93242]

A new chuck will be in 2 parts, the chuck itself and a back plate which is fastened to the chuck with screws.  The backplate needs to be threaded to fit on the nose of the lathe and this will incorporate a register for accurate co-axial fitting.  How old and what size is your Grayson?  I understand that the 3 1/2″ Grayson had the same nose fitting as the Myford ML7/ Super 7 so in that case finding a suitable back plate should not be difficult.

The Lathes archive has more information:

https://www.lathes.co.uk/grayson/index.html

Hope this helps,

Rod

 

[Nev WhitehurstParticipant @nevwhitehurst53938]

Thank you for the information Rod

[not done it yetParticipant @notdoneityet]

The 4 jaw is preferable to a 3 jaw, IMO.

As most turning jobs will entail a reduction in diameter of the feedstock, absolute concentricity is not generally required.  If a job is removed from a 3 jaw and later replaced it will unlikely be concentric!  That is simply the way 3 jaw chucks are built – they nearly always have some run-out.

Of course, if an item needs to be removed and replaced, that is a where the 4 jaw would be needed anyway if concentricity is required.

The cutting tool is often quite adequate for setting up initially – no need for a dial gauge to be involved.

[Howard LewisParticipant @howardlewis46836]

I have fitted a “Myford” backplate to other chucks, by boring out the standard thread and inserting a bush suitable for the lathe in question (In one case a Myford ML4 with a 3/4 x 9 tpi thread, and in another a backplate suitable to match a modern 4 jaw chuck to a very much older lathe)

The backplates were fully machined to suit the chuck on the lathe for which the chuck is to be fitted, so as to maxmise concentricity. A 3 jaw is convenient for many purposes, but depending upon its quality / wear will not hold work concentric to much less than 0.005″.

For minimum eccentricity it is necessary to clock the work in the 4 jaw to a figure that is acceptable to you.

Howard

[BazyleParticipant @bazyle]

If buying changewheels that you see with a pin be aware that Drummonds use a thicker pin and are 14DP so not compatible but RandA are 20DP like Myford with a thinner pin but not sure of its dimensions.

[Howard LewisParticipant @howardlewis46836]

The 20 DP gears used on the Myford ML1, 2,3 and 4 are driven/ compounded by a 3/32″ pin in a blind drilling in each gear ((so that it doesn’t fallout)

They are the same DP, thickness and bore as the keyed gears for the later 7 Series. (Indeed I modified a ML7 gear by drilling, for use on a ML4.

So it should not be too difficult to adapt a ML7 gears for use on the Grayson.

A normal “Myford” fitting bacplate will fit the 1 1/8 x 12 tpi thread, but the 1 1/4 register will be too big. If you want the register, the backplate will need to be bored out and bushed to provide the smaller register.

Once that has been done, the backplare can be turned to size, and faced to suit the chuck to be fitted.

Once for an aquaintance, I bushed a Myford fitting backplate to fit a modern Asian chuck onto a smaller old lathe. On another ocasion, I made and adaptor which allowed Myford fitting chucks to be used on a ML4 with the original 3/4 x 9 tpi spindle thread.

So it is doable!

Howard

[Howard LewisParticipant @howardlewis46836]

Acquiring the skill to centre work in a 4 jaw will stand you in good stead (I knew somone who always used a 4 jaw, claiming that he could quickly centre work more accurately than in a 3 jaw (Obviously well practiced)

For some work, especially when concentricity is imperative, or with irregular or square items, you don’t have the option.

By all means use a 3 jaw, (To have two or more concentric diameters, just machine them without disturbing anything) for speed and ease of operation not that hobbyists are on piecework!

Howard

[Howard Lewis]

On Howard Lewis Said:

 

Once for an aquaintance, I bushed a Myford fitting backplate to fit a modern Asian chuck onto a smaller old lathe. On another ocasion, I made and adaptor which allowed Myford fitting chucks to be used on a ML4 with the original 3/4 x 9 tpi spindle thread.

So it is doable!

Howard

Indeed it is.  When, some 2 decades ago, I made a cast iron backplate for my SC 4 jaw chuck.  The resulting register was too slack so I bored it to 1/8″ larger, loctited in a slug of steel and got it right the second time. Still going strong.

Rod

[JasonBModerator @jasonb]

I’d say go for a half decent 3-jaw. Unless you need exacting levels of accuracy, a 3-jaw will do for most round work, Mine is good for 0.0005″ runout or about 13 microns. That means you could make yourself a steam or IC engine and get it done a lot quicker than trying to set a 4-jaw to levels of accuracy that are not really needed.

My 4-jaws only come out for irregular shapes or larger round items that won’t fit the 3-jaws.

[bernard towersParticipant @bernardtowers37738]

That good at all dimensions, Ill have one of those1

[JasonBModerator @jasonb]

Talk to Mr Bison though not sure if he will have anymore NOS

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